Onsite Chlorination of Greywater in a Vertical Flow Constructed Wetland—Significance of Trihalomethane Formation

To reduce public health hazards, greywater reuse may involve disinfection, which is often performed through chlorination. The formation of toxic disinfection by-products a negative side-effect chlorine’s reaction with organic matter, trihalomethanes (THM) are one the most dominant (though not toxic) groups. Greywater treatment in vertical flow constructed wetlands leads to decrease dissolved matter. We hypothesized that these carbon (DOC) changes would be reflected differences THM formation. samples, at different levels (i.e., decreasing matter content), were exposed 5 mg/L chlorine for 1 h. raw samples was significantly lower than more treated (recirculated) despite their higher DO concentrations. This trend verified six systems. Furthermore, this also shown when doses (25 and 50 mg/L). It suggested increase longer recirculated water result two factors: competition between number reactive sites water’s smaller yields, abundance moieties DOC. latter SUVA water. Overall, formation, following chlorination concentration studied, expected pose an environmental risk reused irrigation.