超/亚临界水中四溴双酚A的脱溴降解特性研究

在超/亚临界水及其碱溶液中对四溴双酚A进行了水热脱溴降解研究。考察了温度、时间和碱类型对降解特性的影响。结果表明,在纯水中温度是影响四溴双酚A降解的关键参数,350℃下反应180 min和400℃反应30 min,脱溴率分别达到98.7%和96.7%,降解产物中苯酚和4-丁基苯酚分别占50%和20%以上,另外还有少量的烷基酚;向反应体系中加入碱不仅可以中和反应过程中产生的氢溴酸以保护超临界反应釜,而且可以在较低温度下实现高的脱溴率,产物中苯酚含量达50%以上、4-异丙烯基苯酚占10%左右,可以实现脱溴同时回收化工产品的目的。与传统的热解技术相比,超/亚临界水处理TBBPA具有明显的优势,本研究为含溴电子废弃物的清洁高附加值资源化利用提供了一条新的途径。

Debromination properties of tetrabromobisphenol A in super/subcritical water

Hydrothermal decomposition of tetrabromobisphenol A(TBBPA)in super/subcritical water in the presence or absence of alkali was investigated in this study.The influences of temperature,reaction time,and alkali type on debromination properties were investigated.The results showed that temperature was the key parameter for the degradation of TBBPA in super/subcritical water in the absence of alkali.The removal rates of bromine were 98.7% and 96.7% after 180 min treatment at 350 ℃ and 30 min treatment at 400 ℃,respectively.The major debromination products identified by GC/MS were phenol and 4-butyl phenol,occupying more than 50% and 20%,respectively,with small amount of alkyl phenols.In order to neutralize the hydrobromic acid generated in the debromination process and protect the autoclave,alkali was added into the hydrothermal system.In this case,high debromination rate was obtained at lower temperature.The main products were phenol and 4-isopropenylphenol,occupying 50% and 10%,respectively.These products could be recycled as useful chemical feedstock.Super/subcritical water has obvious predominance for bromine-contained e-waste treatment compared with traditional pyrolysis.This study provides a new approach for clean and high-valuable recycle of bromine-contained e-wastes.