Which two methods are commonly used for wastewater treatment?

Biological treatment and physical-chemical treatment are widely recognized as effective methods for wastewater treatment, each playing a crucial role in removing contaminants from wastewater.

Biological treatment utilizes microorganisms to decompose organic matter present in the wastewater. Techniques such as activated sludge processes, trickling filters, and biofilms are common in this category. These methods rely on the natural processes of bacteria and other microorganisms to break down pollutants, leading to a reduction in biochemical oxygen demand (BOD) and suspended solids.

Physical-chemical treatment involves processes that use chemical reactions or physical means to remove contaminants. This can include coagulation, flocculation, sedimentation, and filtration. These processes help in removing solids and dissolved substances, making them integral to the treatment process. Chemical treatments might also involve disinfection methods, such as chlorination or ozone treatment, which is crucial for ensuring the safety of the treated water before it is released back into the environment or reused.

Together, these two methods address both the biological and chemical aspects of wastewater treatment, making them fundamental in the overall treatment process. The combination of biological and physical-chemical methods enables comprehensive treatment, ensuring that the water meets regulatory standards for discharge or reuse.