研究报告

  • 李民,陈炜鸣,蒋国斌,张爱平.Fe-Ce/GAC催化臭氧降解高浓度腐殖酸废水[J].环境科学学报,2017,37(9):3409-3418

  • Fe-Ce/GAC催化臭氧降解高浓度腐殖酸废水
  • Ozonation treatment of high humic acid wastewater catalized by Fe-Ce/GAC
  • 基金项目:四川省教育厅项目(No.15ZB0034);四川省科技厅苗子工程项目(No.2015039)
  • 作者
  • 单位
  • 李民
  • 四川师范大学化学与材料科学学院, 成都 610068
  • 陈炜鸣
  • 西南交通大学地球科学与环境工程学院, 成都 611756
  • 蒋国斌
  • 西南交通大学地球科学与环境工程学院, 成都 611756
  • 张爱平
  • 四川师范大学化学与材料科学学院, 成都 610068
  • 摘要:采用浸渍焙烧法制备了Fe-Ce/GAC催化剂,并用于催化臭氧降解模拟高浓度腐殖酸废水.以废水COD、腐殖酸浓度为考察指标,研究了Fe-Ce/GAC催化剂的前驱体无机铁盐种类、焙烧温度、铁盐浓度、助剂稀土元素种类及浓度、分散剂硝酸钾浓度等不同制备条件对催化臭氧降解腐殖酸的效果.试验表明,在腐殖酸浓度为3.00 g·L-1、pH值约8.0、温度为25℃、臭氧投量为1.24 g·h-1,反应40 min后COD、腐殖酸去除率仅为17.1%、43.0%;添加以2.0%硝酸铁、1.5%硝酸铈、1.0%硝酸钾溶液浸渍,经350℃焙烧3 h后制备的Fe-Ce/GAC催化剂,可使COD、腐殖酸去除率分别提高40.3%、31.8%.且Fe-Ce/GAC催化剂具有较好的稳定性,重复使用5次后,COD、腐殖酸去除率仅小幅降低了4.2%、9.1%.SEM图象显示活性炭经改性后,比表面积明显增大,有利于活性物质的负载;EDS分析表明催化剂负载了大量的Fe、Ce等金属物质;XRD图谱显示催化剂含有Fe2O3、CeO2等多种活性物质.Fe-Ce/GAC催化臭氧的机理可解释为:活性成分氧化铁在催化过程中生成的羟基氧化铁会促进羟基自由基的生成,而铈元素在催化过程中不仅会提高催化剂的活性,而且生成的化学吸附氧可促进对有机物的吸附及氧化.
  • Abstract:Fe-Ce/GAC was prepared by using the impregnation calcination method and was applied for catalytic ozonation of simulated high humic acid wastewater. The preparation conditions, such as the inorganic iron species of the Fe-Ce/GAC catalyst precursor, calcinations temperature, molysite concentration, lanthanon auxiliary type and concentration, and potassium nitrate concentration in impregnation solutions were explored by evaluating the removal efficiencies of COD and humic acid through catalytic ozonation. The result shows that the removal efficiencies of COD and humic acid were only 17.1% and 43.0%, respectively, under the condition of 3.00 g·L-1 humic acid, pH 8.0, temperature of 25℃, ozone dosage of 1.24 g·h-1 and 40 min reaction time. In contrast, the removal efficiencies could be improved by 40.3% and 31.8% respectively after adding the Fe-Ce/GAC, which was prepared with 2.0% ferric nitrate, 1.5% cerium nitrate, 1.0% potassium nitrate and then calcinated 3 h at 350℃. The Fe-Ce/GAC was able to maintain its stability since the removal efficiencies reduced slightly by 4.2% and 9.1% after five times reuse. SEM results indicate that the specific surface area of modified GAC was increased. The result from EDS analysis confirmed that lots of metallics such as Fe and Ce are loaded on GAC. XRD analysis result shows the catalyst contained Fe2O3, CeO2 and other active substances. Collectively, the catalytic mechanism might be that the hydroxyl ferric oxide produced by iron oxide could promote the formation of hydroxyl radical in catalytic process; cerium could not only increase the catalytic activity, but also produce the chemical adsorption of oxygen to enhance the absorption and oxidation of organic compounds.

  • 摘要点击次数: 171 全文下载次数: 183