FINAL DISPOSAL OF VOCS FROM INDUSTRIAL WASTEWATERS

Vapor phase carbon adsorption followed by spent carbon regeneration an d catalytic oxidation where evaluated as methods for disposal of volat ile organic compounds (VOCs) released from industrial wastewaters duri ng treatment operations such as aeration, air-stripping and aerobic bi odegradation. Adsorptive capacities and breakthrough characteristics f or eight VOCs found in many hazardous landfill leachates and contamina ted groundwater were compared for selection of the best adsorbent and optimum treatment conditions. Coconut shell-based activated carbons ex hibited higher VOC loading capacities than coal-based carbons, fiber c arbon, molecular sieve and zeolite. Steam and hot nitrogen were both e ffective for regeneration of the spent carbon. A small quantity of ads orbates left in the regenerated carbon did not result in immediate VOC breakthrough in the next cycle adsorption treatment. Catalytic oxidat ion was found to be an attractive alternative for VOC disposal. Using a new commercial catalyst developed for destruction of halogenated org anic compounds, even stable VOCs such as trichloroethylene and tetrach loroethylene were completely destroyed at < 350-degrees-C when oxidati on was conducted at a space velocity of 17000/hr.