| 1. |
- Davidsson, Åsa, et al.
(författare)
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Effect of anaerobic digestion at 35, 55 and 60 °C ON pharmaceuticals and organic pollutants
- 2013
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Ingår i: Presented at the 1st International IWA Conference on Holistic Sludge Management, Västerås, Sweden, May 6-8, 2013. ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- The application of treated sewage sludge on farmland is a suggested method for recycling nutrients and reducing demand for commercial fertilizer. However sludge needs to be rendered safe from possible contaminants which can cause acute and long-term health and environmental problems. Residual pharmaceuticals and organic contaminants in sludge are mentioned as emerging threats since wastewater treatment plants are not designed to degrade these substances thus yielding an accumulation in sludge. The aim of this study was to evaluate the presence, and reduction, of pharmaceuticals and polycyclic aromatic hydrocarbons (PAHs) during anaerobic digestion at 35, 55 and 60ºC and during pasteurization at 70°C. The substrate used was mixed primary and secondary sludge from a 300 000 person-equivalents municipal wastewater treatment plant in southern Sweden. In general no reduction of pharmaceuticals could be observed at any temperature or minimum exposure time, except for the beta-blocker Irbesartan and the antibiotic Trimethoprim. The results from pharmaceuticals in mesophilic sludge agreed with results in recent Swedish studies. Also, no reduction of PAHs during digestion or pasteurization (70°C – 1 hour) was seen, but for single PAHs digestion could lead to reduction.
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| 2. |
- Eriksson, Eva, 1973-, et al.
(författare)
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Barley seed germination/root elongation toxicity test for evaluation of sludge pre-treatment
- 2013
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Ingår i: Presented at the 1st International IWA Conference on Holistic Sludge Management, Västerås, Sweden, May 6-8, 2013. ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- Application of sludge from wastewater treatment plants (WWTPs) on agricultural land is an approach for nutrient recycling that rise challenges due to recalcitrant and harmful pollutants. In this study we assessed the feasibility of a seed germination test to evaluate sludge ecotoxicity and compared germination responses from two test parameters, root elongation and seed germination (sprouts elongation) of the barley (Hordeum vulgare). 2nd objective was to evaluate sewage sludge pre-treatments at batch-scale of sludge samples from two WWTPs using anaerobic digestion, and thermal and ozonation pre-treatments. Glyphosate and eco-labelled soil were used as references. Inhibition of germination of seeds exposed to the glyphosate and sludge was registered and thus germination was successfully applied for sludge ecotoxicity assessment, and using the root elongation as the end-point was both faster and more precise than the sprout elongation. In comparison of pre-treated raw samples and pre-treaded and subsequently digested sludge the effects of the pre-treatments were limited and hence, the anaerobic digestion in it-self gave the foremost detoxification.
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| 3. |
- Davidsson, Åsa, et al.
(författare)
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Effect of anaerobic digestion at 35, 55 and 60 °C on pharmaceuticals and organic contaminants
- 2014
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 69:6, s. 1282-1288
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Tidskriftsartikel (refereegranskat)abstract
- The application of treated sewage sludge on farmland is a suggested method for recycling nutrients and reducing demand for commercial fertilizer. However, sludge needs to be safe from possible contaminants which can cause acute and long-term health and environmental problems. Residual pharmaceuticals and organic contaminants are mentioned as emerging threats since wastewater treatment plants are not designed to degrade these substances. The aim of this study was to screen and evaluate the presence, and reduction, of pharmaceuticals and polycyclic aromatic hydrocarbons (PAHs) during anaerobic digestion of mixed primary and waste-activated sludge at 35, 55 and 60°C and during pasteurization at 70°C. The study showed the difficulty of analysing pharmaceutical compounds in low concentrations in the sludge matrix. No general reduction of these compounds was seen during treatment, but for individual substances some reduction occured. The PAHs were generally not reduced during digestion or pasteurization, but for three substances (indeno[1,2,3-cd]pyrene and dibenzo[a,h]anthracene (analysed together) and benzo[g,h,i]perylene) reduction (up to 60%) during digestion was seen. Digestion at 35 and 55°C resulted in about the same order of reduction of the three individual PAHs, which was higher than for digestion at 60°C.
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| 4. |
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| 5. |
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| 6. |
- Nielsen, Katrine, et al.
(författare)
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Nano- and microparticles and associated pollutants in stormwater runoff : effects of disc filtration with and without flocculant addition
- 2014
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Ingår i: Specialist Conference. Advances in particle science and separation: from mm to nm scale and beyond. - : IWA Publishing. ; , s. 1-11
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Konferensbidrag (refereegranskat)abstract
- Danish municipalities work towards separating stormwater and sewage. But stormwater runoff may be heavily polluted and therefore it is needed to find Best Available Technologies (BAT) to source separate and treat stormwater before discharge into surface waters. The aim here was to determine the sizes of particles found in stormwater from roads and to evaluate the use of a cationic organic flocculant to increase the size of the particles and thereby increase the removal efficiency of a 10 μm disc filter. The samples were collected in connection with a project testing a pilot scale disc filter for treating stormwater runoff. The micro-sized particles were found to be mainly 2.1-19 μm in diameter and nano-sized particles were also observed (86-228 nm). Although the flocculant increased the observed volume of the micro-sized particles by 46%, the majority of the particles where still < 10 μm. Partial removal of particle-associate polycyclic aromatic hydrocarbons was confirmed.
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| 7. |
- Nielsen, Katrine, et al.
(författare)
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Removal of stormwater particulates by disc filter technology
- 2013
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Ingår i: Presented at the 8th International Conference on Planning and Technologies for Sustainable Urban Water Management, Lyon, France, June 23-27, 2013.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The trend in the Danish society is toward disconnection of stormwater from the combined sewers and, where needed, local treatment using the best available technologies (BAT). The aim here was to assess a fast filtration technology for removal of particulate matter in stormwater with an emphasis on colloidal and nanosized particles. During the project period it rained 8.5 % of the time and the average daily rainfall was 2.9 mm/day. Based on three individual storm events it was found that 95 % of the particles were <10 µm. The nanosized particles (0.01-1.2 µm) were found to be anionic charged and in the size-range of 100 nm. The physical treatment of particle filtration at 10 µm was inadequate to remove the small particles identified in this project. Coagulation with a cationic coagulant and subsequently flocculation is suggested as process improvements technologies.
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| 8. |
- Nielsen, Katrine, et al.
(författare)
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Sorption of PAHs to humic acid- and iron(III)carbonate particles by using passive dosing vials for investigating the transport of organic contamination in stormwater runoff
- 2013
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Ingår i: Interdisciplinary Discourse on Current Environmental Challenges. - Krakow : SETAC.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- During the last decades, the growing urbanisation a nd increasing anthropogenic activities in urban areas have turned urban stormwater runoff int o a surface water quality contamination problem. The concerns of urban stormwater runoff as a source of contamination in the receiving surface water (lakes, rivers or sea) have been raised by researchers throughout the world (e.g. Broman et. al., 1987, and Xanthopoulos et. al., 1990), and have in Europe gained increased interest in relation to the implementatio n of the Water Framework Directive (WFD, 2000/60/EC). Particles (often defined as >0.45 μm) has been foun d to facilitate transport of organic contaminants and metals in stormwater runoff system s, but little is known about the role of the colloidal fraction including nano-sized particl es (0.001-1 μm). Based on the large specific surface area of colloids and nanosized particles, t heir abundance, and knowledge about their facilitated transport of persistent organic polluti on in natural waters, they are likely to diminish the efficiency of engineered treatment sys tems unless appropriately accounted for. In this work organic and inorganic nanosized partic les were investigated for their ability to sorb polycyclic aromatic hydrocarbons (PAH’s) in an aqueous solution. These particles were used as indicators for stormwater particles which a re diverse in size and composition. For controlling the sorption onto the particles, passiv e doing vials were used (Birch et. al., 2010). Using passive dosing vials gives the possible to co ntrol freely dissolved analyte by equilibrium partitioning from a preloaded silicone membrane. It has been found that the presence of humic acid particles (80 nm) leads to an increasing amount of two PAHs (fluoranthene and phenanthrene) in the suspension. For iron(III)carbo nate particles (22 nm) sorption experiments are ongoing. Based on these results and a literature review, the importance of including particulate fractions for surface water q uality assessment in relation to the WFD will be discussed.
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| 9. |
- Sørud, Mai, et al.
(författare)
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DEMFIL - treatment of stormwater for recreational use
- 2013
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Ingår i: Proceedings of the 13th Nordic Wastewater Conference. - Malmö : Svenskt Vatten.
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Konferensbidrag (refereegranskat)abstract
- Decoupling of stormwater (road runoff) in a residential area has been implemented in order to reduce flooding and to increase the hydraulic capacity of a lake with a high recreational value. The object here was to evaluate a disc filter technology in combination with a green polymer for flocculation for its feasibility of particle removal. Secondary, the particulate pollution in the separate road runoff should be assessed.The road runoff was found not to be highly contaminated with particle pollution, here measured as turbidity and total suspended solids (TSS). The particles were generally small (< 10 μm) and negatively charged. The disc filtration was hampered during the winter season and by the large fraction of small particles, but supplementing it with flocculation increased the removal efficiencies. The inlet particle concentrations (mg/L) affected the removal efficiencies, and events with inlet concentrations < 10 mg TSS/L or FNU had no statistically significant removal of the particle pollution whereas the events with the highest concentrations yielded among the highest removal efficiencies. The green polymer is as efficient as previously tested commercial coagulant/ flocculent and the disc technology is promising but need to be further tested with higher hydraulic loadings.
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