Zoology - Microbes in Human Welfare Question with Solution | TestHub

Secondary treatment of effluent is a biological process where the primary effluent is passed into large aeration tanks and allowed for the vigorous growth of useful aerobic microbes like bacteria and fungi to form flocs (mesh-like structure). A constant mechanical agitation with the pumping of air enables the growth of microbes. It consumes the major part of the organic matter and significantly reduces the BOD (biochemical oxygen demand) of the effluent.