Department of Oceanography, University of Dhaka, Dhaka 1000, Bangladesh; Department of Oceanography, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh.
Department of Oceanography, University of Dhaka, Dhaka 1000, Bangladesh.
Ecotoxicol Environ Saf. 2020 Apr 15;193:110347. doi: 10.1016/j.ecoenv.2020.110347. Epub 2020 Feb 27.
We aimed to determine the temporal variation of trace metals concentrations in surface water and surface sediment samples at Kutubdia Channel, Bangladesh. Trace metals of samples were detected using energy dispersive X-ray fluorescence (Energy-dispersive X-ray spectroscopy) method. The lowest concentration of metals was found in water samples during post-monsoon season and the highest during pre-monsoon season (Cu: 0.030 ± 0.001 μg/L in pre-monsoon and 0.026 ± 0.002 μg/L in post-monsoon, Zn: 0.087 ± 0.003 μg/L in pre-monsoon and 0.073 ± 0.002 μg/L in post-monsoon, Fe: 0.080 ± 0.001 μg/L in pre-monsoon and 0.055 ± 0.001 μg/L in post-monsoon). In contrast, metal concentration in surface sediment samples were higher in post-monsoon than in pre-monsoon season i.e. Cr 11 mg/kg in pre-monsoon and 12 mg/kg in post-monsoon, Mn 571 mg/kg in pre-monsoon and 606 mg/kg in post-monsoon, As (8 mg/kg in pre-monsoon and 10 mg/kg in post-monsoon, Pb (22 mg/kg in pre-monsoon and 24 mg/kg in post-monsoon, and Fe 2317 mg/kg in pre-monsoon and 2435 mg/kg in post-monsoon. We found a spatial gradient of high to medium to low in trace metal concentration from river to river mouth to offshore area. Considering the sources of metals, land erosion by waves and tidal action, an influx of water and sediment from the surrounding rivers, agricultural waste, industrial effluent and sewage are the most likely sources of metal pollution in the study area. We conclude that proper management strategies should be adopted to control the pollution and conserve the ecosystem health.
我们旨在确定孟加拉国库图迪亚海峡表层水和表层沉积物中痕量金属浓度的时间变化。使用能量色散 X 射线荧光（能量色散 X 射线光谱法）方法检测样品中的痕量金属。在季风前季节，金属浓度最低，在季风后季节最高（Cu：季风前为 0.030±0.001μg/L，季风后为 0.026±0.002μg/L，Zn：季风前为 0.087±0.003μg/L，季风后为 0.073±0.002μg/L，Fe：季风前为 0.080±0.001μg/L，季风后为 0.055±0.001μg/L）。相比之下，表层沉积物中的金属浓度在季风后季节高于季风前季节，即 Cr 在季风前为 11mg/kg，在季风后为 12mg/kg，Mn 在季风前为 571mg/kg，在季风后为 606mg/kg，As（季风前为 8mg/kg，季风后为 10mg/kg，Pb（季风前为 22mg/kg，季风后为 24mg/kg，Fe 在季风前为 2317mg/kg，在季风后为 2435mg/kg。我们发现从河流到河口再到近海区域，痕量金属浓度存在从高到中到低的空间梯度。考虑到金属的来源，波浪和潮汐作用导致的陆地侵蚀、周围河流的水和沉积物涌入、农业废物、工业废水和污水是研究区域金属污染的最可能来源。我们得出结论，应该采取适当的管理策略来控制污染并保护生态系统健康。
