Fe_(3)O_(4)掺杂改性电极电化学去除Pb^(2+)的效能研究

Electrochemical removal of Pb^(2+) using Fe_(3)O_(4)-doped modified electrode

为了实现水体中Pb^(2+)的高效电化学去除,采用涂覆法将Fe_(3)O_(4)、粉末活性炭、乙炔黑和聚乙烯醇混合后负载于石墨纸上,制备得到了Fe_(3)O_(4)掺杂改性电极。采用差分柱批式反应器模式进行电化学去除Pb^(2+)实验,考察了电压、温度、运行时间、Pb^(2+)质量浓度对去除Pb^(2+)的影响并评估了电极的重复利用性和稳定性。结果表明,所制备的电极表面孔隙丰富,孔径均匀。电压为1.4 V时,运行150 min后电化学体系对Pb^(2+)的去除率达到了98.73%,延长运行时间可以显著强化Pb^(2+)的去除率。在10~35℃的温度范围内,温度升高有利于Pb^(2+)的电化学去除,电化学体系在不同的Pb^(2+)浓度下均有较好的适用性和适应性,随着Pb^(2+)初始浓度的升高,处理单位体积含Pb^(2+)废水的能耗逐渐增加,但去除单位质量Pb^(2+)的能耗反而降低,拟合结果表明Pb^(2+)的去除过程符合准一级动力学。经过8次循环后,电化学体系仍保持原有的Pb^(2+)去除效果。

For efficient electrochemical removal of Pb^(2+)from water bodies,Fe_(3)O_(4)doped modified electrodes were pre⁃pared by loading a mixture of Fe_(3)O_(4),powdered activated carbon,acetylene black and polyvinyl alcohol onto graphite pa⁃per with the coating method.The electrochemical removal of Pb^(2+)with Fe_(3)O_(4)-doped modified electrode was carried out in a differential column batch reactor mode,and the effects of voltage,temperature,operation time,concentration,and other factors on the Pb^(2+)removal performance were investigated.The reusability and stability of the electrode were evaluated based on cycle trials.The results showed that the prepared electrodes had abundant surface pores and uniform pore size.The removal of Pb^(2+)by the electrochemical system reached 98.73%after 150 min at a voltage of 1.4 V,and the extension of the operation time could significantly strengthen the removal of Pb^(2+).In the temperature range of 10-35℃,the in⁃crease of temperature was favorable for the electrochemical removal of Pb^(2+).The electrochemical system had good applica⁃bility and adaptability at different Pb^(2+)concentrations.With the increase of the initial Pb^(2+)concentration,the energy con⁃sumption for treating unit volume of Pb^(2+)wastewater increased gradually,but the energy consumption for removing unit mass of Pb^(2+)decreased on the contrary,The fitting results showed that the removal process of Pb^(2+)was in accordance with the pseudo-first order kinetics.The electrochemical system still maintained the original removal effect after eight cycles,presenting commendable reusability and stability.