Feasibility of Granular, Activated-Carbon Adsorption for Waste-Water Renovation. 2

摘要

Granular, activated carbon in packed-bed column contactors 20 feet deep and operated at a flow rate of 4 gpm per square foot reduced the COD to an average value of 18.5 ppm. The removal was not significantly different from the removal obtained when operating the same column at 10 gpm per square foot. After 4 months of operation, the first quarter of the column length was still accomplishing a significant part of the overall removal. Typical adsorption isotherms for type SGL carbon for COD indicated capacities of approximately 35 percent by weight. The cyclic saturation and regeneration of activated carbon through 16 cycles had an average carbon loss of 4.6 percent per cycle. A practical adsorption capacity was maintained for the regenerated carbon even though reactivation conditions for carbon spent on municipal waste-water treatment purification have not been explored and optimized. Flocculation with alum of secondary effluent prior to carbon adsorption increased the adsorption capacity of the carbon and resulted in much lower final levels of COD than the levels obtained with unflocculated effluent. (Author)