Disinfection secondary sewage effluents

In the United States and Canada even biologically pretreated municipal waste waters (secondary sewage effluents) are usually UV disinfected by passing through huge irradiation channels before they are drained into the surface water and released into natural cycles. It has been shown that UV irradiation is a power-... 

In addition to these chemical pollutants, secondary sewage effluent often contains a number of pathogens (disease-causing micro-organisms), requiring disinfection. Among the bacteria that may be found in the secondary waste water effluent are... 

The most common use of chlorine in sewage treatment is for disinfection, which usually is the last treatment step in a secondary biological wastewater treatment plant. Where the treated secondary effluent is fed into a stream to be used for water supply or for recreational purposes, chlorination is effective in destroying the disease-producing pathogens found in treated wastewater. Other principal uses of chlorine are odor control and control of bulking in activated sludge. 

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