Heavy metal composite passivating agent used for paddy soil and preparation method thereof

Abstract

The invention discloses a heavy metal composite passivating agent used for paddy soil and a preparation method thereof. The heavy metal composite passivating agent is prepared from three raw materials, namely meerschaum mineral powder, iron and manganese oxides and quicklime, in proportion by the following steps of: A, preparing the meerschaum mineral powder; B preparing the iron and manganese oxides; and C, uniformly mixing the raw materials prepared in the steps A and B with the quicklime to obtain the composite passivating agent. The heavy metal composite passivating agent has a reasonable formula, the method is easy and simple to operate; and the heavy metal composite passivating agent can reduce 70.5 to 95.0 percent of the content of the effective components of meerschaum with heavy metal activity, the iron and manganese oxides (Fe2O3+MnO2), calcium oxide (CaO) and the like in the soil, and also has multiple functions of passivating soil heavy metals, restoring acidified soil and the like, can reduce the contents of active cadmium and lead in the soil of a polluted paddy field by 39.7 to 53.8 percent and 49.9 to 59.1 percent respectively, lower the contents of the cadmium and the lead in agriculture products by 35.1 to 46.9 percent and 35.3 to 53.1 percent respectively, and simultaneously improve the pH value of the soil by 0.22 and 0.43. The heavy metal composite passivating agent is mainly used for paddy production of extensive heavy metal pollution zones, and can also be used for the productions of corns, vegetables and the like planted in paddy fields.

Description

technical field [0001] The invention belongs to the technical field of agricultural environment conservation and restoration, and more specifically relates to a heavy metal composite passivator for paddy field soil, and also relates to a preparation method for a heavy metal composite passivator for paddy field soil. Rice production in vast heavy metal polluted areas can also be used in the production of rice fields, corn, vegetables, etc. Background technique [0002] With the continuous advancement of industrialization and urbanization, the problem of heavy metal pollution in my country's soil has been paid more and more attention by people. According to relevant reports, in the early 1980s, the area of ​​cultivated land polluted by heavy metals such as cadmium, lead, mercury, arsenic, chromium, and nickel in my country was only 2.67 million hm 2 , increased to 6.67 million hm in 1988 2 , had exceeded 10 million hm by the end of the last century 2 , has exceeded 20 milli...

AI Technical Summary

Problems solved by technology

The research results of Chen et al. (2000) showed that the addition of manganese oxide can reduce the content of cadmium extracted from EDTA, HAc and Hal in the soil, and reduce the absorption of cadmium in the aboveground parts of crops; the addition of iron oxide can also reduce the content of cadmium extracted from HAc, It also has a greater inhibitory effect on the absorption of cadmium in the aboveground parts of crops, but its effect is weaker than that of manganese oxide

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