氧化石墨烯-铁氧化物改性石英砂表面性能表征及其对腐殖酸的吸附特性研究

Study on the preparation condition optimization of GO-IOCS and its adsorption properties of humic acid

普通石英砂(RQS)滤料对腐殖酸(HA)的去除能力非常有限。以三氯化铁与氧化石墨烯(GO)为改性剂,对RQS进行改性,得到氧化石墨烯-铁氧化物改性石英砂(GO-IOCS),研究其吸附特性,并运用扫描电子显微镜(SEM)、能谱(EDS)和傅立叶变换红外光谱(FTIR)等手段进行表征。结果表明:(1)GO-IOCS对初始质量浓度低于5mg/L的HA溶液,吸附去除率高达98.57%,约为RQS的5倍;(2)GO-IOCS表面负载均匀密集的颗粒,且具有利于吸附的大量官能团(如-OH、C-O、C=O、Fe-O-C等);(3)GO-IOCS和RQS对HA的吸附动力学特性都符合准二级动力学模型,前者对HA的吸附速率约为后者的3倍;(4)GO-IOCS对HA的吸附除了静电作用外,还包括离子交换作用。

The effect of raw quartz sand(RQS)filter material on the removal of humic acid(HA)is negligible.Graphene oxide(GO)-iron oxide modified quartz sand(IOCS)was prepared with RQS as the raw material being coated with two modifiers,ferric chloride and GO.The surface performances of GO-IOCS was characterized by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and Fourier transform infrared spectrometer(FTIR).The adsorption properties were investigated as well.The results showed that:(1)the adsorption removal rate of GO-IOCS to HA was 98.57%,which was 5 times of that of RQS,when the dosage of HA was below 5 mg/L.(2)The GO-IOCS surface load was homogeneous and dense,and the oxygen groups with excellent adsorption characteristics were found on the surface of GO-IOCS by FTIR,such as-OH,C-O,C=O and Fe-O-C.(3)The adsorption kinetics of HA by both GO-IOCS and RQS were in accordance with the pseudosecond-order kinetic model.GO-IOCS had a adsorption rate about 3 times of RQS.(4)The adsorption mechanisms of HA by GO-IOCS were ion exchange in addition to physical adsorption.