In aerobic secondary sewage treatment

In aerobic secondary sewage treatment - ,...

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In  aerobic  secondary sewage treatment, the fluid waste is aerated and then passed through a  trickling filter.  In this process, the liquid waste is sprayed over a bed of crushed rocks, tree bark, or  other filtering material. Colonies of bacteria, fungi, and protozoa grow in the bed and act as  secondary filters to remove organic materials. The microorganisms metabolize organic compounds  and convert them to carbon dioxide, sulfate, phosphates, nitrates, and other ions. The material that  comes through the filter has been 99 percent cleansed of microorganisms.  Liquid waste can also be treated in an  activated digester  after it has been vigorously aerated.  Slime-forming bacteria form masses that trap other microorganisms to remove them from the water.  Treatment for several hours reduces the microbial population significantly, and the clear fluid is  removed for purification. The sludge is placed in a landfill or at sea. 
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This note was uploaded on 11/14/2011 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.

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