Water Supply (Mar 2022)
Effects of hydrogen peroxide preoxidation on clarification and reduction of the microbial load of groundwater and surface water sources for household treatment
Abstract
Household water treatment (HWT) technologies are a promising strategy for addressing the waterborne diseases burden. However, in order to be efficient, these are often limited to water quality and require it to not exceed a certain threshold of physicochemical and microbiological contamination. Additionally, some popular HWTs, such as chlorination, are related to by-product formation. Preoxidation may improve source water quality, and hydrogen peroxide (H2O2) is an oxidant that has not been deeply explored in this specific application, so it could be an innovative approach to HWTs. We investigated effects of H2O2 preoxidation in two natural source waters (surface and groundwater), spiked with a high level of microorganisms. Clarification results suggested this pretreatment may improve life of HWTs. Reduction in microbial load of groundwater was considered ineffective, but 5-min H2O2 preoxidation at 15 mg L−1 led to >4.0 log10 inactivation of Phi X174 coliphage and >3.0 of Escherichia coli in surface water. We believe this performance was increased due to the presence of catalysts in the river water. This raised the point that water quality may be not only impairing, but potentially beneficial to the main HWT and characterization is crucial prior to the implementation of any technologies. HIGHLIGHTS H2O2 preoxidation reduces virus and E. coli contamination levels in surface water.; 5-min oxidation with H2O2 led to >3.0 log10 inactivation of E. coli from surface water.; H2O2 preoxidation may improve microbiological quality of surface water prior to other treatments.; H2O2 preoxidation of groundwater for reducing microbiological load is not encouraged at the tested doses.; Natural catalysts from surface water may have enhanced H2O2 preoxidation performance.;
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