Microbial preparation efficiently converting heavy metal cadmium in contaminated soil and preparation method thereof

Abstract

The invention discloses a microbial preparation efficiently converting heavy metal cadmium in contaminated soil and a preparation method thereof. The microbial preparation is obtained by mixing and conducting enrichment cultivation on a flora 1 composed of candida, phialemonium, rhodosporidium toruloides and cryptococcus and a flora 2 composed of acidithiobacillu thiooxidans, acidithiobacillus caldus, leptospirum ferrooxidans, sulfobacillus thermosulfidooxidans, acidithiobacillus ferrooxidans and ferroplasma thermophilum. By using the microbial preparation for treating the cadmium contaminated soil, after the metal cadmium is converted to be a soluble state from an insoluble state, the removal rate is 70-82%, and the microbial preparation has the advantages of being high in conversion efficiency, short in cycle, low in cost, free of secondary pollution, easy to popularize and the like.

Description

technical field [0001] The invention belongs to the technical field of microbial treatment of heavy metal pollution, and in particular relates to a microbial bacterial agent capable of efficiently biotransforming the form of cadmium in polluted soil and a preparation method thereof. Background technique [0002] In recent years, my country has achieved world-renowned achievements in economic development. However, excessive industrial activities have brought serious environmental pollution, posed a serious threat to the health of residents, and brought huge hidden dangers to the sustainable development of society, economy and environment. . my country's rural environment is facing a variety of environmental problems, mainly including soil heavy metal pollution, soil fertility decline, cultivated land salinization, river water eutrophication, and environmental pollution caused by the abuse of pesticides, fertilizers, and insecticides. [0003] According to relevant national da...

AI Technical Summary

Problems solved by technology

[0005] Among the relevant patents that have been applied for in China, the patent "A Method for Microbial Remediation of Heavy Metal Contaminated Soil" (application number: 201110122739.6, publication date: 2011‐11‐16) discloses a method of treating soil with Rhodobacter sphaeroides preparations combined with flooding The method, whose working principle is mainly to use Rhodobacter sphaericus to absorb heavy metals after multiplying in a large amount in a water-rich anaerobic environment, and then infiltrate into the ground through water to reduce the concentration of heavy metals in the soil, but the soil cannot be used for planting operations during the treatment process. The economic cost is high. On the other hand, the strains are too single, the universality is poor, the scope of application is small, and the types and degrees of heavy metals that can be treated are relatively low.

The patent "Heavy Metal Contaminated Soil Microbial Restoration Agent and Its Application" (application number 201410682558.2, publication date: 2015‐04‐22) discloses a heavy metal contaminated soil treatment agent using Bacillus subtilis and Candida tropicalis as active ingredients, The bioremediation agent of this invention can adsorb a certain proportion of heavy metals and can remain in the soil for a period of time, but Candida tropicalis is anaerobic and cannot survive for a long time in dry and ventilated soil. Aerobic bacteria cannot survive for a long time in wet soil, and the living environment of the two effective strains conflicts. On the other hand, there are too few effective strains. Since each microorganism has its own limitations, its effect on soil treatment is neither long-lasting nor long-lasting. , not comprehensive