Centre for Applied Water Sciences, Institute for Applied Ecology, University of Canberra, Bruce, ACT, 2601, Australia.
New South Wales Environmental Protection Authority, Locked Bag 5022, Parramatta, NSW, 2124, Australia.
Ecotoxicology. 2022 Aug;31(6):967-975. doi: 10.1007/s10646-022-02552-4. Epub 2022 Jun 14.
Concentrations of major ions in coal mine discharge waters and unconventional hydrocarbon produced waters derived from coal bed methane (CBM) production, are potentially harmful to freshwater ecosystems. Bicarbonate is a major constituent of produced waters from CBM and coal mining. However, little is known about the relative toxicity of differing ionic proportions, especially bicarbonate, found in these CBM waters. As all freshwater invertebrates tested are more acutely sensitive to sodium bicarbonate (NaHCO) than sodium chloride (NaCl) or synthetic sea water, we tested the hypotheses that toxicity of CBM waters are driven by bicarbonate concentration, and waters containing a higher proportion of bicarbonate are more toxic to freshwater invertebrates than those with less bicarbonate. We compared the acute (96 h) lethal toxicity to six freshwater invertebrate species of NaHCO and two synthetic CBM waters, with ionic proportions representative of water from CBM wells across New South Wales (NSW) and Queensland (Qld), in Australia. The ranking of LC50 values expressed as total salinity was consistent with the hypotheses. However, when toxicity was expressed as bicarbonate concentration, the hypothesis that the toxicity of coal bed waters would be explained by bicarbonate concentration was not well supported, and other ionic components were either ameliorating or exacerbating the NaHCO toxicity. Our findings showed NaHCO was more toxic than NaCl and that the NaHCO proportion of synthetic CBM waters drives toxicity, however other ions are altering the toxicity of bicarbonate.
煤矿排水和非常规烃类（如煤层气（CBM）生产产生的水）中的主要离子浓度对淡水生态系统可能有害。碳酸氢盐是 CBM 和采煤生产产生水中的主要成分。然而，对于这些 CBM 水中不同离子比例（特别是碳酸氢盐）的相对毒性，人们知之甚少。由于所有测试的淡水无脊椎动物对碳酸氢钠（NaHCO）的急性敏感性都高于氯化钠（NaCl）或合成海水，我们测试了以下假设：CBM 水的毒性是由碳酸氢盐浓度驱动的，并且含有较高比例碳酸氢盐的水对淡水无脊椎动物的毒性大于含较少碳酸氢盐的水。我们比较了碳酸氢钠（NaHCO）和两种合成 CBM 水对 6 种淡水无脊椎动物物种的急性（96 小时）致死毒性，这些水的离子比例代表了澳大利亚新南威尔士州（NSW）和昆士兰州（Qld）的 CBM 井中的水。以总盐度表示的 LC50 值的排序与假设一致。然而，当毒性表示为碳酸氢盐浓度时，碳酸氢盐浓度解释煤层水毒性的假设并没有得到很好的支持，并且其他离子成分要么减轻要么加剧了 NaHCO 的毒性。我们的研究结果表明，碳酸氢钠比氯化钠更具毒性，并且合成 CBM 水的碳酸氢钠比例驱动毒性，但其他离子正在改变碳酸氢盐的毒性。
