BIOLOGICAL TREATMENT IS ALSO CALLED AS ___________ TREATMENT IN WASTE WATER CONTROL METHODS.Question 17Answera.preliminaryb.secondaryc.tertiaryd.sludge

The answer to the question is b. secondary.

Explanation

In wastewater treatment processes, biological treatment specifically refers to the secondary treatment phase. This stage is crucial as it utilizes microorganisms to break down organic matter present in wastewater. During secondary treatment, various methods such as activated sludge processes or biofilm reactors are employed to enhance the degradation of pollutants.

Preliminary treatment involves the physical removal of large solids and grit, while tertiary treatment focuses on further purification and the removal of remaining contaminants after secondary treatment. Sludge refers to the byproduct of both primary and secondary treatments where the organic material is collected and processed. Thus, "secondary treatment" is the most accurate term for biological treatment in the context of wastewater control methods.