Influence of algal organic matter of Microcystis aeruginosa on ferrate decay and MS2 bacteriophage inactivation

Surface water contaminated with algae and with enteric viruses is a global problem. When surface water is used as a drinking water source, it is important to know the influence of algal organic matter on the disinfection of viruses. In this work, we studied the disinfection efficacy of ferrate and the influence of algal organic matter on the disinfection. We determined the MS2 inactivation kinetics by ferrate under three pH conditions (7, 8, and 8.7). The experimental results and pH-dependent calculation suggest that H 2 FeO 4 and HFeO 4 − are 1935 and 8 times as effective as FeO 4 2− in MS2 inactivation. We also found that intracellular algal organic matter (IAOM) had a stronger effect on MS2 inactivation kinetics than extracellular algal organic matter (EAOM) suggesting that IAOM led to higher consumption of Fe(VI) compared to EAOM. At pH 8.7, while significant consumption of FeO 4 2− by as low as 8 mg C/L of EAOM and 2 mg C/L of IAOM was detected, MS2 inactivation was negatively influenced only when 13 mg C/L of IAOM present. This study showed that it is important to control pH and to determine the concentration of algal organic matter if ferrate is used for disinfection of surface water contaminated with algae.