Which of the following describes the function of microorganisms in wastewater treatment?

Microorganisms play a crucial role in the wastewater treatment process, primarily through their ability to break down organic matter. This function is essential because wastewater often contains a variety of organic materials, including human waste, food residues, and other biodegradable substances. Microorganisms such as bacteria, fungi, and protozoa utilize these organic materials as a food source, converting them into simpler compounds through various metabolic processes. This breakdown results in reduced levels of organic pollutants in the water, which is a key objective of wastewater treatment.

The process of microbial digestion not only helps to cleanse the water but also helps in reducing the amount of sludge produced, which must then be treated or disposed of in a manner that minimizes environmental impact. Through this natural process, microorganisms contribute significantly to improving water quality, making their role in wastewater treatment indispensable. Other choices, while they may describe different aspects of water treatment, do not accurately capture the primary function of microorganisms in this context.