Effects of bleaching wastewater irrigation on soil quality of constructed reed wetlands

摘要

Constructed reed wetland microcosms (CRWs) in a lab of east China have been irrigated with bleaching wastewater per month for a reed growth season. The soil physicochemical properties, enzyme activities (i.e. urease, invertase, polyphenol oxidase, alkaline phosphatase and cellulase) and soil microbial diversity were assayed before and after the exposure experiment. Compared to the river water irrigated controls (CKs), bleaching wastewater application has no marked influence on soil pH, but significantly increased soil Na~(+), total halogen and absorbable organic halogen (AOX) contents, which induced the increasing of soil electrical conductivity. Furthermore, soil enzyme activities displayed significant variation (except for polyphenol oxidase). Bleaching wastewater irrigation decreased Sorenson’s pairwise similarity coefficient (C _(s)), which indicated the changes of the structure of bacterial and fungal communities. However, only the diversity of bacterial community was inhibited and has no effect on the diversity of fungal community, as evidenced by the calculated Shannon–Wiener index (H ).