Mwinyihija Mwinyikione, Meharg Andy, Dawson Julian, Strachan Norval J C, Killham Ken
School of Biological Sciences, Plant and Soil Sciences, University of Aberdeen, St. Machar Drive, Cruickshank Building, Aberdeen, AB24 3UU, UK.
Arch Environ Contam Toxicol. 2006 Apr;50(3):316-24. doi: 10.1007/s00244-005-1049-9. Epub 2006 Jan 2.
A study was conducted to investigate the sediment health and water quality of the River Sagana, Kenya, as impacted by the local tanning industry. Chemical analysis identified the main chemical pollutants (pentachlorophenols and chromium) while a bioassay addressed pollutant bioavailability. The bioassay, exploiting the luminescence response of a lux marked bacterial biosensor, was coupled to a dehydrogenase and Dapnia magna test to determine toxicity effects on sediments. Results highlighted the toxicity of the tannery effluent to the sediments at the point of discharge (64% of control bioluminescence) with gradual improvement downstream. There was a significant increase in dehydrogenase downstream, with the enzyme activity attaining a peak at 600 m, also indicating a gradual reduction of toxicity. Biological oxygen demand (19.56 mg L(-1)) dissolved oxygen (3.97 mg L(-1)) and high lethal dose value (85%) of D. magna also confirmed an initial stress at the point of discharge and recovery downstream. Optical density of surface water demonstrated an increase in suspended particulates and colour after the discharge point, eventually decreasing beyond 400 m. In conclusion, the study highlighted the importance of understanding the biogeochemistry of river systems impacted by industries discharging effluent into them and the invaluable role of a biosensor-based ecotoxicological approach to address effluent hazards, particularly in relation to river sediments.
开展了一项研究，以调查受当地制革业影响的肯尼亚萨加纳河的沉积物健康状况和水质。化学分析确定了主要化学污染物（五氯苯酚和铬），同时进行了生物测定以研究污染物的生物可利用性。该生物测定利用发光标记细菌生物传感器的发光反应，并与脱氢酶和大型溞试验相结合，以确定对沉积物的毒性影响。结果表明，制革厂废水在排放点对沉积物具有毒性（对照生物发光的64%），下游毒性逐渐降低。下游脱氢酶显著增加，酶活性在600米处达到峰值，这也表明毒性逐渐降低。生物需氧量（19.56毫克/升）、溶解氧（3.97毫克/升）和大型溞的高致死剂量值（85%）也证实了排放点处的初始压力和下游的恢复情况。地表水的光密度表明，排放点之后悬浮颗粒和颜色增加，最终在400米以外降低。总之，该研究强调了了解受工业废水排放影响的河流系统生物地球化学的重要性，以及基于生物传感器的生态毒理学方法在解决废水危害方面的重要作用，特别是与河流沉积物相关的危害。
