The present situation of soil oil pollution and its harm 1. 1 The present situation of soil oil pollution The oil industry is an important part of the country's comprehensive national strength, but the development of oil exploitation and petrochemical industry and the extensive use of petroleum products have made oil pollution one of the world's public hazards. The total oil output in the world today is about 22× 10 8 t per year. In which onshore oilfield production 17.5× 10 8 t. Oil pollution alone causes 8× 10 6 t to enter the environment all over the world every year. The US Environmental Protection Agency reported that there were 654.38 million+underground oil tanks with different degrees of leakage in the 1990s. As the largest developing country in the world, China is also a big producer and consumer of oil. Due to the relatively backward production conditions and environmental protection technology, the problem of oil pollution, especially in the soil, is very serious. Oil pollution accounts for a considerable proportion in organic contaminated soil. Since 1978, China's crude oil output broke through the 1× 10 8 t mark and became one of the top ten oil-producing countries in the world, more than 400 oil and gas fields and reservoirs have been explored and developed, with an annual output of nearly 1× 10 5 t of oil-contaminated soil, with a cumulative accumulation of nearly 5×/kloc. 1998, the amount of oily solid waste produced by China's oil and refining enterprises reached 4.29× 10 6 t, and the utilization rate was less than 50%, resulting in soil pollution of 3.3× 10 6 hm 2. Every year, 6× 10 5 t oil enters the environment through running, running, dripping and leaking. According to incomplete statistics, the area of soil pollution caused by sewage irrigation in China is 9.3× 10 3 hm 2, and that of similar farmland in China is 1× 10 5 hm 2. The pollution area of crude oil in the northern oil-producing areas is expanding year by year. The crude oil content in the heavily polluted soil of Liaohe Oilfield reached 1× 104mg/kg, which was 20 times of the critical value (200 mg/kg). The results showed that when the crude oil content in soil was 365,438+000 mg/kg, the corn yield decreased by 65,438+00%. If the crude oil content reaches 500mg/kg, the benzopyrene residue in corn exceeds the standard, and corn is inedible [2]. To sum up, petroleum pollutants pollute and destroy the environment, endangering human health and living environment. Therefore, oil pollution control is an urgent problem to be solved at present, which is of great significance to human survival and social sustainable development. 1.2 Main hazards of soil oil pollution 1.2. 1 Damage to soil When petroleum substances enter the soil, it will cause changes in soil physical and chemical properties, such as blocking soil pore structure, destroying soil structure and reducing soil water permeability; Its rich active groups can combine with inorganic nitrogen and phosphorus in soil, limiting nitrification and phosphorus removal, thus reducing the content of available phosphorus and nitrogen in soil, resulting in changes in the carbon-nitrogen ratio (C/N) and carbon-phosphorus ratio (C/P) of soil organic matter. Due to these changes, on the one hand, the living environment of soil microorganisms has deteriorated, on the other hand, oil itself has a certain negative impact on soil microorganisms. Furthermore, the number of microorganisms reflecting soil activity decreased, and the microbial community and flora changed, which significantly reduced the five functions of microorganisms in unpolluted soil environment, reduced soil activity or even inactivated, and destroyed the soil microecological environment [3]. 1.2.2 The oil in the polluted water body soil leaks downward to pollute the groundwater, or is carried by rainwater to pollute the surface water body, which affects the safety of water use and crop safety. Long-term use of oily sewage for irrigation will hinder the normal growth and development of crops, reduce the ability of lodging resistance and pest resistance, and directly lead to the reduction of grain production. Toxic and harmful substances such as aromatic compounds will produce residue and enrichment effects in crops, which will endanger human health through the food chain. For example, the rice in the sewage irrigation area upstream of Shenfu irrigation canal has the phenomena of slow growth, rotten roots and shriveled grains, and the produced rice is oily and has poor sensory indexes. It is precisely because of these hazards that many gas stations that affect the surrounding environment are closed. For example, Anjialou gas station and Liulitun gas station in Beijing have suffered serious oil leakage accidents in recent years, which once stopped the operation of nearby waterworks. 1.2.3 The oil in polluted air soil volatilizes, diffuses and transfers into the air, which reduces the air quality and directly affects human health, life safety and offspring reproduction. Some fat-soluble substances can erode the central nervous system; Some volatile components react with oxygen under ultraviolet irradiation to generate toxic gases, which are harmful to the respiratory system of people and animals. Polycyclic aromatic hydrocarbons affect the normal function of liver, kidney and cardiovascular system, and even cause cancer. To sum up, oil pollution in soil has become an environmental problem that cannot be ignored because of its hidden danger, long incubation period, wide coverage, great difficulty in control and increasingly prominent harm. 2. Research progress of soil oil pollution control technology 2. 1 Physical remediation technology research progress is the utilization of soil and pollutants [Source: paper lunwentianxia.com, paper net] [1] [2] [3] [4] Next page-

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