Seasonal variations in heavy metals in water and sediment samples from River Tano in the Bono, Bono East, and Ahafo Regions, Ghana
Seasonal variations in heavy metals in water and sediment samples from River Tano in the Bono, Bono East, and Ahafo Regions, Ghana
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DOI：
10.1007/s10661-019-7744-1
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发表时间：
2019-09-01
影响因子：
3
通讯作者：
Fei-Baffoe, B.
中科院分区：
文献类型：
--
作者：
Nyantakyi, A. J.;Akoto, O.;Fei-Baffoe, B.
2016年11月至2017年10月，利用珀金埃尔默原子吸收分光光度计（AAS）研究了塔诺河36个水和36个沉积物样品中汞（Hg）、镉（Cd）、锌（Zn）、铅（Pb）、砷（As）、铜（Cu）和铬（Cr）金属浓度的季节变化。除Pb和Cd含量在旱季较高外，雨季水体和底泥中重金属含量均显著高于旱季。铜仅在沉积物样品中检测到。在空间上，两季河源均未受污染，但中下游汞、铅、镉污染严重，除锌外，其余重金属均超过WHO饮用水标准。在沉积物中，Cd、Hg和Cr的浓度超过了美国环保署的指导标准。Igeo和浓度因子分析显示，沉积物中Cu、Pb、As和Cr未受污染，接近本底浓度，Hg和Cd处于中度至重度污染范围。所有的金属之间都有显著的相关性，表明水的共同来源。因此，将塔诺河中游和下游未经处理的水用于家庭用途仍然存在风险。建议执行缓冲区政策，以避免河水和沉积物质的进一步恶化。
Seasonal variations in mercury (Hg), cadmium (Cd), zinc (Zn), lead (Pb), arsenic (As), copper (Cu), and chromium (Cr) metal concentrations in 36 water and 36 sediment samples from River Tano were studied using Perkin Elmer atomic absorption spectrophotometer (AAS) between November 2016 and October 2017. Significantly higher metal concentrations were recorded in rainy season than dry season for both water and sediment except for Pb and Cd where sediment concentrations were higher in the dry season. Cu was detected only in the sediment samples. Spatially the source of the river is unpolluted for all the metals in both seasons but the midstream and downstream ends of the river were heavily polluted by Hg, Pb, and Cd. All the heavy metals studied except Zn exceeded the WHO standards for drinking water. In the sediment, Cd, Hg, and Cr concentrations exceeded the USEPA guidelines. Igeo and Concentration Factor analysis revealed unpolluted sediments in terms of Cu, Pb, As, and Cr. They were near the background concentrations but Hg and Cd were in the range of moderate to heavy pollution. All the metals correlated significantly among themselves to signify common source to the water. It thus remains risky to use untreated water from the midstream and downstream of River Tano for domestic purposes. Enforcement of the buffer zone policy is recommended to avert further deterioration of the river water and sediment qualities.