Wastewater treatment generates a large quantity of sludge, which can be treated by which of the following?

 In anaerobic digesters.

The correct answer is: In anaerobic digesters.

Wastewater treatment generates a large quantity of sludge, which can be treated in anaerobic digesters. Anaerobic digestion is a biological process that occurs in the absence of oxygen. In the anaerobic digester, the sludge is decomposed by microorganisms in a controlled environment, leading to the production of biogas (mainly methane and carbon dioxide) and a stabilized form of sludge called biosolids.

This process helps reduce the volume of sludge, destroy pathogens, and produce biogas, which can be used as an energy source. The biosolids produced after anaerobic digestion can be further treated and utilized as fertilizer or disposed of in an environmentally friendly manner.

While chemicals, primary treatment, and the use of flocs (aggregates of particles suspended in wastewater) are all important components of wastewater treatment processes, they are not specifically targeted for treating sludge generated in the wastewater treatment process. Chemicals are often used for coagulation and flocculation in primary treatment and floc formation, but they do not specifically address sludge treatment. Primary treatment focuses on the removal of large solid materials and the settling of suspended particles, while the use of flocs aids in the aggregation and settling of fine particles in secondary treatment processes.