NEUTRALIZATION OF PHENOL-CONTAMINATED SOILS

Abstract

To eliminate the consequences of accidental spill of phenol, the results of neutralization of soils contaminated with phenol are presented. As for the analysis of soils by the geological-lithological section it was found that in areas of phenol contamination the soil has a surface soil-plant layer with a thickness of about 0.5m, then there is a heavy clay layer with a thickness of up to 7.0 m and finally a sand layer saturated with groundwater is observed. It revealed that according to physical and mechanical properties, the solid mineral phase of the soil corresponds to a hard plastic and semi-solid consistency of clays. It showed that the filtration of water through the bottom and walls on the area of the former burial of the tank is complicated because of closer to zero water permeability of soil strata due to clay rock. Mineralogical and chemical composition of soils contaminated with phenol is determined. An environmentally safe method of neutralizing phenol-containing soils is developed with a neutralizing composition based on quicklime and bentonite which simplifies the neutralization method of soils contaminated with phenol. Environmental safety was observed in the absence of phenol in water extracts from soils and the in treatment process permissible for the environment рН. Essence of proposed method lies in chemical inactivation of phenol based on its transformation into slow-moving water-insoluble compound - calcium phenolate. Decontamination product of phenol-containing soil is the smallest capsules comprising soil particles and immobilized phenol in the form of calcium phenolate. Material of the capsule represented by calcium hydroxide is neutralized over time by bentonite and СО2 from air resulting in the formation of hydrophobic silicate and calcium carbonate which gives capsules high strength properties. The research into the neutralized phenol containing soil for phenol in water extracts showed that the proposed method is simple, ecologically safe, causes no recontamination of environment with pollutants and provides the phenol content in soils within MAC.