Modified biomass charcoal and remediation method of heavy metal contaminated soil

Abstract

The invention relates to modified biomass charcoal and a remediation method of heavy metal contaminated soil. The modified biomass charcoal is prepared by the following steps: (1) sieving biomass charcoal, and washing so as to remove surface fly dust and impurities until the pH value of a scrubbing solution is 6.5-7.5; (2) uniformly mixing the biomass charcoal and a phosphoric acid solution according to the mass ratio of 1 to (1.5-2.5), and then soaking at room temperature for 24 hours above, wherein the mass percent concentration of the phosphoric acid solution is 10-40%; and (3) carrying out solid-liquid separation on the soaking solution, and then drying the obtained a solid material, namely the modified biomass charcoal. The modified biomass charcoal is reasonable in design, is simple in technology, and overcomes the technical difficulty for a long time; phosphoric acid is detained in the biomass charcoal in the form of metaphosphoric acid, and especially can form sediment substances together with active heavy metal ions under a water containing condition, thereby intensifying the passivation or fixing effect to the heavy metal ions by the biomass charcoal.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a modified biochar suitable for remediation of heavy metal-contaminated soil and a method for remediating heavy metal-contaminated soil. Background technique [0002] With the rapid development of my country's industry, especially with the rapid development of mining, non-ferrous metal smelting and other industries, a large amount of heavy metals are discharged into the soil environment during the production process (such as lead and cadmium, etc. are more common). Heavy metal pollution has caused a huge threat to my country's food security and food security. Restoring or improving the soil polluted by heavy metals to ensure food security in my country has become a top priority. [0003] At present, there are many methods to reduce or repair heavy metal content in low soil, but it takes a long time and the effect is not ideal. The use of biomass acti...

AI Technical Summary

Problems solved by technology

In current studies, nitric acid is often used to modify activated carbon, which can significantly reduce the ash content of activated carbon, reduce the pH value of activated carbon, reduce the specific surface area of ​​activated carbon, and increase the surface oxygen content of activated carbon, thus greatly affecting the structure and surface functional groups of activated carbon. Impact

However, the effect of activated carbon modified with nitrate substances on soil heavy metal pollution remediation is still unsatisfactory.

For a long time, environmental protection workers have been eager to improve the modification method of activated carbon to improve the remediation effect of activated carbon on heavy metal-contaminated soil, but no significant progress has been made.

[0004] Therefore, biochar itself contains impurities and has low adsorption stability efficiency, and it is urgent to seek an effective biochar modification measure to further enhance its heavy metal adsorption capacity.

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