Disinfection enhancement of single ozonation by combination with peroxymonosulfate salt

Abstract

Controlling pathogens and undesired biofouling in aquaculture or shipping activities is important due to the related potential economic and public health impacts. Accordingly, the treatment of seawater has increased interest in the maritime industry. Advanced Oxidation Processes are promising techniques for the treatment of different aqueous matrices. In this context, sulfate radical-based AOPs appear to be a good alternative for seawater applications. Consequently, the goal of this study is to evaluate the disinfection efficacy of combining the peroxymonosulfate salt ([PMS] = 1 and 5 mg L−1) with an ozonation treatment. Different inactivation processes (O3, PMS, and O3/PMS) have been investigated with Vibrio alginolyticus as a target microorganism. In comparison with single ozonation, kinetic rates have been accelerated by 65 % and 123 % with the addition of 1 and 5 mg L−1 of PMS, respectively. It results in a synergistic effect for the O3/PMS combination. The transferred ozone dose is also notably reduced for reaching the 4 Log-removal value (O3: 1.53 mg O3 ·L−1; O3/PMS: 0.87 mg O3 ·L−1 (1 mg PMS·L−1), and 0.59 mg O3 ·L−1 (5 mg PMS·L−1)). O3/PMS treatment also presents a greater residual effect and higher acute toxicity of the treated effluent. Results obtained suggest the peroxymonosulfate as a good promoter of disinfection in the presence of O3, not only by increasing the inactivation rate but also in minimizing bacterial regrowth, which implies greater cell damage during treatment processes. Thus, the O3/HSO5- process deserves further research as an alternative to traditional techniques for water treatment.