Remediation of soil burdened with excesses of hydrophobic organic contaminants (HOCs) and toxic trace metals (TMs)

在优化程序以修复背负着过量疏水有机污染物(HOCs)和痕量金属(TMS)负担的土壤的总体目标范围内，设计了一系列研究，以最大限度地提高整个过程的效率，同时将成本降至最低。该过程由四个连续的步骤组成。污染物(HOCs和TMS)通过含有络合剂(S)的表面活性剂悬浮液(ASS)洗涤同时从土壤中活化/去除。通过用非极性有机溶剂(正己烷)反萃ASS相回收HOC组分，并在与贵金属催化剂接触时通过加氢脱氯/还原脱毒。随后，用零价镁(Mg0)沉淀回收重金属部分，形成不溶于水的氢氧化物，再通过过滤回收。提纯的ASS组分(现在不含HOCS和TMS)被返回以清洁更多的土壤。通过这个过程，这两类毒物都会转化为无毒的产品。

Within the general objective of optimizing procedures to remediate soil that has been burdened with excesses of hydrophobic organic contaminants (HOCs) and trace metals (TMs), a series of studies have been designed to maximize the efficiency of the overall process while minimizing costs. The process consists of four sequential steps. Pollutants (HOCs and TMs) are simultaneously mobilized/removed from the soil by washing with an aqueous surfactant suspension (ASS) containing complexing reagent(s). The HOC fraction is recovered by back-extraction of the ASS phase with a non-polar organic solvent (hexane) and detoxified by hydrodechlorination /reduction during contact with a noble-metal catalyst. Subsequently, the heavy metal fraction is recovered by precipition with zero-valent magnesium (Mg0) to form insoluble oxyhydroxides that are recovered by filtration. The purified ASS fraction (now devoid of both HOCs and TMs) is returned to clean more soil. With this process, both classes of toxicant are converted to toxicologically innocuous products.