Treatment of Metal Finishing Wastewaters in the Presence of Chelating Substances
Abstract:Hill Air Force Base, Utah (Hill AFB) performs repair and maintenance on a variety of aircraft including the F-16, A-10 and C-130 as well as other weapon systems. Because of its breadth of industrial operations, much of the industrial wastewater generated at Hill AFB is subject to specific metal discharge concentration limits found in the national categorical pretreatment standards for metal finishing (i.e., 40 CFR Part 433) as well as electroplating (40 CFR Part 413). However, to ensure its continued ability to land apply its sludge, the local publicly owned treatment works has established pollutant discharge limits that are more stringent than those found in the national pretreatment standards. To comply with the local pretreatment standards, Hill AFB is evaluating a number of novel technologies for treating its industrial wastewater.
A new electrocoagulation (EC) process design has demonstrated significant promise for chromium, cadmium and nickel removal from metal finishing wastewaters in both bench and pilot scale testing. By maintaining a direct current and voltage of 18 amperes and 75 volts, respectively, cadmium, chromium and nickel concentrations were reduced by over 96% in the presence of chelating substances. Other wastewater species whose presence can potentially affect heavy metals removal by EC included chlorine. However, it was determined in pilot scale testing that, by maintaining an influent wastewater pH of between 8.0 and 8.5, the presence of chlorine had a negligible effect on pollutant removal.
Results of EC and ultrafiltration pilot scale testing have demonstrated their potential use in complying with Hill AFB's new pretreatment discharge standards. Documented advantages of employing and EC-ultrafiltration treatment include: 1) achievement of lower metals discharge concentrations, 2) smaller tank volumes, 3) reduced sludge volume and 4) effective metals removal in the presence of chelating compounds.
Document Type: Research Article
Publication date: 2009-01-01
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 These proceedings are not peer reviewed.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