Wastewater must be properly treated before discharge or reuse. A variety of chemical agents are applied in wastewater treatment to bring water quality up to compliance standards. Below is a brief overview of commonly used wastewater treatment chemicals, classified by their functions:

1.Flocculants (also known as coagulants)

These serve to enhance solid liquid separation. They are widely used in sedimentation tanks, flotation tanks, tertiary treatment and advanced treatment processes.

2.Coagulant aids

They work to boost the performance of flocculants.

3.Conditioning agents (dewatering agents)

They condition excess sludge prior to dewatering. Some flocculants and coagulant aids mentioned above also fall into this category.

They are used for pre treatment before air flotation of oily wastewater containing emulsified oil.

4.Defoamers

They eliminate excessive foam generated during aeration or stirring processes.

5.pH adjusters

They neutralize acidic and alkaline wastewater to reach a neutral pH range.

6.Oxidizing and reducing agents

They treat industrial wastewater containing oxidizable or reducible substances.

7.Disinfectants

These are used for disinfection before wastewater discharge or reuse. Based on disinfection efficacy, they can be categorized into sterilants, high level, intermediate level and low level disinfectants. Sterilants can eliminate microorganisms to achieve sterilization effects, including formaldehyde, peracetic acid, chlorine dioxide, chlorine gas, copper sulfate, hydrogen peroxide, quicklime and ethanol.

After wastewater treatment, rea-time monitoring of various water quality indicators is required. Water Quality Analyzers can be adopted to test relevant parameters and verify whether the treated effluent meets applicable standards.