Chromium polluted soil composite microbial repairing agent, preparation method and application thereof

Abstract

The invention provides a chromium polluted soil composite microbial repairing agent, which includes at least one chemical reductant and an active bacterium. The active bacterium at least contains one thermophilic-carbon oxide streptomycete. The invention also provides a preparation method of the chromium polluted soil composite microbial repairing agent. The method includes: mixing the chemical reductant, the active bacterium, an optional carrier and an optional nutrient evenly in proportion. The chromium polluted soil composite microbial repairing agent provided by the invention can quickly reduce the hexavalent chromium in soil and reduce the concentration of hexavalent chromium, is conducive to bacterial colonization growth, and the oxidation product of additives also provides rich nutrition for bacteria to promote the growth of bacteria, and the reduction effect and nutrition effect synergistically promote reduction of hexavalent chromium to nontoxic trivalent chromium so as to achieve the repairing goal. According to the technology, the repairing cost is low, and the project is convenient. The invention provides a new method for soil microbial repairing, and has very good popularization and application value.

Description

technical field [0001] The invention relates to a microbial additive for repairing soil polluted by chromium (VI), a preparation method of the repairing agent, and an application of the composite microbial repairing agent in soil repairing. Background technique [0002] With the rapid development of electroplating, tanning, fuel and other industries, chromium and its compounds are widely used as the main raw materials of these industries. In the production process, a large amount of chromium-containing wastewater, waste gas, and waste residue are discharged into the environment, which leads to the pollution of the environment, especially the soil environment. The pollution of chromium in the soil spreads rapidly and the degree of pollution gradually deepens. It has the characteristics of long residual time, strong concealment, high toxicity, etc., and can be transmitted and migrated through the food chain, directly or indirectly causing great harm to animals, plants and huma...

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Problems solved by technology

[0004] At present, the traditional soil chromium pollution remediation methods include immobilization / stabilization technology. Using this method to remediate chromium-contaminated soil requires excavating the soil, and the cost is high; chemical reduction technology, the principle is to use chemical reducing agents to reduce hexavalent chromium After precipitation of trivalent chromium hydroxide or iron and chromium hydroxide, it can be transformed into a fixed state in the surrounding environment, thereby reducing the mobility and bioavailability of chromium in the environment, thereby reducing the harm of chromium pollution, but when When hexavalent chromium exists inside the soil particles, it is difficult to contact with the reducing agent and undergo a reduction reaction; chemical leaching technology refers to the use of solvents that can promote the dissolution or migration of pollutants in the soil environment, and the use of hydraulic pressure to push the cleaning solution through Clean the chromium out of the soil by polluting the soil, then extract the liquid containing pollutants from the soil layer, and then process the cleaning liquid containing chromium. This method is prone to secondary pollution problems; phytoremediation technology is Utilizing the unique utilization and transformation of pollutants by plants, the pollutants can be degraded and detoxified through oxidation-reduction or hydrolysis. This method has incomparable advantages in physical and chemical restoration, but phytoremediation is resistant to pollutants. It is limited, suitable for remediation of soils that are not very polluted but only shallowly polluted, and plant growth requires suitable environmental conditions, and the growth cycle is generally longer

[0005] The above-mentioned traditional soil remediation technologies have their corresponding shortcomings and have not been widely used, while microbial remediation technology has gradually become a potential soil remediation technology.

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