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| 2. |
- Gustafsson, Jon Petter, et al.
(författare)
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Phosphate removal by mineral-based sorbents used in filters for small-scale wastewater treatment
- 2008
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Ingår i: Water Research. - : Elsevier. - 0043-1354 .- 1879-2448. ; 42:1-2, s. 189-197
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Tidskriftsartikel (refereegranskat)abstract
- The mineral-based sorbents Filtra P, Polonite (R), natural wollastonite and water-cooled blast furnace slag (WCBFS) were studied in terms of their PO4 removal performance. Results from a long-term column experiment showed that both Filtra P and Polonite (R) removed > 95% of PO4 from the applied synthetic solution, and that the used filter materials had accumulated several (1.9-19) g kg(-1) P. Phosphorus was removed also by natural wollastonite and WCBFS, but these materials were less efficient. Batch experiments on the used materials showed that the solubility PO4 was considerably larger than the one expected for crystalline Ca phosphates such as hydroxyapatite, and results from investigations with attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) on the Filtra P material showed that the formed P phase was not crystalline. These evidence suggest that a soluble amorphous tricalcium phosphate (ATCP) was formed in the mineral-based sorbents; the apparent solubility constant on dissolution was estimated to log K-s = -27.94 ( 0.31) at 21 degrees C. However, since only up to 18% of the accumulated PO4 was readily dissolved in the experiments, it cannot be excluded that part of the phosphorus had crystallized to slightly less soluble phases. In conclusion, Filtra P and Polonite are two promising mineral-based sorbents for phosphorus removal, and at least part of the accumulated phosphorus is present in a soluble form, readily available to plants.
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| 3. |
- Renman, Agnieszka, et al.
(författare)
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Metal removal by bed filter materials used in domestic wastewater treatment
- 2009
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 166:2-3, s. 734-739
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Tidskriftsartikel (refereegranskat)abstract
- Bed filters using reactive materials are an emerging technology for on-site wastewater treatment. Used materials, which are enriched with phosphorus, can be used as a fertiliser or soil amendment. However the materials can also be enriched with metals from the wastewater. Six materials (opoka, sand, Polonite (R), limestone, two types of blast furnace slag) exposed to long-term wastewater loading in columns and in a compact filter well filled with Polonite were investigated for metal removal and accumulation. Wastewater applied to the columns had low heavy metal concentrations in the order Zn > Cu > Mn > Ni > Cr. All columns were able to remove 53%-83% of Zn except those filled with sand. Polonite demonstrated a high removal capacity of Mn (>98%), while only the slag materials were able to remove Ni. All materials showed increased Cu, Cr(III). Mn. Pb and Zn content after filtration. Speciation calculations showed that high concentrations of dissolved organic matter might have prevented efficient metal removal, particularly in the case of Cu. The low content of toxic heavy metals in the studied filter materials studied would probably not restrict their use as a fertiliser or soil amendment.
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| 4. |
- Renman, Agnieszka, 1969-
(författare)
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On-site wastewater treatment : Polonite and other filter materials for removal of metals, nitrogen and phosphorus
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bed filters using reactive materials are an emerging technology for on-site wastewater treatment. Chemical reactions transfer contaminants from the aqueous to the solid phase. Phosphorus is removed from domestic wastewater by sorption to filter materials, which can then be recycled to agriculture as fertilisers and soil amendments. This thesis presents long-term column and field-scale studies of nine filter materials, particularly the novel product Polonite®. Phosphorus, nitro-gen and metals were removed by the mineral-based materials to varying degrees. Polonite and Nordkalk Filtra P demonstrated the largest phosphorus removal capacity, maintaining a PO4-P removal efficiency of >95%. Analysis of filter bed layers in columns with downward wastewater flow, showed that phosphorus, carbon and nitrogen content was vertically distributed, with de-creasing values from surface to base layer. Polonite and Filtra P accumulated 1.9-19 g P kg-1. Nitrogen in wastewater was scarcely removed by the alkaline filter materials, but transformation from NH4-N to NO3-N was >90%. Pot experiments with barley (Hordeum vulgare L.) revealed that after wastewater treatment, slags and Polonite could increase plant production. Batch experi-ments and ATR-FTIR investigations indicated that amorphous tricalcium phosphate (ATCP) was formed in the materials, so some of the accumulated PO4-P was readily available to plants. Low heavy metal contents occurred in the materials, showing that they can be applied as soil amend-ments in agriculture without contamination risks. A full-scale treatment system using Polonite as filter material showed an average PO4-P removal efficiency of 89% for a 92-week period, indicat-ing the robustness of the filter bed technology.
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| 5. |
- Renman, Agnieszka, et al.
(författare)
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Transformation and removal of nitrogen in reactive bed filter materials designed for on-site wastewater treatment
- 2008
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Ingår i: Ecological Engineering. - : Elsevier BV. - 0925-8574 .- 1872-6992. ; 34:3, s. 207-214
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Tidskriftsartikel (refereegranskat)abstract
- Nitrogen (N) and phosphorus (P) should be removed and recycled from wastewater in order to reduce the nutrient load to recipient waters, avoid contamination of groundwater and conserve resources. Nitrogen removal and transformation were studied in domestic wastewater percolating in unsaturated conditions through 0.5 m long columns containing potential filter materials. Six materials (three types of slag, limestone, opoka, Polonite(R) and sand) were compared at a design loading rate of 85 L m(-2) d(-1) during 67 weeks. All materials transformed ammonium efficiently to nitrate (>98%). Apparent removal of inorganic N was shown only by the coarsest slag and by Polonite(R), possibly due to losses through volatilisation. All other filter materials leached nitrate at the column effluent. Total N content was highest in the surface layer of the column material, with decreasing values with depth. In contrast, carbon
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| 6. |
- Cucarella Cabañas, Victor
(författare)
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Phosphorus recycling from wastewater to agriculture using reactive filter media
- 2007
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focused on testing the suitability of reactive filter media used for phosphorus (P) removal from wastewater as fertilizers, thus recycling P to agriculture. The work compared the P sorption capacity of several materials in order to assess their suitability as a source of P for plants. The selected materials (Filtra P, Polonite and wollastonite) were saturated with P and used as soil amendments in a pot experiment. The amendments tended to improve the yield of barley and ryegrass compared with no P addition. The amendments also increased soil pH, P availability and cation exchange capacity in the studied soils. The substrates studied here can be of particular interest for acid soils. Of the materials studied, Polonite appears to be the most suitable substrate for the recycling of P from wastewater to agriculture
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| 7. |
- Cucarella Cabañas, Victor
(författare)
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Recycling Filter Substrates used for Phosphorus Removal from Wastewater as Soil Amendments
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis studied the viability of recycling filter substrates as soil amendments after being used in on-site systems for phosphorus (P) removal from wastewater. Focus was put on the materials Filtra P and Polonite, which are commercial products used in compact filters in Sweden. A prerequisite for this choice was to review filter materials and P sorption capacity. The filter substrates (Filtra P, Polonite and wollastonite tailings) were recycled from laboratory infiltration columns as soil amendments to a neutral agricultural soil and to an acid meadow soil to study their impacts on soil properties and yield of barley and ryegrass. The amendments tended to improve the yield and showed a liming effect, significantly increasing soil pH and the availability of P. In another experiment, samples of Filtra P and Polonite were equilibrated in batch experiments with the two soils in order to study the P dynamics in the soil-substrate system. Batch equilibrations confirmed the liming potential of Filtra P and Polonite and showed that improved P availability in soils was strongly dependent on substrate P concentration, phase of sorbed P, and soil type. Finally, samples of Polonite used for household wastewater treatment were recycled as soil amendments to a mountain meadow and to an agricultural field for wheat cropping. The liming effect of Polonite was confirmed under field conditions and the results were similar to those of lime for the mountain meadow soil. However, the results were quite different for the agricultural field, where Polonite did not affect soil pH or any other chemical and physical soil properties investigated and had no impact on wheat yield and quality. The results from field experiments suggested that Polonite can be safely recycled to meadows and cropping fields at rates of 5-10 ton ha-1 but long-term studies are needed to forecast the effects of accumulation.
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| 8. |
- Cucarella, Victor, et al.
(författare)
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Effect of Polonite used for phosphorus removal from wastewater on soil properties and fertility of a mountain meadow
- 2009
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 157:7, s. 2147-2152
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Tidskriftsartikel (refereegranskat)abstract
- Reactive filter materials used for phosphorus (P) removal from wastewater can be disposed of as soil amendments after treatment, thus recycling P and other macro- and micro-nutrients to plants. In addition, materials with a high pH and Ca content, such as Polonite, are potential soil conditioners which, can be particularly beneficial for acid soils. Polonite previously used for on-site wastewater treatment was applied as a soil amendment to a mountain meadow. The amendment significantly increased soil pH and decreased the hydrolytic acidity, thus reducing Al toxicity risks. The effects were comparable to those of liming. No difference in yield and P uptake by meadow plants was observed. The uptake of metals was lower for amended soils, especially the uptake of Mn. Using Polonite after wastewater treatment as a soil amendment is thus a viable disposal alternative that can replace liming, when necessary, being capable of recycling P and other nutrients to meadow plants.
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| 9. |
- Cucarella, Victor, et al.
(författare)
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Effect of reactive substrates used for phosphorus removal from wastewater on the feritlity of acid soils
- 2008
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 99:10, s. 4308-4314
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Tidskriftsartikel (refereegranskat)abstract
- Reactive substrates used in filter systems can reduce phosphorus (P) pollution and, once saturated with P, may be recycled in agriculture. These substrates are usually calcium carbonate derivates with high pH values, which may be particularly beneficial for acid soils. Three reactive substrates (Filtra P, Polonite and wollastonite) saturated with P were used as amendments to an acid soil in a pot experiment. Substrate amendments tended to improve ryegrass yield and P uptake compared with control and potassium phosphate treatments. Polonite produced the highest yield/amendment ratio, while Polonite and Filtra P significantly increased the concentrations of P and Ca in the ryegrass. Addition of all three substrates increased the pH, AL-extractable P and cation exchange capacity of soils during the experiment. These substrates can therefore be applied to acid soils in order to recycle P and improve soil properties.
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| 10. |
- Cucarella, Victor, et al.
(författare)
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Fertilizer potential of calcium-rich substrates used for phosphorus removal from wastewater
- 2007
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Ingår i: Polish Journal of Environmental Studies. - 1230-1485 .- 2083-5906. ; 16:6, s. 817-822
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorus (P) in wastewater is an important source of pollution, but properly managed, it can become a resource. Reactive filter media with a high affinity for P are promising in reducing P from effluents allowing nutrient recycling. In this study, three calcium-rich substrates (Filtra P, Polonite, wollastonite) with ability to remove P from wastewater have been saturated with P and tested as potential fertilizers in a pot experiment. Polonite had a relatively higher P content than Filtra P and wollastonite after saturation. All three materials tended to improve the yield of barley compared with the control treatment. Polonite induced the highest yield per unit of amendment from all three materials due to its higher P content, which could be shown in a higher ammonium lactate (AL)-extractable P in soil after harvesting. The application of the substrates slightly increased soil pH and decreased the hydrolytic acidity.
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