FeS_(2)活化过硫酸盐降解四环素的研究

Degradation of tetracycline with peroxymonosulfate activated by FeS_(2)

采用水热合成法制备了二硫化铁(FeS_(2))纳米片,用于活化过硫酸盐(PMS)降解新污染物四环素(TC).采用X射线衍射仪、X射线光电子能谱仪和扫描电子显微镜对FeS_(2)的结构、组成和形貌进行了表征.研究了铁与硫物质的量比、催化剂质量浓度、PMS物质的量浓度、TC初始质量浓度和4种常见阴离子(Cl^(-)、CO_(3)^(2-)、HCO_(3)^(-)和NO_(3)^(-))共存对TC降解效果的影响,并对FeS_(2)活化PMS机制进行了探讨.当铁与硫物质的量比为1∶2时,FeS_(2)催化活化PMS去除TC效果最好,在TC初始质量浓度20 mg/L、FeS_(2)质量浓度7 mg/L、PMS物质的量浓度0.5 mmol/L的条件下,30 min时TC的去除率可达83.9%.当溶液中共存Cl^(-)和NO_(3)^(-)时,TC降解受到的影响较小,而共存CO_(3)^(2-)和HCO_(3)^(-)时,TC的降解受到了明显的抑制.FeS_(2)/PMS体系中产生的活性物种以单线态氧(1O2)为主,硫酸根自由基(SO_(4)·^(-))和超氧阴离子自由基(O_(2)·^(-))对TC的降解也有一定的贡献.

Iron disulfide(FeS_(2))nanosheets were prepared by hydrothermal synthesis,and used as peroxymonosulfate(PMS)activator to degrade a new pollutant tetracycline(TC).The structure,composition and morphology of FeS_(2) were characterized by X-ray diffraction instrument,X-ray photoelectron spectroscopy and scanning electron microscopy.The effects of Fe/S molar ratio,the mass concentration of the catalyst,PMS molar concentration,initial TC mass concentration and the coexistence of four common anions(Cl^(-),CO_(3)^(2-),HCO_(3)^(-) and NO_(3)^(-))on TC degradation were studied,and the mechanism of PMS activation by FeS_(2) was discussed.When the molar ratio of iron to sulfur was 1∶2,the catalytic activation of PMS by FeS_(2) had the best effect on TC removal.Under the conditions of initial TC mass concentration of 20 mg/L,FeS_(2) dosage of 7 mg/L and PMS molar concentration of 0.5 mmol/L,the removal rate of TC could reach 83.9%after 30 min.When the Cl^(-)and NO_(3)^(-) coexisted in the solution,the degradation of TC was less affected,while CO_(3)^(2-) and HCO_(3)^(-) coexisted,the degradation of TC was significantly inhibited.The active species produced in FeS_(2)/PMS system were mainly singlet oxygen(1O_(2)),sulfate radical(SO_(4)^(·-))and superoxide anion radical(O_(2)^(·-))also contributed to the degradation of TC.