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Effluent
About: Effluent is a research topic. Over the lifetime, 32668 publications have been published within this topic receiving 533991 citations.
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TL;DR: The results indicated that the ozonation of WWTP effluent is a promising technology to further decrease emissions of micropollutants from the treatment process.
126 citations
TL;DR: The proposed emerging technology was shown to be an alternative technology to establish new wastewater treatment systems and upgrade or retrofit conventional systems from secondary-level to tertiary-level.
126 citations
TL;DR: In this paper, a survey was conducted by the U.S. Office of Surface Mining, Reclamation, and Enforcement to assess the status of man-made wetland treatment of acid mine drainage (AMD), which is characterized by low pH and high concentrations of dissolved sulfate, iron, and other metals.
Abstract: The oxidation of pyritic minerals, exposed to oxygen and water during the mining of coal, results in the formation of acid mine drainage (AMD), which is characterized by low pH and high concentrations of dissolved sulfate, iron, and other metals. Federal and State regulations require that discharges from coal surface mines meet water quality criteria. Toward that end, chemical treatment of AMD, usually with soda ash briquettes, lime, limestone, or sodium hydroxide, is effective but expensive. Recently, man-made wetlands have been proposed as a low-cost, low-maintenance alternative to chemical treatment of AMD. To assess the status of man-made wetland treatment of AMD in the eastern U.S., a survey was conducted by the U.S. Office of Surface Mining, Reclamation, and Enforcement. As of May 1988, 142 wetlands had been constructed for AMD treatment. In 50% of the constructed wetlands, treatment efficiencies (reductions in concentration) for H+, acidity, Fe, Al, Mn, and SO4
2 of at least 68, 67, 81, 48, 34, and 8%, respectively, were obtained. However, over 11% of the constructed wetlands yielded greater concentrations in the effluent from the wetland than were present in the influent AMD for one or more of these 6 chemical parameters. Treatment efficiency generally was not correlated with design criteria (e.g., area of wetland, depth of the organic substrate in the wetland, AMD flow rate, metal loading rates). Also, treatment efficiency was generally not affected by either the type of organic substrate used in wetland construction or the addition of lime and/or fertilizer to the constructed wetland. The effectiveness of wetland treatment of AMD is not only extremely variable, but also presently not predictable.
126 citations
TL;DR: It is suggested that reclaimed water may be an important reservoir of antibiotic resistance genes (ARGs), especially at the POU, and that attention should be directed toward the fate of ARGs in irrigation water and the implications for human health.
Abstract: Treated wastewater is increasingly being reused to achieve sustainable water management in arid regions. The objective of this study was to quantify the distribution of antibiotic resistance genes (ARGs) in recycled water, particularly after it has passed through the distribution system, and to consider point-of-use implications for soil irrigation. Three separate reclaimed wastewater distribution systems in the western U.S. were examined. Quantitative polymerase chain reaction (qPCR) was used to quantify ARGs corresponding to resistance to sulfonamides (sul1, sul2), macrolides (ermF), tetracycline (tet(A), tet(O)), glycopeptides (vanA), and methicillin (mecA), in addition to genes present in waterborne pathogens Legionella pneumophila (Lmip), Escherichia coli (gadAB), and Pseudomonas aeruginosa (ecfx, gyrB). In a parallel lab study, the effect of irrigating an agricultural soil with secondary, chlorinated, or dechlorinated wastewater effluent was examined in batch microcosms. A broader range of ARGs were detected after the reclaimed water passed through the distribution systems, highlighting the importance of considering bacterial re-growth and the overall water quality at the point of use. Screening for pathogens with qPCR indicated presence of Lmip and gadAB genes, but not ecfx or gyrB. In the lab study, chlorination was observed to reduce 16S rRNA and sul2 gene copies in the wastewater effluent, while dechlorination had no apparent effect. ARGs levels did not change with time in soil slurries incubated after a single irrigation event with any of the effluents. However, when irrigated repeatedly with secondary wastewater effluent (not chlorinated or dechlorinated), elevated levels of sul1 and sul2 were observed. This study suggests that reclaimed water may be an important reservoir of ARGs, especially at the point of use, and that attention should be directed towards the fate of ARGs in irrigation water and the implications for human health.
126 citations
TL;DR: In this article, Watershed watersheds to residential development with on-site sewage disposal represent a potential change in both the quantity and quality of nutrient inputs to coastal marine systems, with initial concentrations 100-1000-fold greater than receiving coastal waters, with inorganic N/P ratios (17/1) similar to phytoplankton growth requirements.
Abstract: Changes of land use in coastal watersheds to residential development with on-site sewage disposal represent a potential change in both the quantity and quality of nutrient inputs to coastal marine systems. Measurements of dissolved N and phosphate P in septic system effluent indicated initial concentrations 100-1000-fold greater than receiving coastal waters, with inorganic N/P ratios (17/1) similar to phytoplankton growth requirements
126 citations