| 1. |
- Mc Conville, Jennifer R, 1978, et al.
(författare)
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Is the Swedish wastewater sector ready for a transition to source separation?
- 2017
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Ingår i: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 91, s. 320-328
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Tidskriftsartikel (refereegranskat)abstract
- Source separation of urine for recycling has been applied in small-scale and decentralized wastewater systems in Sweden for the past 25 years and for blackwater for pollution control even longer. The Swedish experience with source separating nutrient recycling systems is relatively well documented; however, few reports have specifically studied the potential for expansion of this practice. The aim of this study is to fill this knowledge gap by assessing the status of source-separating technologies in Sweden based on transition theory. This study uses a multi-level perspective to determine how ready the Swedish wastewater sector is for transitioning to alternative systems. Given the stability of the existing sewage wastewater regime, it seems unlikely that changes within the regime will lead to a quick and large-scale transition to source separation. Instead, the initiative must come from the niche itself, exploiting institutional cracks in the regime and opportunities from shifting trends in the landscape. If source separation is to be mainstreamed in Sweden, it will need to break into markets within the wastewater jurisdictions. In order to do so, further knowledge needs to be developed that will overcome glitches with immature technologies, uncertain legal conditions/status, investigate potential risks, and clearly define complementary system advantages. This may require the use of new perspectives that focus on holistic sustainable use of resources, including other nutrients than phosphorous, and taking into account global issues such as planetary boundaries and effects from climate change, such as water scarcity. This knowledge can then be used to establish guidelines, norms, and standards, as well as clarify the legislative structures that can support such a transition. There is also a strong need to improve knowledge dissemination regarding best-practices for implementing source-separation technologies and supporting organizational structures. Similarly, support for entrepreneurial activities within the niche needs to increase, not least through strengthening social networks and communication platforms.
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| 2. |
- Mc Conville, Jennifer R, 1978, et al.
(författare)
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Source separation : Challenges & opportunities for transition in the Swedish wastewater sector
- 2017
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Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 120, s. 144-156
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Tidskriftsartikel (refereegranskat)abstract
- A paradigm shift to waste reuse has started in the wastewater sector with many experts calling for greater resource recovery, often facilitated by alternative solutions such as source separation. Source separation has been shown to be advantageous for improving treatment capacity, food security, and efficiency; yet these systems are still immature, considered risky by professionals and scarcely implemented. This study attempts to answer the question of why source separation is still marginalized by examining the Swedish experience with source separated wastewater from the perspective of Technology Innovation Systems (TIS) in order to identify obstacles and policy recommendations. Considering that source-separation is still in a development phase, the study found that source separation works moderately well within the on-site niche and that blackwater systems in general perform better than urine diversion. Knowledge development is found to be the weakest function. A major blocking mechanism is the weakness of interchange between knowledge development and entrepreneurial activity. Policy recommendations include: increased R&D; building networks and communication platforms; and establishing guidelines for technologies, legislation interpretation and organizational models.
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| 3. |
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| 4. |
- Hellström, Daniel, et al.
(författare)
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Natural sludge dewatering. I : Combination of freezing, thawing, and drying as dewatering methods
- 1997
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Ingår i: Journal of cold regions engineering. - 0887-381X .- 1943-5495. ; 11:1, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- A Swedish full-scale pilot plant employing all-year-round natural sewage sludge dewatering is presented in this paper. The treatment includes three different types of outdoor ditches: a freezing ditch for the winter months, a drying ditch for the early summer months, and a combined drying-freezing-thawing-drying (DFTD) ditch for sludge produced in late summer and early autumn. The test period included two consecutive winters. Complete freezing of the sludge was achieved in the first winter in contrast to the second when incomplete freezing of the sludge occurred due to an unusually warm winter. The dry matter content for the freezing ditch was, at the harvest in August, 30–70 of the first test year. The second test year yielded a sludge with a dry matter content of 20–40 in the freezing ditch. The final dry matter result for the DFTD ditch was 20–40. The summers included were similar to the extent that both late summers were unusually warm, helping to produce sludge of high final dry matter content. The first summer, being somewhat warmer and with a lower sludge loading, yielded a sludge of 60–90 dry matter in the drying ditch. The second summer, when the sludge load was approximately double the preceding year, resulted in a sludge of 20–60 dry matter.
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| 5. |
- Isaksson, Frida, et al.
(författare)
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Greywater reuse for different purposes in Sweden : A literature review
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Globally, water demands are increasing as a result of e.g., population growth and a warmer climate; at the same time freshwater supplies are becoming scarcer. Also in parts of Sweden where water shortage historically has not been a concern, the availability of freshwater for potable water use is declining, especially in the summer. As a result, alternative water management strategies are receiving increased attention in an effort to reduce the pressure on potable water sources. One strategy is the treatment, recirculation and re-use of greywater, a type of water that can be collected in source-separating wastewater systems. Hence, the aim of this literature review was to provide knowledge necessary to understand how greywater can be treated, recycled and re-used in the society, with an emphasis on reuse in Sweden. The review covers different aspects including greywater characteristics, greywater treatment processes, legal frameworks and guidelines on greywater re-use, global examples as well as summary of findings from sustainability analyses conducted on greywater re-use systems.Greywater makes up 75–90% of the total domestic wastewater volume and thereby represents an important source for water reuse in systems with source-separating wastewater systems. Data of the quantity of greywater produced in households globally and in Sweden vary. According to Swedish studies, one person may produce between 66 to 150 l/d. Additionally, research indicates that greywater contains less pathogens and nutrients compared to mix wastewater due to the separation of greywater from blackwater, which in turn contains the human excreta. However, the concentrations of measured parameters vary significantly between different areas. Therefore, in order to ensure the quality of greywater, site-specific measures are necessary.Studies have been conducted on different greywater treatment methods for non-potable re-use, with biological and filtration techniques receiving the most attention. However, it is challenging to make generalizations about the optimal treatment techniques based on the end-usage, due to the variation in greywater characteristics between sites. In addition, this review shows that there is a lack of legal guidance for greywater reuse, which makes it more challenging for practitioners to understand what levels of treatment that are required before the reclaimed water can be reused in used in society. The review also shows that further sustainability analyses should be conducted on greywater reuse systems, in order to understand their benefits more comprehensively.
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| 6. |
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| 7. |
- Kvarnström, Elisabeth, et al.
(författare)
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Changes in the phosphorus availability of a chemically precipitated urban sewage sludge as a result of different dewatering processes
- 2000
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Ingår i: Waste Management & Research. - : Wiley. - 0734-242X .- 1096-3669 .- 1399-3070. ; 18:3, s. 249-258
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to compare the effects of different dewatering processes on the phosphorus (P) availability of an FeCl3precipitated and limeconditioned sludge having an initial dry matter content (DMC) of 4%. The sludge was dewatered by either drying (D), freezing/thawing (FT) or centrifugation (C) until a DMC of about 15% was reached. Thereafter the FT and D sludges were gently dried to obtain a DMC increasing up to 50 to 60%. The plantavailable sludge P was assessed by the change in the isotopic dilution of P taken up by ryegrass (Lolium perenne[L]) after sludge amendments to one soil. After the plant experiment, the soiltosolution transfer of P ions and bicarbonateand ammonium lactate extractable P were determined in selected soil samples. The amount of plantavailable P (Lvalue) and the contribution of sludge P to plant nutrition (%Pdfsl) in soil amended with nondewatered sludge (ND) were not significantly different from the L and percentage Pdfsl values of soils amended with FT, D and C sludges. Nor did the subsequent drying of D and FT sludges significantly change the L and percentage Pdfsl values. Hence, the dewatering processes did not significantly alter the initial sludge P availability. The soiltosolution transfer of P ions and the chemically extracted P did not significantly differ between the different sludgeamended soil samples. The percentage Pdfsl values can be predicted by percentage ΔE1, since the overall average relative increase (%ΔE1) in the immediate soiltosolution transfer of P ions did not significantly differ from the percentage Pdfsl values.
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| 8. |
- Kvarnström, Elisabeth, et al.
(författare)
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Hållbarhetsindex och FN:s hållbarhetsmål : Förslag på vägar framåt för den svenska VA-branschen
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten går igenom olika hållbarhetsmål som VA-branschen bör förhålla sig till. Den tar upp VA-organisationers arbete med Svenskt Vattens Hållbarhetsindex (HBI) och hur det förhåller sig till det globala hållbarhetsarbetet via Agenda 2030 och FN:s 17 hållbarhetsmål. HBI täcker in flera av de globala målen, men det finns möjlighet för VA-organisationer att utöka sitt hållbarhetsarbete. Rapporten ger förslag till fördjupat arbete med hållbarhetsfrågor.
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| 9. |
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| 10. |
- Kvarnström, Elisabeth
(författare)
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Plant-availability of phosphorus removed from wastewater by different processes
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objective of this thesis was to investigate the plant-availability of P removed from wastewater by different processes, with focus on agronomic aspects. Short-term P availability was assessed by greenhouse studies, utilizing four different filter substrates and a sludge-recovered iron phosphate. It was shown that the plant-P availability of these products was not significantly different from that obtained with a water-soluble P fertilizer. It was also found that dewatering method exerted on one FeCl3- precipitated sludge did not influence the plant-P availability. The long-term effects of sludge amendment to agricultural soil was assessed by P ion concentration in solution and P transfer from soil solid phase to solution for soil samples collected from a 19-year old field experiment. The relative plant-P availability (RPA) was found to be 60% for the sludge treatments, a value that was not significantly different from 100%.
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