| 1. |
- Hylander, Lars D., et al.
(författare)
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Phosphorus retention in filter materials for wastewater treatment and its subsequent suitability for plant production
- 2006
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 97:7, s. 914-921
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Tidskriftsartikel (refereegranskat)abstract
- Constructed sand filter beds are advantageous for the treatment of wastewater in areas with a low population density. Phosphorus-sorbing materials with additional beneficial characteristics may be used instead of sand. This study aimed at determining and comparing phosphorus (P) retention capacities of amorphous and crystalline blast furnace slags, limestone, opoka, Polonite (R) and sand, for filtering domestic wastewater through columns over a period of 67 weeks. The P-enriched filter materials were subsequently tested for their fertilizer effectiveness in a pot experiment where barley was cultivated. Polonite (R), i.e. calcinated bedrock opoka, was most effective in removing P. This Occurred at a relatively high hydraulic conductivity that reduced the risk of clogging. Barley grown in two types of slag, with a grain size of 0.25-4, mm. was most effective in dry matter production followed by Polonite (R). Fine-grained slags and Polonite (R) were suggested its most suited of the investigated materials to recycle P back to agriculture.
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| 2. |
- Kietlinska, Agnieszka, et al.
(författare)
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An evaluation of reactive filter media for treating landfill leachate
- 2005
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 61:7, s. 933-940
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Tidskriftsartikel (refereegranskat)abstract
- A laboratory bench-scale column study was conducted to evaluate permeable reactive filter materials as a new method for removal of heavy metals and inorganic nitrogen from landfill leachate. Mixtures of sand and peat, blast-furnace slag (BFS) and peat, and Polonite (R) and peat were tested by loading columns with leachate collected from a pond at Tvetaverket Landfill, Sweden. Sand, peat and Polonite (R) represent natural materials. BFS is a by-product from steel-works. The metal treatment efficiencies of the media were assessed and Polonite (R) was found to perform best, where Mn, Fe, Zn and Cu concentrations were removed by 99%, 93%, 86% and 67%, respectively. This material was also able to reduce inorganic N by 18%. The BFS showed good removal efficiency for Cu (66%), Zn (62%), Ni (19%) and Mo (16%). The sand-peat mixture did not demonstrate a promising removal capacity for any of the elements studied with the exception of Cu (25%). The removal of different elements was suggested to be a combination of several factors, i.e. precipitation, ion exchange and adsorption. Prior to full-scale application of reactive filters at a landfill site, matrix selection, filter design and operational procedures must be developed.
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| 3. |
- Kietliñska, Agnieszka
(författare)
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Engineered Wetlands and Reactive Bed Filters for Treatment of Landfill Leachate
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objectives of this study were to investigate (i) anovel wetland treatment technology and (ii) selected bed filtermedia for the removal of contaminants from landfill leachate. Areview of the literature concerning experiences of the use ofconstructed wetlands (CW) for the removal of nitrogen fromlandfill leachate, showed that at least three groups oftreatment systems are in practice: sub-surface flow wetlands,hybrid systems (a combination of vertical and horizontal flowwetlands) and, compact constructed wetland (CCW). Most of thesetypeswere generally effective in reducing nitrogen (N,e.g.NH4-N, dominant N species in leachate) down toeffluent concentrations of about 10 mg L-1. Unfortunately, very little evidence ofresponsible mechanisms for the removal of N was presented,although some data indicated denitrification. The treatmentperformance of a compact constructed wetland (CCW) applied atthe Tveta Landfill, Södertälje, Sweden, wasevaluated. Chemically purified leachate and untreated leachatewere applied in periods of 7 day submergence and 7 day drainageto different sections of the CCW. The removal efficiency variedbetween 40 and 82%, and a mass removal rate of up to 5.1 g m2d-1was achieved. The chemical pre-treatment had adecisive role for the highest removal efficiencies obtained andit was unclear whether that treatment enhanced the efficiencybecause of lower toxicity and/or content of fewer competingcations. The possible combination of bed filter media and CCWas an ecotechnological treatment method for landfill leachatewas investigated by bench-scale laboratory column experiments.Reactive filter media (sorbents) was selected from their knownor suggested capacities for removal of heavy metals, nitrogenand phosphorus. Quartz sand or natural sand from an esker wasused as reference medium. Peat was used as an additionalcomponent in mixtures with the reactive media Polonite®(product from the bedrock opoka) and blastfurnace slag (BFS). A small column study also involved zeolite.Phosphorus was efficiently removed by Polonite®and NH4-N to some extent. Concerning metal removal, thebest performance was found as well for Polonite®, especially for Mn, Fe, Zn and Cu. The BFSshowed good removal efficiency for Cu, Ni and Mo. The removalof different elements was suggested to be a combination ofseveral factors,e.g.precipitation, ion exchange and adsorption. Priorto full-scale application of reactive filters at a landfillsite, matrix selection, filter design and operationalprocedures must be developed. Keywords:Blast furnace slag; Compact constructedwetland; Metals; Nitrogen; Polonite; Sorbents
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| 4. |
- Kietlinska, Agnieszka, et al.
(författare)
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Nitrogen removal from landfill leachate using a compact constructed wetland and the effect of chemical pretreatment
- 2005
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Ingår i: Journal of Environmental Science and Health. Part A. - 1093-4529 .- 1532-4117. ; 40:07-jun, s. 1493-1506
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Tidskriftsartikel (refereegranskat)abstract
- Onsite treatment of leachate was implemented at the Tveta Landfill, adjacent to the city of Sodertalje, Sweden. The system consists of leachate collection in a pond, precipitation of metals with chemicals, a constructed wetland, and forest irrigation. This article describes the constructed wetland and its effectiveness at removing ammonia in the system. Pulsed-discharge hydrology and wetland ecology formed the basis for the development of a compact constructed wetland (CCW). The system presented here has most design similarities with vertical sub-surface flow wetlands, though this system is run in batch mode. Chemically purified leachate and untreated leachate were applied to separate sections of the CCW using a filling and emptying schedule. A leachate treatment cycle of about 14 days duration was used, involving a 7 day submerged phase followed by a 7 day drained period. The removal efficiency varied between 40 and 75% on a mass basis. A maximum mass removal rate of up to 5.1 g m(-1) d(-1) was achieved in wetlands receiving leachate after chemical pretreatment. In wetlands receiving non-treated leachate a net release of up to 18 g m(-2) N occurred in the form of nitrate. This indicated a considerable nitrification but limited denitrification in those systems. It was unclear whether the chemical treatment enhanced the nitrogen removal efficiency because of lower toxicity and/or content of fewer competing cations, or other mechanisms. Mechanisms responsible for the NH4-N removal in the CCW system have to be further investigated.
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| 5. |
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| 6. |
- Renman, Gunno, et al.
(författare)
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A multi-stage treatment system for landfill leachate : design and performance
- 2004
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Ingår i: Waste 2004 - Integrated waste management and pollution control: Policy and practice, research and solutions. - : The Waste Conference Limited, The Barclay centre, University of warwick Science Park, Coventry, UK. ; , s. 528-535
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A new system for on-site treatment of leachate has been implemented at the Tveta landfill, adjacent to the city of Södertalje, Sweden, and an initial investigation of its performance has been carried out. This is a multi-stage treatment system consisting of steps for aeration and sedimentation in an open pond, indoor treatment with chemicals for precipitation of metals, use of a constructed wetland and forest irrigation for removal of nitrogen. Treatment results from 2002 and 2003 show that the system is able to meet very high effluent standards and therefore the water can be discharged to sensitive water bodies. The chemical treatment can be questioned since operational problems occur with clogging of mechanical devices due to precipitation of calcium as well as generally low metal concentrations do not motivate the high treatment costs. The constructed wetland is of novel design with a removal efficiency of up to 75% for NH4-N, corresponding to an inorganic mass removal rate of up to 5.1 g m-2 d-1. Water sampling in a control ditch adjacent to the forest irrigation revealed a concentration of 1 mg/l for NH4-N.
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| 7. |
- Renman, Gunno, et al.
(författare)
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A natural filter substrate for efficient phosphorus removal from wastewater - column studies
- 2003
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Ingår i: Scientific Papers of the Agricultural University of Crakow - Environmental Engineering. - Kraków : Wydawnictwo AR w Krakowie. - 1233-569X. ; :24, s. 397-404
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Tidskriftsartikel (refereegranskat)abstract
- Sorption to the bed substrate is a major phosphorus (P) removal mechanism in constructed wetlands. Hence it is important to select a substrate with high sorption capacity. A column experiment was performed where Polonite®, a product from opoka (a silica-calcite sedimentary rock from Poland) was mixed with Sphagnum peat in a weight proportion of 1:0.8 (column 2, 4) and 1:0.4 (column 3).Secondary treated wastewater with a mean soluble phosphorus (P-PO4) concentration of 5.1 mg·dm-3 was supplied during 378 days by gravity to four columns, 0.3 m in diameter and filled with substrate to 0.5 m. Column1 was filled solely with peat. Two different grain sizes of Polonite®: 0.05-0.2 mm (column 2, 4) and 2-6 mm (column 3) were used in the experiment. The hydraulic residence time varied from 36 to 48 hours during the experiment. The substrate in column 1 and 2 were kept under un-saturated conditions, while saturated conditions prevailed in columns 3 and 4. The column filled with peat showed an overall P-PO4 removal of 18% and an average effluent concentration of 4.2 mg· dm-3. However, after four months of wastewater discharge, the colour of the effluent from column1 exceeded 10000 mg Pt dm-3 and no further analysis of P was carried out. In the other three columns, where Polonite® was present, the average removal was 99%. The mean concentration of P-PO4 in effluent water from these columns was only 0.03 mg dm-3. Conditions of saturated and un-saturated substrates did not reveal any difference in P-sorption capacity. The results obtained show that the incorporation of the reactive media Polonite® into a peat matrix will enhance the long-term P-sorption capacity significantly.
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| 8. |
- Renman, Gunno, et al.
(författare)
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Reactive bed filters for treatment of landfill leachate
- 2004
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Ingår i: Waste 2004 - Integrated waste management and pollution control: Policy and practice, research and solutions. - : The Waste Conference Limited, The Barclay Centre, University of Warwick Science Park, Coventry, UK. ; , s. 491-498
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Konferensbidrag (refereegranskat)abstract
- A laboratory experiment demonstrated the use of reactive bed filters to effectively remove metals and other elements from landfill leachate. Filter media composed of sand/peat, blast furnace slag (BFS)/peat and Polonite®/peat were tested by loading filter columns with leachate collected from a pond at Tveta Landfill, located in Södertalje, Sweden. Leachate was discharged to each column with a hydraulic loading rate of 1.34 m/d. Sand and Polonite® represent natural materials, although the latter is manufactured from the bedrock opoka. BFS is a by-product from steel-works. Polonite® provided the best removal capacity when compared to the other media. Mn, Fe, Zn and Cu were removed by 99%, 93%, 86% and 67% respectively. This filter media was also able to reduce phosphorus by 90% and nitrogen by l8%.The BFS showed good removal efficiency for Cu (66%), Ni (19%) and Mo (16%). Reactive bed filters may be an economical and practical method for augmenting current, and future onsite treatment of landfill leachate disposal systems with metal, phosphorus and nitrogen removal capabilities.
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| 9. |
- Renman, Gunno, et al.
(författare)
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Reactive bed filters for treatment of storm water from roads and motorways
- 2004
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Ingår i: International Scientific-Technical Conference. Surface water, underground water and soils protection along roads and motorways. - : Eurosystem. - 839194994X ; , s. 109-113
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A reactive bed filter is designed according to the purpose of treatment, e.g. for storm water from roads. The construction may be a filter well or a constructed wetland where the most important component is the reactive medium or sorbent. Different types of artificial adsorbents or ion exchange materials are available as commercial products and most of them are utilized when very high treated water standards are required. A filter technology using reactive media has been developed at the Royal Institute of Technology (KTH), where separate filter wells were constructed as a step following the storm water pond. Besides the filter construction, the most important part is the medium or sorbent used. The sorbent is ‘reactive’ for one or several contaminants that have to be removed from the storm water. The term sorbent refers not only to adsorption, but also to processes such as precipitation, ion exchange, complexation and mechanical filtration. Sorption depends heavily on conditions such as pH, concentration of pollutants, ligand concentration, competing ions and particle size. Sorbents may consist of natural materials that are available in large quantities and at a low cost, or of by-products from industrial or agricultural operations. Since they are non-expensive, these materials can be disposed of without expensive regeneration, although one must bear in mind that they can contain hazardous substances after use and have to be treated accordingly. A promising reactive media is Polonite® which has been developed from the bedrock opoka. The paper presents different technical solutions for treating polluted water from traffic areas.
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| 10. |
- Renman, Gunno, et al.
(författare)
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Treatment of phosphorus and bacteria by filter media in onsite wastewater disposal systems
- 2004
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Ingår i: Ecosan - closing the loop. - Eschborn : Deutsche Gesellschaft für Technische Zusammenarbeit. - 3000127917 ; , s. 573-576
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Konferensbidrag (refereegranskat)abstract
- Correctly designed infiltration beds or phosphorus traps are advantageous for the treatment of wastewater in areas with a low population density. The efficiency can be increased by replacing the commonly used sand with materials that have a higher sorption capacity. Some of these materials are capable of delivering the sorbed phosphorus (P) to plants if subsequently used in agriculture, thereby recycling P in crop production in a sustainable way. A long-term column study was performed using municipal wastewater. Columns were filled with seven different filter media. PoloniteÒ, a product from the bedrock opoka, had the largest sorption capacity for P of the studied materials and its high pH resulted in a filtrate of good hygienic quality. No coliform bacteria was found in the effluent from four selected columns and the removal efficiency approached 99.5 %.
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