Sarkar Dhruba Jyoti, Das Sarkar Soma, Das Basanta Kumar, Sahoo Bigan Kumar, Das Akankshya, Nag Subir Kumar, Manna Ranjan Kumar, Behera Bijay Kumar, Samanta Srikanta
Aquatic Environmental Biotechnology and Nanotechnology Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata 700120, India.
Fisheries Resource Assessment and Informatics Division, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata 700120, India.
Water Res. 2021 Mar 15;192:116853. doi: 10.1016/j.watres.2021.116853. Epub 2021 Jan 19.
Microplastics pollution in aquatic ecosystems is of great concern; however, systemic investigations are still lacking in freshwater wetland systems used for wastewater treatment. The present study discusses such freshwater wetland system in Eastern India to understand its microplastics transport mechanism, heavy metals association and microplastics removal efficiency. Microplastics (63 µm - 5 mm) were heavily found in surface water and sediments of treatment ponds (7.87 to 20.39 items/L and 2124.84 to 6886.76 items/kg) and associated wastewater canals (30.46 to 137.72 items/L and 1108.78 to 34612.87 items/kg). A high content of toxic metals (As, Cd, Cr, Cu, Ni, Pb and Zn) were found on the microplastics with polyethylene terephthalate and polyethylene as major plastics types which were also found in fishes and macroinvertebrates of treatment ponds. Machine learning algorithm revealed a close association between microplastics content in fishes and surface water, indicating risk associated with floating microplastics to the aquatic biota. The study also revealed that microplastics were acting as heavy metals vector and potentially causing fish contamination. Surface water microplastics removing efficiency of the treatment ponds was estimated to be 53%. The study bespeaks about transport of microplastics through wastewater canals and their retention in treatment ponds emphasizing sustainability maintenance of natural wastewater treatment systems especially considering microplastics contamination to the aquatic biota of freshwater wetland systems.
水生生态系统中的微塑料污染备受关注；然而，用于废水处理的淡水湿地系统仍缺乏系统性研究。本研究探讨了印度东部的此类淡水湿地系统，以了解其微塑料传输机制、与重金属的关联以及微塑料去除效率。在处理池塘的地表水和沉积物（7.87至20.39个/升和2124.84至6886.76个/千克）以及相关废水渠道（30.46至137.72个/升和1108.78至34612.87个/千克）中大量发现了微塑料（63微米至5毫米）。在以聚对苯二甲酸乙二酯和聚乙烯为主要塑料类型的微塑料上发现了高含量的有毒金属（砷、镉、铬、铜、镍、铅和锌），这些微塑料也在处理池塘的鱼类和大型无脊椎动物中被发现。机器学习算法显示鱼类中的微塑料含量与地表水之间存在密切关联，表明漂浮微塑料对水生生物群存在风险。该研究还表明，微塑料充当了重金属载体并可能导致鱼类污染。处理池塘地表水微塑料的去除效率估计为53%。该研究说明了微塑料通过废水渠道的传输及其在处理池塘中的滞留情况，强调了自然废水处理系统可持续性的维持，特别是考虑到微塑料对淡水湿地系统水生生物群的污染。
