Treatment, drinking water sewage effluent

Hexachloroethane may also be released to air during combustion and incineration of chlorinated wastes, from hazardous waste sites, and in small amounts during chlorination of sewage effluent prior to discharge and chlorination of raw water during drinking water treatment (Gordon et al. 1991 Howard 1989). 

Planas C, Palacios O, Ventura F, Rivera J, Caixach J (2008) Analysis of nitrosamines in water by automated SPE and isotope dilution GC/HRMS - Occurrence in the different steps of a drinking water treatment plant, and in chlorinated samples from a reservoir and a sewage treatment plant effluent. Talanta 76 906-913... 

Dimethylformamide has been measured in ambient air near a fibre plant and near waste facilities. It has rarely been found in water samples in the United States, other than at sewage treatment plants or in effluents of plants likely to have been using dimethylformamide. Levels measured were very low (WHO, 1991). It has been detected at low levels in drinking-water, surface water, wastewater and ambient air samples (United States National Library of Medicine, 1997). 

The oestrogen ethynyloestradiol is, as we saw earlier, known to be present in sewage treatment plant effluents and could potentially appear in drinking water. It has apparently been detected in drinking water in the UK but the data have been questioned. Even if it were present, it is not known whether the concentrations would be high enough to affect human males. 

Lopez de Alda and Barcelo [14] reported the determination of natural and synthetic estrogens and progestogens in influents and effluents from a sewage treatment plant (STP), surface water, and drinking water. The estrogens were determined as [M-H] in negative-ion ESI, the progestogens as [M-i-Na] in positive-ion mode ESI or APCI. Detection limits of <1 ng/1 water have been achieved. 

The object of modem methods of sewage treatment is to convert the unstable sewage into a stable effluent suitable for discharge to the local watercourse. The object is not, as is sometimes imagined, to produce an effluent of the quality of drinking water nor, necessarily, of the water in the receiving watercourse. In this treatment an offensive sludge is produced which must also be disposed of. 

Chlorine is used to treat water other than drinking water. It is employed to disinfect effluent from sewage treatment plants, as an additive to the water in electric power plant cooling towers, and to control microorganisms in food processing. 

Tertiary treatment Ghemical and physical treatment of sewage to produce an effluent of water pure enough to drink. 

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