| 1. |
- Isaksson, Frida, et al.
(författare)
-
Greywater reuse for different purposes in Sweden : A literature review
- 2023
-
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.
|
|
| 2. |
- Kvarnström, Elisabeth, et al.
(författare)
-
Hållbarhetsindex och FN:s hållbarhetsmål : Förslag på vägar framåt för den svenska VA-branschen
- 2021
-
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.
|
|
| 3. |
- Mcconville, Jennifer, et al.
(författare)
-
Possibilities for changing to resource recovery in Kampala's on-site sanitation regime
- 2022
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier B.V.. - 0921-3449 .- 1879-0658. ; 181
-
Tidskriftsartikel (refereegranskat)abstract
- Pressure is growing to develop innovative decentralized sanitation systems that protect public health and recover resources. This study evaluates the opportunities for niche technologies focusing on nutrient resource recovery to enter the market in Greater Kampala, Uganda. It applies methodology from sustainability transition studies in a novel way to provide new insights into possibilities for change in the on-site sanitation sector. The study 1) characterizes the existing socio-technical regime for on-site sanitation, 2) identify stress points in the regime and 3) possible advantages for the niches. Assessment of the regime covers technology, epistemic practice, sector values, organisational modes, policy and financing. The niches include urine diversion toilets, on-site resource recovery, and container-based models. The on-site sanitation regime is under performing and the niches all offer advantages for improved service and resource use. However, it will be difficult for the niches to break into a sector in which epistemic practice, organisational modes and financing are heavily dominated by the sewage regime. Recommendations for creating a more open environment for innovation are provided for specific stakeholders. © 2022 The Authors
|
|
| 4. |
- Mcconville, Jennifer, et al.
(författare)
-
Structured Approach for Comparison of Treatment Options for Nutrient-Recovery From Fecal Sludge
- 2020
-
Ingår i: Frontiers in Environmental Science. - : Frontiers Media S.A.. - 2296-665X. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to present a structured approach for comparing possible nutrient-recovery fecal sludge (FS) treatment systems in order to support transparent decision-making. The approach uses a multi-dimensional sustainability assessment of treatment technologies for nutrient recovery from FS, using a typical case of Kampala City, Uganda. A synthesized list of 22 treatment technologies was prepared from literature. This list included wastewater treatment technologies, which could be adapted to treat fecal sludge, and established fecal sludge treatment technologies that are available or potentially applicable in Kampala. Based on the local situation, the list was reduced to eight possible options, which were carried forward into a multi-dimensional sustainability assessment that incorporated input of stakeholders. The technologies included in the final assessment were optimization of the existing system, lactic acid fermentation (LAF), composting, vermicomposting, Black-Soldier Fly (BSF) composting, ammonia treatment, alkaline stabilization and solar drying. Optimization of the existing system performed well against the set criteria and is a recommended short-term solution. This will require e.g., adding narrower screens to remove more trash from the incoming sludge and respecting storage times prior to selling the sludge. To maximize the agricultural value of the recovered product, while respecting the need for safe reuse, a combination of technologies becomes relevant; the use of a combination of BSF, and subsequent ammonia or alkaline treatment of the remaining organic fraction would allow for maximized safe nutrient recovery and can be the aim for long-term sanitation planning in Kampala. The results of this process provide supporting information for a discussion of trade-offs between stakeholder groups as part of a decision-making process within a larger planning context.
|
|
| 5. |
- Sami, Mashreki, et al.
(författare)
-
Greywater treatment in a green wall using different filter materials and hydraulic loading rates
- 2023
-
Ingår i: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 340
-
Tidskriftsartikel (refereegranskat)abstract
- Green walls in urban environments can be both an aesthetic feature and be of practical use in greywater treatment. This study evaluates the effect of different loading rates (4.5 l/d, 9 l/d, and 18 l/d) on the efficiency of treating actual greywater from a city district in a pilot-scale green wall with five different filter materials as substrates (biochar, pumice, hemp fiber, spent coffee grounds (SCG), and composted fiber soil (CFS)). Three cool climate plant species, Carex nigra, Juncus compressus, and Myosotis scorpioides, were chosen for the green wall. The following parameters were evaluated: biological oxygen demand (BOD), fractions of organic carbon, nutrients, indicator bacteria, surfactants, and salt. Three of the five materials investigated – biochar, pumice, and CFS - showed promising treatment efficiencies. The respective overall reduction efficiencies of BOD, total nitrogen (TN) and total phosphorus (TP) were 99%, 75%, and 57% for biochar; 96%, 58%, and 61% for pumice; and 99%, 82% and 85% for CFS. BOD was stable in the biochar filter material with effluent concentrations of 2 mg/l across all investigated loading rates. However, higher loading rates had a significantly negative effect on hemp and pumice for BOD. Interestingly, the highest loading rate (18 l/d) flowing over pumice removed the highest levels of TN (80%) and TP (86%). Biochar was the most effective material in removing indicator bacteria, with a 2.2–4.0 Log10 reduction for E. coli and enterococci. SCG was the least efficient material, giving a higher BOD in the effluent than in the influent. Therefore, this study presents the potential of natural and waste-derived filter materials to treat greywater effectively and the results can contribute to the future development of nature-based greywater treatment and management practices in urban areas.
|
|
| 6. |
- Sami, Mashreki, et al.
(författare)
-
On-site greywater treatment systems - influent and effluent quality
- 2023
-
Annan publikationabstract
- The dataset presented here consists of raw data on the quality of influent and effluent greywater from eight on-site greywater treatment systems situated in Södertälje municipality, Sweden. These on-site treatment systems included three types of commercially available package plants and one sand filter. The influent and effluent samples were taken as grab samples between August 2020 and December 2021 and analysed for organic material, nutrients, pathogens, anionic surfactants, salt and (for two of the eight on-site systems) microplastics. Supporting parameters, e.g. suspended solids and pH, are also included. Further, for microplastics, results from blank samples are included.This dataset was used to evaluate the treatment efficiency of the on-site greywater treatment systems and to assess the suitability of the treated water for reuse.
|
|
| 7. |
- Sami, Mashreki
(författare)
-
Performance of on-site systems and a green wall for greywater treatment
- 2023
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Greywater contains inorganic and organic substances, nutrients, pathogens, micropollutants and microplastics. Source-separated greywater using decentralized systems can potentially provide energy-efficient and low-maintenance treatment. If effectively treated, greywater could be a source for non-potable water use in for instance urban landscaping or agricultural irrigation. The overall aim of this thesis was to investigate the treatment efficiencies of two different types of decentralized greywater treatment systems: a) on-site package plants and b) a nature-based solution (NBS) - green wall. These two different treatment systems were assessed based on their removal efficiency of organic matter (BOD, COD, TOC), nutrients (nitrogen (N) and phosphorus (P)), surfactants, indicator bacteria (E. coli and enterococci) as well as microplastics.The study of the on-site package plants investigated eight on-site greywater treatment facilities of four different types (A, B, C and D). Systems types A-C were commercially available and type D was an onsite built sand filter. The treatment unit of type A consisted of a trickling filter fitted with geotextile resting on a sand filter bed. The treatment unit of type B included a fibrous mineral wool filter material while type C contained a series of fine-meshed plastic filters. Prior to types A, B and D, septic tanks were located to contribute with pre-treatment, whereas type C, the smallest system investigated, included a septic tank within the treatment unit. >90% removal of organic matter (BOD and COD) was achieved by types A and D, but the N removal was comparatively higher by type B (44-68%). Effective P removal was only observed in type D (56%). However, the effluent concentration from all the systems was <3mg/l. The treatment efficiency of type C was found to be relatively low.In the green wall study, the efficiency of five filter materials (pumice, biochar, hemp fiber, spent coffee ground (SCG) and compost fiber soil) were evaluated with regards to hydraulic loading rates (HLRs) (4.5, 9, and 18 l/d). The treatment efficiency varied significantly with materials and HLRs. Biochar consistently removed 99% of BOD for all HLRs. High N removal (>80%) was observed by pumice and biochar during the high HLR (18 l/d). However, P removal by hemp was comparatively higher (75-85%) than by biochar and pumice. SCG and compost soil was tested with only 4.5 l/d, where compost soil showed effective treatment of BOD (99%), N (82%) and P (85%). SCG was the least effective material releasing more organics and nutrients in the effluent. Both the studies showed high concentration (>105 cfu/100 ml) of E. coli and enterococci in the influent and effluent greywater. The treatment systems were in general not effective in removing E.coli and enterococci. The most efficient system was the sand filter (D), achieving 1.4-3.8 log10 E.coli reduction and 2.3-3.3 log10 reduction for enterococci. Biochar achieved similar removal at HRL 4.5 l/d. Using thermal extraction desorption gas chromatography-mass spectrometry (TED-GCMS) technique, polyvinylchloride, polystyrene, poly-ethylene-terephthalate, polyethylene, polypropylene, and polyamide 6 were detected in the influent and effluent greywater in both studies. Even though there was variability in the influent concentrations, low concentrations were observed in the effluents, suggesting the systems were effective in retaining the microplastics.
|
|
| 8. |
|
|
| 9. |
- Sami, Mashreki, et al.
(författare)
-
Quality of greywater from a city district before and after treatment in a green wall
- 2023
-
Annan publikationabstract
- The dataset presented here consists of raw data on the quality of influent greywater generated from a city district with 800 PE (population equivalent) and the effluent quality of greywater after treatment using a green wall. Five natural filter materials (pumice, biochar, hemp fiber, spent coffee ground, and composted fiber soil) were used in the green wall and tested for three hydraulic loading rates (54, 108 and 216 l/m2/d). The influent and effluent samples were taken manually between November 2021 and March 2022 and were analyzed for organic material, nutrients, pathogens, anionic surfactants, salt and microplastics. Supporting parameters e.g. suspended solids and pH, are also included in the dataset. Further, for microplastics, results from blank samples are included. This dataset was used to evaluate the treatment efficiency of the filter materials at different hydraulic loading rates.
|
|
| 10. |
- Sami, Mashreki, et al.
(författare)
-
Removal of Microplastics from Greywater Using a Green Wall Treatment System
- 2022
-
Ingår i: 17th International Conference on Wetland Systems for Water Pollution Control: Conference Proceedings. ; , s. 505-508
-
Konferensbidrag (refereegranskat)abstract
- A green wall with four filter media - pumice, biochar, hemp, and compost soil - was investigated with regard to the removal of microplastics from real greywater. Nine polymers were analysed using thermal extraction desorption gas chromatography-mass spectrometry (TED-GC/MS). The results showed the presence of polyvinylchloride (PVC), polystyrene (PS), poly-ethylene-terephthalate (PET), polypropylene (PP), and polyamide (PA) in the influents and effluents. High concentration of PS (22 μg/l) and PET (73 μg/l) were observed in the influent but were removed efficiently in the green wall with effluent concentrations of <2 μg/l from all filter materials except for hemp. The effluent from one hemp replicate showed higher concentrations of PVC (58 μg/l) and PET (114 μg/l) than the influent. During the sampling period, all filter materials removed TSS, BOD and TOC by >90%.
|
|
