【摘要】 以铝屑和活性炭微粒为原料,采用铝炭微电解的处理方法对重金属废水中Cr(Ⅵ)的去除效果进行了研究,考察了反应时间、铝炭质量比、初始pH值、震荡速度、震荡时间等因素对Cr(Ⅵ)离子去除效果的影响.采用扫描电镜(SEM)、比表面积分析仪(BET)、X射线能量色散谱仪(EDS)和电子能谱仪(XPS)等测试手段,研究铝炭微电解反应前后铝屑和活性炭的表面物理形貌及物质组成的变化,分析铝炭微电解原理.结果表明,影响Cr(Ⅵ)离子去除效果的影响因素的主次为:初始pH值>震荡速度>铝炭质量比>震荡时间,得到最佳处理条件为:初始pH值为3.0,铝炭质量比为2:1,震荡速度为150r/min,震荡时间为40min,在该条件下Cr(Ⅵ)的去除率可达95.40%.实验证明,以铝炭微电解法替代纯铝的直接还原法或铁炭微电解法可以大大提高对Cr(Ⅵ)的去除率.Cr(Ⅵ)的主要去除机理是在微电解过程中炭阴极通过还原作用将Cr(Ⅵ)还原为Cr(Ⅲ).更多还原

【Abstract】 Aluminum-carbon micro electrolysis was adopted to study the removal efficiency of Cr(Ⅵ) in heavy metal wastewater by taking aluminum scraps and activated carbon particles as the experimental materials. The influences of settling time, the mass ratio of aluminum and carbon(Al/C mass ratio), initial pH, oscillation speed and oscillation time on Cr(Ⅵ) removal efficiency were investigated. Scanning Electron Microscope(SEM), Specific Surface Area Analyzer(BET), Energy Dispersive X-ray Spectrometer(EDS) and X-ray Photoelectron Spectroscopy(XPS) were used to analyze the variations in surface physical morphology and composition of aluminum scraps-activated carbon particles before and after the operations, and to study the mechanism of aluminum-carbon micro electrolysis The results showed that the influences factors on Cr(Ⅵ) removal efficiency could be listed from the highest to the lowest as follows: initial pH, the mass ratio of aluminum and carbon, oscillation speed and oscillation time. The removal efficiency of Cr(Ⅵ) reached the highest value of 95.40% under the optimum conditions when the Al/C mass ratio was 2:1, initial pH was 5, oscillation speed was 150 r/min, and oscillation time was 40 min. It was proved that the removal efficiency of Cr(Ⅵ) could be greatly improved by using aluminium-carbon micro electrolysis instead of direct reduction of pure aluminium or iron-carbon micro electrolysis. The main removal mechanism of Cr(Ⅵ) was the reduction of Cr(Ⅵ) to Cr(Ⅲ) by carbon cathode during the micro electrolysis process.更多还原