Study On Prevention Of "Red Water" By Removal Of Trace Iron And Manganese In Waterworks

Water is the basis for survival. Drinking water safety directly relates to broad masses'life and health. Red water, a popular problem in urban watersupply, causes water quality deterioration and public doubt about drinking water safety. Red water for extensive areas once happened many times in Shaoxing City drinking water supply system and resulted to more complaints. Therefore it is a important research subject for water supply enterprises to reduce or destroy red water.Red water in drinking water supply and its formation mechanism were studied in the paper. Solutions to red water problem were presented and proved effective by small-scale and middle-scale experiments. Research and experiment results in the paper showed that by means of such control measures as combining preoxidation of chlorine and permanganate, enhancing online monitoring of water quality and observing transparent pipes,when residual chlorine in precipitated water were maintained at 0.08~0.20mg/L, ferro and manganese in treated water could be reduced respectively below 0.01mg/L and 0.005mg/L (the ratio up to the internal standard was above 98%), so as to achieve the aim of red water prevention. According to the actual effect , pipeline brown scaling improved greatly and complaints about red water decreased sharply after ferro and manganese in treated water came up to the internal standard.Through experimental study, red water formation mechanism has been clear and red water issue has been basically solved, which has allayed 200 million peole'anxieties and ensured the urban drinking water quality and security. The study results provide reference and experience to the Southern China using reservoirs as drinking water resources, have utility value and play a exemplary role. It will produce economic and social benefits after popularization and application of these study results.