In order to make the sewage discharged up to standard or reused after treatment, a variety of chemicals need to be used in the treatment process. According to different uses, these agents can be divided into the following categories:
1. Flocculant: sometimes called coagulant, can be used as a means to strengthen solid-liquid separation, and can be used in the process links such as primary sedimentation tank, secondary sedimentation tank, flotation tank, tertiary treatment or advanced treatment.
2. coagulants: auxiliary flocculants play a role in enhancing the coagulation effect.
3. Conditioner: also known as dehydrator, is used for conditioning excess sludge before dehydration. Its varieties include some of the flocculants and coagulants mentioned above.
4. Demulsifier: sometimes called destabilizer, mainly used for pretreatment of oily sewage containing emulsified oil before air flotation. Its varieties include some of the flocculants and coagulants mentioned above.
5. Defoaming agent: mainly used to eliminate a large amount of foam during aeration or stirring.
6. pH adjustor: used to adjust the pH value of acidic sewage and alkaline sewage to neutral.
7. Disinfectant: used for disinfection after sewage treatment or before reuse.
