Impact Study On Ecotoxicity Of Oil-contaminated Soil By Aged Refuse

Soil oil pollution is one of the issues that China needs urgently to solve.Aged refuse is used to treat oil-contaminated soil because of its excellent physical,chemical,and biological properties.Therefore,how to safely and efficiently utilize the aged refuse into the oil-contaminated soil is of practical significance and imminent.In this paper,the toxicity test of higher plants was used to indicate the ecotoxicity of oil-contaminated soils under different conditions such as different landfill ages,different particle size,different amount of aged refuse.And reveal the characteristics of ecological toxicity in different degrees of pollution.At the same time,the aged refuse was modified by fly ash,rice hush carbon and leaves to further study the effect of improved aged refuse on the ecotoxicity of oil-contaminated soil.The research shows as follows:(1)Appropriate application of aged refuse to oil-contaminated soil can reduce the ecotoxicity of oil-contaminated soil.Within the scope of experimental design,the selection of aged refuse with a filling age of 8 years,a particle size of 2000 μm to 850 μm,and a blending ratio of 50% had the best effect on reducing the ecotoxicity of oil-contaminated soil.In combination with the actual situation,the proposed method for the disposal of petroleum contaminated soil by aged refuse is: the filling age of 8 years,the particle size is 2,000 μm to 0 μm,and the blending ratio is 50%.Aged refuse is added to oil pollution soil of the experimental design(2.5%,5%,7.5%,10%),can reduce the ecological toxicity of contaminated soil,and the high concentration of pollution of soil,improving ecological toxicity range is bigger.(2)Improvement of aged refuse with improved fly ash,rice hush carbon,and deciduous leaf can further reduce the ecotoxicity of oil-contaminated soil.The best improvement effect of the three modifiers was: 5%rice husk carbon>20% fly ash> 10%deciduous leaf.From the viewpoint of improving the effect and improving the cost,the fly ash was selected for improvement.The improvement scheme is the fly ash with a quality score of 20% in the Aged refuse.(3)After adding aged refuse or improved aged refuse to oil-contaminated soil,the promotion effect of root elongation is greater than that of plant height.The promotion effect of underground biomass is greater than that of the above ground biomass.That is,the underground index is more sensitive than the ground index,and the variation range is larger.