AWWA SOURCES55720

This paper summarizes the results of the Ultraviolet (UV) alternative investigation and pilot study conducted at the City of Henderson Water Reclamation Facility (WRF). The WRF is a major wastewater treatment facility in the Las Vegas Valley that is being expanded from 20 million gallons per day (mgd) to 35 mgd. As part of the design for the plant expansion, three different types of UV equipment were researched and evaluated. The three types of UV equipment were low-pressure/low intensity, low pressure/high intensity, and medium pressure/high intensity. The evaluation of the three systems included economic and non-economic factors, which are presented in this paper. The paper provides a general overview of the WRF, including background information and supplemental phosphorous removal plant components. Treated effluent discharge options, consisting of surface discharge to the Las Vegas Wash or discharge for reclaimed water use, is described, as are established treatment standards for the two discharge options. The paper presents the various UV systems evaluated, and tabulates several pertinent system characteristics that were investigated during the UV system selection process. Present worth construction and operation and maintenance costs for two alternate systems are presented in tabular and graphic form. A collimated beam study and pilot test were conducted after a specific UV system was selected, to verify equipment performance under actual operating conditions at the Henderson WRF. Results of the collimated beam study and pilot test are presented, including determination of the UV dose required to achieve the desired disinfection results, and determination of the transmittance range of the WRF treated effluent. Collimated beam study and pilot test results are compared graphically, showing fecal coliform concentrations resulting from various UV doses. In closing, a plan view of the completed UV disinfection basin design is included to demonstrate the scope of the full-scale facility. This paper includes an informative case history of the selection process conducted by the City of Henderson WRF Expansion project team to determine the appropriate UV system/technology to comply with the City's demanding disinfection requirements. Includes figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/2002

Number of Pages:

8

File Size:

1 file , 1.3 MB