Biological coal cinder granules for repairing pyrene and indeno (1,2,3-cd) pyrene contaminated soil

The invention provides a preparation method of biological coal cinder granules which are used for purifying high-molecular-weight polycyclic aromatic hydrocarbons (pyrene) and indeno (1,2,3-cd) pyrene in petroleum contaminated soil. The method is characterized by comprising the following steps: firstly, selecting high-efficiency degrading bacteria from the reported pyrene and indeno (1,2,3-cd) pyrene degrading bacteria, and inoculating an enriched liquid culture medium to the selected high-efficiency degrading bacteria to obtain the turbid solution of the pyrene and indeno (1,2,3-cd) pyrene degrading bacteria; then preparing a gel solution by taking the pretreated coal cinder as a carrier, and the modified PVA as a gel; and finally, mixing the turbid solution of the pyrene and indeno (1,2,3-cd) pyrene degrading bacteria and the sterilized gel solution uniformly according to the weight proportion of 10% to 20%, granulating by using a granulator with a sieve size of 4-10mm at room temperature to obtain immobilized granules, crosslinking the immobilized granules chemically for 12 hours by using a crosslinking agent, soaking in sterile water for 4 days, and proliferating and culturing for 3 days to obtain the biological coal cinder granules. Due to the porosity and high carrying capacity of coal cinder, the living environment of the degrading bacteria fixed in the biological coal cinder granules can be improved, and the environment impact resistance can be enhanced.