Which of the following is a primary byproduct of the biodegradation process in wastewater treatment?

The primary byproduct of the biodegradation process in wastewater treatment is gases. During the treatment process, microorganisms break down organic matter in the wastewater. This microbial activity leads to the production of various gases, including carbon dioxide and methane, as organic materials decompose. This gas generation is an expected and essential part of the biological treatment process, as it reflects the activity of the microbial community breaking down waste components and transforming them into simpler substances.

Non-toxic sludge, while an important byproduct of the treatment process, is not the primary gas emitted during degradation. Rather, it is the solid mass that results from the accumulation of microorganisms and the residual material after the treatment process has occurred. Chlorinated compounds and heavy metals are not byproducts of biodegradation but rather contaminants that may be present in wastewater, and their removal often requires different treatment approaches. Thus, the generation of gases is a fundamental aspect of the biodegradation process in wastewater treatment.