Calcium-iron-silicon-based composite material for restoring heavy metal polluted acid soil and application thereof

Abstract

The invention discloses a calcium-iron-silicon-based composite material for restoring heavy metal polluted acid soil and application thereof. The mass ratio of component elements of the composite material is calcium:iron:silicon:manganese:magnesium:phosphorus:aluminum= 30-40:19-25:8-12:1-3:5-6:1-3:2-5, the composite material is particularly prepared from, by volume, 55-70% of calcium silicate, 20-30% of calcium ferrite and 5-15% of compound mixture, and the compound mixture is a mixture of calcium-iron-aluminum oxides, calcium iron silicate, calcium aluminate, calcium-aluminum oxides, calcium-manganese-iron oxides, hydroxyl aluminium phosphate and hydroxyl manganese phosphate. The composite material is used for improving and restoring the heavy metal polluted acid soil, the pH value of the soil can be increased by 0.5-2.5 units, the content of effective state heavy metal in the soil is reduced by 64-98%, the content of heavy metal in agricultural products is reduced by 33-94% compared with a control group, and the yield of the agricultural products is increased by 16-1412% compared with the control group.

Description

technical field [0001] The invention belongs to the technical field of soil pollution restoration. More specifically, it relates to a calcium-iron-silicon-based composite material for remediating acidic soil polluted by heavy metals and its application. Background technique [0002] With the rapid development of society and economy, the human demand for mineral resources is increasing day by day, and the environmental problems brought about by mining activities are becoming more and more serious. [0003] The unreasonable discharge of acidic mineral water formed during mining and metal smelting has led to ecological degradation in mining areas and serious pollution of farmland. Acid mine water polluted farmland mainly has two problems: extremely acidic pH value and high heavy metal content. Heavy metal pollution of farmland not only leads to soil degradation, but also threatens human health through the food chain. It is particularly worth noting that due to the lack of ar...

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Problems solved by technology

[0004] The technical problem to be solved in the present invention is to overcome the defects of the existing soil heavy metal pollution and the deficiency of repairing technology, to provide a formula of calcium-iron-silicon-based composite material, and the composite material is resistant to heavy metals (Cd, Pb, As, Cr, Cu or Zn) compound pollution or single metal pollution acidic soil, especially paddy field and dry land soil (such as vegetables, corn, fruit trees or sugar cane and other economic crop land) remediation method, adjust the pH of acidic heavy metal polluted soil through calcium-based substances (improving soil acidity and Reduce the activity of heavy metals), regulate the accumulation effect of agricultural products such as rice and vegetables on heavy metals through iron-based and silicon-based substances, improve the soil environment, reduce the accumulation of heavy metals in agricultural products, realize the restoration of polluted soil, reduce the food safety risk of agricultural products and The triple benefit of increasing the output of agricultural products; the heavy metal content in the produced agricultural products meets the national food safety standards, and provides a cost-effective restoration method for the restoration of heavy metal-contaminated soils in southern my country, especially rice fields and vegetable soils