EVALUATION OF BIOKINETIC COEFFICIENTS IN DEGRADATION OF OIL-FIELD PRODUCED WATER UNDER VARYING SALT CONCENTRATIONS

Biokinetic coefficients were evaluated for a New Mexico oilfield produced water. Total n-alkane removal efficiencies greater than 99% were achieved. Using respirometric techniques for determination of the biokinetic constants, values of 1.37 mg/l and 0.136 h(-1) were obtained for K-s and mu(max), respectively. Evaluation of specific growth rates at various levels of total dissolved solids (TDS) concentration exhibited a distinct reduction from 0.131 to 0.047 h(-1), when TDS concentrations exceeded 90,000 mg/l. Changes in cell yield were also evident, however, yields increased from 0.41 to 0.69 mg biomass/mg total n-alkane. Carbon material balances for all respirometric substrate level testing achieved recoveries greater than 98%.