Quality of harvested rainwater In Gansu and disinfection alternatives

摘要

An economical and optimal construction of rainwater storage cistern in the Loess Plateau of Gansu is introduced. The collection alternatives of rainwater showed a dramatic difference on cistern water quality. Roof-yard catchment systems can harvest drinking water that generally meets the international guidelines. Among the tested disinfectants - chlorine dioxide, potassium permanganate, chloramines and hydrogen peroxide, a particular study was paid to chlorine dioxide that proved to be the most feasible and effective oxidant for drinking disinfection of rainwater due to its high efficiency and simple way of utilization. A series of experiments in laboratory indicated that chlorine dioxide could significantly decompose organic contaminants and control bacteria growth. Disinfection efficiency of chlorine dioxide, especially for removing petroleum compounds, was affected by adding method, and pH value of rainwater.