Method for repairing heavy metal contaminated soil

Abstract

The invention relates to a method for repairing heavy metal contaminated soil. According to the method, organic acid and a seaweed organic polymer oxidant are utilized to realize reduction conversionof heavy metals in the soil, and a seaweed organic polymer energy agent is utilized to realize flocculating settling of the heavy metals. The method for repairing the heavy metal contaminated soil hasthe beneficial effects that the form of the heavy metals can be effectively changed, the proportion of the stable state of the heavy metals is increased, and the mobility, solubility and bioavailability of the heavy metals are reduced; only organic substances are used for reducing, stabilizing and settling heavy metal pollutants, especially heavy metal cadmium and hexavalent chromium, in farmlandsoil, the cultivation function of the soil is not damaged, the side effect of soil hardening is avoided, and secondary pollution is avoided; and the method is short in treatment time, quick in effect, easy to operate and applicable to paddy fields and dry fields, especially cadmium-polluted paddy fields.

Description

technical field [0001] The invention belongs to the technical field of soil treatment, and in particular relates to a method for repairing heavy metal polluted soil. Background technique [0002] Heavy metals are pollutants in the ecological environment that have great potential harm to humans and other lives. It is basically not decomposed by microorganisms in the environment. On the contrary, when heavy metals are soluble and mobile, they can migrate to organisms such as animals and plants. Heavy metals can migrate through water and soil to the crops and plants eaten by humans and animals. Once humans and animals consume these crops and plants containing heavy metals, it will be very harmful. The scientific community has already proved the hazards of heavy metals, and has been seeking various effective methods to solve the problem of heavy metals in soil. The horror of heavy metal pollution also lies in its potential and long-term harm. In the initial stage of heavy meta...

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Problems solved by technology

However, these methods all have some deficiencies and defects, which are concentrated in: the method for plant adsorption of heavy metals takes a long time and is slow to take effect, and requires farmland to be fallow, which directly affects the normal cultivation of rice; the method for absorbing heavy metals by microorganisms has poor absorption effect, Moreover, there are potential hidden dangers to the safety and stability of long-term cultivation of farmland; the use of chemical substances to absorb heavy metals or change the form of heavy metals may cause secondary pollution of the soil, which will affect the normal farming function of the soil; after the heavy metals are reduced and stabilized, when When chemical fertilizers or pesticides are used, it is easy to restore the original state

By changing the agronomy and using lime to increase the pH value of the soil and keep the paddy field covered with water, the operation is complicated and it is easy to cause soil compaction, which will affect the grain yield.

Soil replacement by physical methods is basically not feasible due to the heavy workload and high cost

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