A study on Feasibility of Bioremediation of Crude Oil contaminated soil from Kalol with Indigenous Mixed Culture

Abstract

Bioremediation is a technique for treating various contaminants with application of microorganisms and provision of their kinetics renders implementation of biochemical reactions based on their rates of decomposition. The present study aims to test the feasibility of bioremediation of crude oil contaminated soil from agricultural land in Kalol area of Ahmedabad district, Gujarat, India. The experiment comprises five batches with descending levels of contamination that was measured in Total Petroleum Hydrocarbon percentage (TPH%); initial contamination present in both batch A and B was 11.7% TPH whereas, batch C, D and E was contaminated with 7.3%, 7.24% and 2.3% TPH respectively. The indigenous mixed culture was prepared from the collected soil sample and used to remediate batch A, C and E whereas an unknown culture provided by OTBL (ONGC TERI Biotech Limited) as reference was applied to batch B and C. The kinetics of indigenous mixed culture revealed a pattern of diauxic growth upon observation which gives suitability to Verlhurst growth model. The degradation of crude oil was estimated using solvent extraction at regular intervals of time that showed 40% to 70% in degradation range amongst the batches. The rate of degradation was implied using integral method resulting in first order kinetics. Other characteristics of indigenous mixed culture such as morphology and substrate utilization zones were observed using standard determination methods. The variation in physical and chemical properties of soil such as pH, ORP, conductivity, colour, TPH were observed on prior and latter basis of bioremediation.