Effect of In-Situ Oxidation Method on Soil Biological Properties in Total Petroleum Hydrocarbon Contaminated Soil

Abstract

Total petroleum hydrocarbon (TPH) is one of the main pollutant in soil environment and oxidation treatment method using hydrogen peroxide (H2O2) is common for TPH remediation in soil. The main objective of this research was to monitor change of soil biological properties including soil respiration (SR) and soil enzyme activity in TPH contaminated soil after oxidation treatment. Laboratory batch experiment was conducted to simulate field treatment. Five percent of H2O2 was applied to TPH contaminated soil and soil biological properties was monitored at 3, 7, and 11 days after H2O2 application. Result showed that reduction efficiency of TPH was 64.8% after 11 days and SR rate was increased to 58.4% as TPH was reduced to 64.8% after 11 days. However, soil enzyme activity was not significantly increased and even dehydrogenase and urease activity were decreased to 59.0 and 56.3% after H2O2 application. This result might indicate that certain period is necessary to recover nutrient cycle in soil after remediation. In addition, long time of monitoring might be necessary to understand microbial activity for nutrient utilization in soil.Schematic diagram of remediation experiment for TPH contaminated soil and change of biological properties.