Study on treatment of micro-polluted yangtze river raw water by pre-oxidation

In this paper, the pilot-scale pretreatment experiment of micro-polluted raw water was conducted. The results showed that pre-oxidation process could enhance the organic pollutant removal than conventional process, such as the indices of COD_Mn, UV₂₅₄, THMs and HAAs formation potential. Ozone exhibited better performance than potassium permanganate and sodium hypochlorite. According to the pilot experiments, ozone pretreatment has the higher efficiency in removing COD_Mn and UV₂₅₄. The optimal dose of ozone, potassium permanganate and sodium hypochlorite was 0.50, 0.25 and 2.0mg/L, when COD_Mn was less than 1.5mg/L. The ozone treatment dramatically reduced the amount of disinfection by-product precursors. This paper also reports the range of total efficiency of different indices in order to choose the appropriate water treatment process.