Effect of pH adjustment and chlorination on water and effluent characteristics to prevent emitter obstruction

The aim of this study was to determine the concentration of free residual chlorine in the effluent at different concentrations of chlorine injection، between 50 to 350 ppm، at the pH levels of 6، 6. 5 and 7 and the effect of chlorination on pH، electrical conductivity and the concentration of total dissolved solids in drinking water and effluent. The results showed that the concentration of free residual chlorine changes by changing the concentration of added chlorine in the effluent samples. To achieve the concentration of free residual chlorine to more than 1 ppm at drinking water، effluent samples at pH levels of 6 and 6. 5 and effluent at pH of 7، 1، 150 and 200 ppm of chlorine was used. By reduction of effluent pH from 7 to 6-6. 5 the amount of added chlorine to achieve free residual chlorine concentration at 1 ppm، decreases in 25 percent. Adding chlorine in liquid sodium hypochlorite form to drinking water and effluent samples at all pH levels، increased electrical conductivity، the concentration of total dissolved solids and pH. The use of liquid sodium hypochlorite for chlorination of drip irrigation systems reduces the risk of biological obstruction but increased concentrations of dissolved solids، salinity and pH of irrigation water that increases the risk of chemical obstruction of emitters.