Department of Chemistry and Applied Chemistry, Graduate School of Science and Engineering, Saga University 1, Honjo-machi, Saga 840-8460, Japan.
Waste Manag. 2013 Feb;33(2):356-62. doi: 10.1016/j.wasman.2012.10.019. Epub 2012 Nov 30.
Dioxins like polychlorinated dibenzo-p-dioxins (PCSDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) are mainly emitted from waste incinerators (WIs) and have become an international research focus because of its serious concerns over the adverse health effects. The detoxification of PCCDs/Fs and PCBs is very difficult because of their stable chemical structure. A significant hydrodechlorination/detoxification of polychlorinated 1-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were achieved in fly ash by using an aqueous mixture of calcium hydroxide and sulfur. Two different fly ashes were studied: originating from municipal waste incinerator (FA1) and industrial waste incinerator (FA2). They were heated with the aqueous mixture at 150°C for 30 or 60 min with agitation. Higher decomposition (87%) and detoxification (87.7%) of PCDD/Fs and PCBs were achieved at 150°C with two runs; every run was for 30 min, compared to one run for 60 min. FA2 gave higher decomposition and detoxification as compared to FA1, which might be due to higher metal content that played a catalytic role to decompose and detoxify the PCDDs, PCDFs and PCBs. The decomposition and detoxification of PCDFs in fly ash was higher than PCDDs and was augmented with increasing number of chlorides on aromatic compounds. As the highly significant decomposition and detoxification of higher concentration of PCDD/Fs and PCBs were achieved in 1 hour without additive catalyst and at low temperature of 150°C, therefore, the developed method is cost effective and most suitable to apply on commercial/industrial level. The detail results of hydrodechlorination/detoxification of PCDD, PCDFs at different conditions are described and its mechanism is discussed.
二恶英类，如多氯代二苯并对二恶英（PCDDs）、多氯代二苯并呋喃（PCDFs）和多氯联苯（PCBs），主要由废物焚烧炉（WIs）排放，因其对健康的严重危害而成为国际研究热点。由于其稳定的化学结构，PCDD/Fs 和 PCBs 的解毒非常困难。在飞灰中，使用氢氧化钙和硫的水溶液混合物，可显著进行多氯代 1-二恶英（PCDDs）、多氯代二苯并呋喃（PCDFs）和多氯联苯（PCBs）的加氢脱氯/解毒。研究了两种不同的飞灰：一种来自城市废物焚烧炉（FA1），另一种来自工业废物焚烧炉（FA2）。将它们与水溶液混合物在 150°C 下加热 30 或 60 分钟并搅拌。在 150°C 下，通过两个运行实现了 87%的 PCDD/Fs 和 PCBs 的更高分解（87%）和解毒（87.7%）；每个运行持续 30 分钟，而一个运行持续 60 分钟。与 FA1 相比，FA2 给出了更高的分解和解毒，这可能是由于更高的金属含量发挥了催化作用，可分解和解毒 PCDDs、PCDFs 和 PCBs。飞灰中 PCDFs 的分解和解毒高于 PCDDs，并且随着芳香族化合物上氯原子数量的增加而增加。由于在 1 小时内无需添加剂催化剂且在 150°C 的低温下实现了高浓度 PCDD/Fs 和 PCBs 的高显著分解和解毒，因此，所开发的方法具有成本效益，最适合在商业/工业层面应用。描述了不同条件下 PCDD、PCDFs 加氢脱氯/解毒的详细结果，并讨论了其机制。
