Study On Remediation Of Benzene Componds Contaminated Soil

Benzene componds, which contain polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated Binaphthyl (PCNs), are important environmental organic pollutants due to their carcinogenicity. They are physically and chemically stable, volatile and semi-volatile, and resistant to degradation. Their strong hydrophobic characteristics make them bind to soil tightly, resulting in remediation of Benzene componds contaminated soils a challenge problem.Remediation of Benzene componds contaminated soils was studied in this thesis. When surfactant was choosed as auxiliary using in contaminated soil nitrobenzene and aniline by chemical washing treatment, it was found that 85% nitrobenzene in the soil was removed by about 6 BV (1500 mL) of water, and the remained nitrobenzene in the soil was only 0.3% of the pre-washing soil content, the remaining 14.7% of nitrobenzene was lost through volatilization, degradation and other channels. As for phenylamine,98% was removed by about 3 BV (750-800 mL) of water,1.1% was lost through volatilization, degradation and other channels, and the remained phenylamine in soil was 0.9% compared with the pre-washing soil. When electrocatalytic reactor contained with activated carbon particles swarm was used to treat the organic pollutants (nitrobenzene and aniline) of the soil washing water, the degradation rate of benzene and aniline were 99% and 96%, respectively, under the stay time of 30 min and current slot 1.5～2.0 A conditions. Phytoremediation was also studied in this thesis, it was found that the nitrobenzene and aniline were reduced from 168.9-859.9 mg/kg and 233.2～980.4 mg/kg to 1.08～12.27 mg/kg and 2.63～52.13 mg/kg, respectively, after 30d treatment, with the the removal rate of 98.5-99.3% and 94.6～98.8%, respectively. It was found that remediation efficiency of nitrobenzene and aniline was different by different plant phytoremediation. The removal of nitrobenzene and aniline by Ryegrass was strongest, followed by Alfalfa, and Dichondra was worst. Based on the results, it may conclude that the remediation of Benzene componds contaminated soils by the above methods is a viable way.