Comparisons of Efficiency of Bioremediation Methods in Diesel Contaminated Soil.
Sung-Hwan Kim1, Sanghwan Lee2, Dae-Yeon Kim1, and Jeong-Gyu Kim1. (1) Division of Environmental Science and Ecological Engineering, Korea University, AnamDong 5-1, SungbukGu, Seoul, South Korea, (2) Korea agricultural & rural infrastructure corp. Environmental response team, office of environmental geology, P.O. box 12, Poil-Dong, Euwang-Shi, South Korea
This research was carried out to compare efficiency of bioremediation treatments which included natural attenuation, biostimulation, bioaugmentation, and compost treatment. Examined parameters were the total petroleum hydrocarbon(TPH), microbiological activity, and soil water potential. The phytotoxicity of contaminated soils was assessed by plant germination tests. After 35 days of incubation, the initial TEM contamination of 6537.85 mg/kg soil was reduced to 3259.61 mg/kg, 3757.63 mg/kg, 4049.63 mg/kg, 5460.08 mg/kg at compost 1, bioaugmentation, biostimulation, control. The highest degradation activity was observed in compost treated soil. Initially the number of HUB were in the range of 3.04~4.54 log MPN/g. Throughout the experiment, the number of HUB decreased with time exception of compost treatment. Dehydrogenase activity increased with time, especially in compost treatments. The maximum value of dehydrogenase activity was observed in the compost 1 treatments 28 days after, with 4.56 µg TPF/g. Phytotoxicity and soil water potential played as a meaningful tools in monitoring bioremediation processes. Initially plant germination and growth are strongly inhibited afterward residual fraction did not show any phytotoxicity. We can presume that bioremediation processes reduce low molecular-weight hydrocarbons by degradation. After bioremediation, soil water potential increased from -0.0177MPa to -0.0072MPa, -0.0059MPa, -0.0054Mpa at 60% of water holding capacity in natural attenuation, biostimulation, and bioaugmentation, respectively. It was attributed to the irregular and ungraded soil moisture distributions for the contaminated soil. Keywords: bioremediation, phytotoxicity, Soil water potential.