This study was conducted to reuse the rice straw ash as washing agent for oil contaminated soils. The results are summarized as follows. The physical characteristics of rice straw before and after burning were as follows ; In case of burning rice straw 1g, the rice straw ash was generated 0.14g and pH was changed neutrality into alkali(pH 10.9) and specific surface area was increased to five times and particle distribution was corresponded to fine silt(under 0.05㎜) The physical charateristics of rice straw ash were Carbon 10.9%, Hydrogen 1.5%, Oxygen 23.4%, Nitrogen 5.2%, Sulfate 1.2% and chemical charateristics were Si 189.2ppm, Ca 10.2ppm, Mg 4.7ppm. Oil cleanup ratio by pH varation were about 40～50% of initial concentration of oil by pH 10～11. As the result of cleanup comparative experiment, the rice straw ash was about 20～30%, the tritonX-100 about 40～50% of washing efficiency, and then in the future it will be possibility of substitute washing agent.

This study was carried out to develop an efficient process for the elimination of phenol pollutant from soils. An microwave-assisted process (MAP) and a conventional Soxhlet extraction method (SEM) were employed to extract phenol from two types of soils. The effects of extraction methods, aged time of the spiked soil samples, extraction solvent and extraction time on the extraction performance were compared. Our results demonstrate that the recoveries from standard soil spiked were at least 10% higher for MAP than those for the conventional Soxhlet. The extraction time by MAP requires significantly shorter time (1 min) than 18 h of the conventional Soxhlet. The recoveries from non-contaminated soil spiked with phenol were also almost identical for above results. The reduction of the extraction times with efficiency higher than that afforded by the conventional Soxhlet technique supports the suitability of the MAP method.