| 1. |
- Abubaker, Jamal, et al.
(författare)
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Nitrous Oxide Production from Soils Amended with Biogas Residues and Cattle Slurry
- 2013
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Ingår i: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 42, s. 1046-1058
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Tidskriftsartikel (refereegranskat)abstract
- The amount of residues generated from biogas production has increased dramatically due to the worldwide interest in renewable energy. A common way to handle the residues is to use them as fertilizers in crop production. Application of biogas residues to agricultural soils may be accompanied with environmental risks, such as increased N2O emission. In 24-d laboratory experiments, N2O dynamics and total production were studied in arable soils (sandy, clay, and organic) amended with one of two types of anaerobically digested biogas residues (BR-A and BR-B) generated from urban and agricultural waste and nondigested cattle slurry (CS) applied at rates corresponding to 70 kg NH4+-N ha(-1). Total N2O-N losses from the sandy soil were higher after amendment with BR-B (0.32 g N2O-N m(-2)) than BR-A or CS (0.02 and 0.18 g N2O-N m(-2), respectively). In the clay soil, N2O-N losses were very low for CS (0.02 g N2O-N m(-2)) but higher for BR-A and BR-B (0.25 and 0.15 g N2O-N m(-2), respectively). In the organic soil, CS gave higher total N2O-N losses (0.31 g N2O-N m(-2)) than BR-A or BR-B (0.09 and 0.08 g N2O-N m(-2), respectively). Emission peaks differed considerably between soils, occurring on Day 1 in the organic soil and on Days 11 to 15 in the sand, whereas in the clay the peak varied markedly (Days 1, 6, and 13) depending on residue type. In all treatments, NH4+ concentration decreased with time, and NO3- concentration increased. Potential ammonium oxidation and potential denitrification activity increased significantly in the amended sandy soil but not in the organic soil and only in the clay amended with CS. The results showed that fertilization with BR can increase N2O emissions and that the size is dependent on the total N and organic C content of the slurry and on soil type. In conclusion, the two types of BR and the CS are not interchangeable regarding their effects on N2O production in different soils, and, hence, matching fertilizer type to soil type could reduce N2O emissions. For instance, it could be advisable to avoid fertilization of organic soils with CS containing high amounts or organic C and instead use BR. In clay soil, however, the risk of N2O emissions could be lowered by choosing a CS.
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| 2. |
- Arwidsson, Zandra, et al.
(författare)
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Remediation of soils and sludges containing organic contaminants as well as metals – soil-wash procedures combining biodegradation, chemical complexation and mechanical separation of particulate matter
- 2009
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Konferensbidrag (refereegranskat)abstract
- Soil contamination is an urgent issue world wide. More than 83,000 contaminated sites have been identified in Sweden alone, of which approximately some 4,000 require treatment in the near future. Most of the sites carry a mixture of contaminants, metals as well as persistent organics. Most soil remediation efforts are made ex situ, which means that the soil or sludge is dug up and transported to a facility for treatment, or simply for deposition. The aim of the present project is to design a strategy for ex situ treatment of soils with mixed contaminants. A variety of soils and sludges from different sites (around 10), essentially all with organic as well as inorganic (metallic) contaminants, have been selected for experimental studies in laboratory and pilot scale: Military sites (metals, explosives), wood preservation sites (PAHs, As, metals), industrial sites (metals, hydrocarbons, mercury, dioxins and others). Of particular importance in the present study are:Metals – Pb, Cu, Zn, Cr, Hg, as well as As Organics – PAHs, nitro aromatics, dioxinsA number of processes are selected and applied: •Biodegradation - use of commercially available cultures, as well as bacteria cultivated from the contaminated site itself •Mobilisation of organics - use of surface active agents •Mobilisation of metals - use of (1) complexing microbial metabolites produced in the soil (by fungii in paricular), (2) complexing agents generated by degradation of natural organic products (polyhydroxy carboxylic acids), and (3) artificial complexing agents (polyamino carboxylic acids).Biodegradation is performed in batches (anaerobic in most cases), while release and mobilisation of contaminants from soil aggregates are achieved during soil-wash performed in a dynamic system where wash solution is forced through the soil under high pressure (the WTC-process). The efficiency of biodegradation and subsequent soil-wash under various conditions is evaluated from chemical analysis, but also by several ecotoxicological tests. Some results are given that illustrates suitable strategies for treatment of mixed contaminated soil from real sites (soil) as well as for treatment of residues from industrial production (sludges etc).
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| 3. |
- Ashihmina, Olga, et al.
(författare)
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REMEDIATION OF TNT USING PINE BARK IN A BATCH STUDY: COMETABOLIC REDUCTION AND SORPTION
- 2011
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Konferensbidrag (refereegranskat)abstract
- Water contaminated with 2,4,6-trinitrotoluene (TNT) is regulated as a hazardous material. The objective of this study was to evaluate two bioremediation methods, namely, sorption and anoxic degradation for the removal of TNT from contaminated water in 7-day long batch experiment. TNT was co-metabolized with glucose under oxygen-limiting conditions using a mixed inoculum culture from a wastewater treatment plant, enriched with glucose and TNT. By the third day of the experiment most of TNT was adsorbed onto the pine bark and 96-98% of TNT was degraded. The results also indicated that the concentration of glucose is an important factor for the effective degradation of TNT, which is consistent with earlier research; the content of 0.15% w/v resulted in a more rapid TNT removal in comparison with 0.50% w/v. Two metabolites; 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) were detected. The para nitro group of TNT was preferentially reduced compared to the ortho nitro group. On the seventh day of incubation the concentration of 4-ADNT had decreased by 10% and 2-ADNT was no longer detectable.
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| 4. |
- Avelin, Anders, et al.
(författare)
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Forest biomass for bioenergy production – comparison of different forest species
- 2014
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102.
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Konferensbidrag (refereegranskat)abstract
- Forest biomass is a renewable and sustainable source of energy that can be used for producing electricity, heat, and biofuels. The production of biomass for energy is considered to be an important step in developing sustainable communities and managing greenhouse gas emissions effectively. Biomass properties vary and are commonly associated with plant species. Hence, efficient methods to predict biofuel characteristics will greatly affect the utilization and management of feedstock production. In this paper attempt was made to correlate various chemical characteristics with NIR spectra. Wood chips from various plant species was analyzed for lignin content, heating value, ash content and NIR and the results were evaluated with correlation, PCA and PCR. Initial evaluation showed promising results where chemical components in the wood correlate to NIR spectra. A selection of results will be presented in this paper. Further analysis as well as results from PCA and PCR models will be presented in the full paper version.
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| 5. |
- Bartusch, Cajsa, 1965-
(författare)
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Boosting behavioral change in residential electricity consumption : demand response programs and feedback
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As part of realizing national and European climate ambitions, it is imperative to bring about increased energy efficiency and consumption flexibility in the residential sector of the Swedish power market. In addition to governmental policy instruments to this end, market-based measures play an important role in making behavioral change in domestic electricity use happen. In light of the prevailing lack of incentives for residential consumers to save electricity and cut peak demand at times of physical and financial market constraints, the research studies that form the basis of this thesis have the aim of adding to the body of knowledge on policy instruments for the purpose of boosting behavioral change in residential electricity consumption. The research has accordingly contributed to the general statistics on residential electricity consumption, which constitute the starting point for policy instrument development, and augmented knowledge on the merits of residential demand response programs involving hourly settlements in power trading and demand-based, time-of-use tariffs in power distribution as well as graphic feedback on individual households’ electricity use by means of a statistics service provided over the Internet. The overall results have shown that household behavior, together with physical factors such as heating systems, help explain the sizeable differences in electricity consumption among homeowners. Statistical analysis of variance has in this context proven to be an effective method for identifying key indicators of policy development. Power suppliers and electricity consumers as well as society as a whole have been found to gain substantially from hourly settlements in retail. To suppliers, the greatest benefits are associated with risk management, while the major advantage to customers is that they are provided with an opportunity to reduce their electricity costs. It has also been empirically demonstrated that electricity users are willing to adjust their consumption to a demand-based, time-varying distribution tariff. Households generally have a favorable attitude towards this type of distribution tariff, seeing as they indirectly have a positive impact on the environment. Providing households with feedback over the Internet on their individual electricity use and demand has been shown to contribute to an increased awareness and lead to energy efficiency in homes. Easy accessibility and simplicity have proven to be key success factors in this context. Combining conventional bar charts, color symbolism and historic feedback is expedient in this respect.
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| 6. |
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| 7. |
- Bartusch, Cajsa, 1965-, et al.
(författare)
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Exploring variance in residential electricity consumption : Household features and building properties
- 2012
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 92, s. 637-643
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Tidskriftsartikel (refereegranskat)abstract
- Improved means of controlling electricity consumption plays an important part in boosting energy efficiency in the Swedish power market. Developing policy instruments to that end requires more in-depth statistics on electricity use in the residential sector, among other things. The aim of the study has accordingly been to assess the extent of variance in annual electricity consumption in single-family homes as well as to estimate the impact of household features and building properties in this respect using independent samples t-tests and one-way as well as univariate independent samples analyses of variance. Statistically significant variances associated with geographic area, heating system, number of family members, family composition, year of construction, electric water heater and electric underfloor heating have been established. The overall result of the analyses is nevertheless that variance in residential electricity consumption cannot be fully explained by independent variables related to household and building characteristics alone. As for the methodological approach, the results further suggest that methods for statistical analysis of variance are of considerable value in indentifying key indicators for policy update and development.
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| 8. |
- Bartusch, Cajsa, 1965-, et al.
(författare)
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Introducing a demand-based electricity distribution tariff in the residential sector : demand response and customer perception
- 2011
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Ingår i: Energy Policy. - : Elsevier. - 0301-4215 .- 1873-6777. ; 39:9, s. 5008-5025
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Tidskriftsartikel (refereegranskat)abstract
- Increased demand response is essential to fully exploit the Swedish power system, which in turn is an absolute prerequisite for meeting political goals related to energy efficiency and climate change. Demand response programs are, nonetheless, still exceptional in the residential sector of the Swedish electricity market, one contributory factor being lack of knowledge about the extent of the potential gains. In light of these circumstances, this empirical study set out with the intention of estimating the scope of households’ response to, and assessing customers’ perception of, a demand-based time-of-use electricity distribution tariff. The results show that households as a whole have a fairly high opinion of the demand-based tariff and act on its intrinsic price signals by decreasing peak demand in peak periods and shifting electricity use from peak to off-peak periods.
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| 9. |
- Beckinghausen, A., et al.
(författare)
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From removal to recovery : An evaluation of nitrogen recovery techniques from wastewater
- 2020
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- Nitrogen recovery is the next step in the improvement of the wastewater treatment process, utilizing this important nutrient for fertilizers to decrease use of energy, petrochemicals, and impact on the environment. The majority of wastewater treatment plants currently employ methods to remove nitrogen which are energy intensive and have no additional benefits besides complying with effluent concentration limits. Instead, recovering nitrogen allows simultaneous treatment of wastewater while collecting a concentrated ammonia product, creating a circular economy solution. This review acts to compile current research regarding nitrogen recovery and compare different techniques' recovery efficiencies and energy requirements. One outcome of this review is that more than one third of the techniques reviewed had little comments around the energy question, and thus more research needs to take place as these recovery systems continue to evolve towards full scale implementation. Additionally, a basic economic analysis was completed to demonstrate potential investment opportunities to implement these technologies. From this investigation, gas permeable membrane technology has the potential to recover ammonia from wastewater using little energy and may provide a small income with the sale of the product. Other techniques such as vacuum membrane distillation with acid absorption need further validation to determine the energy costs, as the amount of heat recycling has a great impact on the overall energy and economic balances. Finally, a discussion of the misalignment of products from recovery techniques and fertilizers in use today highlights the lack of communication and information sharing between the research community and the end users.
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| 10. |
- Beckinghausen, Aubrey, 1991-
(författare)
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Investigation of nitrogen recovery from concentrated wastewater
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nitrogen recovery from wastewater treatment for fertilizers is a research topic that exists at the intersection of multiple topics important to the future of sustainable society. First, nitrogen recovery from wastewater implies a departure from the current methods of nitrogen mitigation, which involve nitrogen removal by conversion of various aqueous species to inert nitrogen gas. Secondly, by recovering nitrogen from wastewater specifically, there is the opportunity to begin a circular economy where value added products can be obtained from material that has historically been seen as a “waste”. Current wastewater treatment involves nitrogen removal through the biological transformation of aqueous nitrogen species to inert nitrogen gas. This process is energy intensive and risks the production of air pollutants such as N2O as intermediates in the biological transformation. If this nitrogen can be captured in a form that can be reused, a valuable product can be achieved with the potential reduction of both the energy required at the wastewater treatment plant as well as the carbon footprint. Finally, by recovering nitrogen in a form that can be used in agriculture as a fertilizer, additional environmental benefits can be realized by reducing reliance on Haber-Bosch based ammonia production, which is also energy intensive and contributes harmful emissions to the atmosphere.The work described in the following licentiate aims to consider the current status of nitrogen recovery from wastewater for fertilizers as a research topic. Literature was analytically examined to compare different techniques in terms of energy requirements, cost for fertilizer production, market for final fertilizer product, and technological readiness. The most interesting findings from this review were that there seems to be a disconnect between the fertilizer product produced by nitrogen recovery techniques and the market, which will become a challenge if these techniques are implemented at a large scale. The attitude of the farmers with regards to fertilizers from waste was overall positive, with their concerns mainly focused on the performance ability and cost of the product. Additionally, many techniques such as microbial fuel cells and microbial electrolysis cells have been unable to move past the laboratory phase despite being researched for many years. This indicates there are cost and technological barriers that are preventing the further scale up and implementation of these techniques. Energy and cost analyses will be crucial to motivate investment into these processes, and these are missing for many of the techniques found around this topic.To contribute to this field, experimental work was also included to assess the potential for ammonium adsorption from concentrated wastewater for fertilizer production. The experimental work focused on the utilization of the solid product of pyrolysis of sewage sludge (biochar) for adsorption and explored the potential enhancement of the char with various chemical treatments. The char with the best ammonium adsorption performance was found to be using a treatment of HNO3 followed by and NaOH, with an adsorption capacity of 4 mg NH4/g biochar. This char was compared with commercially activated carbon and clinoptilolite for full scale applications. It was found that even with this increased adsorption capacity, the use of chemically enhanced sewage sludge biochar for full scale applications is not realistic. The amount of raw material required for the complete recovery of ammonium from reject water at the municipal wastewater treatment plants exceeds the total amount of sewage sludge generated. Therefore it is recommended that the goal of incorporating sewage sludge biochar with wastewater treatment is to produce a solid fertilizer product loaded with ammonium (which would provide ammonium-N and phosphorus for plant growth, as well as carbon and other minerals for soil amendment) rather than having the goal be complete ammonium recovery from the wastewater stream.
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| 11. |
- Bulut, Mehmet Börühan, et al.
(författare)
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Active buildings in smart grids - Exploring the views of the Swedish energy and buildings sectors
- 2016
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 117, s. 185-198
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Tidskriftsartikel (refereegranskat)abstract
- The development of smart grids is expected to shift the role of buildings in power networks from passive consumers to active players that trade on power markets in real-time and participate in the operation of networks. Although there are several studies that report on consumer views on buildings with smart grid features, there is a gap in the literature about the views of the energy and buildings sectors, two important sectors for the development. This study fills this gap by presenting the views of key stakeholders from the Swedish energy and buildings sectors on the active building concept with the help of interviews and a web survey. The findings indicate that the active building concept is associated more with energy use flexibility than self-generation of electricity. The barriers to development were identified to be primarily financial due to the combination of the current low electricity prices and the high costs of technologies. Business models that reduce the financial burdens and risks related to investments can contribute to the development of smart grid technologies in buildings, which, according to the majority of respondents from the energy and buildings sectors, are to be financed by housing companies and building owners.
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| 12. |
- Bulut, Mehmet Börühan, 1987-, et al.
(författare)
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Buildings in the future energy system : Perspectives of the Swedish energy and buildings sectors on current energy challenges
- 2015
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 107, s. 254-263
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Forskningsöversikt (refereegranskat)abstract
- Buildings are expected to play a key role in the development and operation of future smart energy systems through real-time energy trade, energy demand flexibility, self-generation of electricity, and energy storage capabilities. Shifting the role of buildings from passive consumers to active players in the energy networks, however, may require closer cooperation between the energy and buildings sectors than there is today. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this study presents the views of the energy and buildings sectors on the current energy challenges in a comparative approach. Despite conflicting viewpoints on some of the issues, the energy and buildings sectors have similar perspectives on many of the current energy challenges. Reducing CO2 emissions is a shared concern between the energy and buildings sectors that can serve as a departure point for inter-sectoral cooperation for carbon-reducing developments, including the deployment of smart energy systems. The prominent energy challenges were identified to be related to low flexibilities in energy supply and use, which limit mutually beneficial cases, and hence cooperation, between the energy and buildings sectors today.
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| 13. |
- Chusova, Olga, et al.
(författare)
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Biotransformation of pink water TNT on the surface of a low-cost adsorbent pine bark
- 2015
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Ingår i: Biodegradation. - : Springer Science and Business Media LLC. - 0923-9820 .- 1572-9729. ; 26:5, s. 375-386
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Tidskriftsartikel (refereegranskat)abstract
- This two-week anaerobic batch study evaluated 2,4,6-trinitrotoluene (TNT) removal efficiency from industrial pink water by (1) adsorption on low-cost adsorbent pine bark, and (2) adsorption coupled with TNT biotransformation by specialised microbial communities. Samples of the supernatant and acetonitrile extracts of pine bark were analysed by HPLC, while the composition of the bacterial community of the experimental batches, inocula and pine bark were profiled by high-throughput sequencing the V6 region of the bacterial 16S rRNA gene. Integrated adsorption and biotransformation proved to be the most efficient method for TNT removal from pink water. The type of applied inoculum had a profound effect on TNT removal efficiencies and microbial community structures, which were dominated by phylotypes belonging to the Enterobacteriaceae family. The analysis of acetonitrile extracts of pine bark supported the hypothesis that the microbial community indigenous to pine bark has the ability to degrade TNT.
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| 14. |
- Chusova, Olga, et al.
(författare)
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Effect of pine bark on the biotransformation of trinitrotoluene and on the bacterial community structure in a batch experiment
- 2014
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Ingår i: Environmental technology. - : Informa UK Limited. - 0959-3330 .- 1479-487X. ; 35:19, s. 2456-2465
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Tidskriftsartikel (refereegranskat)abstract
- Pine bark, a low-cost industrial residue, has been suggested as a promising substitute for granular activated carbon in the on-site treatment of water contaminated with 2,4,6-trinitrotoluene (TNT). However, the complex organic structure and indigenous microbial community of pine bark have thus far not been thoroughly described in the context of TNT-contaminated water treatment. This two-week batch study examined the removal efficiency of TNT from water by (1) adsorption on pine bark and (2) simultaneous adsorption on pine bark and biotransformation by specialized TNT-biotransforming microbial inocula. The bacterial community composition of experimental batches, inocula and pine bark, was profiled by Illumina sequencing of the V6 region ofthe 16S rRNA gene. The results revealed that the inocula and experimental batches were dominated by phylotypes belonging to the Enterobacteriaceae family and that the tested inocula had good potential for TNT biotransformation. The type of applied inocula had the most profound effect on the TNT-transforming bacterial community structure in the experimental batches. The indigenous microbial community of pine bark harboured phylotypes that also have a potential to degrade TNT. Altogether, the combination of a specialized inoculum and pine bark proved to be the most efficient treatment option for TNT-contaminated water.
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| 15. |
- Chusova, Olga
(författare)
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Remediation of TNT-contaminated water by using industrial low-cost residue pine bark
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the process of demilitarization of explosives, army ammunition plants generate a waste stream known as pink water. The principal component of the wastewater is the nitro-aromatic compound 2,4,6-trinitrotoluene (TNT). Although the persistence of TNT when dissolved in surface water is very limited due to its susceptibility to photo- and biotransformation, discharge of pink water to the environment has been prohibited in Sweden, the U.S. and many other countries for decades because of the toxicity of the compound and its metabolites to various ecological receptors.The most frequently used method for treatment of pink water in Sweden today is adsorption on activated carbon, which as well as being costly, creates a sludge that must be incinerated off site.In many countries, the timber industry residue pine bark is discarded and has no high value application. The overall aim of this thesis was to investigate the potential of pine bark for the removal of TNT from contaminated water such as pink water. Several batch studies and a column experiment were conducted. Acetonitrile extraction of pine bark and 16S rRNA sequencing for analysis of the indigenous bacterial community of pine bark were used to investigate its performance in the treatment of pink water.The results show that pine bark has great potential as an adsorbent medium for TNT from contaminated pink water. Simultaneous use of biotransformation and adsorption methods was shown to be an improvement over adsorption alone for the removal of TNT from contaminated water bodies. Pine bark showed higher affinity towards the amino metabolites of TNT than for TNT itself. Molecular analysis of the indigenous microbial community of pine bark and chemical analysis of its acetonitrile extracts provided evidence for its ability to biotransform TNT and its metabolites. The efficiency of the transformation was enhanced by the addition of glucose and/or inoculum.Overall, this work demonstrates the versatility of this organic industrial residue with respect to pink water treatment. Not only does it have a high affinity towards TNT and its amino metabolites, but its native microbial community even in the absence of external inoculation can also be taken advantage of, opening new possibilities for remediation of pink water.
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| 16. |
- Ferrans, Laura
(författare)
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Sustainable management of dredged sediments : potential recovery of valuable compounds
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dredging of sediments occurs worldwide to increase water depth in harbours, bays, lakes and rivers, as well as to recover aquatic ecosystems. Landfilling and open-ocean discharge are traditional disposal routes for dredged material. However, the methods are restricted by environmental and legal concerns. Using dredged sediments for beneficial uses can contribute to implementing circular economies and avoiding traditional disposal methods. This thesis aimed to contribute to the sustainable management of dredged sediments by increasing the knowledge of the beneficial use of the material. The work focused on Malmfjärden bay, located in Kalmar, Sweden, which is currently shallow and presents a high concentration of nutrients. The LIFE SURE project aimed to dredge the bay and use the dredged material for beneficial purposes.The results from the thesis showed a high potential to use Malmfjärden sediments for beneficial uses. The first step involved the characterisation of sediments, which showed a medium-high content of N and P was also present. The main pollution concerns were As, Pb and Cd, since their contents overpassed the Swedish limits for sensitive uses. The speciation and extraction of elements were also performed to assess their risk of pollution. The results showed that the most labile elements were Zn and Pb, and both presented the highest extraction rates using EDTA and EDDS. The results showed that the chemical extraction of metals could contribute to treating metal-polluted sediments and become a mining technique. Further studies focused on the recovery of nutrients from the sediments. They were mixed with compost, and lettuce grew in different substrates. However, the plants prematurely stopped growing, possibly due to the lack of available forms of N. Moreover, the harvested lettuces overpassed permissible contents for Cd, slightly threatening human health. It was shown that dredging could provide nutrients to soils, but the risk of metal pollution should be assessed. Finally, a life cycle assessment was calculated to assess the environmental impacts associated with landfilling Malmfjärden sediments or using the material in soil conditioning. Both scenarios presented negative impacts on global warming, eutrophication and toxicity categories. However, soil conditioning showed the most positive score due to the environmental savings of avoiding the production and use of fertilisers.The thesis concludes by encouraging the performance of more interdisciplinary projects. This could combine the knowledge from several sectors to enhance the implementation of the beneficial use of dredged sediments.
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| 17. |
- Gorji, Reyhaneh, et al.
(författare)
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Applications of optical sensing and imaging spectroscopy in indoor farming : A systematic review
- 2024
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Pergamon-Elsevier Science LTD. - 1386-1425 .- 1873-3557. ; 322
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Tidskriftsartikel (refereegranskat)abstract
- As demand for food continues to rise, innovative methods are needed to sustainably and efficiently meet thegrowing pressure on agriculture. Indoor farming and controlled environment agriculture have emerged aspromising approaches to address this challenge. However, optimizing fertilizer usage, ensuring homogeneousproduction, and reducing agro-waste remain substantial challenges in these production systems. One potentialsolution is the use of optical sensing technology, which can provide real-time data to help growers makeinformed decisions and enhance their operations. optical sensing can be used to analyze plant tissues, evaluatecrop quality and yield, measure nutrients, and assess plant responses to stress. This paper presents a systematicliterature review of the current state of using spectral-optical sensors and hyperspectral imaging for indoorfarming, following the PRISMA 2020 guidelines. The study surveyed existing studies from 2017 to 2023 toidentify gaps in knowledge, provide researchers and farmers with current trends, and offer recommendations andinspirations for possible new research directions. The results of this review will contribute to the development ofsustainable and efficient methods of food production.
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| 18. |
- Gorji, Reyhaneh, et al.
(författare)
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Determining Moisture Content of Basil Using Handheld Near-Infrared Spectroscopy
- 2024
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Ingår i: Horticulturae. - 2311-7524. ; 10:4, s. 336-336
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Tidskriftsartikel (refereegranskat)abstract
- Accurate and rapid determination of moisture content is essential in crop production and decision-making for irrigation. Near-infrared (NIR) spectroscopy has been shown to be a promising method for determining moisture content in various agricultural products, including herbs and vegetables. This study tested the hypothesis that NIR spectroscopy is effective in accurately measuring the moisture content of Genovese basil (Ocimum basilicum L.), with the objective of developing a respective calibration model. Spectral data were obtained from a total of 120 basil leaf samples over a period of six days. These included freshly harvested and detached leaves, as well as those left in ambient air for 1–6 days. Five spectra were taken from each leaf using a handheld NIR spectrophotometer, which covers the first and second overtones of the NIR spectral region: 950–1650 nm. After the spectral acquisition, the leaves were weighed for fresh mass and then put in an oven for 72 h at 80 °C to determine the dry weight and calculate the reference moisture content. The calibration model was developed using multivariate analysis in MATLAB, including preprocessing and regression modeling. The data obtained from 75% of the samples were used for model training and 25% for validation. The final model demonstrates strong performance metrics. The root mean square error of calibration (RMSEC) is 2.9908, the root mean square error of cross-validation (RMSECV) is 3.2368, and the root mean square error of prediction (RMSEP) reaches 2.4675. The coefficients of determination for calibration (R2C) and cross-validation (R2CV) are consistent, with values of 0.829 and 0.80, respectively. The model’s predictive ability is indicated by a coefficient of determination for prediction (R2P) of 0.86. The range error ratio (RER) stands at 11.045—highlighting its predictive performance. Our investigation, using handheld NIR spectrophotometry, confirms NIR’s usefulness in basil moisture determination. The rapid determination offers valuable insights for irrigation and crop management.
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| 19. |
- Ivan, Heidi Lynn, 1996-
(författare)
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Fault Detection in Wastewater Treatment : Process Supervision to Improve Wastewater Reuse
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As wastewater treatment plants transition to water resource recovery facilities, the need for improved control and consequently supervision increases. Despite the large volume of research that has been performed on this topic, the use in industry is scarce. Practical implementation is challenging due to the nature of the process, and a lack of standardisation in the research results in uncertainty as to the state of the art. This is one of the main challenges identified. Experimental work is performed using the Benchmark Simulation Model No. 1 to identify monitoring requirements and evaluate the performance of univariate fault detection methods. For the former, residual based process fault signatures are used to determine minimal sensor requirements based on detectability and isolability goals. Sensor faults are the focus of the latter issue, using the Shewhart, cumulative sum, and exponentially weighted moving average control charts to detect bias and drift faults in a controlled variable sensor. The use of a standard model and known fault detection methods is useful to establish a baseline for future work. Given the lack of standardised use in industry this is considered critical. Both proposed methods emphasise ease of visualisation which is beneficial for industrial implementation.
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| 20. |
- Jani, Yahya, 1975-
(författare)
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Landfills and glass dumpsites as future bank accounts of resources : waste characterization and trace elements extraction
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Environmental pollution and health threats as well as scarcity of raw materials, water, food and energy are among the main challenges our world are now facing. Simultaneously, landfills and open dumpsites still are the dominant global waste disposal option even with their long term environmental impacts in case of greenhouse gases and contaminated leachates. In this thesis, landfill mining is suggested as a tool that should be included in an enhanced circular economy model (repair, reuse and recycle + extract and recovery) by considering the extraction/recovery of the lost materials in landfills and dumpsites as secondary resources.Characterization data (composition and physicochemical properties) is considered as a vital source for information for: i. the valorization of excavated wastes, ii. to explore potential hazards and iii. as an important tool for theassessment of the waste management systems and policies. In this thesis,excavated wastes from a classic landfill (Högbytorp in Sweden), a landfill buildup according to the European Directive requirements (Torma in Estonia) andhazardous glass dumpsite (Pukeberg in Sweden) was characterized as a centralstep in exploring the potential of recovering of valuables. In addition, the extraction of trace elements from waste glass and different finefractions were also investigated. The reduction-melting method was developedto extract hazardous concentrations of trace elements from old art and crystalglasses with more than (99%) of recovery of Pb, Cd and As. While threechelating agents (EDTA, DTPA and NTA) were used to extract Pb, Cd, Asand Zn from fine fraction (<2 mm) sampled from Pukeberg glasswork with anextraction efficiency of (40%). Besides, the fractionations of the metals Cu, Znand Cr in the fine fractions (<10 mm) excavated from Högbytorp and Tormalandfills were studied by using a modified sequential extraction procedure.The findings of this thesis highlighted the need to consider the dumped wastesas secondary resources and landfills and dumpsites as future bank accounts offuture raw materials instead of being burden to the human health and theenvironment.
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| 21. |
- Khan, MD. Ershad Ullah, 1979-
(författare)
-
Renewables Based Polygeneration for Rural Development in Bangladesh
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Despite the country's rural electrification programme, kerosene is the predominant source for lighting, and unsustainable and polluting woody biomass is virtually the only option available for cooking. The rural population also struggles with unsafe drinking water in terms of widespread arsenic contamination of well water. The present work has taken an integrated approach in an attempt to mitigate problems through small-scale polygeneration, a concept linking renewable energy sources to these energy needs via novel energy conversion systems.Anaerobic digesters (AD) for biogas production are promising in the rural setting, and field surveys have identified problems in the construction, maintenance and operation of existing AD, particularly in overall performance of household digesters. Based on these results, a number of operational and technological improvements are suggested for employing digesters in polygeneration units. This study also examines one approach for small-scale, low cost arsenic removal in groundwater through air gap membrane distillation, a thermally-driven water purification technology.Integration of biogas production with power generation and water purification is an innovative concept that lies at the core of feasibility analyses conducted in this work. One of the case studies presents a new concept for integrated biogas based polygeneration and analyzes the techno-economic performance of the scheme for meeting the demand of electricity, cooking energy and safe drinking water of 30 households in a rural village of Bangladesh. The specific technologies chosen for the key energy conversion steps are as follows: plug-flow digester; internal combustion engine; and membrane distillation. One major concern is local feedstock availability for the digester, since a single feedstock is impractical to serve both cooking, lighting and water purification systems. In this circumstance solar PV could be a potential option for integrated hybrid systems.
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| 22. |
- Klintenberg, Patrik, et al.
(författare)
-
Assessing biogas potential of slaughter waste : Can biogas production solve a serious waste problem at abattoirs?
- 2014
-
Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 61, s. 2600-2603
-
Tidskriftsartikel (refereegranskat)abstract
- Management of solid waste and wastewater in Namibia is a growing concern. This study investigated the biogas potential of slaughter waste at a small stock abattoir in southern Namibia. Laboratory experiments with five different mixes of blood; stomach content and manure from sheep were tested. Preliminary findings suggest that the most optimum mixture of slaughter waste was relatively large amounts of stomach and intestine content. The blood proportion should be kept relatively low, since the high nitrogen contents in the blood may inhibit the biogas production. The substrate mixture reflecting the actual ratio of waste generated in the slaughter process resulted in the highest methane production. This suggests that it is possible to produce viable amounts of biogas only using the waste produced at the abattoir, without adding other green substrate. Findings presented here together with results from a larger biogas digester, will be elaborated in the full paper.
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| 23. |
- Krustok, Ivo, et al.
(författare)
-
Algae biomass cultivation in nitrogen rich biogas digestate.
- 2015
-
Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 72:10, s. 1723-1729
-
Tidskriftsartikel (refereegranskat)abstract
- Because microalgae are known for quick biomass growth and nutrient uptake, there has been much interest in their use in research on wastewater treatment methods. While many studies have concentrated on the algal treatment of wastewaters with low to medium ammonium concentrations, there are several liquid waste streams with high ammonium concentrations that microalgae could potentially treat. The aim of this paper was to test ammonium tolerance of the indigenous algae community of Lake Malaren and to use this mixed consortia of algae to remove nutrients from biogas digestate. Algae from Lake Malaren were cultivated in Jaworski's Medium containing a range of ammonium concentrations and the resulting algal growth was determined. The algae were able to grow at NH4-N concentrations of up to 200 mg L(-1) after which there was significant inhibition. To test the effectiveness of the lake water algae on the treatment of biogas digestate, different pre-cultivation set-ups and biogas digestate concentrations were tested. It was determined that mixing pre-cultivated suspension algae with 25% of biogas digestate by volume, resulting in an ammonium concentration of around 300 mg L(-1), produced the highest algal growth. The algae were effective in removing 72.8 ± 2.2% of NH4-N and 41.4 ± 41.4% of PO4-P.
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| 24. |
- Krustok, Ivo, 1987-, et al.
(författare)
-
Characterization of algal and microbial community dynamics in a wastewater photo-bioreactor using indigenous algae from lake mälaren
- 2014
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Microalgae grown in photo-bioreactors can be a valuable source for biomass especially when combined with the treatment of wastewater. While most published research has been studying pure cultures, consortia of algae and bacteria from the wastewater have more complex dynamics affecting both the biomass production and pollutant removal. In this paper we investigate dynamics of algal and bacterial communities in mixed culture photo-bioreactors using chlorophyll and real-time PCR analysis. Wastewater photo-bioreactors were inoculated with water from a nearby lake to add native algae species. The results indicated a decline in bacterial 16S rDNA copy numbers before algae started to multiply. The photo-bioreactors inoculated with lake algae produced more biomass and grew faster than the algae originating only from wastewater. The reactors were effective in removing ammonia from the wastewater which seemed work to mostly through nitrification thus causing an increase in nitrate concentration. There was also an increase in Cr, Co and Ni ion concentrations during the experiment suggesting they may have moved from organic complexes to the water phase as free ions.
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| 25. |
- Krustok, Ivo, 1987-, et al.
(författare)
-
Characterization of algal and microbial community growth in a wastewater treating batch photo-bioreactor inoculated with lake water
- 2015
-
Ingår i: Algal Research. - : Elsevier. - 2211-9264. ; 11:Sept, s. 421-427
-
Tidskriftsartikel (refereegranskat)abstract
- Microalgae grown in photo-bioreactors can be a valuable source of biomass, especially when combined with wastewater treatment. While most published research has studied pure cultures, the consortia of algae and bacteria from wastewater have more complex community dynamics which affect both the biomass production and pollutant removal. In this paper we investigate the dynamics of algal and bacterial growth in wastewater treating batch photo-bioreactors. The photo-bioreactors were inoculated with water from a nearby lake. Lake water was obtained in August, November and December in order to add native algal species and study the effects of the season. The photo-bioreactors inoculated with lake water obtained in August and November produced more biomass and grew faster than those that only contained the algae from wastewater. The results indicated a rapid decline in bacterial abundance before algae began to multiply in reactors supplemented with lake water in November and December. The reactors were also successful in removing nitrogen and phosphorous from wastewater.
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| 26. |
- Krustok, Ivo, 1987-
(författare)
-
Communities of microalgae and bacteria in photobioreactors treating municipal wastewater
- 2015
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Everyone who uses water produces wastewater. This inevitability creates several problems that increase with the growth of the population and industry. What to do with the wastewater, how to purify it and how to design the infrastructure are all important questions that each municipality has to deal with, taking into account ever growing demands to reduce environmental impact. In these conditions scientists and engineers have turned to biological processes to help treat the water. Currently the most commonly used wastewater treatment method known as the activated sludge process involves bacteria that help break down the pollutants. While it has been used successfully for around 100 years now, it has many limitations when faced with modern demands. As an alternative, microalgae reactors, commonly known as photobioreactors, have been suggested.Microalgae are microscopic water organisms that can use photosynthesis to form sugars from CO2 and water. To do this they require energy from light, hence the photo part of the photobioreactor. In addition to taking up CO2 from their environment, they take up nutrients such as nitrogen and phosphorous compounds. This is a reason why microalgae have great potential for use in wastewater treatment. When grown in wastewater together with the microorganisms already present, they are able to reduce the amount of pollutants by taking them up into their cells, effectively purifying the water.Since wastewater has its own microbial community, the biological processes taking place in a wastewater treating photobioreactor are more complex compared to growing a single species of algae in a sterile medium. With the work presented in this licentiate, we characterized the algae and bacterial communities present in photobioreactors treating wastewater in addition to finding the most optimal ways to grow algae originating from a local lake in a wastewater medium. We looked at the species found, most important metabolic pathways, growth dynamics for both algae and bacteria and water purification dynamics.Overall, we were successful in inoculating municipal wastewater from Västerås wastewater treatment plant with algae from Lake Mälaren. The dominant algae growing in our systems belonged to the genera Scenedesmus, Desmodesmus and Chlorella. We also saw that the bacterial community was involved in synthesis of vitamins essential for algae growth. The information presented in this thesis is another step towards a better design of control and monitoring systems in full-scale photobioreactor plants.
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| 27. |
- Krustok, Ivo, 1987-, et al.
(författare)
-
Comparative analysis of the metagenomes extracted from wastewater treating photobioreactors
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The metagenomes of lab-scale municipal wastewater treating batch photobioreactors were studied with a focus on nitrogen metabolism, pathogen abundance and antibiotic resistance genes. Previous studies based on the dataset showed that in general, as algae growth in the reactors increased, nitrogen metabolism and virulence genes decreased. With this study, a more detailed view of these gene groups is presented.
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| 28. |
- Krustok, Ivo, et al.
(författare)
-
CULTIVATION OF INDIGENOUS ALGAE FOR INCREASED BIOGAS PRODUCTION
- 2013
-
Konferensbidrag (refereegranskat)abstract
- There is an increased demand for biogas in the society and one way to meet this is to use cultivated microalgae as fermentation substrate. In the present study, a co-digestion experiment was established where municipal food waste was fermented with harvested microalgae cultivated in lake water. The experiment was carried out as a laboratory batch experiment with fermentation bottles, where 0, 12, 25 and 37% of the food waste was replaced with harvested microalgae, respectively. The results showed that the biogas production was generally improved after addition of microalgae. During the first 25 days of fermentation, replacement of 12% food waste with microalgae gave the highest biogas production rate. However, higher proportions of microalgae (25% and 37%) slightly decreased the gas production rate compared to 12% and compared to using food waste alone.
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| 29. |
- Krustok, Ivo, et al.
(författare)
-
Cultivation of microalgae for potential heavy metal reduction in a wastewater treatmet plant
- 2012
-
Konferensbidrag (refereegranskat)abstract
- Sorption capacity of microalgae in 10 different mixtures of wastewater and lake water was evaluated for their ability to reduce heavy metal concentrations in wastewater. Cu, Zn and Ba concentrations were mostly reduced whereas Al and As concentrations actually increased in some samples. Co and Ni concentrations were more reduced in samples with pure wastewater compared to samples with wastewater/lake water mixtures. Hence, a mixture of wastewater and lake water seemed to decrease the metal reduction process in the water. Finally, for Fe and Mn concentrations, there was no significant difference between samples with pure wastewater and wastewater/lake water mixture. In positive cases reduction of heavy metal concentrations in the samples with 50-70% of wastewater worked best.
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| 30. |
- Krustok, Ivo, 1987-, et al.
(författare)
-
Effect of lake water on algal biomass and microbial community structure in municipal wastewater based lab-scale photobioreactors
- 2015
-
Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 0175-7598 .- 1432-0614. ; 99:21, s. 6537-6549
-
Tidskriftsartikel (refereegranskat)abstract
- Photobioreactors are a novel environmental technology that can produce biofuels with the simultaneous removal of nutrients and pollutants from wastewaters. The aim of this study was to evaluate the effect of the lake water addition to the production of algal biomass, and phylogenetic and functional structure of the algal and bacterial communities in the lab-scale bioreactors treating municipal wastewater.The lake water addition has significant benefit to the overall algal biomass growth and nutrient reduction in the reactors with wastewater and lake water (ratio 70/30 v/v). The metagenome based survey showed that the most abundant algal phylum in these reactors was Chlorophyta with Scenedesmus being the most prominent genus. The most abundant bacterial phyla were Proteobacteria and Bacteroidetes with most dominant families being Sphingobacteriaceae, Cytophagaceae, Flavobacteriaceae, Comamonadaceae, Planctomycetaceae, Nocardiaceae and Nostocaceae. These photobioreactors were also effective in reducing the overall amount of pathogens in wastewater compared to reactors with wastewater/tap water mixture. Functional analysis of the photobioreactor metagenomes revealed an increase in relative abundance genes related to photosynthesis, synthesis of vitamins important for auxotrophic algae, and decrease in virulence and nitrogen metabolism subsystems in lake water reactors.
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| 31. |
- Krustok, Ivo, 1987-, et al.
(författare)
-
Inhibition of nitrification in municipal wastewater treating photobioreactors: effect on algal growth and nutrient uptake
- 2016
-
Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 202, s. 238-243
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of inhibiting nitrification on algal growth and nutrient uptake was studied in photobioreactors treating municipal wastewater. As previous studies have indicated that algae prefer certain nitrogen species to others, and because nitrifying bacteria are inhibited by microalgae, it is important to shed more light on these interactions. In this study allylthiourea (ATU) was used to inhibit nitrification in wastewater-treating photobioreactors. The nitrification-inhibited reactors were compared to control reactors with no ATU added.Microalgae had higher growth in the inhibited reactors, resulting in a higher chlorophyll a concentration. The species mix also differed, with Chlorella and Scenedesmus being the dominant genera in the control reactors and Cryptomonas and Chlorella dominating in the inhibited reactors. The nitrogen speciation in the reactors after 8 days incubation was also different in the two setups, with N existing mostly as NH4-N in the inhibited reactors and as NO3-N in the control reactors.
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| 32. |
- Krustok, Ivo, 1987-
(författare)
-
Microbiological analysis of municipal wastewater treating photobioreactors
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Microalgae reactors, commonly known as photobioreactors, have become increasingly popular as an alternative for wastewater treatment. These systems reduce pollutants and remove nutrients such as nitrogen and phosphorous compounds from wastewater utilizing microalgae and bacteria. The biomass produced in the reactors can potentially be used to produce biofuels and decrease some of the energy demands of the process.Wastewater treating photobioreactors are a relatively new technology and many aspects of their microbiology need further study. This thesis presents a broad overview of the algal and bacterial communities present in these systems by looking at the most important species, metabolic pathways and growth dynamics of both algae and bacteria.The experiments presented in this thesis were conducted using municipal wastewater from the Västerås wastewater treatment plant. The wastewater was inoculated with algae from Lake Mälaren and compared to non-inoculated reactors. Overall, the inoculated reactors demonstrated better algal growth than those that were not inoculated. The tested systems also removed much of the ammonium and phosphorous present in the wastewater.The dominant algae in the tested systems belonged to the genera Scenedesmus, Desmodesmus and Chlorella. In addition to algae, the systems contained a large number of bacteria, mostly from the phyla Proteobacteria and Bacteroidetes.The algal photobioreactors contained a lower abundance of genes related to nitrogen metabolism, virulence and antibiotic resistance compared to the initial wastewater, showing that a shift in the bacterial community had occurred. The bacteria found in the systems were shown to be involved in synthesis of vitamins essential for algae growth such as vitamin B12, suggesting cooperation between the bacteria and algae.
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| 33. |
- Kumm, Mia, 1967-, et al.
(författare)
-
Innovative Measures for Environmental Technologies at Tunnel Fires
- 2008
-
Ingår i: Research of Technogenic Envionment Protection. ; , s. 152-159
-
Konferensbidrag (refereegranskat)abstract
- Many tunnels are built below the ground water level. In case of a fire or oil spill there is a risk of environmental contamination of ground water supplies or sensitive recipients. Successful treatment of extinguishing water or spills needs rapid attention in such cases. This paper discusses the environmental consequences of a tunnel fire or an oil spill inside the tunnel. It is suggested from the present study of existing technologies, that the work of development within this field be divided into three different areas where two are pro-active while the last requires the development of new technologies for on-site collection and treatment of water. In sensitive areas, this treatment could be combined with in-situ surveys and treatments both prior to and after an incident. The two pro-active steps are characterization and categorization of tunnels along with the development of a digital system where site specific properties can be modeled. Additionally, at the fire scene, new mobile technologies are needed for effective treatment.Finally the paper discusses the environmental challenges the fire officer has to with deal during an incident and the need for further education of first responders on how to deal with these issues both in terms of short term and long term incident management priorities.
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| 34. |
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| 35. |
- Loutfi, Amy, 1978-, et al.
(författare)
-
Using e-noses for environmental monitoring
- 2009
-
Ingår i: Proc. 12<sup>th</sup> EuCheMS International Conference on Chemistry and the Environment, June 14-17, Stockholm. ; , s. 46-
-
Konferensbidrag (refereegranskat)
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| 36. |
- Maes, Sharon, Dr. 1990-, et al.
(författare)
-
Airborne monitoring of water quality in remote regions
- 2023
-
Konferensbidrag (refereegranskat)abstract
- The Intergovernmental Panel on Climate Change (IPCC) points out alpine regions worldwide as climate change hotspots. Expanding and diversifying summer tourism in northern Scandinavian mountains exerts additional severe pressure to these areas and their oligotrophic and sensitive aquatic ecosystems. Previous research at Mid Sweden University has shown that fecal contamination of mountain rivers, indicated by the enumeration of E. coli, is frequent in areas that are intensively being used for tourism and reindeer herding. According to the IPCC, climate change is projected to reduce raw water quality, posing risks to drinking water quality even with conventional treatment. Therefore, there is an urgent need for improved monitoring of water quality in such areas to be able to protect the ecosystem as well as the rights of indigenous people, human and animal health and to provide support for water management decision. To be able to monitor the water quality is of great importance for the sustainability of mountain regions and water sources in general. The inaccessibility of the watercourses in remote mountain areas makes it difficult to establish sufficient monitoring programs.In this research, the use of airborne monitoring systems to assess water quality in remote regions is investigated. Remote monitoring systems based on e.g. drones and satellites have the potential to replace less climate friendly options making use of terrain vehicles, snow mobiles and helicopters. The drones can be equipped with various sensors or sampling equipment, can overcome long transportations as well as time-consuming and expensive field samplings. Drones have great potential to be employed in everyday practices as an essential part of decision support systems for monitoring, evaluation and remediation of contaminated sites. The goal is to use drones to establish water quality monitoring programs in remote regions such as the mountain areas of Northern Sweden. In this research we intend to cover the catchment area of upper parts of river Indalsälven situated in the mountain region on the Swedish/Norwegian border, including the catchment areas of the tributaries Handölan and Enan covering approximately 777km2.One approach in this research is to image large areas of interest by the use of a multispectral camera on a drone and to identify spectral bands or band ratio´s which correlate to physicochemical parameters that are related to water quality. Another approach is to further explore the use of dronebased water sampling for laboratory or in-field analysis of microbial and chemical parameters.Both approaches should eventually lead to the development of a drone-based monitoring program for oligotrophic rivers that can image or measure water pollution with sufficient spatial coverage and time resolution to enable early warning of outbreaks of fecal pollution. Results of this research will contribute to SDG 6, targets 3 and 6 and SDG 14.
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| 37. |
- Maes, Sharon, Dr. 1990-, et al.
(författare)
-
Fecal indicator organisms in northern oligotrophic rivers : An explorative study on Escherichia coli prevalence in a mountain region with intense tourism and reindeer herding
- 2022
-
Ingår i: Environmental Monitoring & Assessment. - : Springer Nature. - 0167-6369 .- 1573-2959. ; 194:4
-
Tidskriftsartikel (refereegranskat)abstract
- Increasing pollution levels in waters from remote mountain areas in northern Sweden have been observed. To support a sustainable water quality management, it is necessary to know which environmental and antrophogenic factors influence the water quality. The purpose of this study was to map the Escherichia coli prevalence in the catchment area of the upper part of a large northern Scandinavian river and investigate the controlling factors of microbial contamination. A total of 112 water samples were collected from various locations in the research area between July 2020 and December 2020. These samples were analyzed for microbial and chemical characteristics, and information about tourism and reindeer herding was compiled. Additionally, microbial and physicochemical water characteristics collected by Indalsälven Water Conservation Association (IWCA, 1993–2020) and Swedish Meteorological and Hydrological Institute (SMHI, 2004–2020) were analyzed. The results showed that E. coli enumerations ranged between 0 and 500 CFU/100 ml. There was generally no obvious relation between suspected point sources, e.g., sewage treatment plants at mountain stations, and E. coli levels at downstream sampling points. Principal component analysis showed that E. coli was correlated to coliforms, total heterotrophic count, river discharge, CODMn and river color. Since microbial analyses are time-consuming, expensive and difficult to perform in remote areas, it is important to find more easily extracted water parameters that can serve as a proxy for E. coli. In particular, river color and discharge are promising parameters that may serve as an early indication of bacterial outbreak and fecal contamination in mountain waters.
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| 38. |
- Maes, Sharon, et al.
(författare)
-
Monitoring Tools For Sustainable Water Management In Mountain Areas
- 2022
-
Ingår i: 2022: Book of abstracts: Linnaeus ECO-TECH '22. - Kalmar. - 9789189460850
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The naturally oligotrophic rivers in Northern Sweden are generally characterized by a low pollution level. However, an increasing trend in E. coli contamination has been observed in the most upstream catchment area of one of the large rivers of Norhtern Sweden. This decrease in microbial water quality will have a severe negative impact on the ecosystem, wild animals, visitors, inhabitants as well as indigenous people dependent on the land for their daily income, such as Sami herders. The source area of river Indalsälven is part of a very remote, mountainous region with few roads, which makes it challenging to conduct regular water quality monitoring covering the whole area of ±780km2. The aim is to evaluate and implement monitoring tools that are more environmentally friendly and faster than the currently applied methods which can be implemented as an early warning system for fecal contamination in remote mountain areas. Currently, the presence of fecal contamination in Indalsälven´s catchment area is assessed by strategic river-side water sampling, followed by long transport times and laboratory analysis of fecal indicator organisms such as E. coli. The use of drones for water sampling could significantly increase the accessibility and coverage of the research area. Also, analysis time can drastically decrease by doing field analysis of the water samples, e.g. by performing a field-PCR for the detection and quantification of E. coli. On the other hand, the monitoring of proxies for fecal contamination can also be a promising approach for continuous monitoring and the development of an early warning system. Our previous research has shown that river flow rate and river color are potential parameters for this. Continuous measurement of these parameters at well-chosen locations or remote imaging by drones over the whole research area are proposed to investigate this track.
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| 39. |
- Maes, Sharon, et al.
(författare)
-
Source Tracking of Fecal Contamination in Northern Oligotrophic Rivers
- 2022
-
Ingår i: PROCEEDINGS of the 28th Annual Conference, International Sustainable Development Research Society. - Stockholm. - 9789189504172
-
Konferensbidrag (refereegranskat)abstract
- The naturally oligotrophic rivers in northern Sweden are generally characterized by a low pollution level. However, an increasing trend in E. coli contamination has been observed in the most upstream catchment area of one of the large rivers of Norhtern Sweden. This change in microbial water quality will have a severe negative impact on the ecosystem, wild animals, visitors, inhabitants as well as indigenous people dependent on the land for their daily income, such as Sami herders. To limit or prevent the discharge of fecal pollution into the river system and also to estimate the danger that this contamination can pose to human health, it is important to know the source of this contamination. Based solely on structured water sampling, it is still very difficult to pinpoint the sources of fecal pollution. Therefore, a combined analysis of eDNA and microbial source tracking of E. coli isolates from river samples was performed to identify the source of fecal pollution in the research area. E. coli isolates were collected from water samples taken along the tributaries Enan and Handölan. Simultaneously, eDNA samples were collected on the same locations. Additionally, fecal and sewage samples were taken to collect E. coli isolates with a known host source being either human, beaver or reindeer. Also, sequences from genomic E. coli DNA originating from human (obtained from NCBI and University of Alberta, School of Public Health) and from beaver (obtained from University of Alberta, School of Public Health) were collected and included in the study. E. coli isolates were used for the amplification of three Intergenic Regions and subsequent analysis of Single Nucleotide Polymorphisms to identify host-specific genetic markers in the E. coli genome. eDNA samples were subjected to metabarcoding targeting mammal DNA to determine the relative species abundance in the water samples. The E. coli prevalence in the research area varies between <1 and 210 CFU/100mL and is dependent on e.g. sampling location (possible point sources), time (tourist intensity and area specific events such as reindeer calve marking) and weather (precipitation, river flow, UV radiation). A library containing the data from E. coli isolates that are known to be originating from the species human, beaver and reindeer was developed and used to identify the host source of the E. coli isolates collected from water samples. Consequently, E. coli isolates could be identified as originating from human, beaver, reindeer or a different mammal species. Results from the eDNA analysis provides information about the relative abundance of mammal species on a certain location. Although these results don´t provide a direct link to the presence or absence of fecal pollution by these species, it can provide interesting knowledge about the source of fecal pollution when combined with the E. coli prevalence data from the same sampling locations and times.
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| 40. |
- Mara, Grube, et al.
(författare)
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Application of FT-IR Spectroscopy for Investigation of Pink Water Remediation by Pine Bark
- 2015
-
Ingår i: Open Biotechnology Journal. - : Bentham Science Publishers Ltd.. - 1874-0707. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- This study demonstrates the application of FT-IR spectroscopy for investigating the remediation of pink water with the low cost adsorbent pine bark. The removal of 2,4,6-trinitrotoluene (TNT) from pink water by adsorption to pine bark was accompanied by a reduction in intensities of peaks at 1544 and 1347 cm-1 in the spectra of acetonitrile extracts of the pine bark. Hierarchial cluster analysis differentiated samples with high (30-180 mg/L) and low (0-4 mg/L) TNT concentrations, demonstrating the potential of this approach as a quick screening method for the control of the removal of TNT from pink water. The amount of lignin in pine bark was inversely proportional to the size of the pine bark particles, while the concentration of phenolic hydroxyl groups increases with increasing size of pine bark particles. FT-IR spectra showed that as well as TNT, pine bark can also adsorb nitramine explosives such as RDX and HMX.
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| 41. |
- Marais, Heidi Lynn, 1996-, et al.
(författare)
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Comparing statistical process control charts for fault detection in wastewater treatment
- 2022
-
Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 85:4, s. 1250-1262
-
Tidskriftsartikel (refereegranskat)abstract
- Fault detection is an important part of process supervision, especially in processes where there are strict requirements on the process outputs like in wastewater treatment. Statistical control charts such as Shewhart charts, cumulative sum (CUSUM) charts, and exponentially weighted moving average (EWMA) charts are common univariate fault detection methods. These methods have different strengths and weaknesses that are dependent on the characteristics of the fault. To account for this the methods in their base forms were tested with drift and bias sensor faults of different sizes to determine the overall performance of each method. Additionally, the faults were detected using two different sensors in the system to see how the presence of active process control influenced fault detectability. The EWMA method performed best for both fault types, specifically the drift faults, with a low false alarm rate and good detection time in comparison to the other methods. It was shown that decreasing the detection time can effectively reduce excess energy consumption caused by sensor faults. Additionally, it was shown that monitoring a manipulated variable has advantages over monitoring a controlled variable as setpoint tracking hides faults on controlled variables; lower missed detection rates are observed using manipulated variables.
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| 42. |
- Marais, Heidi L., 1996-, et al.
(författare)
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Outlining Process Monitoring and Fault Detection in a Wastewater Treatment and Reuse System
- 2020
-
Ingår i: European Control Conference 2020, ECC 2020. - : Institute of Electrical and Electronics Engineers Inc.. - 9783907144015 ; , s. 558-563
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Konferensbidrag (refereegranskat)abstract
- Process control is an important part of any industrial system. In a wastewater reuse system this remains true. Process monitoring and fault detection (FD) are important to ensure that the control system has access to reliable data which can be used in making decisions about the operation of the process. The reuse scenario being considered in this work is that of utilizing the nutrients from the wastewater as fertilizer to agricultural soil along with using the water for irrigation purposes. This paper identifies variables that are important to the control of the process and should be a focus of monitoring and FD. In wastewater treatment these variables include temperatures, pressures, liquid levels, flow rates, pH, conductivity, biomass content, suspended solids concentration, dissolved oxygen content, total organic carbon, and the concentrations of nitrate and ammonium. The variables of interest in the reuse of nutrients and water for agriculture include soil moisture, ambient conditions, plant height, biomass content, photosynthetic activity of the crop, leaf area and leaf water content, as well as the concentrations of several ions both in the soil and in the plant. Challenges associated with process monitoring and FD specific to the two processes are also discussed, examples of these are the high dimensionality of the problem, the harsh conditions that sensors must operate in and the non-linear relationships between variables. This information will be used in future work when comparing specific FD methods to ensure that methods chosen are capable of overcoming the commonly encountered problems.
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- Nehrenheim, Emma, et al.
(författare)
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Biological degradation of explosives in columns - new research ideas
- 2006
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Ingår i: The Swedish Section for Detonics and Combustion, Fourth International Disposal Conference November 13-14, 2006, Katrineholm, Sweden. - Linköping : Linköping University Electronic Press, Linköpings universitet. ; , s. 9-11
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Konferensbidrag (refereegranskat)
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| 46. |
- Nehrenheim, Emma, 1979-, et al.
(författare)
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RECIRCULATION OF BIOGAS RESIDUE TO AGRICULTURAL LAND IN NAMIBIA– RISKS AND POTENTIALS IN FULL UTILIZATION OF ORGANIC WASTE
- 2011
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Konferensbidrag (refereegranskat)abstract
- The current situation of waste disposal in Namibia is under developed. The country has a large meat and dairy industry as well as some breweries and wineries and today, none of the organic wastes are reused, recycled or utilized for energy utilization. Little has been done in order to collect and utilize the resources in the organic waste from these industries but there is currently some early stage projects in planning related to biogas production from organic wastes. This study aims at evaluating the potential for some three planned biogas projects in Namibia at early stage, especially regarding the management of the biogas residue. In this processes, a first screening of the potential biogas substrate in the southern part of Namibia (south of Windhoek) was conducted. Moreover, the paper aims to point out the potentials in using organic waste for biogas production and thereafter recycling the nutrient rich residue to the farmland of Namibia. The risks in such utilization will be touched upon, such as the toxic effects of the alkali rich liquid phase or the NO2-emissions. Of which the first can be considered a risk but also a potential if the alkali residue partly can replace the use of pesticide. We conclude that the availability of substrates, i.e. organic wastes, is sufficient for supplying one or several biogas plants to the area. According to our conclusions, fertilization with biogas residue should be promoted in Namibia as an alternative to the current fertilization.
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| 47. |
- Nehrenheim, Emma, et al.
(författare)
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Retention of 2,4,6-trinitrotoluene and heavy metals from industrial waste water by using the low cost adsorbent pine bark in a batch experiment
- 2011
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 64:10, s. 2052-2058
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Tidskriftsartikel (refereegranskat)abstract
- Pine bark is a low cost sorbent originating from the forest industry. In recent years, it has been found to show promise as an adsorbent for metals and organic substances in contaminated water, especially landfill leachates and storm water. This study aims to investigate if pine bark can replace commercial adsorbents such as active carbon. An industrial effluent, collected from a treatment plant of a demilitarization factory, was diluted to form concentration ranges of contaminants and shaken with pine bark for 24 hours. Metals (e.g. Pb, Zn, Cd, As and Ni) and explosives, e. g., 2,4,6-trinitrotoluene (TNT), were analysed before and after treatment. The aim of the experiment was twofold; firstly, it was to investigate whether metals are efficiently removed in the presence of explosives and secondly, if adsorption of explosive substances to pine bark was possible. Langmuir and Freundlich isotherms were used to describe the adsorption process where this was possible. It was found that metal uptake was possible in the presence of TNT and other explosive contaminants. The uptake of TNT was satisfactory with up to 80% of the TNT adsorbed by pine bark.
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