表面活性剂强化PAC-Pd/Fe纳米颗粒降解四溴双酚A的研究

Pd/Fe纳米材料对卤代有机污染物有较强的降解能力，但四溴双酚A的强疏水性会阻碍污染物与Pd/Fe的有效接触.为促进四溴双酚A的降解，考察了不同表面活性剂对PAC-Pd/Fe纳米颗粒降解四溴双酚A的影响，结果表明:少量阴离子表面活性剂SDS对四溴双酚A的降解有明显的促进作用，反应速率可提高1.7~2.5倍；非离子表面活性剂TX-100对四溴双酚A降解的促进效果不明显，当其质量浓度超过临界胶束浓度时，甚至表现出抑制作用；阳离子表面活性剂CTAB对四溴双酚A的降解起抑制作用，且质量浓度越大，其抑制效果越明显；PAC-Pd/Fe纳米颗粒对四溴双酚A的降解是连续脱溴反应，四溴双酚A和其中间产物三溴双酚A、二溴双酚A和一溴双酚A的表观降解速率常数分别为0.466 2、0.435 6、0.338 0和0.271 1 min-1，与苯环上溴原子的数目成正比.

Degradation of Tetrabromobisphenol A with Surfactant-Enhanced PAC-Pd/Fe Nanoparticles

Pd/Fe nanoparticles are considered effective agents for the degradation of halogenated organic compounds (HOCs). However, the high hydrophobicity of tetrabromobisphenol A (TBBPA) hinders its degradation owing to the inefficient contacts of TBBPA and Pd/Fe nanoparticles. To promote the degradation of TBBPA, the effects of different surfactants on TBBPA degradation with PAC-Pd/Fe nanoparticles were investigated. The results show that the anionic surfactant SDS had the best promoting effect on TBBPA degradation and the rate of reaction increased by 1.7-2.5 times. The nonionic surfactant TX-100 had little enhancement in TBBPA degradation. It even exerted an inhibitive effect as its concentration went above the critical micelle concentration. The cationic surfactant CTAB displayed the most inhibitive effect on TBBPA degradation, and the inhibition was stronger as the surfactant concentration increased. The degradation of TBBPA with PAC-Pd/Fe nanoparticles was a consecutive debromination reaction. The corresponding degradation rate constants of parent TBBPA and its intermediates tri-BBPA, di-BBPA and mono-BBPA were 0.466 2, 0.435 6, 0.338 0 and 0.271 1 min-1, respectively, which were proportional to the amount of bromide atoms on benzene rings.