| 1. |
- Elgh-Dalgren, Kristin, et al.
(författare)
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Bioremediation of a soil industrially contaminated by wood preservatives : degradation of polycyclic aromatic hydrocarbons and monitoring of coupled arsenic distribution
- 2011
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Ingår i: Water, Air and Soil Pollution. - Dordrecht : Springer Netherlands. - 0049-6979 .- 1573-2932. ; 214:1-4, s. 275-285
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Tidskriftsartikel (refereegranskat)abstract
- Two commercially available aerobic bioremediation methods (Daramend® and BioSan) were utilized to study the aerobic biodegradation of polycyclic aromatic hydrocarbons (PAH) and the effect of the simultaneously present arsenic. The soil was collected at an old wood preservation site and the initial PAH16-concentration was 46 mg/kg, with mainly high molecular weight congeners. The As-concentration was105 mg/kg with low availability as assessed with sequential extraction. To enahce the availability of PAH, the effect of a non-ionic surfactant was evaluated. Degradation of both low and high molecular weight PAH was observed, however after 30 weeks, the degradation was generally low and no treatment was significantly better than the others. The treatments had, on the other hand, an effect on As-distribution, with increased As-concentration in the available fraction after treatment. This may be due to both the microbial activity and the presence of anoxic micro sites in the soil. The overall efficiency of the biological treatment was further evaluated using the standardized ecotoxicity test utilizing Vibrio fischeri (Microtox®). The toxicity test demonstrated that the bioremediation led to an increase in toxicity, especially in treatments receiving surfactant. The surfactant implied an increase in contaminant availability but also a decrease in surface tension, which might have contributed to the overall toxicity increase.
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| 2. |
- Elgh-Dalgren, Kristin, 1980-, et al.
(författare)
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Laboratory and pilot scale soil washing of PAH and arsenic from a wood preservation site : Changes in concentration and toxicity
- 2009
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Ingår i: Journal of Hazardous Materials. - Amsterdam : Elsevier. - 0304-3894 .- 1873-3336. ; 172:2-3, s. 1033-1040
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Tidskriftsartikel (refereegranskat)abstract
- Soil washing of a soil with a mixture of both polycyclic aromatic hydrocarbons (PAH) and As was evaluated in laboratory and pilot scale, utilizing both single and mixtures of different additives. The highest level of decontamination was achieved with a combination of 0.213 M of the chelating agent MGDA and 3.2xCMC* of a nonionic, alkyl glucoside surfactant at pH 12 (Ca(OH)2). This combination managed to reach Swedish threshold values within 10 min of treatment when performed at elevated temperature (50°C), with initial contaminant concentrations of As = 105±4 mg/kg and US-EPA PAH16 = 46.0±2.3 mg/kg. The main mechanisms behind the removal were the pH-effect for As and a combination of SOM-ionization as a result of high pH and micellar solubilization for PAHs. Implementation of the laboratory results utilizing a pilot scale equipment did not improve the performance, which may be due to the shorter contact time between the washing solution and the particles, or changes in physical characteristics of the leaching solution due to the elevated pressure utilized. The ecotoxicological evaluation, Microtox®, demonstrated that all soil washing treatments increased the toxicity of soil leachates, possibly due to increased availability of contaminants and toxicity of soil washing solutions to the test organism.
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| 3. |
- Huerta Buitrago, B., et al.
(författare)
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Hazard assessment of sediments from a wetland system for treatment of landfill leachate using bioassays
- 2013
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Ingår i: Ecotoxicology and Environmental Safety. - Maryland Heights, MO : Elsevier BV. - 0147-6513 .- 1090-2414. ; 97, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- Four bioassays were used in this study for the hazard assessment of sediments from sediment traps and several ponds in a treatment wetland for landfill leachate at Atleverket, Sweden. In the 6-day solid phase microbiotest with the sediment-dwelling crustacean Heterocypris incongruens both acute and chronic effects were observed with a gradual decrease and loss of toxicity with treatment in the wetland system. Some samples showed a low toxicity in porewater and only one sample was weakly toxic in the whole sediment test when assessed with Aliivibrio fischeri (Vibro fischeri). No genotoxicity was detected in the umu test. The toxicity response in the H4IIE- luc test evaluating the presence of dioxin-like compounds was considerably higher in the samples from the sediment traps. The hazard of the sediment therefore appears to be highest in the sediment traps and pond 1 with the methods employed. The result indicates that the wetland system has a design supporting the concentration and sequestration of toxic substances in the first part of the wetland. Based upon the results we suggest that hazard assessment of sediments from other treatment wetlands for landfill leachate should be conducted.
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| 4. |
- Gustavsson, Lillemor, et al.
(författare)
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Industrial sludge containing pharmaceutical residues and explosives alters inherent toxic properties when co-digested with oat and post-treated in reed beds
- 2014
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Ingår i: Environmental Sciences Europe. - Heidelberg, Germany : Springer. - 2190-4707 .- 2190-4715. ; 26:8, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Methane production as biofuels is a fast and strong growing technique for renewable energy. Substrateslike waste (e.g. food, sludge from waste water treatment plants (WWTP), industrial wastes) can be used as a suitable resource for methane gas production, but in some cases, with elevated toxicity in the digestion residue. Former investigations have shown that co-digesting of contaminated waste such as sludge together with other substrates canproduce a less toxic residue. In addition, wetlands and reed beds demonstrated good results in dewatering and detoxifying of sludge. The aim of the present study was to investigate if the toxicity may alter in industrial sludgeco-digested with oat and post-treatment in reed beds. In this study, digestion of sludge from Bjorkborn industrial area in Karlskoga (reactor D6) and co-digestion of the same sludge mixed with oat (reactor D5) and post-treatment in reed beds were investigated in parallel. Methane production as well as changes in cytotoxicity (Microtox(R); ISO 11348–3), genotoxicity (Umu-C assay; ISO/13829) and AhR-mediated toxicity (7-ethoxyresorufin-O-deethylase (EROD) assay using RTW cells) were measured.Results: The result showed good methane production of industrial sludge (D6) although the digested residue was more toxic than the ingoing material measured using microtox30min and Umu-C. Co-digestion of toxic industrial sludge and oat(D5) showed higher methane production and significantly less toxic sludge residue than reactor D6. Furthermore, dewatering and treatment in reed beds showed low and non-detectable toxicity in reed bed material and outgoingwater as well as reduced nutrients.Conclusions: Co-digestion of sludge and oat followed by dewatering and treatment of sludge residue in reed beds canbe a sustainable waste management and energy production. We recommend that future studies should involve co-digestion of decontaminated waste mixed with different non-toxic material to find a substrate mixture that producethe highest biogas yield and lowest toxicity within the sludge residue.
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