SBIR-STTR Award

Regulated heavy metals are typically removed from industrial wastewater through a metal hydroxide precipitation and sedimentation process. Complicating the treatment of these waste streams is the presence of commingled chemicals such as detergents, surfactants and other chelating substances associated with the metal finishing and electroplating processes. During wastewater treatment, these chelating substances form highly stable complexes with heavy metals thus inhibiting them from being removed. Oxidation of chelating substances using a variety of strong chemical oxidants is a financially expensive and potentially hazardous approach used to overcome the negative effects of heavy metal complex formation. Development and implementation of innovative redox chemistry offers numerous advantages over chemical oxidation in treating industrial wastewater impacted by chelating substances. By completely eliminating the need to remove the chelating substances, the new redox chemistry method reduces both the chemical treatment costs as well as the capital costs associated with installation of unit operations required to support chemical oxidation. Moreover, with the reduction in chemical use, implementation of the new redox chemistry method significantly reduces the facility’s operations and maintenance costs as well as increasing the protection of worker health and safety from hazardous chemical exposure.

Benefit:
The anticipated benefits in developing and implementing cutting edge redox chemistry for the treatment of industrial wastewaters impacted by chelating substances include the following: • The ability to consistently and reliably achieve legally enforceable wastewater discharge standards for heavy metal pollutants in the presence of strong chelating agents. • Reduction in wastewater treatment operation and maintenance costs needed to support chemical oxidation of chelating substances. • Reduction in wastewater treatment capital costs associated with installation of new physical unit operations and flow separation. • Increase in the protection of worker health and safety associated with hazardous chemical exposure. • Technology is completely compatible with current facility wastewater treatment operations and associated infrastructure.

Keywords:
Heavy Metals, Chelating Substances, Industrial Wastewater, Redox Chemistry

With shrinking facility budgets and increasingly stringent environmental regulations, United States Department of Defense (DoD) weapon system maintenance facilities are faced with the difficult challenge of maintaining regulatory compliance with limited resources. Moreover, the growing diversity in DoD workloads as well as the increased use of low volatile organic compound industrial cleaners has increased the presence of chelating substances found in industrial wastes and wastewaters. During industrial wastewater treatment, these chelating substances form highly stable complexes with heavy metals thus inhibiting them from being effectively removed from solution. Recently, a new sulfur-based redox industrial wastewater treatment method has been developed that has the potential to consistently meet water quality compliance standards for regulated heavy metals in the presence of chelating substances. The new sulfur-based redox chemistry method utilizes a proprietary chemical mixture (Compliance MX), which is added to industrial wastewater under controlled pH and oxidation-reduction conditions. The chemical mixture, which is applied to negate the effects of chelation, results in the rapid destabilization of heavy metal ions leading to the subsequent formation of metal precipitates that are easily removed through sedimentation.

Benefit:
Beyond having the capability of treating electroplating and metal finishing wastewaters in the presence of chelating substances, the sulfur-based redox chemistry method provides a number of other potential benefits to both DoD weapon system maintenance facilities as well as private industry including; 1) elimination of the need to employ the acidic reduction process for hexavalent chromium removal, 2) elimination of the need for chlorine and/or other chemical oxidants for treating chelating substances, 3) significant improvements to the occupational health and safety environment for facility employees, 4) lower compliance and regulatory risks to the wastewater treatment facility, 5) significant financial savings with regard to reducing hazardous waste disposal costs and 6) elimination of capital improvement expenditures required to achieve industrial waste source segregation.

Keywords:
Heavy Metals, Chelating Substances, Industrial Wastewater Treatment, Hazardous Waste, Regulatory Risk