Study on Flocculation Performance of New Cationic Starch‐Based Sludge Wastewater Flocculant

Abstract From the perspective of ecological environment and human health, efficient and easily biodegradable starch‐based flocculants for replacing the currently used polyacrylamide (PAM) and cationic PAM (CPAM) flocculants are the future development trend. In this paper, starch graft polymerization of acrylamide‐allyl trimethyl ammonium chloride (St‐g‐ATMAC) is prepared by grafting and copolymerizing acrylamide and the short‐chain quaternary ammonium cationic monomer ATMAC onto the molecular chain of soluble starch. Compared with PAM and CPAM, this flocculant has a lower water content in the filter cake after treating wastewater, making the subsequent treatment easier. Moreover, the flocculant is resistant to high temperature. Specifically, at 40 °C, the filter cake moisture content (FCMC) is still lower than those of PAM and CPAM. Furthermore, the flocculant is resistant to acid and alkali. In the over‐acidic and over‐alkaline environment after treatment, the FCMC remains lower than that of the PAM‐ and CPAM‐treated mud cake. In summary, St‐g‐ATMAC is a new type of water treatment flocculant that can effectively treat wastewater with low dosage, wide temperature, and pH range and has the potential to be widely used in water treatment.