Department of Civil Engineering, Indian Institute of Technology, Guwahati, 781039, India.
Environ Sci Pollut Res Int. 2024 Aug;31(40):53552-53569. doi: 10.1007/s11356-024-34734-4. Epub 2024 Aug 28.
Advances in sustainable toxic heavy metal treatment technologies are crucial to meet our needs for safer land to develop an urban resilient future. The heavy metals bioaccumulate in the food chain due to their persistence in the soil, which poses a serious challenge to its removal and control. Utilisation of hyperaccumulators to reduce the mobility, accumulation and toxic impact of heavy metals is a promising and ecologically safe technique. Amendments such as biochar and chelates have been shown to enhance the phytoremediation efficiency. However, the potential soil improvement is influenced by the properties of the amendment, plant and metal heterogeneities. In this study, an organic sugarcane bagasse biochar amendment for the 60-day pot experiment using Catharanthus roseus L. (NT) and Chrysopogon zizanioides L. (VT) in a heavy metal-contaminated soil was applied. The influence of biochar on the phytoremediation of lead (Pb), zinc (Zn) and cadmium (Cd) from the soil was explored. The plant survival rate enhanced to 100% with biochar amendment, and the biomass increased from 5.83 to 15 g in Zn-contaminated samples. Nutrients such as potassium concentration are directly correlated to the amendment rates, whereas phosphate decreases beyond the 2% biochar amendment rate in both plants. High heavy metal accumulation capacities with improved growth with biochar indicate the sustainability of the process. The translocation factor (TF) > 1 for Zn in NT represents the phytoextraction efficiencies whereas VT indicates high BCF values in the range of 0.5-3.53 for the amended Zn-contaminated soils. The findings indicate that the amendment rate of 2% improves nutrient cycling, plant biomass and heavy metal removal efficiencies. The insights from this study establish that the synergy between biochar amendment and the selected medicinal plants improved the phytoremediation efficiency.
可持续的有毒重金属处理技术的进步对于满足我们对更安全土地的需求至关重要，以开发具有弹性的城市未来。由于重金属在土壤中持久存在，它们会在食物链中生物累积，这对其去除和控制构成了严重挑战。利用超累积植物来降低重金属的迁移性、积累性和毒性影响是一种很有前途且生态安全的技术。生物炭和螯合剂等改良剂已被证明可以提高植物修复效率。然而，土壤改良的潜力受到改良剂、植物和金属异质性的特性的影响。在这项研究中，使用卡特兰（NT）和香根草（VT）在受重金属污染的土壤中进行了为期 60 天的盆栽实验，应用了一种有机甘蔗渣生物炭改良剂。研究了生物炭对土壤中铅（Pb）、锌（Zn）和镉（Cd）的植物修复的影响。生物炭的添加使植物存活率提高到 100%，锌污染样本中的生物量从 5.83 增加到 15g。钾浓度等营养物质与改良剂的添加率直接相关，而在两种植物中，磷酸盐的添加率超过 2%时会减少。生物炭的高重金属积累能力和生长改善表明该过程具有可持续性。NT 中 Zn 的转运因子（TF）>1 代表了植物提取效率，而 VT 在添加 Zn 污染土壤的范围内表示高 BCF 值为 0.5-3.53。研究结果表明，添加率为 2%的改良剂提高了养分循环、植物生物量和重金属去除效率。这项研究的结果表明，生物炭改良剂与选定药用植物之间的协同作用提高了植物修复效率。
