Skip to main content


Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


Residual chlorine loss due to ultraviolet sunlight in the chlorine disinfection contact basins were investigated at two full-scale wastewater treatment plants. The investigation compared the chlorine loss in chlorine contact basins that were covered against the basins that were open to direct sunlight. Chlorine decay due to UV-catalyzed reaction was found to be significant. The average chlorine loss across the contact basin due to sunlight photocatalytic decay at peak sunlight hours was 6.6 and 4.7 mg/L for the two plants studied. The total chlorine loss due to sunlight was about 28% and 19% of the total chlorine chemical usage at the two plants. One plant had about 36 percent reduction of total chlorine usage after they covered both chlorine contact basins, which result in approximately 37,000/year savings on chemical purchase. Covering chlorine contact basins also led to more stable chlorine demand throughout the day and throughout the year regardless of the diurnal and seasonal sunlight intensity. Therefore, it offers more stable/accurate chlorine dosage and effluent residual control, and less effort from the plant operators. A mathematical model was developed to calculate the amount of UV-catalyzed chlorine decay. The parameters in the model were determined by calibrating the model to the field observed data. Then the model was employed to evaluate the average UV-catalyzed chlorine decay rate at various average chlorine concentration in the DCB, as well as estimated total chlorine loss due to sunlight at various flow rates.

Document Type: Research Article


Publication date: 2005-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more