Class 12th Biology 2017 Set2 Delhi Board Paper Solution
Question 20
Describe how do ‘flocs’ and ‘activated sludge’ help in sewage treatment.
Answer
Flocks are masses of bacteria associated with fungal filaments to form mesh like structure. It helps in aerobic decomposition as well as filament help in traping particles.
Activiated sludges is used as inoculum to produce flocks during secondary treatment. Process for treating sewage and in industrial waste water using air and a biolgical floc composed of bacteria and protozoa.
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