ABSTRACT

Total and sequentially extracted fractions (exchangeable, bound to carbonate, bound to iron and manganese oxides, bound to organic matter and residual) of eight heavy metals (Cu, Mn, Zn, Ni, Fe, Cr, Cd and Pb) were estimated in rhizosphere sediment along with their accumulation in roots and leaves of Phoenix paludosa plants at Dhamra estuary. The Cu, Mn, Zn, Ni, Fe, Cr, Cd and Pb content in rhizosphere sediments were 162.2, 563.3, 289.1, 228.8, 31,524.3, 475.5, 8.5 and 256.8 mg/kg, respectively. For almost all the heavy metals, sequential extraction estimation showed residual>bound to iron and manganese>bound to organic matter>bound to carbonate>exchangeable fractions. Exceptionally very high residual Cr (77.36%) and organic matter-bound Cd fraction (41.10%) highlighted the sedimentary mine run-off and industrial activities as their main source of pollution, respectively. Phoenix paludosa exhibited maximum bio-concentration (0.34), bio-accumulation (0.51) and translocation (0.50) factor for Cd. The primary results revealed the phyto-accumulation behaviour of different heavy metals in Phoenix paludosa and showed its relatively higher remediation potential for Cd and Cr pollution. In view of the above facts, heavy metals-polluted estuarine sites can be remediated through afforestation of Phoenix paludosa plant species.

摘要

估算了八种重金属（Cu，Mn，Zn，Ni，Fe，Cr，Cd和Pb）的总馏分和相继提取的馏分（可交换，与碳酸盐结合，与铁和锰氧化物结合，与有机物和残留物结合）。根际沉积物及其在凤凰树根和叶中的积累达姆拉河口的植物。根际沉积物中铜，锰，锌，镍，铁，铬，镉和铅的含量分别为162.2、563.3、289.1、228.8、31,524.3、475.5、8.5和256.8 mg / kg。对于几乎所有的重金属，顺序萃取估算显示残留量>与铁和锰结合>与有机物结合>与碳酸盐结合>可交换馏分。极高的残留铬含量（77.36％）和有机物结合的镉含量（41.10％）分别突出了矿山沉积径流和工业活动的主要污染源。Phoenix paludosa表现出最大的Cd生物浓度（0.34），生物富集（0.51）和易位（0.50）。初步结果揭示了凤凰重金属中不同重金属的植物累积行为并显示出较高的Cd和Cr污染修复潜力。鉴于以上事实，可以通过对Phoenix paludosa植物物种进行造林来修复重金属污染的河口。