AWWA WQTC60749

A regional reactivation facility located within the Phoenix metropolitan area could ultimatelyprocess the granular activated carbon (GAC) that services as much as one billion gallons per dayof drinking water. Cities in the metropolitan area anticipate a demand of 30 million pounds peryear (30 MM-lbs/yr) of GAC by 2013. Cities use, or will use, GAC in filters or post-filtercontactors to meet Stage 2 Disinfectant/Disinfection Byproducts Rule requirements. TheCities of Chandler, Glendale, Mesa, Peoria, Phoenix, Scottsdale and Tempe, Arizona havecollaborated in a feasibility study for a regional reactivation facility. GAC reactivation is anenvironmentally friendly option that is expected to result in lower overall costs as comparedwith the purchase of virgin GAC. Required reactivation capacity was estimated at 36 MM-lb/yr(additional capacity to meet peak demand and reduce the amount of onsite storage).The general reactivation process involves thermal reactivation through heating spent GAC to700-900° C under steam and carbon dioxide for 30 minutes to 2 hours. Facility technologies will includereactivation furnaces, acid bath, and air pollution control equipment. Real estate requirements of6 to 10 acres are anticipated based on design capacity, technological considerations and zoningand setback requirements.Cost analysis was conducted in September of 2003 to determine savings through reactivatingGAC when compared to purchase of virgin GAC. Reactivating GAC is approximately 40% less than purchase of virgin GAC. Within fouryears capital costs will be recovered through savings from reactivation.Air quality concerns were evaluated using the U.S. Environmental Protection Agency (USEPA) approved SCREEN3 model. The maximumimpact is anticipated to be less than 3 percent of the National Ambient Air Quality Standards atground level, and less than 14 percent at flagpole heights. The model also indicated that theambient air quality impact of toxic chemicals will be below current guidelines.Viable sites for locating a reactivation facility throughout Maricopa County were examined. Siteselection criteria included public concerns, accessibility, permitting requirements, proximity toutilities, transportation and zoning. Includes 4 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/15/2004

Number of Pages:

14

File Size:

1 file , 1 MB