| 1. |
- Nilsson, Charlotte, 1985-, et al.
(författare)
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Effect of organic load on phosphorus and bacteria removal from wastewater using alkaline filter materials
- 2013
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 47:16, s. 6289-6297
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Tidskriftsartikel (refereegranskat)abstract
- The organic matter released from septic tanks can disturb the subsequent step in on-site wastewater treatment such as the innovative filters for phosphorus removal. This study investigated the effect of organic load on phosphorus (P) and bacteria removal by reactive filter materials under real-life treatment conditions. Two long-term column experiments were conducted at very short hydraulic residence times (average similar to 5.5 h), using wastewater with high (mean similar to 120 mg L-1) and low (mean similar to 20 mg L-1) BOD7 values. Two alkaline filter materials, the calcium-silicate material Polonite and blast furnace slag (BFS), were tested for the removal capacity of total P, total organic carbon (TOC) and Enterococci. Both experiments showed that Polonite removed P significantly ( p < 0.01) better than BFS. An increase in P removal efficiency of 29.3% was observed for the Polonite filter at the lower concentration of BOD7 ( p < 0.05). Polonite was also better than BFS with regard to removal of TOC, but there were no significant differences between the two filter materials with regard to removal of Enterococci. The reduction in Enterococci was greater in the experiment using wastewater with high BOD7, an effect attributable to the higher concentration of bacteria in that wastewater. Overall, the results demonstrate the importance of extensive pre-treatment of wastewater to achieve good phosphorus removal in reactive bed filters and prolonged filter life.
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| 2. |
- Renman, Agnieszka, et al.
(författare)
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Long-term phosphate removal by the calcium-silicate material Polonite in wastewater filtration systems
- 2010
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 79:6, s. 659-664
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Tidskriftsartikel (refereegranskat)abstract
- The mineral-based filter material Polonite was tested for its PO4 removal capacity in column and full-scale systems using synthetic and domestic wastewater. Three long-term experiments (67, 68 and 92 wk), operated under different hydrological conditions, were compared. The best PO4 removal capacity (97%) was observed in an intermittent saturated column fed with a synthetic solution (530 L m(-2) d(-1)) without organic matter during 68 wk. An unsaturated column system using municipal wastewater (76.7 L m(-2) d(-1)) showed no tendency for PO4 breakthrough and effluent PO4 concentration was still low (0.2 mg L-1) after 67 wk. For a compact bed filter containing 560 kg of Polonite and fed with 70 m(3) of wastewater from a single house, the average PO4 removal was 89% after 92 wk of operation. The column experiments revealed that a design volume of 1-2 kg of material of a particle size of 2-5 mm was required amount for treating 1 m(3) of wastewater in on-site systems operating at target 90% P mass removal. Poor pre-treatment of the wastewater was suggested to reduce the phosphate removal capacity of Polonite in the bed filter trial, where 8 kg were required per m(3). To measure pH of the treated effluent water proved not to be a simple tool for determining when the filter material is exhausted and should be replaced. (C) 2010 Elsevier Ltd. All rights reserved.
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| 3. |
- Renman, Gunno, et al.
(författare)
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Reaktiva sorbent för fastläggning av fosfor i Östersjöns bottnar
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The release of phosphorus (P) from sediments is of concern for the eutrophication process of the Baltic Sea. In this investigation a number of reactive and alkaline sorbents were tested for their P removal efficiencies in the environment of anaerobic sediments. Batch, pot and column experiments were performed and simulated real bottom conditions. The calcium silicate material Polonite®, a commercial product for P-traps in wastewater treatment, performed best particularly as used for thin-layer placement. The by-product AOD slag also showed promising sorption capacity. The presence of P in the materials after four months use at sediment surfaces was documented by means of ESEM-EDS and the analysis with XANES revealed that for Polonite, amorphous calcium phosphate (ACP) and apatite had formed when saturated with pore water from anaerobic sediments. This study shows promising results for reactive materials to be used as binding agents for the sequestration of P from sediment. Further work will be performed to develop the technology with submerged thin-layer placement for full-scale application.
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| 4. |
- Renman, Gunno, et al.
(författare)
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Småskaliga lösningar för avloppsrening med mineralbaserade filtermaterial
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Mineralbaserade filtermaterial har tidigare visats kunna avskilja fosfor från avloppsvatten, något som kan utnyttjas i hållbara småskaliga avloppssystem. Den verksamma mekanismen är främst utfällning som kalciumfosfater. Fosforn i använda material kan sedan återföras till brukad mark. Dock har de flesta tidigare studier studerat fosforavskiljning i laboratorieskala, med små belastningar och med fosfatsalter istället för avloppsvatten. Syftet med detta projekt var att studera fosforavskiljningsförmågan i fältförhållanden för fyra olika mineralbaserade filtermaterial; Filtra P (Nordkalk Oyj Abp), Polonite (Bioptech AB), hyttsand (SSAB Merox AB) samt wollastonit (Aros Mineral AB). Materialen placerades i kolonner inuti en container, vilken matades kontinuerligt med avloppsvatten vid en relativt hög belastning (1 m/dygn), som är en realistisk nivå då kompakta system används. Försöket lades upp som två delförsök där avloppsvattnets BOD-värde varierades. Resultaten visar att materialen Filtra P och Polonite ur ett rent kemiskt perspektiv klarar av fältförhållandena relativt väl eftersom de avskiljer fosfor effektivt trots ett högt BOD-värde och en hög belastning (> 80 % genomsnittlig avskiljning). Däremot uppvisade Filtra P stora problem med igensättning p.g.a. disintegration och kalcitutfällning, särskilt i försöket med högt BOD-värde, och dessa kolonner fick därför stängas av i förtid. Hyttsand och wollastonit var däremot ineffektiva som fosforavskiljande material under de rådande förhållandena (< 40 % genomsnittlig avskiljning). I samtliga fall visade resultaten att avskiljningen fungerade klart bättre då BOD-värdet är lågt. Projektet visar att det är stor skillnad mellan förhållanden i laboratorieskala och tuffa förhållanden i fält. Såväl BOD-värde som hydraulisk belastning tycks vara viktiga faktorer som påverkar effektivitet och livslängd för filtermaterialen. För att ha en bra fosforavskiljning kan det vara viktigt att ställa krav på en effektiv förbehandling av avloppsvattnet i slamavskiljare och mark/biobädd. Detta bör beaktas i den vidare utvecklingen av material för småskalig avloppsrening.
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| 5. |
- Renman, Gunno, et al.
(författare)
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Sustainable use of crushed autoclaved aerated concrete (CAAC) as a filter medium in wastewater purification
- 2012
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Ingår i: 8th International conference on sustainable management of waste and recycled materials in construction, Gothenburg, Sweden, 30 May – 1 June, 2012. Proceedings. - : ISCOWA and SGI.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Scrap material from the production of autoclaved aerated concrete (AAC) should be considered a valuable by-product and not a waste, as should residues from the demolition of houses built with AAC. This paper presents an innovative use of AAC that can contribute to environmental improvement. We tested crushed AAC (CAAC, 2-4 mm) for its phosphorus (P) removal efficiency by filtering a solution containing phosphate phosphorus (PO4-P) or pure wastewater in batch, bench-scale and field pilot-scale experiments. Slow phosphate removal kinetics of CAAC were demonstrated, but the removal efficiency was very high (93-99%). Mineralogical analyses (by ICP-OES) of the solid CAAC after contact with flowing wastewater yielded concentrations of 39.6 g P kg-1. Application of X-ray powder diffraction (XRPD) for mineral phase identification confirmed that the dominant mineral in AAC was tobermorite (Ca5Si6O16(OH)2 · 4H2O). Dissolution of this crystalline structure was followed by formation of calcium phosphates and the porous, tobermorite-rich material produced proved excellent in removal of P and organic matter from domestic wastewater. Only crushing and sieving to achieve a suitable particle size distribution is needed prior to application in different technical solutions.
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| 6. |
- Cucarella, Victor, et al.
(författare)
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Recycling of calcium-silicate material after wastewater filtration to agriculture -Soil condition impact
- 2012
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Ingår i: Ecological Chemistry and Engineering S. - : Walter de Gruyter GmbH. - 1898-6196. ; 19:3, s. 373-382
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Tidskriftsartikel (refereegranskat)abstract
- Reactive filter materials aimed at phosphorus (P) recovery is a novel method for on-site wastewater treatment. Once the bed filter is no longer effective, the sorbent must be replaced and can then be recycled as a soil amendment to agriculture. This study investigated the short-term effects of such amendments in a field with a wheat crop in order to evaluate the risks and/or potential benefits of this disposal option. The developed product Polonite (manufactured from Opoka) was used as a model filter sorbent in the field trial. Rates corresponding to approximately 6 and 8 tons per hectare were applied. In the short-term, this amending did not affect soil physical and sorption properties. The rate of Polonite used here, as P source for wheat was irrelevant in this kind of soil. The usefulness of this disposal option of exhausted filter material is discussed.
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| 7. |
- Earon, Robert, et al.
(författare)
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Initial Effects of a New Highway Section on Soil and Groundwater
- 2012
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 223:8, s. 5413-5432
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Tidskriftsartikel (refereegranskat)abstract
- The environmental impacts of 16 different contaminants originating from the E18 Highway (17,510 annual average daily traffic) were studied over the initial months of the highway's operational life. Investigative methods used included electrical resistivity surveying, water chemistry analyses, soil analyses, distribution modeling, and transportation modeling of contaminants. The study conclusively showed a year-round infiltration due to melting of the snowpack from road salt, and a strong preferential, anthropogenic pathway due to increased hydraulic conductivities of road construction materials relative to in situ soils. The resistivity surveys produced values well below the expected values for the highway materials, indicating increased ionic content within the unsaturated zone. Time lapse resistivity modeling showed a clear downwards spreading of contamination from the roadway to subsurface distances greater than 5 m. Elevated concentrations of nearly every studied contaminant relative to baseline values were observed, with many metal concentrations within the snow pack averaging values in excess of the Swedish Environmental Protection Agency's groundwater limitations. Distribution modeling demonstrated a potential offset of peak values from the road surface due to plowing and splash transport processes, and indicated different distribution behavior during winter months than during summer months. One-dimensional transport modeling demonstrated the importance of adsorption and other retentive factors to the migration of contaminants to groundwater and provided an estimate for potential long-term contaminant concentrations.
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| 8. |
- Eveborn, David
(författare)
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Bed filters for phosphorus removal in on-site wastewater treatment : Removal mechanisms and sustainability
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For many surface waters, phosphorus (P) leaching is a serious problem that should be minimized to prevent eutrophication. In Sweden there is a demand for physical and technical development of high-performance P removal techniques to reduce phosphorus leaching from on-site wastewater treatment systems to the Baltic Sea. However, although these systems are designed to reduce eutrophication there are also other environmental impacts to be considered when implementing them in on-site systems; energy use and global warming potential are two examples. This study has investigated several bed filter materials (reactive media and natural soils) for their total environmental impact (in commercial applications) as well as for the predominating chemical phosphorus removal mechanisms. The use of life cycle assessment revealed that several reactive bed filters are relatively energy-consuming due to the material manufacturing process. Characterization of phosphorus compounds in used reactive media provided evidence for calcium phosphate precipitation as the predominating P removal mechanism in alkaline filter materials. However, in soil treatment systems with noncalcareous soils, batch experiments and extractions suggested that aluminium compounds were important for P removal. According to mass balance calculations that compared accumulated P with the estimated P load in a soil treatment system, the long term P removal capacity was very low; only 6.4 % of the applied phosphorus had been removed during 16 years of operation.
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| 9. |
- Eveborn, David, 1978-, et al.
(författare)
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Phosphorus in soil treatment systems : accumulation and mobility
- 2014
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Ingår i: Water Research. - : Elsevier. - 0043-1354 .- 1879-2448. ; 64, s. 42-52
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Tidskriftsartikel (refereegranskat)abstract
- In several western countries, septic tanks with subsequent soil treatment systems (STS) are a common treatment technique for domestic wastewater in rural areas. However the suitability of STS (especially relatively close to surface waters) can be questioned since the discharge of phosphorus (P) from such effluents is not well known. In this study, six STS in Sweden (11 to 28 years old) were investigated by means of batch and column experiments on samples taken from the unsaturated subsoil beneath the distribution pipes. At all sites the wastewater had clearly influenced the soil. This was observed through decreased pH, increased amounts of oxalate extractable metals and altered P sorption properties. The amount of accumulated P in the STS (defined as the amount of total P in the STS samples minus the amount of total P in unused soil samples) were found to be between 0.32 and 0.87 kg m-3, which in most cases was just a small fraction of the estimated P load (< 30%). Column studies revealed that remarkably high P concentrations (up to 6 mg L-1) were leached from the material when deionized water was applied. However, the response to deionized water varied between the sites. The affinity for P in the soils was well correlated to the amount of oxalate-extractable aluminium (as evidenced by a strong relationship between oxalate-extractable Al and oxalate-extractable P) and generally soils with high content of oxalate extractable Al was also less vulnerable to P leakage.
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| 10. |
- Eveborn, David, 1978-
(författare)
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Sustainable phosphorus removal in onsite wastewater treatment
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aquatic eutrophication is a serious environmental problem that occurs all over the world. To protect surface waters (in particular the Baltic Sea), the regulatory pressure on onsite wastewater treatment (OWT) systems have increased in Sweden. Stringent requirements have led to uncertainties regarding the capability of conventional treatment techniques (soil treatment systems (STS)) to remove phosphorus (P), but they have also stimulated the development and introduction of enhanced P treatment techniques. In this thesis the accumulation and mobility of P as well as the chemical P removal mechanisms were studied in soils and reactive filter media. This knowledge was then used in environmental systems analysis. A model based on life cycle assessment (LCA) methodology was developed to evaluate the overall environmental performance of conventional and enhanced P treatment systems under various local conditions. The P accumulation in the studied STS varied (320-870 g m-3) and the accumulated P was rather mobile in some soils. Phosphorus compounds were identified in alkaline reactive filter media (calcium phosphates predominated) by means of X-ray Absorption Near Edge Structure (XANES). In sandy soils from STS aluminium was found to be a key element for P removal, as evidenced by a strong relationship between oxalate-extractable P and Al. The LCA studies indicated that enhanced P treatment systems may be beneficial from an eutrophication and P recycling perspective but causes increased impacts in terms of global warming and acidification. Despite the drawbacks, enhanced P treatment techniques should be considered suitable substitutes to surface water discharge STS under most conditions. This is because the latter systems have such a strong eutrophication impact. On the other hand, under appropriate conditions, STS with groundwater discharge may be advantageous. These systems generally caused low environmental impacts except for the dispersion of P resources.
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