| 摘要: |
| 【目的】以陕西杨凌某自来水厂铝污泥(Al-WTRs)为原料，对其进行改性，研究改性后铝污泥对Pb2+和Cu2+的吸附性能，以期为Al-WTRs的利用提供途径。【方法】采用KMnO4和FeCl2·4H2O对Al-WTRs进行改性，制备铁锰氧化物改性铝污泥(M-Al-WTRs)，采用比表面(BET-N2)、扫描电镜(SEM-EDS)、X射线衍射(XRD)、红外光谱(FTIR)等方法对改性前后Al-WTRs进行表征分析，并探讨不同pH、吸附时间、重金属初始质量浓度、温度和离子强度等条件下M-Al-WTRs对Pb2+和Cu2+的吸附性能。【结果】与Al-WTRs(9.10 m2/g)相比，M-Al-WTRs比表面积显著增大到100.8 m2/g；SEM-EDS、XRD、FTIR分析结果显示，M-Al-WTRs表面粗糙，且负载许多颗粒，并保持无定形态。M-Al-WTRs对Pb2+和Cu2+的吸附量随着pH的增加逐渐增大，最终趋于稳定，其中当pH=5时，M-Al-WTRs对Pb2+和Cu2+的吸附量分别为67.18和20.81 mg/g，分别比Al-WTRs提高了109.1%和68.64%。M-Al-WTRs对Pb2+和Cu2+的吸附动力学符合准二级吸附动力学模型，吸附等温线符合Langmuir等温模型。热力学分析表明，M-Al-WTRs对Pb2+和Cu2+的吸附是自发、吸热、增熵的过程。M-Al-WTRs对Pb2+和Cu2+的吸附几乎不受离子强度的影响，属于专性吸附。【结论】成功制备了对Pb2+和Cu2+具有良好吸附效果的M-Al-WTRs。 |
| 关键词: 铝污泥；铁锰氧化物 重金属吸附 |
| DOI： |
| 分类号: |
| 基金项目:陕西省科技统筹创新工程计划项目“重金属污染土壤的稳定化修复技术与示范”(2016KTCQ03-20) |
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| Adsorption of Pb2+ and Cu2+ on alum water treatment residuals modified by iron manganese oxides |
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JIANG Yahui,ZHANG Zengqiang,LI Ronghua,et al
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| Abstract: |
| 【Objective】The adsorption of Pb2+ and Cu2+ on modified alum water treatment residuals were investigated to improve the utilization of Al-WTRs.【Method】Al-WTRs from a water plant in Yangling,Shaanxi were modified by KMnO4 and FeCl2·4H2O to obtain M-Al-WTRs.Adsorbents (Al-WTRs and M-Al-WTRs) were characterized by BET-N2,SEM-EDS,XRD and FTIR.Batch adsorption experiments were conducted to investigate the effects of pH,adsorption time,initial mass concentration of heavy metals, temperature and ion strength on adsorption properties of Pb2+ and Cu2+ by M-Al-WTRs.【Result】Compared with Al-WTRs(9.10 m2/g),specific surface of M-Al-WTRs was significantly increased to 100.8 m2/g.SEM-EDS,XRD,and FTIR showed that the surface of M-Al-WTRs was rough and loaded with many particles,and the amorphous structure was well maintained after modification.Adsorption capacities of Pb2+ and Cu2+ on M-Al-WTRs increased with increasing pH and reached steady gradually.When pH=5,the adsorption capacities of Pb2+ and Cu2+ on M-Al-WTRs were 67.18 and 20.81 mg/g, which were 109.1% and 68.64% higher than that of Al-WTRs,respectively. The adsorption of Pb2+ and Cu2+ by M-Al-WTRs could be described with the pseudo-second-order kinetic model,and the adsorption isotherm fitted Langmuir model well.Thermodynamic analysis showed that the adsorption process of Pb2+ and Cu2+ on M-Al-WTRs was spontaneous,endothermic and entropy increasing.The adsorption of Pb2+ and Cu2+ on M-Al-WTRs was hardly affected by ionic strength.【Conclusion】M-Al-WTRs with relative good adsorption capacities of Pb2+ and Cu2+ could be prepared by alum water treatment residuals. |
| Key words: Al-WTRs iron manganese oxides heavy matal adsorption |
