固定化微生物技术修复镉污染红黏土的室内试验研究

Indoor Experimental Study on Remediation of Cadmium-Contaminated Red Clay by Immobilized Microbial Technology

为了探究固定化微生物技术对镉(Cd)污染红黏土物理力学性质和环境污染的修复效应,以活性炭为载体,菌种选取巴氏芽孢杆菌,开展基本物理试验、无侧限抗压强度试验、毒性浸出试验和重金属形态提取试验。试验结果表明:巴氏芽孢杆菌对镉离子有较强的耐受性;对比单加微生物或活性炭,固定化微生物技术的修复效果更显著;14%活性炭微生物土样的无侧限抗压强度为229.7 kPa,较镉污染土提升174.7%;修复21 d后,10%活性炭微生物土样的镉离子浸出浓度降低到0.002 mg/L,较镉污染土样降低99.8%;修复后,土中的镉从弱酸态向可还原态和残渣态转化。总的来说,固定化微生物技术对镉污染红黏土具有良好的修复效果,活性炭的掺量以10%为宜。研究成果可为贵州省镉污染红黏土的治理提供参考。

To investigate the efficacy of immobilized microorganism technology in remediating cadmium(Cd) contamination in red clay and its impact on environmental pollution,we conducted a series of basic physical tests,unconfined compressive strength tests,toxic leaching tests,and heavy metal extraction tests.Activated carbon served as the carrier with Bacillus pasteuri as the strain.Results revealed Bacillus pasteuri' s robust cadmium ion tolerance.Compared to either microorganism or activated carbon alone,immobilized microorganism exhibited superior remediation efficacy.Unconfined compressive strength of soil containing 14% activated carbon and microorganisms reached 229.7 kPa,a 174.4% increase over cadmium-contaminated soil.Within 21 days,cadmium leaching concentration in soil containing 10% activated carbon and microorganisms decreased to 0.002 mg/L,down by 99.8%compared to Cd-contaminated soil samples.After remediation,cadmium in soil transitioned from a weak acid state to reducible and residual states.In summary,immobilized microorganism technology demonstrates effective remediation of cadmium-contaminated red clay,particularly at a 10% activated carbon concentration.These findings offer valuable insights for addressing cadmium pollution in red clay in Guizhou Province.