Which term describes a wastewater treatment process that involves adding chemicals to achieve desired results?

The term that describes a wastewater treatment process involving the addition of chemicals to achieve desired results is chemical treatment. This approach utilizes various chemical agents to aid in the removal of contaminants from wastewater. These chemicals can help in several ways, such as precipitation of solids, disinfection, odor control, and enhancing biological processes by managing pH and nutrient levels.

In contrast, biological treatment relies on the use of microorganisms to break down organic matter and is primarily a natural process. Physical treatment focuses on the removal of solids and other particles using physical methods such as filtration or sedimentation, without the use of chemicals. Secondary treatment generally refers to the biological processes that follow primary treatment to further reduce organic matter and is not defined by the use of chemicals. Therefore, chemical treatment is specifically characterized by its reliance on chemical means to improve water quality.