A comparative evaluation of potassium permanganate and chlorine dioxide for preoxidation at the Sioux Falls Water Purification Plant.

摘要

Chlorine dioxide (ClO₂) was compared with potassium permanganate (KMnO₄) to determine which may be the better chemical for pretreatment of the Sioux Falls surface water source. Factors evaluated included impacts on taste and odor, removal of total organic carbon, coagulation, flocculation, sedimentation, oxidant demand, and THM production. The ClO₂ decay and chlorite production kinetics were investigated, as was the removal of chlorite using ferrous iron.; Impacts of each chemical were determined using bench-scale experiments, such as jar tests and simulated distribution system tests. Tests were repeated during three seasons to simulate several possible river conditions.; The degradation of ClO₂ was a rapid reaction that depended on water temperature. KMnO₄ appeared to be the better preoxidant for taste and odor control. KMnO₄ appeared to enhance flocculation, sedimentation, and filtration, but ClO₂ appeared to have a minor effect on these processes. Reactions using ferrous iron were able to reduce chlorite to chloride.