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

一种超临界两级超临界流体技术 多氯联苯(PCbs)/氯化的萃取物(SCE) 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/氯代烃(SCWO)的含量已提高到 修复受污染的土壤和沉积物。的优势 与传统方法相比，超临界流体工艺包括提高了 有机化合物，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，降低了加工过程中的能源成本， 处理后的土壤/沉积物不含有毒溶剂。 本供资期间的结果包括加工的定义 土壤和土壤中达到低于5ppm的多氯联苯(Aroclor 1248)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，这项SDCF技术成本为220美元- 每立方米处理270美元的土壤在经济上与其他方法相比具有竞争力 高级。此外，基本热力学溶解度数据具有 已为SC-CO2中的特定多氯联苯同系物获得，并基本 Aroclor 1248对不同土壤/沉积物的解吸速率数据 接触条件。为描述这些数据而开发的模型将是 对工艺计算很有用。开展实验室规模的姊妹项目研究(参见2.0版 升抽取器体积)来定义抽取器配置并确保 工程数据和SCWO实验的工作将只有 已启动。 该项目的具体目标是；(10项小规模研究将确定 萃取器配置(土壤/沉积物-超临界流体接触)并确定 萃取器效率使用清洁土壤、Aroclor 1248添加土壤和 实际被污染的材料。搜索结果将用于移动 示范装置设计和精细化的工艺经济性。研究将会是 扩展到多氯联苯/多环芳烃混合污染土壤。(2)动力学实验 将确定销毁多氯联苯的SCWO条件，并确定动力学 反应堆设计的速率数据。这项技术将扩展到 多环芳烃/多氯联苯混合有机体系 受污染的土壤/沉积物。我们会进行筛选研究，以 确定合适的二氧化碳/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 系数数据和解吸率数据将被获取和分析。 将进行初步的经济成本分析，结果将 具体说明实验室规模实验的条件。

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.