Plant and in-situ remediation method for heavy metal contaminated soil

Abstract

The invention discloses a plant and in-situ remediation method for heavy metal contaminated soil. The plant and in-situ remediation method comprises the following steps that (1) contaminated soil is mixed with soil modifiers to be subjected to modified treatment; (2) a heavy metal ion passivator and water are mixed at the solid-liquid rate of 1:10 and then sprayed on the soil by 20 kg / m<2> to conduct remediation treatment; (3) fertilizers are applied to the treated soil, and then plants are grown, rooted out after growing for 4-6 months, dried in the sun and burned; and (4) burned plant ash is added into chelating agent solution and then put into a reactor containing a graphite electrode, and heavy metal pollutants migrating from the soil are captured through adsorption material on the graphite electrode. The plant and in-situ remediation method for heavy metal contaminated soil is small in work amount, low in cost, easy and convenient to operate, high in remediation efficiency and high in available value.

Description

technical field [0001] The invention relates to the field of remediation and treatment of heavy metal-contaminated soil, in particular to a method for in-situ remediation of heavy metal-contaminated soil by combining plants. Background technique [0002] With the rapid development of industry and economy, the soil in many areas of our country is polluted by heavy metals to varying degrees, and the polluted area and degree of pollution are constantly expanding. According to the survey of the Ministry of Agriculture, the land area polluted by heavy metals in my country accounts for 100% of the sewage irrigation area. 64.8% of the total area. Cadmium that pollutes the environment mainly comes from waste water, waste gas and waste residues discharged by metal mines, non-ferrous metal smelting, electroplating, alloy manufacturing, and glass, ceramics, paints and pigments. [0003] At present, there are mainly four methods for soil heavy metal pollution control: physical engineeri...

AI Technical Summary

Problems solved by technology

Each method has its advantages and disadvantages: using engineering measures to control heavy metal-contaminated soil has the advantages of thorough and stable effects, but the amount of engineering is large, the cost of treatment is high, and it is easy to cause soil fertility to weaken

The implementation of biological measures is relatively simple, with less investment and less disturbance to the environment, but the treatment efficiency is low (such as hyperaccumulator plants are usually short, low biomass, slow growth and long cycle), and cannot treat heavily polluted soil (due to high resistance to heavy metals) Plants are hard to find)

However, the microorganisms added to the soil environment of the remediation site have poor resistance, are difficult to adapt quickly, have poor mobility in the soil environment, and are easily inhibited by the toxic effects of pollutants

The use of agricultural measures to treat heavy metal-contaminated soil has the advantages of combining with conventional agricultural operations, low cost, and convenient implementation, but there are some disadvantages such as long cycle and insignificant effect.