摘要
本文综述了处理被多氯代芳香化合物,尤其是被二恶英和呋喃(PCDD/Fs)污染土壤的方法。与其它土壤污染物所不同的是PCDD/Fs与土壤颗粒紧密结合,这严重削弱了大多数水处理过程的效果,也使得除传统方法以外(填埋法、固化/稳定化、原位玻璃化技术)没有几种切合实际的选择方案。焚化法的应用时间很长,并且仍是最有效的处理技术,清除效率超过99.9999%。但是超临界水氧化法、碱性催化分解法、蒸馏法和其它多种萃取技术的清除效率也可超过95%,例如溶剂和液化气体以及亚临界水提取等。这些替代技术中的很多种可能比焚化法更廉价,有可能适用于被二恶英中度污染的土壤。然而,许多方法仍然处于发展初期,需要进行更多的试验评估其真正的潜力。
This review provides a summary of methods for treating soils contaminated with polychlorinated aromatic compounds,especially polychlorinated dibenzop -dioxins and dibenzofurans (PCDD/Fs).Unlike many other soil pollutants, PCDD/Fs bind tightly to the soil,which severely reduces the efficiency of most aqueous treatment procedures and leaves few realistic alternatives besides the traditional containment techniques (landfill,sohdification/stabilization,and in situ vitrification).Incineration has long been,and still is,the most efficient destruction technique,with a removal efficiency of.99.9999%.However, supercritical water oxidation,base-catalyzed decomposition,steam distillation, and various extraction techniques,such as solvent and liquefied gas and subcritical water extraction,may provide removal efficiencies of.95%.Many of the alternative techniques are expected to be cheaper than incineration and may therefore be attractive for moderately polluted soils.However,some of them are at an early stage of development and need to be further tested before their true potential can be assessed.