SP-Fe/PMS去除河流缓流区水中含苯环有机污染物的性能及机理

Study on the removal mechanism of benzene-containing contaminants(BCCs)in slow-flowing areas of river by SP-Fe/PMS

河流缓流区水体由于自净能力较差,导致含苯环有机污染物(BCCs)在其中积累且不易降解,从而对人类健康和水生态系统造成潜在威胁.因此,本研究通过浸渍法制备了一种新型铁掺杂藻基生物质催化剂(SP-Fe),采用扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、傅里叶红外光谱(FTIR)等技术对SP-Fe的结构形貌、元素和官能团进行表征,并考察其在不同环境条件下活化过一硫酸盐(PMS)对河流缓流区水体中BCCs的去除性能及去除机理.结果表明:SP-Fe在实际河流缓流区水体中可迅速活化PMS,30 min内对两种典型BCCs—罗丹明B(Rh-B)和亚甲基蓝(MB)的去除率分别可达100%和95%.此外,SP-Fe含氮量高达6.24%(原子百分比),表明通过藻类蛋白质中的高N含量实现了自身的N掺杂.以Rh-B作为BCCs典型代表,通过自由基淬灭和电子自旋共振(ESR)实验表明,硫酸根自由基(SO_(4)^(·-))、羟基自由基(·OH)和超氧自由基(O_(2)^(·-))在SP-Fe/PMS去除BCCs的过程中起着重要作用.SP-Fe对PMS的活化性能随着重复使用次数的增加有所降低,但3次循环后对Rh-B的去除效率仍能达76.23%.这将为河流缓流区中BCCs的消减提供新的途径.

Due to the poor-purification capacity of the slow-flowing areas of the river,the benzene-containing contaminants(BCCs)accumulate in the water and are not easily degraded,posing a potential threat to human health and aquatic ecosystem.Therefore,a new type of iron doped algal-based biomass catalyst(SP-Fe)was made by the impregnation method.The structural morphology,elements and functional groups of SP-Fe were characterized by scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS)and Fourier infrared spectroscopy(FTIR).The removal performance and mechanism of SP-Fe/PMS on BCCs in the slow-flowing area of rivers were investigated under different environmental conditions.The results showed that SP-Fe could rapidly activate PMS,and the removal ratio of Rhodamine B(Rh-B)and Methylene Blue(MB)could reach 100%and 95%within 30 min in the water sampled from slow-flowing area of the actual river,respectively.The nitrogen content of SP-Fe is 6.24%(atomic percentage),which indicates that the high N content in algal protein realizes its own N doping.Taking Rh-B as a typical representative of BCCs,the radical quenching and electron spin resonance(ESR)experiments show that sulfate radical(SO_(4)^(·-)),hydroxyl radical(·OH)and superoxide radical(O_(2)^(·-))play an important role in the removal of BCCs by SP-Fe/PMS.The activation performance of SP-Fe to PMS decreased with the increase of reuse times,but the removal efficiency of Rh-B could still reach 76.23%after three cycles.Our results will provide a new way for the reduction of BCCs in the slow-flowing areas of rivers.