Question

Why is aerobic degradation more important than anaerobic degradation for the treatment of large volumes of waste waters rich in organic matter. Discuss.

Answer 1

Organic matter in wastewater consumes a lot of oxygen to carry on various biological processes. It results in reduction of oxygen level. In the surrounding air and thus can Increase air pollution. Consumption of oxygen by organic matter in wastewater is measured by BOD (Biochemical Oxygen Demand). A higher level of BOD indicates a higher polluting potential of wastewater. It is important to reduce the BOD so that pollution can be reduced. Hence, aerobic degradation is more important than anaerobic degradation for the treatment of large volumes of wastewaters rich in organic matter. BOD level is reduced by aerobic degradation which is carried out by floc. Flocs are associations of bacteria and fungi which form mesh-like structures. Flocs eat away most of the organic matter in wastewater and thus help in reducing BOD. Once BOD Is pulled down below a threshold level the sludge is ready for anaerobic degradation.