ANAEROBIC BIOTRANSFORMATION OF PCBS IN SEDIMENTS AND BIOREMEDIATION

氯联苯的厌氧脱氯降低潜在的公共健康 通过降低氯化程度和环境危害 产生的同系物通常毒性较小，很容易 被好氧或厌氧微生物机制降解的。还原的 脱氯是有利的，因为它可以克服这个难题。 对高度氯化的同系物进行降解或解毒。活动和 脱氯的模式因地点而异。多氯联苯污染的沉积物 马塞纳超级基金的网站在实验室中显示了脱氯 孵化研究和沉积物分析。我们的调查力度很大 表明多氯联苯的同系物也可以在厌氧条件下进行生物降解 沉积物。这项研究的总体目标是设计环境- 通过确定合理和具有成本效益的生物修复战略 微生物脱毒的生态因素 超级基金网站和其他地方类似污染地区的多氯联苯。 具体目标是：(1)确定其模式和程度 多氯联苯中的生物转化(还原脱氯和生物降解) 超级基金遗址和圣劳伦斯河的受污染沉积物 测量6年内的就地转化率，采用 ~(137)Cs测年技术，(2)确定调控因素 生物转化，特别是多核芳烃的影响 碳氢化合物(PAHs)在显著浓度下与多氯联苯一起出现在 雷诺金属公司和雷诺金属公司排放的河流沉积物 环境因素，如有机物、无机营养物质、电子 受体、微量营养物质、重金属、微生物区系、同系物 组成、沉积物质地、微生物种群等因素 将使用两种方法进行研究：用 研究地点的沉积物和圣劳伦斯的比较研究 河流和哈德逊河沉积物，以及(3)确认多氯联苯同系物 进行生物降解，而那些只在一个上有奥美康取代的 环比两者都有取代的环更容易被生物降解 戒指。这项研究将由三名同类人进行。 添加适当同系物的不含多氯联苯沉淀物中的取代类型 具有严格的物料平衡和产品测定。 生物转化产物将用毛细管色谱柱进行测定 (HP Ultra II和C-87 Apolane)，带有MSD或傅里叶变换红外的GC 检测器、高效液相色谱和薄层层析。

Anaerobic dechlorination of chlorobiphenyls reduces potential public health and environmental hazards by lowering the degree of chlorination and yielding congeners which are generally less toxic and can readily be degraded by aerobic or anaerobic microbial mechanisms. Reductive dechlorination is advantageous, since it can overcome the difficult problem of degrading or detoxifying highly chlorinated congeners. The activity and pattern of dechlorination are site-specific. PCB-contaminated sediments at the Massena Superfund site showed dechlorination in the laboratory incubation studies and sediment analysis. Our investigation strongly indicated that PCB congeners may also undergo biodegradation in anaerobic sediments. The general goal of this study is to design environmentally- sound and cost-effective bioremediation strategies by determining ecological factors which are essential for the microbial detoxification of PCBs for the Superfund site and similarly contaminated areas elsewhere. The specific aims are (1) to determine the pattern and the extent of biotransformations (reductive dechlorination and biodegradation) in PCB- contaminated sediments in the St. Lawrence River at the Superfund site and measure in situ transformation rates covering a 6-year period, employing the Cs-137 dating technique, (2) to determine the factors regulating biotransformations, especially the effects of polynuclear aromatic hydrocarbons (PAHs) which occur at significant concentrations with PCBs in river sediments receiving discharges from the Reynolds Metals and environmental factors such as organic matter, inorganic nutrients, electron acceptors, trace nutrients, heavy metals, microbial flora, congener composition, sediment texture, microbial populations, etc. The factors will be studied using two approaches: enrichment experiments with the sediments from the study sites and a comparative study of St. Lawrence River and Hudson River sediments, and (3) to confirm that PCB congeners undergo biodegradation and that those with omicron-substitution on only one ring are more readily biodegraded than those with the substitution on both rings. this study will be carried out with three congeners for each substitution type in PCB-free sediments spiked with appropriate congeners with a rigorous material balance and product determination. Biotransformation products will be determined by GC with capillary columns (HP Ultra II and C-87 Apolane), GC with MSD or Fourier transfer infrared detector, HPLC, and thin-layer chromatography.