Transport and biodegradation of benzene in the saturated groundwater layer

Abstract

The objective of this study was to investigate the biotic and abiotic processes that affected benzene transportation in the saturated groundwater layer. The study was performed in the laboratory using synthetic groundwater and soil sample from Maptaput Industrial Estate, Rayong. This study was divided into 3 parts; batch test, column test and computer modeling. The biotic, biodegradation, and the abiotic processes were studied in the batch system. The column experiment was performed to investigate the transport behavior of benzene. The computer program, CXTFIT, with parameters acquired from batch and column experiments was used to simulate the benzene transport behavior. It was found that benzene adsorption followed the linear adsorption isotherm with its coefficient (Kd) of 0.544 cm3/g and the retardation factor of 5.43. The biodegradation rate could be estimated using the firstorder biodegradation rate equation with the degradation rate of 0.0009- 0.0092 per day. The dispersion coefficient estimated from column experiments was 0.0102 cm2/s. The results from computer simulation did not fit the experimental data well. It can be concluded that the transport of benzene was a non-equilibrium transport. It was also found that biodegradation of benzene had significant effect on benzene transportation in saturated groundwater. The simulated transport with biodegradation process fitted the data fairly.

Keywords

• benzene
• transport
• biodegradation
• adsorption