Total solids in wastewater consist of suspended solids and which other type of solids?

Total solids in wastewater are composed of two main categories: suspended solids and dissolved solids. Suspended solids are particles that are not settled and can remain in suspension in the water, whereas dissolved solids are those that have dissolved in the water and are not visible as separate particles.

When we refer to total solids in the context of analyzing wastewater, we are often looking at the sum of both these components. Dissolved solids are an important factor because they include a variety of substances, including salts and organic matter, that affect the overall quality and treatment of wastewater. Understanding the proportion of dissolved solids helps in assessing the treatment needed and the environmental impact of the wastewater once it's discharged.

The other terms mentioned—volatile solids, insoluble solids, and fixed solids—pertain to specific characteristics or states of solids but do not encompass the complete definition of total solids, which is specifically the sum of suspended and dissolved solids in the water.