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研究报告

Degradation of carbon tetrachloride by nanoscale zero-valent iron@magnetic Fe₃O₄ compound with ultrasound assistance

基金项目：北京市产学研项目（No.51900265005）；国家水体污染控制与治理科技重大专项（No.2009ZX07207-008，2009ZX07419-002，2009ZX07207-001，2015ZX07406005-001）；中央高校基本科研业务费专项资金（No.2652013101，2652013086，2652013087）；国家重大科学仪器设备开发专项（No.2012YQ060115）

摘要：采用附着在Fe₃O₄纳米颗粒上的纳米零价铁（nZVI）对四氯化碳（CCl₄）还原脱氯.同时，利用SEM和BET等技术对Fe⁰@Fe₃O₄的表面形貌和粒径进行表征，探究了不同反应条件如Fe⁰@Fe₃O₄投加量、超声功率、初始pH值、温度和CCl₄初始浓度对CCl₄去除率的影响.最后，比较了Fe⁰@Fe₃O₄、nZVI和Fe₃O₄颗粒对CCl₄的去除效果.结果表明，Fe⁰@Fe₃O₄比nZVI比表面积更大、分散性更好.超声功率和温度的提高对CCl₄的降解有明显的促进作用.在最佳条件（催化剂投加量0.5 g·L^-1，超声功率300 W，初始pH=7.0，温度30℃，CCl₄初始浓度2 mg·L^-1）下，Fe⁰@Fe₃O₄复合材料在60 min内对CCl₄的去除效率为88.5%，明显高于nZVI（60.9%）和Fe₃O₄颗粒（13.2%）.Fe⁰@Fe₃O₄对CCl₄去除过程符合伪一级动力学模型.

Abstract：Nano-scale zero-valent Iron (nZVI) attached on the Fe₃O₄ nanoparticles were applied in the reductive dechlorination of Carbon Tetrachloride (CCl₄). The surface morphology and particle size of Fe⁰@Fe₃O₄ were characterized by way of SEM and BET measurements. The effects of different reaction conditions such as Fe⁰@Fe₃O₄ dosage, ultrasound power, initial pH value, temperature and initial concentration of CCl₄ on the removal rate of CCl₄ were investigated. At the same time, the degradation of CCl₄ by Fe⁰@Fe₃O₄, nZVI and Fe₃O₄NPs under the same conditions was compared. The results showed that both the specific surface area of Fe⁰@Fe₃O₄ NPs was lager and the dispersibility was better than that of nZVI. The improvement of ultrasonic power and temperature can effectively promote the degradation ratio of CCl₄. Under the optimum conditions (the catalyst dosage was 0.5 g·L^-1, the ultrasonic power was 300 W, the initial pH value was 7.0, the temperature was 30℃, the initial concentration of CCl₄ was 2 mg·L^-1), the Fe⁰@Fe₃O₄ showed a CCl₄ removal efficiency of 88.5% in 60 min, which was much greater than that of nZVI (60.9%) and Fe₃O₄NPs (13.2%). The removal process obeyed the pseudo first-order kinetic model.

Key words：carbon tetrachloride degradation nano-scale Fe⁰@Fe₃O₄ pseudo first order kinetics