彭菲,黄震,黄占斌,顾森源,崔贤.纳米铁锰氧化物对钒的吸附特性研究[J].环境科学学报,2019,39(4):1191-1197
纳米铁锰氧化物对钒的吸附特性研究
- Study on the adsorption characteristics of vanadium by nano-iron-manganese oxide
- 基金项目：国家科技支撑计划课题（No.2015BAD05B03）；三峡后续工作科研课题（No.2015HXKY2-4）
- 彭菲
- 中国矿业大学(北京)化学与环境工程学院, 北京 100083
- 黄占斌
- 中国矿业大学(北京)化学与环境工程学院, 北京 100083
- 顾森源
- 中国矿业大学(北京)化学与环境工程学院, 北京 100083
- 崔贤
- 中国矿业大学(北京)化学与环境工程学院, 北京 100083
- 摘要：为寻求处理土壤和地下水钒污染的吸附剂，采用模拟实验，开展了纳米铁锰氧化物（MnFe2O4）对五价钒（V5+）的吸附特征研究，分析了纳米铁锰氧化物浓度、pH值、时间、温度和初始钒浓度等因素对MnFe2O4吸附V5+的影响，以揭示纳米铁锰氧化物的吸附动力学及热力学等特征，并通过扫描电镜（SEM）和红外光谱（IR）等表征方法分析了纳米铁锰氧化物吸附V5+的机理.结果表明，在初始钒溶液为100 mg·L-1，MnFe2O4加入量为0.1 g，pH=4，温度为25℃的条件下，吸附过程在24 h达到平衡，且此条件下有最大吸附值和吸附率，分别为15.14 mg·g-1和60.54%.纳米铁锰氧化物吸附钒的动力学过程符合伪二级动力学模型，等温吸附线符合Langmuir模型.热力学研究表明，升高温度有利于吸附，吸附过程为吸热过程.由扫描电镜结果可知，纳米铁锰氧化物有较大的比表面积，可提供较多的活性位点.因此，纳米铁锰氧化物可作为一种吸附材料用于钒污染废水处理.
- Abstract：In order to look for the suitable adsorbents to treat vanadium contamination in soil and groundwater, the adsorption characteristics of pentavalent vanadium (V5+) on nano-iron-manganese oxide (MnFe2O4) were studied by batch experiments. The influencing factors on the adsorption of V5+ by MnFe2O4 were investigated, including MnFe2O4 concentration, pH, reacting time, temperature, and initial concentration of vanadium. The adsorption kinetics and thermodynamics of V5+ by MnFe2O4 were studied. Moreover, the adsorption mechanism of V5+ by MnFe2O4 was investigated by using scanning electron microscope (SEM) and infrared spectroscopy (IR). The results demonstrate that the maximum adsorption capacity and the removal rate were 15.14 mg·g-1, and 60.54%, respectively, under the optimum conditions:initial vanadium concentration=100 mg·L-1, temperature=25℃, pH=4.0, MnFe2O4 dosage=0.1 g, and adsorption time=24 h. In addition, the kinetic curve of vanadium adsorption by MnFe2O4 was well fitted by the pseudo-second-order model. The adsorption isotherm followed the Langmuir model. The results of thermodynamics analysis indicate that the adsorption of V5+ on MnFe2O4 was a endothermic process.results of SEM show that MnFe2O4 had a large specific surface area that could provide more active sites. It is concluded that MnFe2O4 could be used as an adsorbent to treat vanadium contaminated wastewater.
