What percentage of solids is typically removed during primary wastewater treatment?

In primary wastewater treatment, the goal is to remove a significant portion of suspended solids and some organic matter before the wastewater proceeds to secondary treatment processes. Typically, this initial stage of treatment can effectively remove about 50% to 60% of the total suspended solids present in the wastewater.

The process involves the physical methods of sedimentation, where solids settle to the bottom of a settling tank, along with screening to eliminate larger debris. The percentage of solid material removed during this phase can vary depending on the design and operational effectiveness of the treatment facility, the characteristics of the wastewater being treated, and the specific technologies employed.

Given this context, a removal percentage of 60% aligns well with the expected performance of many primary treatment systems, as they are designed specifically to address and reduce the bulk of solids before further treatment steps, making the selection of 60% a valid representation of what is typically achieved during primary treatment.