Wijeyaratne W M Dimuthu Nilmini, Wickramasinghe P G Minola Udayangani
Department of Zoology and Environment Management, Faculty of Science, University of Kelaniya, Kelaniya, Sri Lanka.
J Toxicol. 2020 Aug 3;2020:8814196. doi: 10.1155/2020/8814196. eCollection 2020.
Appropriate effluent treatment processes are expected to significantly reduce the toxicity of effluents before they are released to the natural environment. The present study was aimed to assess the spatial and temporal variations of the physical and chemical water quality parameters of a natural water body receiving treated textile effluents and to assess the chromosomal abnormalities induced by the treated textile effluents. Four sampling sites (A: effluent discharge point; B: 100 m downstream from site A along the tributary; C: 200 m downstream from site A along the tributary; D: 100 m upstream from site A along the tributary) were selected associated to a tributary that received treated textile effluent. The physical and chemical water quality parameters were measured in the composite water samples collected from the study sites, and bioassay was conducted using aged tap water as the control. Sampling was conducted in both rainy and dry seasons. The conductivity, TDS, COD, and colour intensity of the water samples collected from the study sites were significantly higher during the dry season compared to those in the rainy season. root meristematic cells exposed to water samples from sites A, B, and C showed a significantly high interphase and prophase indices compared to those exposed to aged tap water and upstream site during both rainy and dry seasons. The mitotic index of the root tip cells of bulbs exposed to the water samples collected from the effluent discharge point (site A) and from the 100 m downstream site from site A (site B) was significantly lower than that of the other sites in both rainy and dry seasons. However, the mitotic index of the root tip cells of bulbs exposed to the water samples from the upstream site was not significantly different from that of the control treatment during both sampling seasons. The bioassay indicated that the mitotic index and phase index of the root meristematic cells of can be affected by the treated textile effluents released to the water body and the occurrence of C metaphase, chromosomal adherence, bridges, disturbed anaphase, vagrant chromosomes, and chromosomal breaks indicated that the treated textile effluent receiving tributary can possibly contain genotoxic and mutagenic compounds which can induce chromosomal abnormalities.
适当的污水处理工艺有望在废水排放到自然环境之前显著降低其毒性。本研究旨在评估接受经处理的纺织废水的天然水体的物理和化学水质参数的时空变化，并评估经处理的纺织废水所诱导的染色体异常。与一条接收经处理的纺织废水的支流相关联，选择了四个采样点（A：废水排放点；B：沿支流在A点下游100米处；C：沿支流在A点下游200米处；D：沿支流在A点上游100米处）。在从研究地点采集的混合水样中测量物理和化学水质参数，并以老化的自来水作为对照进行生物测定。在雨季和旱季均进行采样。与雨季相比，旱季从研究地点采集的水样的电导率、总溶解固体、化学需氧量和颜色强度显著更高。在雨季和旱季，暴露于来自A、B和C点水样的根尖分生细胞与暴露于老化自来水和上游地点的根尖分生细胞相比，显示出显著更高的间期和前期指数。在雨季和旱季，暴露于从废水排放点（A点）和A点下游100米处（B点）采集的水样的鳞茎根尖细胞的有丝分裂指数均显著低于其他地点。然而，在两个采样季节，暴露于上游地点水样的鳞茎根尖细胞的有丝分裂指数与对照处理相比无显著差异。生物测定表明，排放到水体中的经处理的纺织废水会影响根尖分生细胞的有丝分裂指数和分期指数，并且C中期、染色体粘连、桥接、后期紊乱、游离染色体和染色体断裂的出现表明，接收经处理的纺织废水的支流可能含有可诱导染色体异常的遗传毒性和致突变化合物。
