Maintenance of Wastewater UV Systems – Ensuring Compliance

Over the past thirty years, ultraviolet (UV) technology has become a commonly applied method of disinfecting wastewater effluent. UV disinfection involves passing wastewater effluent through a confined chamber with rows of underwater lamps emitting UV energy. Viruses and bacteria become inactivated upon exposure to dosages of UV light, thereby disinfecting the wastewater.The UV system is defined by the physical (electrical and mechanical) requirements of the equipment. These requirements must be matched with the water quality of the wastewater plant to provide effective disinfection. For the purpose of trouble-shooting UV equipment, the UV system can be divided into three components: process, electrical, and mechanical. The process system deals with the quality of the water to be treated by the UV system and the disinfection goals that must to be attained. The electrical system consists of the lamps, wiring, and control system. The mechanical system includes the quartz sleeves, frames, cleaning mechanism, and reactor configuration.When the UV system functions as intended, it is easy for operations staff to maintain compliance with the treatment facility's NPDES permit requirements. A survey was conducted of existing wastewater UV facilities to determine the key operational practices that treatment plant operators deemed critical. In addition, a review of recent literature was conducted to assess the most recent published information on operating UV systems.