Specifications water/sewage

Another standard test, which is much simpler and more convenient, is the membrane filter technique. A suitable volume of sample is filtered through a sterile, 0.45-p.m membrane filter. The filter is placed in a petri dish containing a specific growth medium (M-Endo nutrient broth, M-Endo medium) and incubated for 24 h at 35°C. If after this time the colonies show the characteristic green sheen, this is taken as positive evidence for the presence of the coliform group (see Water, sewage). 

The Clean Water Act also establishes a framework whereby states and Indian tribes survey their waters, determine an appropriate use (such as recreation or water supply), then set specific water quality criteria for various pollutants to protect those uses. These criteria, together with the national industry standards, are the basis for permits that limit the amount of pollution that can be discharged to a water body. Under the National Pollutant Discharge Elimination System, sewage treatment plants and industries that discharge wastewater are required to obtain permits and to meet the specified limits in those permits. 

Membrane-retained components are collectively called concentrate or retentate. Materials permeating the membrane are called filtrate, ultrafiltrate, or permeate. It is the objective of ultrafiltration to recover or concentrate particular species in the retentate (eg, latex concentration, pigment recovery, protein recovery from cheese and casein wheys, and concentration of proteins for biopharmaceuticals) or to produce a purified permeate (eg, sewage treatment, production of sterile water or antibiotics, etc). Diafiltration is a specific ultrafiltration process in which the retentate is further purified or the permeable sohds are extracted further by the addition of water or, in the case of proteins, buffer to the retentate. 

Abwasser, n. waste water, waste liquor specif., sewage. anlage, /. sewage disposal plant, leitung, /. drain. 

Effluent containing methyl parathion may not be discharged into lakes, streams, ponds, estuaries, oceans, or public waters unless the compound is specifically identified in a National Pollutant Discharge Elimination System (NPDES) permit. Moreover, discharge of effluent that contains methyl parathion is forbidden without prior notice to the sewage treatment plant authority (NPIRS 1986). 

J. Porter, C. Edwards, J. A. W. Morgan, and R. W. Pickup, Rapid, automated separation of specific bacteria from lake water and sewage by flow cytometry and cell sorting, Appl. Environ. Microbiol. 59 3327 (1993). 

AS Treatability and Environmental Concentrations. Studies of AS degradation in the environment or during actual sewage treatment have been limited because specific analytical methods to measure AS were not available until recently. We developed a method that isolated AS from water samples on a strong anion-exchange column. The AS were then hydrolyzed to a fatty acid and analyzed by gas chromatography with flame-ionization detection (GC-FID). The method has a detection limit of 5 xg/L per component (50). 

AES are typically measured in environmental matrices by nonspecific colorimetric analyses (MBAS) that collectively measure LAS, AS, and naturally occurring anionic surfactants. Alternatively, a specific gas chromatographic method for AES, developed by Neubecker (55), was employed to measure AES concentrations in influent and effluent from STPs and river water. Total AES measured in influent wastewater to a STP was 1.88 mg/L. AES removal of 94-100% was measured during actual sewage treatment by activated sludge the resulting effluent concentration was 0.06 mg/L. Total AES levels in river water were less than 0.01 mg/L. AES accounted for 6-13% of MBAS measured in natural water. 

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