In the biological water treatment process, microorganisms such as bacteria are used to biochemically decompose the wastewater and stabilize the end product. Biological water treatment method is divided into two sub-divisions, aerobic and anaerobic. In the aerobic process, bacteria consumes the organic matter and helps convert it to carbon dioxide in the presence of oxygen, while in the anaerobic process, sludge is fermented at a particular temperature in the absence of oxygen. Composting is yet another aerobic process, wherein the sludge is mixed with carbon sources such as sawdust to treat wastewater.