Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
International Research Center in Critical Raw Materials for Advanced Industrial Technologies (ICCRAM), University of Burgos, Centro de I+D+I, Plaza Misael Bañuelos s/n, 09001, Burgos, Spain.
J Environ Manage. 2024 Nov;370:122575. doi: 10.1016/j.jenvman.2024.122575. Epub 2024 Sep 20.
Metal contamination in soil poses environmental and health risks requiring effective remediation strategies. This study introduces an innovative approach of synergistically employing biochar and bacterial inoculum of Serratia marcescens to address toxic metal (TM) contamination. Physicochemical, enzymatic, and microbial analyses were conducted, employing integrated biomarker response (IBR) and machine-learning approaches for toxicity estimation. The combined application significantly reduced the Cd, Cr, and Pb concentrations by 71.6, 31.2, and 57.1%, respectively, while the Cu concentration increased by 85% in the individual Serratia marcescens treatment. Biochar enhanced microbial biomass by 33-44% after 25 days. Noteworthy physicochemical improvements included a 44.7% increase in organic content and a decrease in pH and electrical conductivity. The K⁺ and Ca⁺ concentrations increased by 196.9 and 21.6%, respectively, while the Mg⁺ content decreased by 86.4%. Network analysis revealed intricate relationships, displaying direct and indirect negative correlations between metals and soil physicochemical parameters. The IBR index values indicated effective mitigation of TM toxicity in Serratia marcescens and biochar with individual and combined treatments. Binary classification demonstrated high sensitivity (80.1%) and specificity (80.5%) in identifying TM-contaminated soil. These findings indicate significant biochar- and Serratia marcescens-induced impacts on toxic metal availability, physicochemical properties, and enzymatic activities in metal-contaminated soil, suggesting that blending soil with biochar and microorganisms is an effective remediation strategy.
土壤中的金属污染物对环境和健康构成风险，需要采取有效的修复策略。本研究提出了一种创新方法，即协同使用生物炭和粘质沙雷氏菌细菌接种物来解决有毒金属（TM）污染问题。通过采用综合生物标志物响应（IBR）和机器学习方法进行毒性评估，进行了理化、酶和微生物分析。联合应用显著降低了 Cd、Cr 和 Pb 的浓度，分别降低了 71.6%、31.2%和 57.1%，而单独使用粘质沙雷氏菌处理时 Cu 的浓度增加了 85%。生物炭在 25 天后使微生物生物量增加了 33-44%。值得注意的理化性质改善包括有机含量增加 44.7%，pH 值和电导率降低。K⁺和 Ca⁺浓度分别增加了 196.9%和 21.6%，而 Mg⁺含量降低了 86.4%。网络分析显示了金属与土壤理化参数之间存在直接和间接的负相关关系。IBR 指数值表明，单独和联合处理粘质沙雷氏菌和生物炭对 TM 毒性有有效缓解作用。二进制分类显示出对 TM 污染土壤的高灵敏度（80.1%）和特异性（80.5%）。这些发现表明，生物炭和粘质沙雷氏菌对有毒金属的有效性、土壤理化性质和酶活性有显著影响，表明将生物炭和微生物混入土壤是一种有效的修复策略。
