Classification and properties of flocculants

According to their sources and properties, flocculants currently used can be divided into three categories: inorganic flocculants, synthetic organic polymer flocculants and natural biopolymer flocculants. Inorganic flocculants are mainly iron salts and aluminum salts, which consume a lot in the process of use, are corrosive and toxic, and will have adverse effects on human health and ecological environment; Synthetic polymer flocculants, such as poly (phthalamide) and polyacrylic acid, have the advantages of low dosage and fast flocculation speed, but the residual monomers of such polymers have the effects of teratogenesis, carcinogenesis and mutation, and their application scope is limited; In contrast, natural biopolymer flocculants, such as chitosan, starch derivatives, gelatin and so on. , is extracted from natural substances, a little chemical modification. These flocculants are non-toxic or low-toxic, and have no secondary pollution, but their flocculation activity is low, and the purification effect of flocculation alone is not ideal. Now a new type of microbial flocculant is proposed.