Method for intensively removing hexachloro-cyclohexane soprocide and dichlorodiphenyl trichloroethane in soil by zero-valent iron

Abstract

The invention relates to a method for intensively removing hexachloro-cyclohexane soprocide and dichlorodiphenyl trichloroethane in soil by zero-valent iron. The method comprises the following steps: immersing reduced iron powder into a copper solution to prepare a micron Fe / Cu duplex metal material, so that the load amount of Cu is 1%; sequentially adding duplex metal and triton X-100 into the soil according to the adding amounts of 5% and 0.1%; adjusting the initial pH value of the soil to 4-5 and adjusting the water content rate of the soil to 25%-30%; and isolating oxygen and piling to react for a certain time so as to degrade and remove hexachloro-cyclohexane soprocide and dichlorodiphenyl trichloroethane in the soil. The method does not need to use complicated equipment, is simple to operate and environment-friendly; the method has economical cost and has no secondary pollution; and the method has a relatively good application prospect in the remediation of the soil polluted by low-medium concentration hexachloro-cyclohexane soprocide and dichlorodiphenyl trichloroethane.

Description

technical field [0001] The invention belongs to a method for removing organic residues in soil, in particular to a method for strengthening removal of HCH and DDT in soil by zero-valent iron. Background technique [0002] In most provinces and cities in my country, especially economically developed areas such as Jiangsu Province, organochlorine pesticides such as HCH and DDT have been produced and used in large quantities, causing serious environmental pollution. For example, in the past 30 years, the total production of DDT in China has reached 400,000 tons, which is 22% of the world's total production. In 1980 alone, the output of 666 raw powder in my country was as high as 286,400 tons. In recent years, with the implementation of the Stockholm Convention and the rapid development of urbanization, these HHC and DDT production enterprises have been closed down one after another, but a series of soil pollution problems have been left behind. [0003] Due to the extremely s...

AI Technical Summary

Problems solved by technology

There are relatively few studies on the remediation of soil by zero-valent iron, and they mainly focus on nitrobenzenes and polychlorinated biphenyls (PCBs), and the treatment of organochlorine pesticide pollution in soil has not been reported yet.

At the same time, there are only a few reports on ZVI remediation of OCPs-contaminated soil in the world, which needs further research

[0006] For refractory organochlorine pesticides such as HCH and DDT, the effect of traditional zero-valent iron technology will be limited in two aspects: first, HCH and DDT are typical hydrophobic organic compounds with extremely low water solubility, which limits The contact between pollutant molecules and the surface of zero-valent iron is not conducive to the reduction and dechlorination reaction in the soil; second, the structure of HCH and DDT is stable, while the activity of ordinary iron powder is limited, and it is difficult to degrade them quickly

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