MCHM Degradation Data Release

This USGS data release includes all the data presented in peer-reviewed publication entitled "Degradation of MCHM (4-methylcyclohexanemethanol) in Sediments from Elk River, West Virginia". We conducted experiments on crude MCHM to examine photooxidation or biodegradation. We also assessed the potential of sediments to serve as a long-term source of MCHM and well as the potential for native microbial communities to catalyze the anaerobic breakdown of MCHM. We developed a quantitative method to measure the 2 isomers (cis- and trans-) of 4-MCHM, using solid phase micro-extraction (SPME), which had a minimum detection limit of 5 µg/L. The data release shows that the abiotic degradation experiments showed no evidence of photooxidation or abiotic degradation over 35-days for either MCHM isomer. Experiments with sterilized Elk River sediments showed sorption within 2 weeks, with 31% of trans-4-MCHM and 17.5% of cis-4-MCHM lost from solution. Impacted sediments from the spill site released substantial concentrations of trans-4-MCHM (up to 40 µg/L) and minor amounts of cis-4-MCHM (at the detection limit ~ 4 µg/L) into the overlying water solution after sterilization, indicating that sediments retained MCHM 10 months after the spill. In anoxic microcosms, 300 µg/L cis- and 150 µg/L trans-4-MCHM degraded to non-detectable levels in 8-13 days in both impacted and background sediments coupled to iron and sulfate reduction. MCHM degraded to non-detectable levels within 4 days under aerobic conditions. Microbial communities at impacted sites differed in composition compared to background and were less affected by MCHM amendments. Our results to date indicate that MCHM is readily biodegradable under environmentally relevant conditions.

本美国地质调查局（United States Geological Survey，简称USGS）数据集发布包，包含同行评议学术论文《西弗吉尼亚州埃尔克河沉积物中4-甲基环己甲醇（MCHM，4-methylcyclohexanemethanol）的降解行为》所载的全部实验数据。本研究以粗制4-甲基环己甲醇（MCHM）为实验对象，探究其光氧化与生物降解特性；同时评估了沉积物作为MCHM长期储库的潜力，以及本土微生物群落催化MCHM厌氧降解的潜能。我们建立了基于固相微萃取（SPME）的定量分析方法，可同时检测4-甲基环己甲醇的两种异构体——顺式（cis-）与反式（trans-）4-MCHM，该方法的最低检测限为5 μg/L。本数据集显示，在35天的实验周期内，两种MCHM异构体均未发生可观测的光氧化或非生物降解反应。针对灭菌后的埃尔克河沉积物开展的吸附实验显示，两周内溶液中31%的反式4-MCHM与17.5%的顺式4-MCHM被沉积物吸附去除。泄漏点位的受污染沉积物经灭菌处理后，可向上覆水体释放高浓度反式4-MCHM（最高可达40 μg/L）与微量顺式4-MCHM（浓度约为检测限4 μg/L），这表明泄漏事件发生10个月后，沉积物仍留存有MCHM。在缺氧微宇宙体系中，受污染与背景沉积物体系均以铁还原与硫酸盐还原作为代谢路径，其中300 μg/L顺式4-MCHM与150 μg/L反式4-MCHM可在8至13天内降解至无法检出水平。好氧条件下，MCHM可在4天内降解至无法检出水平。受污染点位的微生物群落组成与背景点位存在显著差异，且受MCHM添加物的影响更小。截至目前的研究结果表明，MCHM在环境相关条件下具备良好的可生物降解性。