Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China.
Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lakes Resources, Xining 810008, China.
Int J Environ Res Public Health. 2022 Jul 25;19(15):9067. doi: 10.3390/ijerph19159067.
The abundance and chemical composition of dissolved organic matter (DOM) in the brine of solar ponds affect the efficiency of mineral extraction and evaporation rates of the brine, and cause undesired odor and color of the products. Here, we report an investigation into the composition and changes of DOM in solar ponds from Salt Lake brine with multiple complementary analysis techniques. The results showed that the DOM derived from Salt Lake brine was primarily composed of carbohydrates, aliphatic and aromatic compounds. The concentrations of dissolved organic carbon in solar ponds increased with exposure time by up to 15-fold (from 23.4 to 330.8 mg/L) upon evaporation/irradiation of Salt Lake brine. Further qualitative analyses suggest that the relative abundance of aliphatic compounds (including functionalized ones) increased from 49.5% to 59.2% in the solar pond process, while the opposite was observed for carboxylic acid moieties, aromatics and carbohydrates, which decreased from 15.7%, 7.1% and 26.1% to 13.4%, 5.3% and 23.0%, respectively. The pyrolysis-gas chromatography-mass spectrometry results reveal that the presence of some sulfur-containing organics implied some anaerobic biotic decay, but microbiological processes were probably subordinate to photo-induced DOM transformations. In the Salt Lake brine, exposure-driven decay decreased the abundance of polysaccharides and increased that of mono- and polyaromatic pyrolysis products. Our results here provide new insights for better understanding the changes of DOM chemical composition in the solar ponds of Salt Lake brine.
盐湖卤水太阳能池中的溶解有机物（DOM）的丰度和化学组成会影响矿物提取效率和卤水的蒸发速率，并导致产品产生不良气味和颜色。在这里，我们报告了一项使用多种互补分析技术对盐湖卤水太阳能池中的 DOM 组成和变化的研究。结果表明，盐湖卤水来源的 DOM 主要由碳水化合物、脂肪族和芳香族化合物组成。随着蒸发/辐照盐湖卤水，太阳能池中的溶解有机碳浓度增加了 15 倍（从 23.4 增加到 330.8mg/L）。进一步的定性分析表明，在太阳能池过程中，脂肪族化合物（包括官能化的脂肪族化合物）的相对丰度从 49.5%增加到 59.2%，而羧酸部分、芳香族化合物和碳水化合物则相反，从 15.7%、7.1%和 26.1%减少到 13.4%、5.3%和 23.0%。热解气相色谱-质谱分析结果表明，一些含硫有机物的存在暗示了一些厌氧生物降解，但微生物过程可能次于光诱导的 DOM 转化。在盐湖卤水中，暴露驱动的衰减降低了多糖的丰度，增加了单环和多环芳烃热解产物的丰度。我们的研究结果为更好地理解盐湖卤水太阳能池中 DOM 化学组成的变化提供了新的见解。
