The Efficacy of Bioaugmentation on Remediating Oil Contaminated Sandy Beach Using Mesocosm Approach

Bioremediation is basically consists of two approaches, biostimulation and bioaugmentation. The efficacy of bioaugmentation for combating oil pollution in field application is still argued. The purpose of study was to evaluate the efficacy of bioaugmentation and to compare the affectivity of single strain and consortium application in remediating oil polluted sandy beach. Experimental study in a field has been conducted with two (2) treatments and one (1) control in three different plots. The treatmens were introduction of a single strain (Alcanivorax sp TE-9) and a consortium (Alcanivorax sp. TE-9, Pseudomonas balearica st 101 and RCO/B/08-015) cultures into oil contaminated sediment. The experiment in mesocosm approach was taken place in Cilacap coast. Arabian light crude oil was used in the concentration of 100.000 mg.kg^-1 sediment. Changes of oil concentration, bacterial density and pore water quality have been monitored periodically for 3 months. The result showed that oil degradation percentage and bacterial growth in both treatments were higher than in control. After 3 months, the percentage of oil degradation experiment in control, single strain and formulated consortium treatments were observed at 60.4%, 74.5% and 73.5%. It proves that bioaugmentation tehnique can enhance significantly oil biodegradation in sandy beach. The applications of bacteria in single or consortium culture give no different impact on their affectivity for bioremediation in Cilacap sandy beach. By data extrapolation it can be predicted that both of treatments able to reduce remediation time from 210 days into 135–137 days. Bioaugmentation can be proposed as a good solution for finalizing oil removing in Cilacap sandy beach when oil spilled occurred in this environment.