Disinfecting with ultraviolet radiation

Wastewater disinfection using ultraviolet (UV) radiation, a relatively new technology, has proven to be both efficient and cost effective for a new municipal treatment facility at Albert Lea, Minn. Designed for a flow of 12. 5 mgd (47,300 m**3/d), this is the largest UV plant in the U. S. Since June 1983, when data first became available, the effluent BOD, TSS NH//3-N and fecal coliform levels have been below permitted maximums. Operating costs are . 02 per 1000 gallons treated as opposed to an estimated . 04 to . 08 per 1000 gallons for chlorination/dechlorination and . 10 to . 25 per 1000 gallons for ozonation. Disinfection, the destruction of potentially harmful organisms, is the final step in the treatment of wastewater before it is discharged.