ANAEROBIC BIOTRANSFORMATION OF PCBS IN SEDIMENTS AND BIOREMEDIATION

氯联苯的厌氧脱氯降低了潜在的公共健康 和环境危害，降低氯化程度， 产生的同系物一般毒性较小， 通过需氧或厌氧微生物机制降解。 还原 脱氯是有利的，因为它可以克服这一难题， 降解或解毒高度氯化的同系物。 的活性和 脱氯模式因地点而异。 受多氯联苯污染的沉积物 马塞纳超级基金的现场在实验室中显示脱氯 孵化研究和沉积物分析。 我们的调查 表明，PCB同系物也可能在厌氧条件下发生生物降解， 沉积物 本研究的总体目标是设计环境- 合理和具有成本效益的生物修复策略， 生态因素是微生物解毒的关键， 超级基金场址和其他类似受污染地区的多氯联苯。 具体目标是：（1）确定 生物转化（还原脱氯和生物降解） 在圣劳伦斯河污染的沉积物在超级基金网站， 测量6年期间的原地转化率， ~（137）Cs测年技术;（2）确定控制因素 生物转化，特别是多核芳香族化合物的影响 碳氢化合物（多环芳烃），发生在显着浓度与多氯联苯， 河流沉积物接收来自雷诺兹金属公司的排放， 有机质、无机营养盐、电子 受体，微量营养元素，重金属，微生物植物群，同源物 成分、沉积物结构、微生物种群等。 将使用两种方法进行研究： 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，并且那些仅在一个表面上具有omicron取代的物质 环上的取代比环上的取代更容易生物降解 环. 本研究将使用三种同系物进行， 添加适当同系物的无多氯联苯沉积物中的替代类型 严格的物料平衡和产品测定。 生物转化产物将通过毛细管柱气相色谱法测定 (HP Ultra II和C-87 Apolane），GC（含MSD）或傅立叶转移红外 检测器、HPLC和薄层色谱法。

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.