盐酸羟胺/铁基MOFs/过硫酸盐体系降解磺胺嘧啶

Degradation of sulfadiazine by hydroxylamine hydrochloride/Fe-MOFs/persulfate system

使用盐酸羟胺(HA)促进Fe(Ⅲ)/Fe(Ⅲ)循环,强化铁基金属有机骨架(Fe-MOFs)/过硫酸盐(PS)体系降解水中磺胺嘧啶(SDZ).通过X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶变换红外光谱(FTIR)和X射线光电子能谱仪(XPS)对Fe-MOFs进行结构和形貌的表征.探究了溶液初始pH值、PS浓度、Fe-MOFs投加量、HA浓度、SDZ浓度、共存离子、腐殖酸等对SDZ去除效果的影响,并考察了该体系的实际应用前景.结果表明,Fe-MOFs/PS/HA体系在较宽的初始pH值范围(3~6)内,对于SDZ的180min去除率可达到90.1%以上.适量的HA可以促进Fe-MOFs/PS体系降解SDZ的性能.自由基清扫实验和电子顺磁共振实验表明,Fe-MOFs/PS/HA体系降解SDZ的过程中产生了SO_(4)^(-)•、•OH、O_(2)^(-)•以及^(1)O_(2).在本文考察范围内,Fe-MOFs/PS/HA体系对SDZ的降解性能随pH值(pH=3~6)升高逐渐下降;随着PS、HA、Fe-MOFs浓度的升高,SDZ去除率呈现率先上升后下降的趋势.氯离子、腐殖酸等因素对该体系应用于实际地表水存在负面作用,但HA可以强化该体系在自然环境下降解SDZ的效果.循环实验结果表明,Fe-MOFs具有良好的重复使用性,表现出了良好的应用潜力.

Hydroxylamine hydrochloride was used to promote Fe(Ⅲ)/Fe(Ⅲ)cycle in iron-based metal organic framework(Fe-MOFs)/persulfate(PS)system to degrade sulfadiazine(SDZ)in water.The structure and morphology of Fe-MOFs were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).The influence of initial pH,PS,Fe-MOFs,HA,SDZ,co-existing ions and humic acid on the removal of SDZ were investigated and the prospect for practical application of this system was also evaluated.The results showed that Fe-MOFs/PS/HA system had a good removal performance of SDZ in a wide initial pH range(3~6),and the removal of SDZ at 180min reached above 90.1%.The appropriate amount of HA could promote the degradation of SDZ in Fe-MOFs/PS system.The results of the free radical scavenging and electron paramagnetic resonance experiments showed that the SO_(4)^(-)•、•OH、O_(2)^(-)•and^(1)O_(2)were produced in the Fe-MOFs/PS/HA system during the degradation process of SDZ.Within the experiment scope of this study,the degradation performance of SDZ by Fe-MOFs/PS/HA system decreased gradually with the increase of pH value in the range of(pH=3~6).With the increase of the concentration of PS,HA and Fe-MOFs,the removal of SDZ exhibited the rising-then-falling pattern.Chlorine ion,humic acid and other factors had the negative effects on the removal of SDZ in the system in actual surface water,however HA could enhance the degradation of SDZ in the natural environment.The result of recycle experiment revealed that Fe-MOFs system had a good reusability and exhibited a great application potential.