A passivation material for repairing cadmium-copper polluted acidic soil and its preparation method and application

Abstract

The invention provides a passivation material capable of repairing cadmium and copper-polluted acidic soil as well as a preparation method and application of the passivation material. The pH value of the passivation material is 10 to 13; the passivation material is prepared from the following raw materials in percentage by mass: more than or equal to 60 percent and less than or equal to 85 percent of biomass power plant ash, more than or equal to 10 percent and less than or equal to 25 percent of lime, and more than or equal to 5 percent and less than or equal to 15 percent of phosphorus lime. The passivation material takes the green and cheap biomass power plant ash as the main raw material, the biomass power plant ash is mixed with the lime and the phosphorus lime, any binding agent or a colloid auxiliary material is not added, and spherical grains are prepared; the granulation rate of the raw materials is more than 95 percent and the material returning rate is low. Negative influences of the auxiliary materials including the binding agent and the like can be avoided, and a raw material washing phenomenon is avoided; the application amount of the passivation material is less and only occupies 0.2 percent to 0.6 percent of the mass of soil of a plough layer; a heavy metal passivation effect is remarkable and stable, and the growth of plants is accelerated, so that the aim of efficiently and lastingly repairing the heavy metal cadmium and copper-polluted acidic soil in situ at a low cost is realized, and economic benefits, ecological benefits and a repairing effect are integrated.

Description

technical field

[0001] The invention belongs to the technical field of remediation of heavy metal-contaminated soil, and in particular relates to a composite passivation material with biomass power plant ash as the main raw material for treating cadmium-copper-contaminated soil, and a preparation method and application thereof. Background technique

[0002] In recent decades, with the rapid development of social economy, my country's farmland soil environment is facing unprecedented challenges, especially heavy metal cadmium pollution has become increasingly prominent, and heavy metal copper pollution in some areas has seriously exceeded the standard, causing crop failure. In 2014, the Ministry of Environmental Protection and the Ministry of Land and Resources issued the "National Soil Pollution Survey Bulletin", pointing out that the environmental quality of cultivated land soil is worrying, cadmium has become the primary pollutant (point exceeding the standard rate of 7.0%)...

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