过渡金属/亚硫酸盐体系去除水中TBBPA研究

Study on Removal of TBBPA from Water by Transition Metal/Sulfite System

文章以四溴双酚A(TBBPA)为代表性的溴代有机物,考察过渡金属/亚硫酸盐体系去除水中TBBPA的效能,并对TBBPA的降解机理进行研究。结果表明:在酸性(p H=4)条件下,Fe(Ⅲ)/亚硫酸盐体系、Fe(Ⅱ)/亚硫酸盐体系与Cr(Ⅵ)/亚硫酸盐体系对TBBPA的去除效果较好。对于Fe(Ⅲ)/亚硫酸盐体系与Fe(Ⅱ)/亚硫酸盐体系,Fe(Ⅲ)、Fe(Ⅱ)与亚硫酸盐投量比值为1∶10时反应体系呈现出最优的去除效果,10μmol/L TBBPA反应5 min后的去除率可达到66.8%;对于Cr(Ⅵ)/亚硫酸盐体系,升高金属离子浓度可促进TBBPA的去除效果。Cu(Ⅱ)/亚硫酸盐体系与Co(Ⅱ)/亚硫酸盐体系在中性条件下对TBBPA具有一定的去除效果,而在酸性条件下无法去除TBBPA。实际水体中常见的腐殖酸与HCO_(3)-均对过渡金属/亚硫酸盐体系去除TBBPA表现出抑制作用。结合密度泛函理论计算与LC-MS实际测得TBBPA降解的中间产物,推测了TBBPA可能的初始降解路径为TBBPA分子苯环上的碳原子脱溴或发生取代反应。

The efficiency of removing TBBPA(tetrabromobisphenol A)from water by transition metal/sulfite systems was investigated in the laboratory,with TBBPA as a representative brominated organic compound,and the degradation mechanism of TBBPA was studied as well.The results showed that on condition that solution acidity was pH of 4,the removals of TBBPA in the systems of Fe(Ⅲ)/sulfite,Fe(Ⅱ)/sulfite or Cr(Ⅵ)/sulfite were going comparatively well;when in the systems of both Fe(Ⅲ)/sulfite and Fe(Ⅱ)/sulfite,the ratio of iron ions to sulfite being 1∶10,the removal efficiencies of TBBPA culmi⁃nated,i.e.,the removal rate of TBBPA(10μmol/L)could reach 66.8%after the reaction for 5 min;and as for Cr(Ⅵ)/sul⁃fite system,increasing metalic ion concentration could promote the removal of TBBPA.Besides,in the systems of Cu(Ⅱ)/sul⁃fite and Co(Ⅱ)/sulfite and under neutral condition,there appeared a certain degree of TBBPA removal,but the removal was negligible under acidic condition;and both humic acid and HCO_(3)-that were ubiquidously in the water bodies could inhibit the removal of TBBPA in the transition metal/sulfite systems.Furthermore,by combining density functional theory(DFT)cal⁃culation and the determined intermediate products of TBBPA degradation,which were measured by LC-MS,it was conjec⁃tured that the TBBPA degradation initial path might be the debromination or the substitution reactions which took place at the carbon atom of benzene ring.