- 1:08 PM

Laboratory Scale Treatment of Cca Contaminated Wood Waste

Mark Bricka, Dave C. Swalm School of Chemical Engineering, Mississippi State University, MS 9595, Mississippi State, MS 39762 and J. Broussard, Chemical Engineering, Mississippi State University, MS 9595, Mississippi State, MS 39762.

Since the early 1970's, the most widely used preservative in the wood preservation industry has been chromated copper arsenate (CCA) treatment. Current estimations suggest that there may be as much as 240 million tons of CCA wood waste available for Disposal by the year 2020. Until recently, landfilling the out of service materials was the generally accepted method of disposal. Recently, problems with soil and groundwater contamination have arisen, and the role of CCA impregnated wood waste in the matter has been confirmed. As a result, the need for an efficient and effective method of heavy metal separation form wood waste has become eminent.

In this research, electrokinetic treatment of CCA impregnated wood fines was examined. Out of service CCA wood waste was subjected to electrokinetic treatment in a batch reactor under pH controlled conditions. The ionic nature of the metal oxides contained in the CCA impregnated wood will allow for the metals to be mobilized and metal concentrations are expected to decrease in the waste wood while increasing the proximity of the electrodes. In addition to this base case study, chemical extractions with electrode amendments were examined under controlled conditions before thy were subjected to electrokinetic treatment, and final overall metal removal. Mass balances were performed using ICP-AES equipment. In the extended research plan, the more effective reactions sequences will be subjected to further testing where the roles of independent variables such as reactor solution pH, particle size, current density, Oxidation/Reduction potential, and treatment time will be examined. The ultimate goal of this research will be to evaluate the feasibly of Electrokinetic pretreatment for CCA impregnated wood.