Effects of nutrients on crude oil biodegradation in the upper intertidal zone

Abstract

To enhance biodegradation, nutrients in the form of slow-release fertilizer (SRF) were applied to oil-contaminated microcosms (3%, v/v) which simulated intertidal environmental systems. Although nutrient concentrations in the interstitial water were not proportional to those in amended SRF, microbial activity, growth of oil-degrading microorganisms, and oil-degradation rate were closely related to the concentration of nutrients in the interstitial water. Adding nutrients at higher dose (microcosm 1, 144.4 mg C/kg sand/day, versus microcosm II, 8.5 mg C/ kg sand/day) had a positive effect on oil degradation rate, which was especially obvious during the early phase of treatment. Use of pristane, phytane, and nor-hopane as biomarkers enabled the detection of significant treatment differences in hydrocarbon biodegradation, which were not reliable enough when the data were normalized to sand mass. (C) 2001 Elsevier Science Ltd. All rights reserved.