School of Food and Bioengineering, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China.
State Key Laboratory of Motor Vehicle Biofuel Technology, Nanyang 473000, China.
Int J Environ Res Public Health. 2019 Sep 30;16(19):3676. doi: 10.3390/ijerph16193676.
The objective of this study was to explore the effect of heavy metal-resistant bacteria and biochar (BC) on reducing heavy metal accumulation in vegetables and the underlying mechanism. We tested HC-2, BC, and BC+HC-2 for their ability to immobilize Cd and Pb in culture solution. We also studied the effects of these treatments on the dry weight and Cd and Pb uptake of radish in metal-contaminated soils under field conditions and the underlying mechanism. Treatment with HC-2, BC, and BC+HC-2 significantly reduced the water-soluble Cd (34-56%) and Pb (31-54%) concentrations and increased the pH and NH concentration in solution compared with their vales in a control. These treatments significantly increased the dry weight of radish roots (18.4-22.8%) and leaves (37.8-39.9%) and decreased Cd (28-94%) and Pb (22-63%) content in the radish roots compared with the control. Treatment with HC-2, BC, and BC+HC-2 also significantly increased the pH, organic matter content, NH content, and NH/NO ratio of rhizosphere soils, and decreased the DTPA-extractable Cd (37-58%) and Pb (26-42%) contents in rhizosphere soils of radish. Furthermore, BC+HC-2 had higher ability than the other two treatments to protect against Cd and Pb toxicity and increased biomass. Therefore, HC-2 combined with biochar can ensure vegetable safety in situ for the bioremediation of heavy metal-polluted farmland.
本研究旨在探索耐重金属细菌和生物炭（BC）对降低蔬菜重金属积累的影响及其作用机制。我们测试了 HC-2、BC 和 BC+HC-2 固定培养溶液中 Cd 和 Pb 的能力。我们还研究了这些处理方法在田间条件下受重金属污染土壤中对萝卜干重和 Cd 和 Pb 吸收的影响及其作用机制。与对照相比，HC-2、BC 和 BC+HC-2 处理显著降低了水溶态 Cd（34-56%）和 Pb（31-54%）浓度，提高了溶液 pH 值和 NH浓度。这些处理方法显著增加了萝卜根（18.4-22.8%）和叶（37.8-39.9%）的干重，降低了萝卜根中 Cd（28-94%）和 Pb（22-63%）的含量。与对照相比，HC-2、BC 和 BC+HC-2 处理还显著提高了根际土壤的 pH 值、有机质含量、NH 浓度和 NH/NO 比，降低了根际土壤中 DTPA 可提取 Cd（37-58%）和 Pb（26-42%）的含量。此外，BC+HC-2 比其他两种处理方法更能保护萝卜免受 Cd 和 Pb 毒性的影响，增加了生物量。因此，HC-2 与生物炭相结合可以确保原位蔬菜安全，用于农田重金属污染的生物修复。
