Effectiveness of Pteroceltis tatarinowii Biochar in Enhancing Chlorophytum comosum for Remediation of Soil with Combined Contamination of Cu and Pb

［Objective］ To investigate the effect of applying Pteroceltis tatarinowii biochar on the remediation of soil with combined contamination of Cu and Pb by Chlorophytum comosum. ［Methods］ Taking the farmland soil with combined contamination of Cu and Pb around the copper tailings in Laoyaling, Tongling City as the research object, pot planting test method was used to grow C. comosum in the soil with different mass ratios of Pteroceltis tatarinowii biochar (1%, 3%, 5%, 7% and 10%). The pots without adding P. tatarinowii biochar were taken as the blank group, and the pots without planting C. comosum were set as the control group. The effects of different mass ratios of P. tatarinowii biochar on remediation of Cu- and Pb-contaminated soil by C. comosum were studied, and the potential of P. tatarinowii biochar in enhancing the remediation of Cu- and Pb-contaminated soil was evaluated. ［Results］ Plant height, root length and underground fresh weight of C. comosum were significantly increased by adding P. tatarinowii biochar. Soil pH, organic matter, total nitrogen, available phosphorus and available potassium were significantly increased. The mass fractions of available Cu and Pb in soil were significantly decreased, and the uptake of Cu and Pb by C. comosum was significantly increased. The maximum increases of Cu and Pb in the above-ground part are 51.39% and 59.77%, respectively, and the maximum increases of Cu and Pb in the undergroud part are 15.63% and 45.46%, respectively. The maximum enrichment and transfer coefficients were 0.61 and 0.40 for Cu and 0.37 and 0.68 for Pb, respectively. The relative abundances of Acidobacteria and Proteobacteria were decreased, while the relative abundances of Chloromycetes and Bacteroidetes were increased, and the soil nutrient metabolism was promoted. ［Conclusion］ Combined application of P. tatarinowii and C. comosum has better remediation effect.