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Water Treatment Plant (water + treatment_plant)
Selected AbstractsUsing artificial streams to assess the effects of metal-mining effluent on the life cycle of the freshwater midge (Chironomus tentans) in situENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2004Kimberly A. Hruska Abstract In 2002, we developed an in situ life-cycle bioassay with Chironomus tentans in artificial streams to evaluate the effects of a complex metal mine effluent under ambient environmental conditions. The bioassay was tested in the field using effluent from the Copper Cliff Waste Water Treatment Plant at INCO (Sudbury, ON, Canada). Chironomus tentans were exposed throughout the life cycle to 45% Copper Cliff effluent, which is the average effluent concentration measured in Junction Creek (ON, Canada), the natural receiving environment. Chironomus tentans in the effluent treatment exhibited reduced survival (p = 0.001), reduced total emergence (p = 0.001), increased time-to-emergence (p = 0.001), and reduced hatching success (p = 0.001) relative to animals in the reference water treatment. Chironomus tentans in the effluent treatment were not significantly different from the reference in terms of growth, sex ratio, number of egg cases/female, and number of eggs/egg case. This research showed how a life-cycle bioassay could be used in situ to assess metal mine effluent effects on a benthic invertebrate. [source] A simple system for biofilm potential monitoring in drinking waterJOURNAL OF BASIC MICROBIOLOGY, Issue 1 2006Eric Delahaye Dr. SAGEP-EAU DE PARIS produces drinking water for the city of Paris (France). In order to supply a high quality water, one of the main SAGEP's concerns is to monitor the Biofilm Formation Potentials of the produced drinking waters. Biofilm incubators were installed at the outlet of three Water Treatment Plants (WTP). These incubators allowed biofilm formation and quantification in terms of Fixed Total Organic Carbon (FTOC), fixed culturable bacteria (HPC-R2A) and fixed total bacteria. During this study, quantitative differences appeared between the biofilms formed at the outlet of the three WTPs, leading to different classifications of the Biofilm Formation Potentials of the three produced waters, depending on the used parameter for biofilms quantification. This observation underlined the necessity of a multi-parametric approach for the study of biofilms. More generally, our results validated the use of these sturdy stainless steel incubators, highly adapted to industrial field conditions, for the monitoring of Biofilm Formation Potentials in drinking water networks. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Wet scrubbing intensification applied to hydrogen sulphide removal in waste water treatment plantTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2010Pierre-François Biard Abstract Hydrogen sulphide removal in a waste water treatment plant at semi-industrial scale in a compact wet scrubber has been investigated. The gas residence time in the scrubber was reduced to 30,ms using a NaOCl caustic scrubbing solution. The contactor is composed of a wire mesh packing structure where liquid and gas flow co-currently at high velocity (>12,m,s,1). H2S removal percentages higher than 95% could be achieved whereas a moderate pressure drop was measured (<4000,Pa). Both the hydrodynamic and chemical conditions can influence the efficiency of the process. Correlations were developed to predict both the pressure drop and the H2S removal efficiency at given operating conditions. Le traitement du sulfure d'hydrogène dans un laveur de gaz compact a été étudié à l'échelle semi-industrielle en station d'épuration. Le temps de contact dans le laveur est réduit à une trentaine de ms en utilisant une solution d'hypochlorite de sodium à pH basique. Le contacteur se compose d'une structure tissée métallique dans laquelle le gaz et le liquide circulent à co-courant et grande vitesse (>12,m,s,1). Un abattement de l'H2S de plus de 95% peut être obtenu avec une perte de charge modérée (<4000,Pa). A la fois les conditions chimiques et hydrodynamiques influencent les performances de traitement. Des corrélations ont été développées pour prédire la perte de charge mais aussi l'abattement dans des conditions opératoires données. [source] Developmental toxicity of UV filters and environmental exposure: a reviewINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2008Margret Schlumpf Summary Several ultraviolet (UV) filters exhibit estrogenic, some also anti-androgenic activity. They are present in waste water treatment plants, surface waters and biosphere including human milk, suggesting potential exposure during development. Developmental toxicity was studied in rats for the UV filters 4-methylbenzylidene camphor (4-MBC, 0.7, 7, 24, 47 mg/kg/day) and 3-benzylidene camphor (3-BC, 0.07, 0.24, 0.7, 2.4, 7 mg/kg/day) administered in chow to the parent generation before mating, during pregnancy and lactation, and to the offspring until adulthood. Neonates exhibited enhanced prostate growth after 4-MBC and altered uterine gene expression after both chemicals. 4-MBC and 3-BC delayed male puberty and affected reproductive organ weights of adult offspring. Effects on the thyroid axis were also noted. Expression and oestrogen sensitivity of oestrogen-regulated genes and nuclear receptor coregulator levels were altered at mRNA and protein levels in adult uterus, prostate and brain regions involved in gonadal control and sexual behaviour. Female sexual behaviour was impaired by both filters; 3-benzylidene camphor caused irregular cycles. Classical endpoints exhibited lowest observed adverse effect levels (LOAELs) and no observed adverse effect levels (NOAELs) of 7/0.7 mg/kg for 4-MBC and 0.24/0.07 mg/kg for 3-BC. Molecular endpoints were affected by the lowest doses studied. Our data indicate that the potential risk posed by endocrine active UV filters warrants further investigations. [source] ALGAL-RELATED TASTES AND ODORS IN PHOENIX WATER SUPPLY: PRELIMINARY REPORTJOURNAL OF PHYCOLOGY, Issue 2000Q. Hu Frequent episodes of algal-related tastes and odors (T & O) in drinking waters in metropolitan Phoenix, Arizona prompted initiation of a three-year project in July 1999 to investigate the occurrence of T & O metabolites and to develop a comprehensive management strategy to reduce the problems in drinking water supplies in arid environments. Two metabolites, 2-methylisoborneol (MIB) and geosmin, have been identified as compounds responsible for the earthy-musty tastes and odors in water supplies. Both were detected in the water supply system, including source rivers, reservoirs, canal delivery system and water treatment plants. Higher concentrations of MIB and geosmin occurred in distribution canals than in the upstream reservoirs indicating that significant production of the T & O compounds occurs within the canal system. A baseline-monitoring program has been established for the complex water supply system, with special emphasis on the canal system. Efforts are underway to investigate possible correlations between physical/chemical parameters, algal composition and biomass, with the occurrence of MIB and geosmin. In addition, several physical and chemical treatments are planned for the canal system to reduce algal growth and related MIB and geosmin concentrations. [source] | ||||||||||