Synergistic effect of potassium ferrate and hydroxylamine for in-situ coagulation toward algae-laden water treatment.

The release of intracellular organic matter during algal bloom period poses significant challenges to drinking water treatment process. This study introduces a novel strategy integrating ferrate (Fe(VI)) pre-oxidation with hydroxylamine hydrochloride (NH2OH·HCl) in-situ coagulation to achieve efficient algal removal while minimizing cellular damage. At optimal dosages of 25 mg/L Fe(VI) and 27.5 mg/L NH2OH·HCl, the removal efficiencies of algal biomass and dissolved organic matter reached 93.6 % and 59 %, respectively. Characterization analysis indicated that the synergistic effect of Fe(VI) and NH2OH·HCl significantly increased the zeta potential of Microcystis aeruginosa, enhancing the agglomerative tendency of the algal cells, and thus achieving in-situ coagulation through the generated Fe(OH)3 colloids. This strategy offers an efficient, eco-friendly, and easy-operated one-step solution for algae-laden water treatment.