SUPERCRITICAL FLUID TECHNOLOGY--REMEDIATION OF PCB/PAH CONTAMINATED SOILS

两级超临界流体技术（SCF） 多氯联苯（PCBs）的萃取（SCE）/氯化 污染土壤中的碳氢化合物与超临界水氧化 提取的多氯联苯/氯化烃的超临界水氧化（SCWO）已被推进， 补救受污染的土壤和沉积物。 的优点 超临界流体方法优于常规方法包括提高的溶解度， 有机物，使用超临界水氧化完全氧化，分离简单， 来自溶剂流的污染物，降低了加工中的能量成本， 并且处理的土壤/沉积物不含有毒溶剂。 本供资期间的结果包括处理的定义 土壤中多氯联苯（多氯联苯1248）残留量低于百万分之五的条件， 初始污染水平约为1，000 - 4，500 ppm的沉积物。 初步经济分析表明，SDCF技术成本为220美元- 处理的土壤每立方米270美元，与其他工艺相比具有经济竞争力 先进 此外，基本的热力学溶解度数据 获得了SC-CO2中特定多氯联苯同系物的数据， Aroclor 1248在各种土壤/沉积物中的解吸率数据， 接触条件。 用于描述这些数据的模型将 用于工艺计算。 实验室规模SCE研究工作（约2.0 升提取器体积）以限定提取器配置并固定 工程数据和超临界水氧化实验的工作将只 启动。 该项目的具体目标是：（10项基准规模研究将确定 提取器配置（土壤/沉积物-SCF接触）并确定 使用清洁土壤、Aroclor 1248掺入土壤和 真正的污染物。 结果将用于移动的 示范装置设计和完善的工艺经济性。 研究将 扩展到PCB/PAH混合污染土壤。 (2)动力学实验 将确定多氯联苯的超临界水氧化销毁条件， 反应堆设计的速率数据。 (30该技术将扩展到 多环芳烃/多氯联苯混合有机体系 被污染的土壤/沉积物。 将进行筛选研究， 确定合适的CO2/改性剂系统和操作条件， 高效提取 热力学溶解度数据，吸附平衡 系数数据和解吸速率数据将被采集和分析。 将进行初步的经济成本分析，结果将 规定了实验室规模实验条件。

A Two-stage supercritical fluid technology (SCF) of supercritical extraction (SCE) of polychlorinated biphenyls (PCBs)/chlorinated hydrocarbons from contaminated soil and supercritical water oxidation (SCWO) of the extracted PCBs/chlorinated hydrocarbons has been advanced to remediate contaminated soils and contaminated sediments. The advantages of SCF processes over conventional methods include enhanced solubility of organics, complete oxidation using SCWO, simplicity of separation of pollutants from the solvent stream, reduced energy costs in the processing, and treated soils/sediments free of toxic solvents. Results of the current funding period include the definition of processing conditions to achieve sub 5 ppm residual PCBs (Aroclor 1248) in soils and sediments from initial contamination levels of ca 1,000-4,500 ppm. Preliminary economic analysis indicates this SDCF technology cost of $220- $270/m3 soil processed is economically competitive with other processes advanced. Additionally, fundamental thermodynamic solubility data have been acquired for specific PCB congeners in SC-CO2, and fundamental desorption rate data of Aroclor 1248 for a variety of soils/sediments and contacting conditions. Models developed to describe these data will be useful for process calculations. Work on bench-scale SCE studies (ca 2.0 liter extractor volume) to define the extractor configuration and secure engineering data, and work on SCWO experiments will have only been initiated. The project's specific aims are; (10 Bench-scale studies will define the extractor configuration (soils/sediments -SCF contacting) and determine extractor efficiency using clean soils, Aroclor 1248 spiked soils and actual contaminated materials. Results will be used for mobile Demonstration unit design and refined process economics. Studies will be extended to mixed PCB/PAH contaminated soils. (2) Kinetic experiments will define SCWO conditions for destruction of PCBs and determine kinetic rate data for reactor design. (30 The technology will be extended to mixed organic systems of polycyclic aromatic hydrocarbons (PAHs)/PCBs contaminated soils/sediments. Screening studies will be conducted to determine suitable CO2/modifier systems and operating conditions for efficient extraction. Thermodynamic solubility data, sorption equilibrium coefficient data, and desorption rate data will be acquired and analyzed. Preliminary economic cost analysis will be made, and the results will specify conditions for bench-scale experiments.