| 1. |
- Dalahmeh, Sahar
(författare)
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Bark and charcoal filters for greywater treatment : pollutant removal and recycling opportunities
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Water scarcity, inappropriate sanitation and wastewater pollution are critically important global issues. Greywater is a sustainable water source for recycling, so this thesis examined simple, robust, low-cost alternatives for on-site treatment of greywater to irrigation water quality. Laboratory-scale pine bark, activated charcoal and sand filters were evaluated as regards their pollutant removal and interactions between medium properties, greywater, microbial activity and bacterial community structure. The effects of hydraulic and organic loading rates (HLR and OLR) were described by general regression models (GRM). The quality of the treated greywater was evaluated against Jordanian standards for irrigation water. A series of experiments examined treatment of artificial greywater in terms of lowering biochemical oxygen demand (BOD5), chemical oxygen demand (COD), phosphorus (Tot-P), nitrogen (Tot-N) and pathogen indicators (total thermotolerant coliforms) and tracer microorganisms (enterohaemorrhagic Escherichia coli (EHEC) and bacteriophage PhiX). Following greywater loading, all filter materials developed biofilms with high bacterial diversity and richness. The driving force shaping bacterial communities in bark material was its organic composition and low pH, while the communities in the charcoal and sand filters were more influenced by the greywater. The GRM indicated that the performance of all filters was influenced by the HLR and OLR of the present and previous runs. The organic matter content and surface and hydraulic properties of the bark filters resulted in high BOD5 removal rates (94-99%), even at increased HLR and OLR, but accompanied by release of dissolved organic substances originating from the bark itself. High nitrification occurred in the bark filters in all loading regimes tested, but with low Tot-N removal. The bark filters demonstrated 1-3 log10 removal of microorganisms, but bark organic nature made its filters more vulnerable to biodegradation and disintegration. The charcoal had large specific surface area, which provided the capacity for intermediate-high removal of BOD5 (83-97%), Tot-N (50-98%) and Tot-P (64-98%), but removal of microorganisms was poor. The sand filters demonstrated low BOD5 removal (67-91%) and high nitrification, but low nitrogen removal. Greywater treatment by bark and charcoal filters reduced their organics content to acceptable irrigation levels. Nitrogen and microorganisms must be further reduced to meet Jordanian standards on treated wastewater for irrigation.
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| 2. |
- Dalahmeh, Sahar, et al.
(författare)
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Biochar efficiently removes recalcitrant pharmaceuticals from wastewater
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This study investigated the potential of biochar as a filter medium for removal of pharmaceutically active compounds (PhACs) and wastewater macro-pollutants in on-site wastewater treatment systems. Removal of carbamazepine among other selected PhACs was investigated over 22 weeks experiment in four treatments: biochar (BC) with active and inactive biofilm (BC-active-biofilm, BC-inactive-biofilm), biochar without biofilm for adsorption only (BC-no-biofilm) and sand with active biofilm (Sand-active-biofilm). Carbamazepine removal in BC-no-biofilm (98%) was high due to adsorption, while nonexistent removal was observed in Sand-active-biofilm, revealing low biodegradability of carbamazepine. Removal of carbamazepine in BC-active-biofilm was stable (>98%), while it declined with time in BC-inactive-biofilm. In conclusion, biochar is a promising filter material supporting active biofilm and adsorption for the removal of PhACs in on-site wastewater treatment systems.
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| 3. |
- Baresel, Christian, et al.
(författare)
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PFAS – how can Swedish wastewater treatment plants meet the challenge? Compilation of knowledge and guidance for water/wastewater actors regarding PFAS
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Per- and Polyfluoroalkyl Substances (PFAS) are everywhere around us in society, found in commercial and industrial products, the atmosphere, waste, water (waste, surface, drinking, and ground), soil, plants, animals, and even in our bodies. The use and spread of PFAS is a global societal challenge, affecting even the most remote places on Earth. One of the reasons why PFAS has been an attractive component in many products and industrial applications is their extreme chemical and thermal stability. However, these same properties allow for the persistence of PFAS in the environment, whereby even low PFAS emissions over time can be accumulated and pose a high risk of negative health and environmental effects. Today there are thousands of known and unknown PFAS with widely varying properties and toxicity, which makes both risk assessments and management of this growing environmental problem difficult. According to a national mass balance for PFAS emissions from products and atmospheric deposition are the major sources of PFAS in Sweden.The amount of PFAS which are environmentally dispersed via wastewater and sewage sludge can be considered a minor part. However, due to the persistence of PFAS, measures to minimize their addition via these pathways may be necessary to reduce the total environmental load. Due to their toxicity and persistence, PFAS have recently become heavily regulated, with many regulatory agencies lowering the accepted PFAS environmental level ranges. Many PFAS have already been banned in Sweden or the EU and assessment grounds or action limits have been defined for various PFAS (e.g., surface water bodies, groundwater and drinking water) to initiate measures to reduce the spread of the substances. Already announced and stricter regulations will further increase the need for measures to minimize human exposure to PFAS and their dispersal in the environment.Regardless of which measures are implemented, PFAS will remain in the environment for a long time, even if a global ban of the chemicals is implemented. Long-term management of PFAS is thus necessary to removal from the cycle gradually. The focus of mitigation actions should primarily be on heavily contaminated land and landfill leachate. The review of existing data from Swedish wastewater treatment plants WWTP and receiving recipients shows that today’s treatment processes do not remove PFAS. At some WWTP, however, an effective separation of certain PFAS is observed, which should be investigated further. Perfluorooctanoic sulfonic acid (PFOS) levels in many of the investigated inland surface waters receiving effluent from treatment plants and PFAS from other sources/pathways exceed existing limits. In many cases, however, analysis limitations prevent an assessment.Ongoing activities around various treatment and destruction techniques for PFAS show that there are currently no techniques that achieve a far-reaching PFAS removal from municipal wastewater without significant resource consumption and related costs. For the continued use of sludge as a fertilizer, upstream mitigation is needed, with e.g., disconnection or treatment of PFAS-contaminated leachate. However, several ongoing projects indicate that a certain part of PFAS in wastewater can be removed as a side-effect of advanced treatment for pharmaceutical removal. This report provides guidance to stakeholders on how the PFAS problem can be tackled. It also demonstrates the need to improve and spread PFAS knowledge, particularly those involved with PFAS measurement data, treatment techniques and PFAS in sludge.
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| 4. |
- Cossio Grageda, Claudia, 1974, et al.
(författare)
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Impact of treatment plant management on human health and ecological risks from wastewater irrigation in developing countries–case studies from Cochabamba, Bolivia
- 2021
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Ingår i: International Journal of Environmental Health Research. - : Informa UK Limited. - 0960-3123 .- 1369-1619. ; 31:4, s. 355-373
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Tidskriftsartikel (refereegranskat)abstract
- Wastewater irrigation is a common practice in developing countries due to water scarcity and increasing demand for food production. However, there are health risks and ecological risks associated with this practice. Small-scale wastewater treatment plants (WWTPs) intend to decrease these risks but still face management challenges. This study assessed how the management status of five small-scale WWTPs in Cochabamba, Bolivia affects health risks associated with consumption of lettuce and ecological risks due to the accumulation of nutrients in the soil for lettuce and maize crops. Risk simulations for three wastewater irrigation scenarios were: raw wastewater, actual effluent and expected effluent. Results showed that weak O&M practices can increase risk outcomes to higher levels than irrigating with raw wastewater. Improving O&M to achieve optimal functioning of small-scale WWTPs can reduce human health risks and ecological risks up to 2 log10 DALY person−1 year−1 and to 2 log10 kg nitrogen ha−1 accumulated in soil, respectively.
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| 5. |
- Cossio Grageda, Claudia, 1974, et al.
(författare)
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Wastewater management in small towns - understanding the failure of small treatment plants in Bolivia
- 2018
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Ingår i: Environmental Technology (United Kingdom). - : Informa UK Limited. - 1479-487X .- 0959-3330. ; 39:11, s. 1393-1403
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Tidskriftsartikel (refereegranskat)abstract
- Wastewater management in developing countries is a challenge, especially in small towns with rapid population growth. This study aims at assessing the performance and management of five treatment plants (TPs) in rural areas of Cochabamba, Bolivia. Pollutants’ concentrations, wastewater flows, hydraulic and organic loads and hydraulic retention times were determined in three small treatment plants (2000–10,000 population equivalent [p.e.]; flow > 432 m3/d) and two very small treatment plants (<2000 p.e.; flow < 432 m3/d). The performance assessment was based on operational parameters, treatment efficiency and effluent quality. Management data were collected through semi-structured interviews with managers of local water associations. The results support that the poor performance of the TPs is due to lack of operational expertise and financial resources for adequate operation and maintenance (O&M). Additionally, effective treatment was affected by the type of technology used and whether the plant design included plans for O&M with available resources. This study contributes to a better understanding of actual operating conditions of wastewater TPs in small towns, thus providing needed information regarding technology selection, design, implementation and operation.
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| 6. |
- Dalahmeh, Sahar
(författare)
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Combined Vertical-Horizontal Flow Biochar Filter for Onsite Wastewater Treatment-Removal of Organic Matter, Nitrogen and Pathogens
- 2019
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Ingår i: Applied Sciences. - : MDPI AG. - 2076-3417. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the performance of a combined vertical-horizontal flow biochar filter (VFF-HFF) system in terms of organic matter, total nitrogen (Tot-N), Escherichia coli and Salmonella removal and explored the effects of hydraulic loading rate (HLR) on pollutant removal. The combined VFF-HFF system used biochar as the filter medium and comprised two stacked sections: (i) an aerobic vertical flow filter (VFF) in which the wastewater percolated through the biochar medium in unsaturated mode and (ii) a horizontal flow filter (HFF), in which the biochar was saturated with water and had limited access to air, to enable anaerobic conditions and enhance the denitrification process. The system was tested over 126 weeks using real wastewater applied at different HLR (23, 31, 39 L m(-2) day(-1)). The results showed that long-term removal of organic matter in the entire system was 93 +/- 3%, with most (87 +/- 5%) occurring in the VFF. For Tot-N, the long-term removal was 71 +/- 12%, with increasing trends for nitrification in the VFF and denitrification in the HFF. Mean long-term nitrification efficiency in the VFF was 65 +/- 15% and mean long-term denitrification efficiency in the HFF 49 +/- 14%. Increasing HLR from 23 to 31 L m(-2) day(-1) increased the nitrification efficiency from 42 to 61%. Increasing the HLR further to 39 L m(-2) day(-1) decreased the denitrification efficiency from 45 to 25%. HLR had no significant effects on VFF and HFF performance in terms of E. coli and Salmonella removal, although the VFF achieved a 1.09-2.1 log(10) unit reduction and the HFF achieved a 2.48-3.39 log(10) unit reduction. Thus, long-term performance, i.e., removal of pollutants measured during the last 52 weeks of the experiment, was satisfactory in terms of organic matter and nitrogen removal, with no signs of clogging, indicating good robustness of the combined VFF-HFF biochar filter system.
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| 7. |
- Dalahmeh, Sahar, et al.
(författare)
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Potential of biochar filters for onsite wastewater treatment: Effects of active and inactive biofilms on adsorption of per- and polyfluoroalkyl substances in laboratory column experiments
- 2019
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 247, s. 155-164
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the potential of biochar filters as a replacement for, or complement to, sand filters for removal of per- and polyfluoroalkyl substances (PFASs) from wastewater in on-site wastewater treatment systems (OWTSs). Concentrations and removal of nine perfluoroalkyl carboxylates (PFCAs; C3-11) and three perfluoroalkane sulfonates (PFSAs; C-4,C- 6,C- 8) and one perfluorooctanesulfonamide (FOSA; C-8) were investigated over 22 weeks in four treatments with column filters: biochar (BC) without biofilm (BC-no-biofilm), biochar with active biofilm (BC-active-biofilm), biochar with inactive biofilm (BC-inactive-biofilm) and sand with active biofilm (Sand-active-biofilm). The filters were operated under hydraulic loading (50 L m(-2) day(-1)) to mimic the loading rate in on-site filtration beds. The initial concentrations of the Sigma PFASs in the influent were in the range of 1500-4900 ng L-1. In BC-no-biofilm, the removal efficiency (20-60%) and adsorption capacity (0-88 ng EPFASs g(-1) BC) of short-chain PFCAs (C3-6) and PFSA (C-4) was low, whereas the removal efficiency (90-99%) and the adsorption capacity (73-168 ng g(-1)) was high for C-7-C-11 PFCAs, C-6, C-8 PFSAs and FOSA. The relative removal was generally lower for C3-9 PFCAs and C-4, C-6, C-8 PFSAs using BC-active-biofilm and BC-inactive-biofilm compared with BC-no-biofilm. This can be explained by the presence of biofilm and solids in BC-active-biofilm and the presence of wastewater solids in BC-inactive-biofilm, which decreased the availability and number of adsorption sites for PFASs compared with BC-no-biofilm. On the other hand, inactivation of the biofilm resulted in lower removal efficiencies for C5-11 PFCAs, C-4, (C)6, C-8 PFSAs and FOSA, probably because the biofilm degraded organic matter and thus increased the availability and number of adsorption sites compared with BC-inactive-biofilm. Sand-active-biofilm showed poor removal (0-70%) for all PFASs except FOSA (90%) and its adsorption capacity was low (0.0-7.5 ng g(-1)). In general, for all biochar treatments, shorter-chain PFASs were more resistant to removal than longer-chain PFASs. In addition, C-4, C-6 and C-8 PFSAs showed 10-30%, 10-50% and 20-30% higher average removal efficiency, respectively, than PFCAs with corresponding perfiuoroalkyl chain length. In conclusion, biochar is a promising filter medium for removal of PFASs in OWTSs, especially for PFASs with a perfluorocarbon chain longer than C-6. 2019 Elsevier Ltd. All rights reserved.
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| 8. |
- Dalahmeh, Sahar
(författare)
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Removal of Selected Pharmaceuticals and Personal Care Products in Wastewater Treatment Plant in Jordan
- 2019
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- The largest wastewater treatment plant in Jordan was monitored in the summer to determine the removal of pharmaceuticals and personal care products (PPCPs). Grab samples were collected from the influent and effluent of As-Samra Wastewater Treatment Plant (WWTP). Liquid chromatography and tandem mass spectrometry (LC-MS/MS) were utilized to determine the concentrations of 18 compounds of pharmaceuticals and personal care products (PPCPs). The results showed that 14 compounds were detected in the collected samples from the influent and effluent of As-Samra WWTP. These compounds are 1,7-dimethylxanthine, amphetamine, acetaminophen, caffeine, carbamazepine, cimetidine, cotinine, diphenhydramine, methylenedioxymethamphetamine (MDMA), morphine, phenazone, sulfamethazine, sulfamethoxazole, thiabendazole, and trimethoprim. However, four compounds were below the detection limit (<0.005 mu g/L), namely cimetidine, methylenedioxyamphetamine (MDA), methamphetamine, and sulfachloropyridazine. Among PPCPs, the highest estimated average concentrations in raw wastewater were caffeine, acetaminophen, 1,7-dimethylxanthine, cotinine, and carbamazepine sampled during the summer, at an estimated concentration of 155.6 mu g/L, 36.7 mu g/L, 10.49 mu g/L, and 1.104 mu g/L, respectively. However, the highest estimated average concentrations in treated wastewater were for carbamazepine, sulfamethoxazole, caffeine, cotinine, and acetaminophen, at 0.856 mu g/L, 0.096 mu g/L, 0.086 mu g/L, 0.078 mu g/L, and 0.041 mu g/L, respectively. In general, the results showed that some compounds in the collected samples of wastewater in Jordan have concentrations exceeding the values reported in the literature. The removal efficiency rates of 1,7-dimethylxanthine, acetaminophen, caffeine, cotinine, morphine, and trimethoprim were higher than 95%, while those of carbamazepine, sulfamethazine, and sulfamethoxazole were lower than 22.5%. Moreover, diphenhydramine and thiabendazole had negative removal efficiency rates. The removal efficiency rates of the PPCPs in As-Samra WWTP were generally consistent with those of indicator compounds reported in the literature for conventional WWTPs.
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| 9. |
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| 10. |
- Dalahmeh, Sahar S., et al.
(författare)
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Efficiency of Iron- and Calcium-Impregnated Biochar in Adsorbing Phosphate From Wastewater in Onsite Wastewater Treatment Systems
- 2020
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Ingår i: Frontiers in Environmental Science. - : Frontiers Media SA. - 2296-665X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the potential of biochar impregnated with Fe3+ or Ca2+, or mixed with Polonite®, as a filter material for removal of phosphate (PO4-P) from wastewater in onsite wastewater treatment systems (OWTS). Four treatments with biochar were investigated: unimpregnated biochar (UBC), biochar impregnated with iron Fe3+ (FBC), biochar impregnated with calcium oxide (CBC), and biochar mixed with Polonite® (PBC). In a batch experiment using phosphate solution at concentrations 0.5, 3.3, 6.5, 13, and 26 mg PO4-P L–1, adsorption of PO4-P in the different treatments was modeled using Langmuir and Freundlich isotherms. Column filters (5 diameter × 55 cm height) packed with UBC, FBC, CBC, and PBC were then furnished with raw wastewater over 148 weeks. During this experiment, adsorption of PO4-P was investigated in response to increasing hydraulic loading rate (HLR; 56, 74, and 112 L m–2 day–1) and increasing phosphate loading rate (PLR; 195, 324, 653, and 1715 mg PO4-P m–2 day–1). Among the materials, FBC had the highest maximum adsorption capacity (Qm) based on Langmuir isotherms (3.21 ± 0.01 mg g–1). FBC and CBC showed robust performance with increasing HLR, while increasing PLR increased the amount of PO4-P retained in all filters. After 148 weeks of operation, removal of PO4-P (averaged over the last 18 weeks of operation) was 13 ± 16% for UBC, 40 ± 20% for CBC, 88 ± 12% for FBC, and 30 ± 18% for PBC. The PO4-P amount retained in filters over the 148 weeks was 84.75, 221.75, 358.38, and 152.36 g m–2 in UBC, CBC, FBC, and PBC, respectively. The adsorption capacity of the filters after 148 weeks was 1.50, 4.02, 6.41, and 2.75 mg g–1 for UBC, CBC, FBC, and PBC, respectively. The adsorption capacity values and breakthrough curves showed that low concentrations (i.e., <2.6 mg L–1) of PO4-P in wastewater would allow the FBC filter to remain active for 58 months and the CBC filter for 15 months, before PO4-P removal declined to <70%. In conclusion, biochar impregnated with iron and calcium is a promising solution for removal of PO4-P from wastewater in OWTS.
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