In the field of sewage treatment, flocculant can be used as a means to strengthen solid-liquid separation. It can be used to strengthen primary sedimentation, flotation treatment and secondary precipitation after activated sludge process. It can also be used for tertiary treatment or advanced treatment of sewage. When used for conditioning before dewatering of excess sludge, the flocculant and coagulant become sludge conditioners or dehydrating agents.
When a conventional flocculant is applied, a coagulant can be added to enhance the flocculation effect. For example, activated silicic acid is used as a coagulant for inorganic flocculants such as ferrous sulfate or aluminum sulfate, and is added in a sequential manner to obtain a good flocculation effect. Therefore, in layman's terms, the inorganic polymer flocculant IPF is actually a combination of a coagulant and a flocculant prepared and then combined to simplify the user's operation. A wide range of flocculants include polyaluminum chloride, aluminum sulfate, alum, and polyferric chloride.
The coagulation treatment is usually placed in front of the solid-liquid separation facility, combined with the separation facility to effectively remove suspended solids and colloidal substances with a particle size of 1 nm to 100 μm in the raw water, reducing the effluent turbidity and CODCr, which can be used in the pretreatment of the sewage treatment process. Treatment, advanced treatment, can also be used for excess sludge treatment. Coagulation treatment can also effectively remove microorganisms and pathogenic bacteria in water, and can remove emulsified oil, color, heavy metal ions and other pollutants in sewage. When using coagulation and sedimentation to treat phosphorus contained in sewage, the removal rate can be as high as 90. ~95% is the cheapest and most efficient method of phosphorus removal.