硫改性铁基材料活化过硫酸盐降解盐酸四环素

Degradation of tetracycline hydrochloride by persulfate activated with sulfur modified iron-based materials

将硫代硫酸钠以及硫酸亚铁铵按照硫和铁摩尔比为1∶2的比例共沉淀后,经过高温煅烧制备出硫改性铁基催化剂S-Fe。采用SEM、XRD和XPS等手段对其进行表征。考察了初始盐酸四环素(TCH)浓度、S-Fe催化剂投加量、过硫酸盐浓度、初始pH等对S-Fe活化过硫酸盐体系(S-Fe/PS)降解TCH的影响,并分析了反应机理。结果表明,S-Fe催化剂具有良好的吸附性能和较大的催化表面,与零价铁相比催化能力更强,且具有磁性,可循环使用。当反应温度为25℃、S-Fe投加量为1 g/L、初始TCH浓度为20 mg/L、过硫酸盐浓度为2 g/L、初始pH值为3时,反应30 min后,TCH的降解率可达到90.1%。猝灭实验发现硫酸根自由基(SO_(4)^(-)·)在反应体系中起着最主要的作用,其次是羟基自由基(·OH)。

The sulfur-modified iron-based catalyst S-Fe is prepared by high temperature calcination after co-precipitating sodium thiosulfate and ferrous ammonium sulfate in a ratio of sulfur to iron molar ratio of 1∶2,it was characterized by means of SEM,XRD and XPS.The effects of initial tetracycline hydrochloride(TCH)concentration,S-Fe catalyst dosage,persulfate concentration,initial pH,etc.on the degradation of TCH by S-Fe activated persulfate system(S-Fe/PS)were investigated,the reaction mechanism was also studied.The results show that the S-Fe catalyst has good adsorption performance,larger catalytic surface,stronger catalytic ability than zero-valent iron,and magnetic which makes it easier to be recycled.When the reaction temperature was 25℃,the dosage of S-Fe was 1 g/L,the initial TCH concentration was 20 mg/L,the persulfate concentration was 2 g/L,and the initial pH was 3,the degradation percentage of TCH could reach 90.1%after 30 min of reaction.The free radical quenching experiments showed that sulfate radical(SO_(4)^(-)·)played the most important role in the reaction system,followed by hydroxyl radical(·OH).