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Vertical Flow Constructed Wetlands fed with raw sewage: historical review and recent developments in France
2010
Liénard, A.
This paper relates to the 1st studies conducted in France on Vertical Flow Constructed Wetlands [VFCWs]. This process was originally designed by Käte Seidel according to her previous research done in Krefeld (Germany) the so-called Max Planck Institute Process [MPIP]. Based on measurements campaigns done successively in Saint Bohaire and Pont-Rémy, it was clearly established that the vertical flow 1st stage filters were significantly more efficient than the horizontal ones. This acknowledgement of success was positively used to design a treatment plant in Gensac la Pallue, still in operation after 23 years, with the special feature that the VFCW are fed with raw sewage. This attribute was then spread to the design of French VFCW systems. The main reasons which explain why representatives of small communities are so enthusiastic about feeding with raw sewage are presented. The state of the art of French VFCWs is detailed and scientific arguments which nowadays lead to new fields of application and a better understanding of small scale processes which occurs in these filters are also suggested.
Afficher plus [+] Moins [-]Ecosystem engineering potential of the gastropod Terebralia palustris (Linnaeus, 1767) in mangrove wastewater wetlands – A controlled mesocosm experiment
2010
Penha-Lopes, Gil | Bartolini, Fabrizio | Limbu, Samwel | Cannicci, Stefano | Mgaya, Yunus | Kristensen, Erik | Paula, Jose
The effect of different sewage concentrations (0, 20, 60 and 100%), vegetation (Bare, Avicennia marina or Rhizophora mucronata) and immersion periods (immersion/emersion period of 12/12 h or 3/3 days just for 100%) conditions were studied for 6 months on survival and growth rates of Terebralia palustris (Linnaeus, 1767). Gastropods' activity and ecosystem engineering preformed at bare and A. marina planted cells and 3 sewage conditions (0, 20 and 60%) were determined. Survival rates were higher than 70% in all treatments. Growth rate decreased significantly with increasing sewage concentrations (mainly at unplanted conditions) and longer immersion periods. A complete shift (from immersion to emersion periods) and a significant decrease in mobility and consequently its engineer potential, due to sewage contamination, lead to a 3–4 fold decrease in the amount of sediment disturbed. Sewage contamination, primary producers' abundance and environmental conditions may have influenced the gastropods survival, growth and its ecosystem engineering potential. Terebralia palustris high ecosystem engineering potential in constructed mangrove wetlands.
Afficher plus [+] Moins [-]Occurrence and fate of pharmaceuticals in wastewater treatment plants and rivers in Korea
2010
Sim, Won-Jin | Lee, Ji-Woo | Oh, Jeong-Eun
We measured 25 pharmaceuticals in ten municipal wastewater treatment plants (WWTPs), one hospital WWTP and five rivers in Korea. In the municipal WWTP influents, acetaminophen, acetylsalicylic acid and caffeine showed relatively high concentrations. The occurrence of pharmaceuticals in the wastewater seems to be influenced by production and consumption of pharmaceuticals. The hospital WWTP influent showed higher total concentrations of pharmaceuticals than the municipal WWTPs, and caffeine, ciprofloxacin and acetaminophen were dominant. In the rivers, caffeine was dominant, and the distribution of pharmaceuticals was related to the inflow of the wastewater. In the municipal WWTPs, the concentrations of acetaminophen, caffeine, acetylsalicylic acid, ibuprofen and gemfibrozil decreased by over 99%. The decrease of these pharmaceuticals occurred mainly during the biological processes. In the physico-chemical processes, the decrease of pharmaceuticals was insignificant except for some cases. In the hospital WWTP, ciprofloxacin, acetylsalicylic acid, acetaminophen and carbamazepine showed the decrease rates of over 80%.
Afficher plus [+] Moins [-]Adverse effects of erythromycin on the structure and chemistry of activated sludge
2010
Louvet, J.N. | Giammarino, C. | Potier, O. | Pons, M.N.
This study examines the effects of erythromycin on activated sludge from two French urban wastewater treatment plants (WWTPs). Wastewater spiked with 10 mg/L erythromycin inhibited the specific evolution rate of chemical oxygen demand (COD) by 79% (standard deviation 34%) and the specific N–NH4+ evolution rate by 41% (standard deviation 25%). A temporary increase in COD and tryptophan-like fluorescence, as well as a decrease in suspended solids, were observed in reactors with wastewater containing erythromycin. The destruction of activated sludge flocs was monitored by automated image analysis. The effect of erythromycin on nitrification was variable depending on the sludge origin. Erythromycin inhibited the specific nitrification rate in sludge from one WWTP, but increased the nitrification rate at the other facility. Erythromycin toxicity on activated sludge is expected to reduce pollution removal.
Afficher plus [+] Moins [-]Determination of antibiotics in sewage from hospitals, nursery and slaughter house, wastewater treatment plant and source water in Chongqing region of Three Gorge Reservoir in China
2010
Chang, Xiaosong | Meyer, Michael T. | Liu, Xiaoyun | Zhao, Qing | Chen, Hao | Chen, Ji-an | Qiu, Zhiqun | Yang, Lan | Cao, Jia | Shu, Weiqun
Sewage samples from 4 hospitals, 1 nursery, 1 slaughter house, 1 wastewater treatment plant and 5 source water samples of Chongqing region of Three Gorge Reservoir were analyzed for macrolide, lincosamide, trimethoprim, fluorouinolone, sulfonamide and tetracycline antibiotics by online solid-phase extraction and liquid chromatography-tandem mass spectrometry. Results showed that the concentration of ofloxacin (OFX) in hospital was the highest among all water environments ranged from 1.660 μg/L to 4.240 μg/L and norfloxacin (NOR, 0.136-1.620 μg/L), ciproflaxacin (CIP, ranged from 0.011 μg/L to 0.136 μg/L), trimethoprim (TMP, 0.061-0.174 μg/L) were commonly detected. Removal range of antibiotics in the wastewater treatment plant was 18–100% and the removal ratio of tylosin, oxytetracycline and tetracycline were 100%. Relatively higher removal efficiencies were observed for tylosin (TYL), oxytetracycline (OXY) and tetracycline (TET)(100%), while lower removal efficiencies were observed for Trimethoprim (TMP, 1%), Epi-iso-chlorotetracycline (EICIC, 18%) and Erythromycin-H2O (ERY-H2O, 24%). Antibiotics were removed more efficiently in primary treatment compared with those in secondary treatment.
Afficher plus [+] Moins [-]Widespread occurrence of estrogenic UV-filters in aquatic ecosystems in Switzerland
2010
Fent, Karl | Zenker, Armin | Rapp, Maja
We performed a trace analytical study covering nine hormonally active UV-filters by LC–MS/MS and GC–MS in river water and biota. Water was analysed at 10 sites above and below wastewater treatment plants in the river Glatt using polar organic chemical integrative samplers (POCIS). Four UV-filters occurred in the following order of decreasing concentrations; benzophenone-4 (BP-4) > benzophenone-3 (BP-3) > 3-(4-methyl)benzylidene-camphor (4-MBC) > 2-ethyl-hexyl-4-trimethoxycinnamate (EHMC). BP-4 ranged from 0.27 to 24.0 μg/POCIS, BP-3, 4-MBC and EHMC up to 0.1 μg/POCIS. Wastewater was the most important source. Levels decreased with higher river water flow. No significant in-stream removal occurred. BP-3, 4-MBC and EHMC were between 6 and 68 ng/L in river water. EHMC was accumulated in biota. In all 48 macroinvertebrate and fish samples from six rivers lipid-weighted EHMC occurred up to 337 ng/g, and up to 701 ng/g in 5 cormorants, suggesting food-chain accumulation. UV-filters are found to be ubiquitous in aquatic systems.
Afficher plus [+] Moins [-]Evaluating the cytotoxicity of palladium/magnetite nano-catalysts intended for wastewater treatment
2010
Hildebrand, Heike | Kühnel, Dana | Potthoff, Annegret | Mackenzie, Katrin | Springer, Armin | Schirmer, Kristin
Palladium/magnetite nanoparticulate catalysts were developed for efficient elimination of halogenated organic pollutants from contaminated wastewater. Particle recovery from treated water can be ensured via magnetic separation. However, in worst-case scenarios, this catalyst removal step might fail, leading to particle release into the environment. Therefore, a toxicological study was conducted to investigate the impact of both pure magnetite and palladium/magnetite nanoparticle exposure upon human skin (HaCaT) and human colon (CaCo-2) cell lines and a cell line from rainbow trout gills (RTgill-W1). To quantify cell viability after particle exposure, three endpoints were examined for all tested cell lines. Additionally, the formation of reactive oxygen species was studied for the human cells. The results showed only minor effects of the particles on the tested cell systems and support the assumption that palladium/magnetite nano-catalysts can be implemented for a new wastewater treatment technology in which advantageous catalyst properties outweigh the risks. Impact of nano-Pd/magnetite on cell viability was studied and appears to be low.
Afficher plus [+] Moins [-]Micropollutant removal during biological wastewater treatment and a subsequent ozonation step
2010
Schaar, Heidemarie | Clara, Manfred | Gans, Oliver | Kreuzinger, Norbert
The design criteria for wastewater treatment plants (WWTP) and the sludge retention time, respectively, have a significant impact on micropollutant removal. The upgrade of an Austrian municipal WWTP to nitrogen removal (best available technology, BAT) resulted in increased elimination of most of the analyzed micropollutants. Substances, such as bisphenol-A, 17α-ethinylestradiol and the antibiotics erythromycin and roxithromycin were only removed after the upgrade of the WWTP. Nevertheless, the BAT was not sufficient to completely eliminate these compounds. Thus, a pilot scale ozonation plant was installed for additional treatment of the effluent. The application of 0.6 g O3 g DOC−1 increased the removal of most of the micropollutants, especially for compounds that were not degraded in the previous biological process, as for example carbamazepine and diclofenac. These results indicated that the ozonation of WWTP effluent is a promising technology to further decrease emissions of micropollutants from the treatment process.
Afficher plus [+] Moins [-]Uptake of Cd(II) and Pb(II) by microalgae in presence of colloidal organic matter from wastewater treatment plant effluents
2010
Worms, Isabelle A.M. | Traber, Jacqueline | Kistler, David | Sigg, Laura | Slaveykova, Vera I.
The present study addresses the key issue of linking the chemical speciation to the uptake of priority pollutants Cd(II) and Pb(II) in the wastewater treatment plant effluents, with emphasis on the role of the colloidal organic matter (EfOM). Binding of Cd(II) and Pb(II) by EfOM was examined by an ion exchange technique and flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry in parallel to bioassays with green microalga Chlorella kesslerii in ultrafiltrate (<1 kDa) and colloidal isolates (1 kDa to 0.45 μm). The uptake of Cd by C. kesslerii was consistent with the speciation analysis and measured free metal ion concentrations, while Pb uptake was much greater than that expected from the speciation measurement. Better understanding of the differences in the effects of the EfOM on Cd(II) and Pb(II) uptake required to take into account the size dependence of metal binding by EfOM. Colloids isolated from WWTP effluents decrease Cd uptake, but increase Pb uptake by microalga Chlorella kesslerii.
Afficher plus [+] Moins [-]The use of nanoparticles in polymeric and ceramic membrane structures: Review of manufacturing procedures and performance improvement for water treatment
2010
Membrane separations are powerful tools for various applications, including wastewater treatment and the removal of contaminants from drinking water. The performance of membranes is mainly limited by material properties. Recently, successful attempts have been made to add nanoparticles or nanotubes to polymers in membrane synthesis, with particle sizes ranging from 4 nm up to 100 nm. Ceramic membranes have been fabricated with catalytic nanoparticles for synergistic effects on the membrane performance. Breakthrough effects that have been reported in the field of water and wastewater treatment include fouling mitigation, improvement of permeate quality and flux enhancement. Nanomaterials that have been used include titania, alumina, silica, silver and many others. This paper reviews the role of engineered nanomaterials in (pressure driven) membrane technology for water treatment, to be applied in drinking water production and wastewater recycling. Benefits and drawbacks are described, which should be taken into account in further studies on potential risks related to release of nanoparticles into the environment.
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