Porous composite material for removing heavy metals in soil and preparation method thereof

Abstract

The invention discloses a preparation method of a porous composite material for removing heavy metals in soil, which comprises the following steps: mixing an inorganic material and an organic material, molding, drying, sintering and the like to prepare a porous material substrate; activating the porous material with acid; and finally, in an organic or inorganic solution, treating the porous material with a silane coupling agent or any other organic molecule with adsorption, complexing and chemical linkage function on heavy metals to obtain a functional molecular layer, thereby obtaining the required porous composite material. The porous composite material has the characteristics of high selectivity for heavy metals and high adsorption efficiency when being used for remediating heavy-metal-containing soil. The porous material has the advantages of low consumption and long service life (up to 3-5 years). The technique can be widely used for remediating farmland or cultivated soil without influencing the normal cultivation and production of crops.

Description

technical field [0001] The invention relates to the technical field of soil cultivation in agricultural production, in particular to a porous composite material for removing heavy metals in soil and a preparation method thereof. Background technique [0002] 1.1 The severity and harm of "cadmium rice" [0003] According to the 2013 Hunan Statistical Yearbook, in 2012, the sown area of ​​grain in Hunan Province was 4.937 million hectares, and the rice output was 26.31 million tons, accounting for 12.9% of the national rice output. It is the largest major rice producing area in the country. But in recent years, there have been endless disturbances about cadmium rice. As early as 2002, the results of the rice safety sampling inspection conducted by the Ministry of Agriculture showed that the rate of cadmium exceeding the standard was 10.3%. , Professor Pan Genxing of Nanjing Agricultural University announced that the 170 samples tested in 2007 had an exceeding rate of about...

AI Technical Summary

Problems solved by technology

The leaching method has a good effect on heavy pollution of hydrocarbons, nitrates and heavy metals, and is suitable for light soil, but the investment is large, and it is easy to cause groundwater pollution, soil nutrient loss, and soil denaturation.

[0023] 3) The heat treatment method is to heat the polluted soil to volatilize the volatile pollutants (Hg) in the soil and collect them for recycling or treatment. This method is only suitable for volatile heavy metals and has limited removal of cadmium.

[0024] 4) The electrolysis method is to remove the heavy metals in the soil at the anode or cathode under the action of electrolysis, electromigration, electroosmosis, and electrophoresis, but the restoration effect is related to soil pH, buffer performance, soil components, and polluted metal types. Big

[0035] Although there are many soil remediation methods for heavy metals, especially cadmium, most of them are still in the stage of laboratory batch experiments and simulation experiments, and there are few mature methods that have reached the level of field application.