摘要
采用大孔树脂D001交换吸附Pd2+、Fe2+并在厌氧条件下以硼氢化钠溶液还原吸附的钯铁离子制备成负载纳米Pd/Fe双金属树脂。利用该树脂对2,2',4,4'-四溴联苯醚(BDE-47)进行脱溴反应,探讨了该法的可行性和特性。结果表明:当大孔树脂D001、氯化钯、硫酸亚铁用量分别为0.75 g、2μg和0.2 g时所制备的双金属树脂脱溴水-乙醇溶液中的BDE-47效果最佳,反应遵循准一级动力学,速率常数k约为0.161 d-1,半减期为1.21 d。负载Pd/Fe的D001连续3次脱溴反应都有较好的效果,水-乙醇溶液中超过90%以上的BDE-47在反应6 d后被降解。负载Pd/Fe双金属的树脂可以重复活化再生,但再生2次后其脱溴效率变差,反应6 d只有47.3%的BDE-47被降解。用气相色谱-质谱联用仪和离子色谱仪跟踪Pd/Fe双金属树脂脱溴BDE-47反应,可知产物包括溴离子、三溴联苯醚、二溴联苯醚、一溴联苯醚和联苯醚。
Macroporous resin D001 was used to adsorb Pd2 ＋,Fe2 ＋,and the adsorbed ions of palladium and iron were reduced by sodium borohydride under anaerobic conditions to prepare a macroporous resin loaded with nanoscale Pd/Fe bimetals（MR-Pd/Fe）.The prepared MR-Pd/Fe was allowed to react with 2,2＇,4,4＇-tetrabromo diphenyl ether（BDE-47） in order to study the feasibility and characteristics of the debromination reactions.Experimental data showed that best debromination of BDE-47 in water-ethanol solution was achieved by a MR-Pd/Fe prepared with 0.75 g macroporous resin D001,2 μg palladium chloride,and 0.2 g ferrous sulfate,respectively.The debromination reaction seemed to follow quasi-first-order kinetics with an estimated rate constant K of 0.161 d-1 and a half-life of 1.21 d.The D001 MR-Pd/Fe could consecutively debrominate BDE-4,it was demonstrated that more than 90% of the BDE-47 in water-ethanol solution was degraded by the MR-Pd/Fe 6 d later even after the same loaded resin was utilized for two prior runs of debromination.The MR-Pd/Fe might be reactivated and regenerated,but its power of debromination tended to diminish after reactivation twice,resulting in only 47.3% of the added BDE-47 was degraded in the third run with a reaction period of 6 d.Gas chromatography-mass spectrometry and ion chromatography were utilized to monitor the debromination reactions,and it could be shown that bromide ions,tribromo,dibromo,monobromo diphenyl ethers and diphenyl ether were the reaction products.
出处
《生态环境学报》
CSCD
北大核心
2012年第3期564-568,共5页
Ecology and Environmental Sciences
