Sewage effluents treatment

A notable example of controlled water reuse was utilization of secondary sewage effluent from the Back River Wastewater Treatment Plant in Baltimore by the Sparrows Point Works of Bethlehem Steel (6). The Sparrows Point plant was suppHed primarily by weUs located near the brackish waters of Baltimore harbor. Increased draft on the weUs had led to saltwater intmsion. Water with chloride concentration as high as 10 mg/L is unsuitable for many steelmaking operations. Rollers, for example, are pitted by such waters. However, treated effluent from the Back River Plant can be used for some operations, such as coke quenching, and >4 x 10 m /d (10 gal/d) are piped 13 km to Sparrows Point. This arrangement has proved economical to both parties for >40 yr. 

Fluidized-bed powdered activated carbon systems represent another important process. The use of activated carbon for the tertiary treatment of secondary sewage effluents has been used extensively. Powdered carbon is as effective as granular activated carbon for removing the organic impurities from the wastewater. 

Before powdered carbon can be used commercially or reused for tertiary treatment of sewage effluents, a method of regeneration is required. The use of the fluidized bed for regeneration offers the key advantages of excellent temperature and atmosphere control and the ability to process the powdered solids conveniently and continuously. 

As a result of several studies, the following conclusions regarding viruses in sewage warrant consideration (1) primary sewage treatment has little effect on enteric viruses (2) secondary treatment with trickling filters removes only about 40 percent of the enteroviruses (3) secondary treatment by activated sludge treatment effectively removes 90 percent to 98 percent of the viruses and (4) chlorination of treated sewage effluents may reduce, but may not eliminate, the number of viruses present. 

Besides the disinfeetion of sewage effluent, ozone is used for sterilizing industrial containers sueh as plastic bottles, where heat treatment is inappropriate. Breweries... 

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). 

For a detailed discussion the reader is referred to a number of recent monographs [9,10,23] and review articles [50,226-231]. The role of electrochemistry in waste water and effluent treatment is still queried, as remarked by Pletcher and Walsh [10]. One answer would be, relatively small since there are many competitive methods which are cheaper on a large scale and use less energy. Principle types of processes used in local-authority sewage works are listed in Table 14. 

Martins da Costa P, Vaz-Pires P, Bernardo F (2006) Antimicrobial resistance in Enterococcus spp. isolated in inflow, effluent and sludge from municipal sewage water treatment plants. Water Res 40(8) 1735-1740... 

Was this your answer Primary treatment uses settling basins to remove the bulk of solid waste and sludge from sewage effluent. Secondary treatment uses aeration to decrease effluent BOD.Tertiary treatment removes pathogens and wastes not removed by eariieT treatments by filtering effluent through powdered carbon or other fine particles. 

Hillman, P. J. (1988). Health aspects of reuse of treated wastewater for irrigation. In Treatment and Use of Sewage Effluent for Irrigation. (M. B. Pescod and A. Arar, eds.). Butterworths, Sevenoaks, Kent. 

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