You are here:
NDMA TREATMENT BY SEQUENTIAL GAC ADSORPTION AND FENTON DRIVEN DESTRUCTION
Citation:
Kommineni, S., W. P. Ela, S G. Huling*, B. J. Hester, E. A. Betterton, AND R. G. Arnold. NDMA TREATMENT BY SEQUENTIAL GAC ADSORPTION AND FENTON DRIVEN DESTRUCTION. ENVIRONMENTAL ENGINEERING SCIENCE 20(4):361-373, (2003).
Description:
N-nitrosodimethylamine (NDMA) is a highly toxic microcontaminant that was first detected in groundwater tainted by rocket fuel manufacturing wastes. More recently NDMA has been detected as a by-product of other industrial processes including the chlorination of treated wastewater. Treatment by carbon adsorption is costly because NDMA partitions only sparingly to carbon and frequent carbon replacement or regeneration is required. If activated carbon could be regenerated cheaply and quickly in-place, this easily implemented technology would become attractive. In this study, the feasibility of adsorption of NDMA onto carbon followed by in-place regeneration using Fenton's reagents is assessed. Batch and column tests indicate that carbon- sorbed NDMA can be destroyed to nondetectible levels in hours using reasonable hydrogen peroxide and iron concentrations. Three-log destruction of sorbed NDMA on carbon loaded to 1.04 mg NDMA/g carbon was achieved in approximately 12 hours. Results of both readsorption studies and modified iodine number tests indicated that the aggressive regeneration treatment results in little loss of carbon adsorptive capacity. The destruction efficiency of Fenton's reagents was dependent on pH and hydrogen peroxide concentration, although little advantage was obtained at very high hydrogen peroxide concentrations. Iron solubility and availability for participation in Fenton's reaction was enhanced by addition of EDTA at near neutral pH, but the NDMA destruction efficiency was still more efficient in a comparable system without the ligand at pH 2.