Wang Yuanzheng, Cai Yuhao, Wu Yuxuan, Yan Caiya, Dang Zhi, Yin Hua
School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangzhou 510006, China.
Materials (Basel). 2024 Jun 5;17(11):2763. doi: 10.3390/ma17112763.
Compound contamination of soil with heavy metals copper (Cu) and lead (Pb) triggered by mining development has become a serious problem. To solve this problem, in this paper, corncob kernel, which is widely available and inexpensive, was used as the raw material of biochar and modified by loading CaAl-layered double hydroxides to synthesize biochar-loaded CaAl-layered double hydroxide composites (CaAl-LDH/BC). After soil remediation experiments, either BC or CaAl-LDH/BC can increase soil pH, and the available phosphorus content and available potassium content in soil. Compared with BC, CaAl-LDH/BC significantly reduced the available content of Cu and Pb in the active state (diethylenetriaminepentaacetic acid extractable state) in the soil, and the passivation rate of Cu and Pb by a 2% dosage of CaAl-LDH/BC reached 47.85% and 37.9%, respectively. CaAl-LDH/BC can significantly enhance the relative abundance of beneficial microorganisms such as , , and in the soil, which can help to enhance the tolerance and reduce the enrichment ability of plants to heavy metals. In addition, it was demonstrated by pea seedling ( L.) growing experiments that CaAl-LDH/BC increased plant fresh weight, root length, plant height, catalase (CAT) activity, and protein content, which promoted the growth of the plant. Compared with BC, CaAl-LDH/BC significantly reduced the Cu and Pb contents in pea seedlings, in which the Cu and Pb contents in pea seedlings were reduced from 31.97 mg/kg and 74.40 mg/kg to 2.92 mg/kg and 6.67 mg/kg, respectively, after a 2% dosage of CaAl-LDH/BC, which was a reduction of 90.84% and 91.03%, respectively. In conclusion, compared with BC, CaAl-LDH/BC improved soil fertility and thus the plant growth environment, and also more effectively reduced the mobility of heavy metals Cu and Pb in the soil to reduce the enrichment of Cu and Pb by plants.
采矿开发引发的土壤中重金属铜（Cu）和铅（Pb）的复合污染已成为一个严重问题。为解决这一问题，本文以广泛可得且价格低廉的玉米芯为生物炭原料，并通过负载钙铝层状双氢氧化物进行改性，合成了负载生物炭的钙铝层状双氢氧化物复合材料（CaAl-LDH/BC）。经过土壤修复实验，BC和CaAl-LDH/BC均可提高土壤pH值以及土壤中有效磷含量和有效钾含量。与BC相比，CaAl-LDH/BC显著降低了土壤中活性态（二乙烯三胺五乙酸可提取态）Cu和Pb的有效含量，2%用量的CaAl-LDH/BC对Cu和Pb的钝化率分别达到47.85%和37.9%。CaAl-LDH/BC可显著提高土壤中有益微生物如 、 和 的相对丰度，有助于增强植物对重金属的耐受性并降低其富集能力。此外，豌豆幼苗（L.）生长实验表明，CaAl-LDH/BC增加了植物鲜重、根长、株高、过氧化氢酶（CAT）活性和蛋白质含量，促进了植物生长。与BC相比，CaAl-LDH/BC显著降低了豌豆幼苗中的Cu和Pb含量，2%用量的CaAl-LDH/BC处理后，豌豆幼苗中的Cu和Pb含量分别从31.97 mg/kg和74.40 mg/kg降至2.92 mg/kg和6.67 mg/kg，分别降低了90.84%和91.03%。总之，与BC相比，CaAl-LDH/BC改善了土壤肥力，从而改善了植物生长环境，还更有效地降低了土壤中重金属Cu和Pb的迁移性，减少了植物对Cu和Pb的富集。
