[Formation mechanism and assessment method for urban black and odorous water body: A review].

Black and odorous (BO) water body reflects very typical serious water pollution related to organic pollution, sediment re-suspension and thermal pollution. Also, the insufficiency of water cycle is one of the most important hydrodynamic factors for formatting BO water body. The blackening substances mainly include suspended particles, Fe- and S-containing substances; the odour causing substances include the small molecule gases such as H ₂ S, NH ₃ and some compounds such as VOSCs, Geosmin and 2-MBI. Evaluation methods of BO water were summarized from the evaluation index, BO index, multiple linear regression model and comprehensive evaluation method in this paper. Correspondingly, the relative research direction in the future was discussed. All these works not only defined the identifying technology for urban BO water body, but also would further support the water environment improvement and ecological recovery in urban region.