Remediation Effects Of Shrub And Forage Residues On The Bio-chemical Properties Of Petroleum Contaminated Soil In The Oil Zone Of Northern Shaanxi

The oil spill occurred in the production, transportation and storage process will causeserious pollution to the surrounding soil, in addition to the results of petroleum hydrocarbonsabsorbed by plants and endangering human and animal health through the food chain. In theother way, residues of petroleum hydrocarbons in soil which doesn’t absorbed by plants willcause serious damage on the biochemical properties of soil. Therefore, repairing the soil is notonly to reduce or eliminate residual petroleum hydrocarbons in the soil, but also need toimprove and repair the bio-chemical properties of petroleum contaminated soil. The organicplant residues as a potential immobilized carrier material, which is not only rich in C, N andother nutrients, but also has a strong affinity for soil microorganism and soil enzyme, and itshumification process will release a large amount of dissolved organic matter in the soil, mostof which are microbial degradation of PAHS metabolic substrates, which can have a strongbiological removal of soil PAHs of persistent organic pollutants. In the dissertation, theinfluences of petroleum contaminated soil on soil properties, repair status and mainremediation of petroleum contaminated soil are briefly introduced, the improve effect,research actuality and existing problems of shrub and grass residues about petroleumcontaminated soil were narrated emphatically. In this paper,9kinds of shrub litter and6kindsof forage straw in oil polluted area in Northern Shaanxi are the research material, andchoosing the representative local wasteland and oil sample to study the effects of differentkinds of shrub litter and forage straw for biological and chemical properties of petroleumcontaminated soil under3kinds of oil pollution levels. Then comprehensive analyzed theimprovement effects of biological properties on three levels of petroleum contaminated soilby shrub and forage residues, and to discuss the feasibility of improving biological propertiesof petroleum contaminated soil, with a view to provide a theoretical basis for the selection ofshrub and grass type on bio-remediation of northern Shaanxi oil zone. The main conclusionsand innovations are as follows: (1) According to comprehensive analysis of the improved results of bio-chemicalproperties of three levels of petroleum contaminated soil by9species of shrub litters, litters ofCaragana microphylla and Hedysarum fruticosum were superior to others in improving theenvironment of three levels petroleum contaminated soil, and it will be also better forAmorpha fruticosa in light pollution(15g kg-1), Ligustrum quihoui in middle pollution(30g kg-1), Tamarix chinensis and Amorpha fruticosa in severe pollution(45g kg-1) than others.The specific results are that the litters of Caragana microphylla, Hedysarum fruticosum,Amorpha fruticosa, Tamarix chinensis and Ligustrum quihoui have shown a positive effect onimproving biochemical properties of petroleum contaminated soil significantly. Among them,Litters of Caragana microphylla, Hippophae rhamnoides, Amorpha fruticosa, Rtemisiadesterorum and Ligustrum quihoui can significantly contribute to the soil respiration andgrowth of microbes in3levels of petroleum contaminated soil. Litters of Tamarix chinensis,Caragana microphylla, Hedysarum scoparium and Hedysarum fruticosum can obviouslypromote soil enzyme activities of alkaline phosphatase, urease, Invertase and dehydrogenaseunder light or severe pollutions. Litters of Caragana microphylla, Rtemisia desterorum,Hedysarum fruticosum, Ligustrum quihoui, Hedysarum scoparium, Tamarix chinensis andAmorpha fruticosa can obviously increase the soil organic carbon and available potassiumcontents in three levels petroleum contaminated soil. Litters of Caragana microphylla, Sabinaprocumbens, Hippophae rhamnoides, Hedysarum scoparium and Ligustrum quihoui cansignificantly improve the contents of soil available Fe, available Mn and available Zn in lightand severe pollutions.(2) In this experiment, according to comprehensive analysis of the improved results ofbio-chemical properties of6kinds of forage straws for three levels of petroleum contaminatedsoil, in light pollution(15g kg-1), the straw of Festuca rubra had the best repair effect on thebio-chemical properties of petroleum contaminated soil, followed by Coronilla varia andAstragalus adsurgens; in middle pollution(30g kg-1), only Medicago sativa straw hadsignificant remediation effect on the bio-chemical properties of petroleum contaminated soil;in severe pollution(45g kg-1), the straw of Medicago sativa had the best repair effect on thebio-chemical properties of petroleum contaminated soil, followed by Festuca rubra andCoronilla varia straws. The specific results are as follows, in light pollution, Festuca rubraand Coronilla varia can significantly stimulate the growth of soil microbes, promote theeffectiveness of N, P and K elements and the activity of other nutrient elements, promote theactivities of soil urease, Invertase, alkaline phosphatase, polyphenol oxidase, peroxidase anddehydrogenase. The straw of Astragalus adsurgens can obviously promote the growth of soilfungi and Actinomyces, promote the release of the elements such as N, P and K and the activities of soil urease, invertase and alkaline phosphatase and dehydrogenase. The straw ofTrrifolium repens and Onobrychis viciaefolia can significantly promote the growth of soilfungi and Actinomyces, promote the release of K element and the activity of soil urease anddehydrogenase. In middle pollution, Medicago sativa straw can obviously stimulate thegrowth of soil microorganisms, promote the effectiveness of N, P and K elements and theactivity of soil urease, Invertase and alkaline phosphatase and dehydrogenase. Trrifoliumrepens, Astragalus adsurgens, Coronilla varia and Festuca rubra can significantly stimulatethe growth of soil microbes, promote the release of N and K element and activities of soilalkaline phosphatase and dehydrogenase. The straw of Onobrychis viciaefolia can obviouslystimulate the growth of soil Actinomyces, promote the effect of the K element and activitiesof soil urease and dehydrogenase. In severe pollution, Medicago sativa, Festuca rubra andCoronilla varia straw can obviously stimulate the growth of soil microbes, promote theeffects of N, P and K elements and the activities of soil urease, Invertase and alkalinephosphatase and dehydrogenase. Astragalus adsurgens straw can significantly stimulate thegrowth of soil Actinomyces, promote the effect of N element and the activities of soil urease,Invertase and alkaline phosphatase and dehydrogenase. The straws of Trrifolium repens andOnobrychis viciaefolia can obviously stimulate the growth of soil bacteria and Actinomyces,promote the effects of P and K element and the activities of soil sucrase, alkaline phosphataseand dehydrogenase.