Study of Enteromorpha polysaccharides as a new-style coagulant aid in dye wastewater treatment

Enteromorpha is one of the common fouling green algae, which has brought serious environmental problems in past years. This study was aimed to apply it in water treatment process. Enteromorpha polysaccharides (Ep) were used as a new-style coagulant aid to assess its effect on coagulation behavior and floc characteristics. Color removal was used to evaluate coagulation effects and floc properties were investigated by Photometric Dispersion Analyzer (PDA). Results showed that when Ep was used in combination with aluminum chloride (AC), color removal could be apparently improved, and the optimal solution pH ranged 6.0–8.0. The growth rate and average size of flocs formed by AC–Ep were larger than those by AC in steady-state after floc growth phase, and meanwhile the distribution of floc size had a wider range. Besides, floc recoverability could be significantly improved when Ep was used as coagulant aid.