APPLICATION OF CHLORAMINES FOR REUSE WATER DISINFECTION AT THE CITY OF LAS VEGAS WATER POLLUTION CONTROL FACILITY

This study evaluates the application of chloramines to disinfect the reuse effluent produced by the City of Las Vegas Water Pollution Control Facility (WPCF) to irrigate golf courses. Although the current chlorination process consistently meets the total coliform standard, it results in high costs associated with chemical consumption. Laboratory and field tests were performed using filtered effluent from the WPCF. Tests included chlorine demand determination, chloramination tests, and disinfection tests. The chlorine demand of the treated wastewater was found to be 3.0 mg/L. Best monochloramine formation was accomplished when a 3.5:1 chlorine-to-ammonia ratio was applied. A 4:1 chlorine-to-ammonia ratio (ammonia dosage of 1.0 mg/L) resulted in 100% removal of total coliform. A cost estimate indicated that the chloramination process would result in a 48% reduction in the current chemical cost.