超声辅助海绵铁/银双金属降解四溴双酚A及生物毒性初步评价

Degradation of Tetrabromobisphenol A by Granular Sponge Iron / Silver Bimetallic Particles under the Ultrasound Irradiation and Assessment of Its Bio-toxicity

采用批处理实验研究了以液相化学沉淀法合成的表面负载金属银的海绵铁/银(SPI/Ag)双金属作为催化还原剂对水体系中四溴双酚A(TBBPA)的降解效果,应用发光菌毒性测试方法测定了反应前后体系生物毒性变化.结果表明:SPI/Ag双金属体系对TBBPA具有良好的还原脱溴能力,120min后降解的去除率可达92%以上,反应符合准一级反应动力学方程,表观速率常数K为0.019 3min-1,比单纯使用海绵铁(SPI)提高了近6倍.反应过程中反应体系对发光菌的生物毒性呈先减小后增大再减小的变化趋势,总体上毒性降低.此外,所制备的SPI/Ag双金属颗粒还具有良好的稳定性及重现性.

The granular sponge iron/silver （SPI/Ag） bimetallic particles synthesized by chemical deposition was used to treat tetrabromobisphenol A （TBBPA） in water solution under the ultrasound irradiation. And the bio-toxicity of the reaction solutions before and after the reaction was assessed by bioluminescence test. The results showed that under ultrasonic radiation （US） the SPI/Ag bimetallic particles could effec- tively debrominate TBBPA with the debromination efficiency reached 92~ in 120 min. The degradations of TBBPA by SPI/Ag and sponge iron （SPI） followed pseudo-first-order kinetics equations. The reaction rate constant （K） of the degradation TBBPA by SPI/Ag was 0. 0193 min-1, which was about six times higher than that of by granular sponge iron （SPI）. In degradation process, the trend of the acute bio-toxicity for the reaction solutions was decreased at first, subsequently increased, and then decreased until the reaction end. At the end of reaction,the acute bio-toxicity was much lower than the beginning.