Dechlorination of 2,4-dichlorophenol by nanoscale magnetic Pd/Fe particles: Effects of pH, temperature, common dissolved ions and humic acid

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• 作者：Jiang Xu ; Lisha Tan ; Shams Ali Baig ; Donglei Wu ; Xiaoshu Lv ; Xinhua Xu
• 关键词：Magnetic ; nFe3O4-Pd/Fe ; 2 ; 4-DCP ; Common dissolved ions ; Stability
• 刊名：Chemical Engineering Journal
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：231
• 期：Complete
• 页码：26-35
• 全文大小：1146 K

文摘

In this study, magnetic Pd/Fe nanoparticles were synthesized using nanoscale Fe₃O₄ (nFe₃O₄) and nanoscale zero-valent iron (nZVI) to significantly enhanced 2,4-DCP dechlorination. nFe₃O₄ was found to restrain the formation of passivated layer on nZVI surface and promoted the electron transfer. Earlier, only 35.8 % 2,4-DCP (C_initial = 20 mg L^?1) was removed by 3.0 g L^?1 Pd/Fe nanoparticles, whereas it remarkably increased to 76.4 % by magnetic nanocomposites (2.0 g L^?1 nFe₃O₄ and 3.0 g L^?1 Pd/Fe). A satisfactory long-term stability of nFe₃O₄-Pd/Fe was exhibited and the 2,4-DCP removal efficiency reached to 100 % , 100 % , 93.5 % , 93.0 % , and 90.1 % in five consecutive cycles, respectively. Moreover, the nanocomposites were easily separated from the solution after reaction and that reduced environment related risks of nanoparticles. Weak acidic condition was considered feasible for 2,4-DCP dechlorination. Negative co-precipitation occurred on nFe₃O₄-Pd/Fe surface in the presence of common dissolved anions (such as Cl^?, , and ) and humic acid (HA). The 2,4-DCP dechlorination was notably accelerated by dissolved metallic ions (Fe²⁺, Cu²⁺, and Ni²⁺), and 2,4-DCP was completely removed in 5 h reaction time. The application of nFe₃O₄-Pd/Fe nanocomposites could be highly effective for an in situ pollutants remediation measures.