| 1. |
- Albers, Eva, 1966, et al.
(författare)
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Influence of preservation methods on biochemical composition and downstream processing of cultivated Saccharina latissima biomass
- 2021
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Ingår i: Algal Research. - : Elsevier BV. - 2211-9264. ; 55
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Tidskriftsartikel (refereegranskat)abstract
- Saccharina latissima biomass cultivated along the Swedish west coast was subjected to four different scalable preservation methods after harvest; freezing, sun-drying, oven-drying and ensiling. Freeze-drying and freezing at -80 ?C were also included to provide dry and wet references. The effects of the different preservation methods on the composition of Saccharina biomass (on dry weight, DW, basis), and the recovery as well as properties of high-quality protein, alginate and biogas were evaluated. Sun-drying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods. Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass, while mannitol and laminarin were reduced compared to the other biomasses. Oven-drying and -20 ?C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasses which translated into the lowest total seaweed protein recovery using the pH-shift process. Highest protein yield was obtained with the freeze-dried reference. Ensiling lead to a significant decrease in the molecular weight of alginate, while sun-drying caused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield in the anaerobic digestion experiments while freezing at -80 ?C gave the highest yield, closely followed by freezing at -20 ?C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima, and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.
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| 2. |
- Ohlsson, Lars-Ola, et al.
(författare)
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Evaluation of Laminaria digitata and Phragmites australis for biogas production and nutrient recycling
- 2020
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 140
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Tidskriftsartikel (refereegranskat)abstract
- Eutrophication and climate change are major global problems. The sea weed Laminaria digitata and the reed Phragmites australis have the potential to absorb nutrients and CO2 during growth, as well as being a source of renewable energy in the form of biogas. The aim of this study was to evaluate Laminaria digitata and Phragmites australis concerning biogas production and nutrient recycling using a two-stage pilot scale process. The plant has a total volume of 430 L and consists of a hydrolysis bed and an up-flow anaerobic sludge blanket reactor (UASB). Two experiments were performed; one with Laminaria digitata as the sole substrate and one with a mixture of Laminaria digitata and Phragmites australis. Frozen substrates were placed in the hydrolysis bed and digestion was performed at 305 K during 70 days for Laminaria digitata and 100 days for the mixture of Laminaria digitata and Phragmites australis. The methane yield achieved was approximately 170 L kg−1 volatile substances (273.15 K, 101.3 kPa) in both experiments. These results suggest that Laminaria digitata can be efficiently digested in larger scale and has the potential to contribute to a future sustainable energy mix, considering its relatively high methane yield when anaerobically digested as the sole substrate. Digestion of Phragmites australis needs further development to make use of its full potential.
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| 3. |
- Thomas, Jean-Baptiste, et al.
(författare)
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The effects of cultivation deployment- and harvest-timing, location and depth on growth and composition of Saccharina latissima at the Swedish west coast
- 2022
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 559
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Tidskriftsartikel (refereegranskat)abstract
- A study has been conducted to shed light on the effect of cultivation parameters on growth and chemical composition of Saccharina latissima. Longline cultivation took place at two separate locations in the Koster ar-chipelago on the Swedish west coast, centred around three experiments that explored duration of pre-deployment hatchery processes (Exp 1), deployment and harvest time-frames (Exp 2), and cultivation at 2 m vs. 4 m depth (Exp 3). For all experiments the effects of these parameters were evaluated in terms of size/weight of specimens, and for experiments Exp 2 and Exp 3, concentrations of moisture, ash, carbohydrates, proteins, fatty acids, phlorotannins and common heavy metals were determined. The specific parameters used in this study are likely to vary from site to site, nevertheless trends were observed that resonate in the literature, and these lead to some general recommendations. The weight of harvested kelp blades was higher for the later harvest, earlier deployment and when grown at a shallower depth. Carbohydrates concentration increased with later harvests and at shallower depth. Later harvests also increased the concen-tration of phlorotannin, while ash and total fatty acids decreased. Protein and fucoidan content was higher for the deeper lines. Growth and chemical composition of the seaweeds showed only minor differences between the two study sites, mostly relating to heavy metal content.
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| 4. |
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| 5. |
- Forss, Jörgen, et al.
(författare)
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Biodegradation of azo and anthraquinone dyes in continuous systems
- 2011
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Ingår i: International Biodeterioration & Biodegradation. - : Elsevier. - 0964-8305 .- 1879-0208. ; 65:1, s. 227-237
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Tidskriftsartikel (refereegranskat)abstract
- The purpose is to develop a complete microbiological model system for the treatment of wastewaterfrom textile mills in developing countries. Artificial wastewater was treated by microorganisms growingon wood shavings from Norway spruce during unsterile conditions. The microorganisms were inoculatedfrom forest residues. Mixtures of the azo dyes Reactive Black 5 and Reactive Red 2 were degraded inbatch as well as continuous experiments. Reactive Red 2 mixed with the anthraquinone dye ReactiveBlue 4 was also treated in the continuous system. The system consisted of three reservoirs e the first twowith an anaerobic environment and the third with an aerobic. The dye concentrations were 200 mg l 1ofeach dye in the continuous system and the retention time was approximately 4 days and 20 h perreservoir. Samples from the process were analysed with spectrophotometer and LC/MS to monitor thedegradation process. 86-90% of the colour was removed after a treatment of 4 days and 23 h in thecontinuous process. Two metabolites were found in the outlets of reactors one and two, but they weredegraded to below the detection limit in the aerobic reactor.
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| 6. |
- Forss, Jörgen, 1973-, et al.
(författare)
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Microbial biotreatment of actual textile wastewater in a continuous sequential rice husk biofilter and the microbial community involved
- 2017
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Ingår i: PLOS ONE. - : PLOS. - 1932-6203. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Textile dying processes often pollute wastewater with recalcitrant azo and anthraquinone dyes. Yet, there is little development of effective and affordable degradation systems for textile wastewater applicable in countries where water technologies remain poor. We determined biodegradation of actual textile wastewater in biofilters containing rice husks by spectrophotometry and liquid chromatography mass spectrometry. The indigenous microflora from the rice husks consistently performed >90% decolorization at a hydraulic retention time of 67 h. Analysis of microbial community composition of bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) gene fragments in the biofilters revealed a bacterial consortium known to carry azoreductase genes, such as Dysgonomonas, and Pseudomonas and the presence of fungal phylotypes such as Gibberella and Fusarium. Our findings emphasize that rice husk biofilters support a microbial community of both bacteria and fungi with key features for biodegradation of actual textile wastewater. These results suggest that microbial processes can substantially contribute to efficient and reliable degradation of actual textile wastewater. Thus, development of biodegradation systems holds promise for application of affordable wastewater treatment in polluted environments.
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| 7. |
- Forss, Jörgen, et al.
(författare)
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Microbial diversity in a continuous system based on rice husks for biodegradation of the azo dyes Reactive Red 2 and Reactive Black 5
- 2013
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 130, s. 681-688
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Tidskriftsartikel (refereegranskat)abstract
- In the present study the degradation of two common azo dyes used in dye houses today, Reactive Black 5 and Reactive Red 2 was evaluated in biofilters. In two experiments, bioreactors performed over 80% decolorization at a hydraulic retention time of only 28.4 h with little production of metabolites. Molecular analyses showed a diverse and dynamic bacterial community composition in the bioreactors, including members of the Bacteroidetes, Acinetobacter (Gammaproteobacteria) and Clostridium (Firmicutes) that possess the capacity to reduce azo dyes. Collectively, the results indicate that the development of mixed bacterial communities from natural biomaterials contributes to an efficient and robust degradation performance in bioreactors even at high concentration of dyes.
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| 8. |
- Gregeby, Erik, et al.
(författare)
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The influence of mixing, addition of buffer, silage and chicken manure on the biogas production from cattle manure
- 2010
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Ingår i: 18th European Biomass Conference and Exhibition, 3-7 May, Lyon. - : ETA Renewable Energies and WIP Renewable Energies.
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Konferensbidrag (refereegranskat)abstract
- A number of batch experiements were performed in order to evaluate the biogas production from cattle manure adter addition of buffer, silage or chicken manure. Some experiments were also performed to investigate the effect of mixing. All experiments were performed at 35 C. The results showed that the extent of mixing did not affect the biogas production to any larger extent. The addition of buffer speeds up the start of the process and increased the volume of biogas produced. The methane content was approximately the same independently on if a buffer was added or not. Chicken manure inhibited the process adn addition of silage gave an increase in the amount of biogas produced. No significant effect of silage addition was found on the methane content of the biogas.
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| 9. |
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| 10. |
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| 11. |
- Pechsiri, Joseph Santhi, et al.
(författare)
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Energy performance and greenhouse gas emissions of kelp cultivation for biogas and fertilizer recovery in Sweden
- 2016
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 573, s. 347-355
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Tidskriftsartikel (refereegranskat)abstract
- The cultivation of seaweed as a feedstock for third generation biofuels is gathering interest in Europe, however, many questions remain unanswered in practise, notably regarding scales of operation, energy returns on investment (EROI) and greenhouse gas (GHG) emissions, all of which are crucial to determine commercial viability. This study performed an energy and GHG emissions analysis, using EROI and GHG savings potential respectively, as indicators of commercial viability for two systems: the Swedish Seafarm project's seaweed cultivation (0.5 ha), biogas and fertilizer biorefinery, and an estimation of the same system scaled up and adjusted to a cultivation of 10 ha. Based on a conservative estimate of biogas yield, neither the 0.5 ha case nor the up-scaled 10 ha estimates met the (commercial viability) target EROI of 3, nor the European Union Renewable Energy Directive GHG savings target of 60% for biofuels, however the potential for commercial viability was substantially improved by scaling up operations: GHG emissions and energy demand, per unit of biogas, was almost halved by scaling operations up by a factor of twenty, thereby approaching the EROI and GHG savings targets set, under beneficial biogas production conditions. Further analysis identified processes whose optimisations would have a large impact on energy use and emissions (such as anaerobic digestion) as well as others embodying potential for further economies of scale (such as harvesting), both of which would be of interest for future developments of kelp to biogas and fertilizer biorefineries.
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| 12. |
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| 13. |
- Risén, Emma, et al.
(författare)
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Assessment of biomethane production from maritime common reed
- 2013
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 53, s. 186-194
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Tidskriftsartikel (refereegranskat)abstract
- Several ongoing projects are harvesting maritime biomass from the Baltic Sea for eutrophication mitigation and utilisation of the recovered biomass. Some of this biomass comprises common reed (Phragmites australis), one of the most widespread vascular plants on Earth. Reed utilisation from eutrophied coastal areas needs to be evaluated. Therefore, a system analysis was performed of reed harvesting for biofuel and biofertiliser production. The specific objectives of the analysis were to: investigate the methane yield associated with anaerobic co-digestion of reed; make a primary energy assessment of the system; quantify Greenhouse Gas (GHG) savings when a fossil reference system is replaced; and estimate the nutrient recycling potential of the system. The results from energy and GHG calculations are highly dependent on conditions such as system boundaries, system design, allocation methods and selected indicators. Therefore a pilot project taking place in Kalmar County, Sweden, was used as a case study system. Laboratory experiments using continuously stirred tank reactor digesters indicated an increased methane yield of about 220 m3 CH4/t volatile solids from co-digestion of reed. The energy balance for the case study system was positive, with energy requirements amounting to about 40% of the energy content in the biomethane produced and with the non-renewable energy input comprising about 50% of the total energy requirements of the system. The net energy value proved to be equivalent to about 40 L of petrol/t reed wet weight. The potential to save GHG emissions compared with a fossil reference system was considerable (about 80%). Furthermore an estimated 60% of the nitrogen and almost all the phosphorus in the biomass could be re-circulated to arable land as biofertiliser. Considering the combined benefits from all factors investigated in this study, harvesting of common reed from coastal zones has the potential to be beneficial, assuming an appropriate system design, and is worthy of further investigations regarding other sustainability aspects.
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| 14. |
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| 15. |
- Rupar-Gadd, Katarina, et al.
(författare)
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Evaluation of the role of microbail activity in self-jheating of stored wood based biofuels
- 2005
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Ingår i: Swedish-Finnish Flame Days. - : International Flame Research Foundation. - 9171781854 ; , s. 262-267
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Konferensbidrag (refereegranskat)abstract
- Self-ignition in storde wood based biofuels is an environmental as well as an economical problem. The amount of biofuels, which is going to be stored, might increase due to the decision taken by the European Union that the emissions of greenhouse gases should decrease. Storage of oragnic material leads to chemical as well as microbial activities. The heat released from aged sawdust (stored outside for three months), dried mixture before it was pressed to pellets and three different kinds of pellets due to microbial activity was measurede with an isothermal calorimeter (TAM Air) under various conditions.- Experiments with and without addition of Cu,Fe and Mn were performed in order to investigate if a catalytical effect could be observed. The results showed that the addition of copper had different efffects depending on which wood material that was studied and the temperature at which the samples had been stored. The addition of Fe or Mn generally did not give any measurable increase in the heat released.
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| 16. |
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| 17. |
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| 18. |
- Welander, Ulrika, 1966-, et al.
(författare)
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Decolourization of reactive azo dyes with microorganisms growing on soft wood chips
- 2009
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Ingår i: International Biodeterioration & Biodegradation. - : Elsevier. - 0964-8305 .- 1879-0208. ; 63, s. 752-758
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Tidskriftsartikel (refereegranskat)abstract
- The decolourization of a mixture of 200 mg/l each of Reactive Black 5 and Reactive REd 2 dye was studied in batch experiments using microorganisms growing on forest residue wood chips in combination with or without added white-rot fungus, Bjerakndera sp. BOL 13. The study was performed as a first stage in the development of a relatively simple treatement process for textile wastewater, designed to work in developing countries. Forest residue wood chips contain a mixture of fungi and bacteria which is an advantage when complex molecules should be degraded. The wood chips furthermore provide the microorganisms with carbon source which make the addition of e.g. glucose unnecessary. The results showed that the microorganisms growing on the forest residue wood chips decolourized the mixture of the two dyes; adding extra nutrients approximately doubled the decolourization rate. The time needed for decolourization was approximately 18 days when nutrients were added. Lignocellulosic material is complex and so were the analysis, microorganisms were therfore transferred to ordinary soft wood chips from forest residue wood chips, Decolourization was measured with spectrophotometer an in order to determine intermediates HPLC was used.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Welander, Ulrika, 1966-, et al.
(författare)
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Treatment of alpha-pinene contaminated air using biofilters with and without silicone oil
- 2010
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley InterScience. - 1944-7442 .- 1944-7450. ; 29:3, s. 313-318
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Tidskriftsartikel (refereegranskat)abstract
- Two biofilters equal in size were filled with perlite for treatment of -pinene-contaminated air. The perlite used for one of the biofilters was partially coated with silicone oil to make the surface of the particles more hydrophobic. The filters were run at 1.5, 2.5, and 5 L/min airflow rate (3.1, 1.9, and 0.9-min retention time). The filters were operated for 5.5 months. The results showed that the silicone oil-coated filter performed better at 2.5 L/min with a maximum elimination capacity of 20 g/(m3 h) in comparison with 15 g/(m3 h) for the filter without oil. The efficiency was approximately the same for both filters at 1.5 L/min (40 g/m3 h), whereas it was slightly higher for the without oil filter at 5 L/min [35 g/(m3 h)]. The flow rate was set to 2.5 L/min once more (day 151). The results showed that the elimination capacity had increased to 35 g/(m3 h) and that the efficiency of both filters was approximately the same. The difference in results between the initial run and the later run at 2.5 L/min is probably depending on that the number of microorganisms had increased during the experiment and that the oil-containing biofilter adsorbed -pinene to a higher extent than the biofilter without silicone oil during the start-up period. © 2009 American Institute of Chemical Engineers Environ Prog, 2010
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| 23. |
- Wollak, Birte, et al.
(författare)
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Evaluation of blue mussels (Mytilus edulis) as substrate for biogas production in Kalmar County (Sweden)
- 2018
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 111, s. 96-102
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Tidskriftsartikel (refereegranskat)abstract
- The Baltic Sea is an over-fertilized inland sea; the blue mussels have potential to absorb nutrients as well as being a source of renewable energy in the form of biogas. The aim of this study was to evaluate technology to utilize blue mussels for biogas production in a pilot scale. Blue mussels (Mytilus edulis) were anaerobically digested in a two-stage digestion process (430 L), consisting of a percolation bed and an up-flow anaerobic sludge blanket reactor. Frozen mussels with shells were placed in the percolation bed and digestion was performed at 36 oC during 37 days. The methane potential achieved with this technique was 310 L kg-1 volatile solid substances (273.15 K, 101.3 kPa). This result suggests that blue mussels can be efficiently digested in a larger scale and have the potential of contributing to a sustainable energy mix in the Baltic region and at the same time decrease the eutrophication of the Baltic Sea. No addition of nutrients and no pretreatment of the mussels (peeling) were needed.
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