Comparative analysis of microbial loads of molecular potential chain disintegrator (MPCD) and potassium permanganate (PP) in remediation of hydrocarbon contaminated soil/groundwater in three dimensional (3D) laboratory sand tank model

Abstract

This paper evaluates the comparative analysis of bacterial loads of molecular potential chain disintegrator (MPCD) and potassium permanganate (PP) in remediation of artificial hydrocarbon contaminated soil and groundwater in 3D laboratory sand tank. Alluvial sand was packed in the sand tank model, and 20 cm chamber was packed with prepared artificial diesel contaminated soil. Free flow of water was allowed through the soil medium from the inlet chamber which was being fed continuously from the storage elevated tank with the discharge port opened at flow rate of 58 ml/min. The remediating agents (MPCD and PP) were prepared differently and introduced through the injection wells (IW) to the sand medium at different experimental design stages. Microbial analysis was carried using standard techniques. The microbial loads of unpolluted soil samples collected from the sand tank model was 3.5 x 104 ± 1.5 Cfu/g while the oil-degraders from the diesel contaminated soil was 9.5 x 104 ± 2 Cfu/g. It could be observed that the population of oil-degraders in the MPCD amended soils and water decreased gradually during the incubation period of 15 days from 36 x 104 ± 4 Cfu/g on day 0 to 12.5 x 104 ± 3.5 Cfu/g for soil samples and from 58.5 x 102 ± 1.35 Cfu/mL to 17.5 x 102 ± 0.5 Cfu/mL for water samples. The decrease in the population of oil-degraders could be attributed to the reduction in the concentration of diesel in the soil and water samples undergoing bioremediation. The composition of the two nutrients (MPCD and PP) can be responsible for the ability of the nutrients to enhance the degradation process.