Department of Environmental Science and Management, Bharathidasan University, Tiruchirappalli 620024, India.
Department of Environmental Science and Management, Bharathidasan University, Tiruchirappalli 620024, India.
Sci Total Environ. 2024 Nov 15;951:175715. doi: 10.1016/j.scitotenv.2024.175715. Epub 2024 Aug 23.
Heavy metals emanate from diverse anthropogenic activities and the top soil in the vicinity of these activities acts as an immediate sink and facilitates diffusion of heavy metals into the food chain. In the semi-arid plains of India, Prosopis juliflora is the most common and dominant weed along the motorways and barren lands including industrial environs. This investigation hypothesizes the adaptive nature of Prosopis juliflora in the metal enriched soils and attempts to understand its hyper-accumulating potential of metals besides bioconversion/detoxification capability. Prosopis juliflora samples (root, stem, leaves, and pods) from 100 sites in the environs of anthropogenic activities (vehicular emissions and industrial operations) were analyzed for heavy metal concentrations (Cu, Fe, Cr, Cd, Ni, Pb). Prosopis juliflora accumulate metals at the rate of 0.138 mg/kg/day DW for Copper (Cu), Fe: 0.142 mg/kg/day DW, Cr: 0.114 mg/kg/day DW, Ni: 0.048 mg/kg/day DW, Pb: 0.052 mg/kg/day DW, Cd: 0.009 mg/kg/day DW. Furthermore, X-ray Photoelectron Spectroscopy (XPS) metal oxidation state analysis revealed that in the pods of Prosopis juliflora heavy metals (Fe, Cr, Pb) largely existed in non-toxic form (toxic:non-toxic - 3:6), while in the under canopy soil, metals predominantly existed in toxic form (toxic:non-toxic - 7:2); conclusively XPS results ascertains the heavy metal bioconversion/detoxification potential of the plant. These findings suggest that presence of Prosopis juliflora coppice in the barren landscapes across the transportation corridors and metal based industrial zones may ideally favor phyto-remediation of heavy metals.
重金属来源于各种人为活动，这些活动附近的表土是重金属的直接汇，促进了重金属向食物链扩散。在印度半干旱平原，刺槐是高速公路和荒地（包括工业环境）最常见和占主导地位的杂草。本研究假设刺槐在富含金属的土壤中的适应性，并试图了解其对金属的超积累潜力以及生物转化/解毒能力。对来自人为活动（车辆排放和工业作业）环境 100 个地点的刺槐（根、茎、叶和荚）样本进行重金属浓度（Cu、Fe、Cr、Cd、Ni、Pb）分析。刺槐以 0.138 mg/kg/天 DW 的速率积累铜（Cu），Fe：0.142 mg/kg/天 DW、Cr：0.114 mg/kg/天 DW、Ni：0.048 mg/kg/天 DW、Pb：0.052 mg/kg/天 DW、Cd：0.009 mg/kg/天 DW。此外，X 射线光电子能谱（XPS）金属氧化态分析表明，在刺槐的荚中，重金属（Fe、Cr、Pb）主要以无毒形式存在（有毒：无毒 - 3：6），而在树冠下的土壤中，金属主要以有毒形式存在（有毒：无毒 - 7：2）；XPS 结果最终确定了植物对重金属的生物转化/解毒潜力。这些发现表明，在运输走廊和金属基工业区的荒地中存在刺槐灌丛，可能非常有利于重金属的植物修复。
