Screening, grit removal, comminution, and flow equalization are all part of what process?

Preliminary treatment is the initial phase in wastewater treatment and is designed to prepare the wastewater for the subsequent treatment processes. It includes several critical steps that help to remove large solids and debris that could damage or interfere with the operations of treatment systems.

Screening is utilized to remove large objects like sticks, leaves, and plastics that can clog pumps and other equipment. Grit removal is aimed at separating heavier inorganic materials, such as sand and gravel, that can settle out of the wastewater to prevent wear and tear on treatment facilities. Comminution involves shredding or grinding the solids to ensure that they are small enough for further processing, and flow equalization helps to maintain a consistent flow rate into the treatment plant, which aids in improving the efficiency of the treatment processes that follow.

In contrast, primary treatment focuses on settling out suspended solids and removing dissolved organic material, while secondary treatment involves biological processes designed to remove biodegradable materials. Tertiary treatment, often referred to as advanced treatment, is aimed at further improving the clarity and quality of the treated water, usually to meet specific discharge standards. Thus, the activities mentioned in the question are foundational steps that constitute preliminary treatment, preparing the wastewater for more advanced treatment stages.