Study On The Treatment Of Water Cr(Ⅵ) Pollution By Iron-based Mineral Materials And Functional Microbial Flora And Their Mechanisms

Rapid industrial development has led to an increase in the discharge of Cr(VI)-containing wastewater,causing environmental problems such as biotoxicity and potential carcinogenicity.The conventional removal methods face problems such as high cost,complicated operation and narrow scope of application.Therefore,in this study,the modified iron-based mineral materials were synthesized as Cr(VI)remediation agents using the inexpensive and widely available ironcontaining secondary minerals potassium iron alum and waste sugarcane bagasse,and the modified iron-based mineral materials were investigated in depth with the help of XRD,XPS,Raman spectroscopy,BET,ESR,electrochemistry and other detection and analysis methods.The mechanism of Cr(VI)reduction by iron-based mineral materials was investigated.The microbial communities and native soil/iron containing minerals enriched around the chromium salt plant were also used as raw materials to investigate the treatment of Cr(VI)pollution in water bodies and its mechanisms,and the main conclusions were as follows:(1)The Cr(VI)reducer jarosite@BC-300 °C was prepared in one step using secondary iron-based minerals and biomass with a "hollow tubular structure",which has the advantages of fast(equilibrium in 10 min),high efficiency(removal up to 79.1 mg/L)and wide pH range.The material has excellent performance.(2)There is a synergistic effect between the native soil and the microbial community,with the native soil + microbial group being 1.8times more efficient in removal than the microbial group alone.In addition,the biological method overcomes the disadvantage that the composite material is not recyclable and has the ability to continuously reduce Cr(VI).(3)The addition of Fe-containing minerals to the microbial system helped to enhance the removal of Cr(VI).Of the four different Fecontaining minerals,the rhombohedral magnetic pyrite was the most effective in promoting the microbial reduction of Cr(VI),being 1.6 times more effective than the pure microbial group.