Biodegradation kinetics at low concentrations (<1µg/L) for aquifer pesticide contaminants

Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 µg/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater.