When it comes to wastewater disinfection, two common methods are widely used today: chemical and physical. Chemical disinfection is typically achieved by chlorine gas or hypochlorite whereas physical disinfection is by UV light. An increased awareness of the disadvantages of chemical disinfectants, specifically chlorine, continues to prompt wastewater treatment plants to convert to UV.
Take the City of Hot Springs, Arkansas for example. Officials there decided to convert the disinfection at its regional wastewater treatment plant from chlorine to UV. This was done in an effort to eliminate the safety issues associated with chlorine, and to also protect and improve receiving waters.
The UV system that the city selected was our TrojanUVSigna™. The TrojanUVSigna is designed to fit into existing chlorine contact chambers without major modifications to the channel depth or width. It also incorporates innovations, including TrojanUV Solo Lamp™ Technology, to reduce the total cost of ownership and drastically simplify operation and maintenance.
UV is Effective, Safe & Environmentally Friendly
With chemical disinfection, the effluent is exposed to chlorine gas (or liquid chlorine) in large tanks to ensure sufficient contact time to kill microorganisms. However, in some jurisdictions regulations place stringent limits on chlorine levels in the final effluent to minimize disinfection by-products being discharged into receiving water. In those cases, an additional chemical process called dechlorination is required to remove residual chlorine, ultimately adding more complexity and cost to the disinfection process.
Alternatively, UV provides an effective, safe and environmentally friendly way to disinfect wastewater. It has significant benefits compared to chlorine and has been proven effective in thousands of installations globally. Furthermore, UV is not affected by temperature or pH of the effluent and does not create disinfection by-products.
More About Upgrading a UV System
- By upgrading to a new TrojanUV system for their wastewater treatment plant, the Honouliuli Water Recycling Facility in Hawaii will see significant energy savings, as power consumption will be reduced by up to 75%. Read the case study.
- In order to improve the treatment performance and ensure that it would eventually have the treatment capacity to meet future population growth equivalent of up to 225,000, Swansea WwTW was in need of an equipment upgrade. Read the case study.
- Wayne Lem (TrojanUV Market Manager) discusses the benefits associated with upgrading an older UV system and Frank Cassisi (Director of Wastewater Operations for the Borough of Hollidaysburg, PA) talks about his recent upgrade project and offers advice to other wastewater treatment plant operators. Read the Q & A.