铁基纤维素微球的制备及其活化过硫酸盐降解盐酸四环素

PREPARATION OF IRON-BASED CELLULOSE MICROSPHERES AND ITS ACTIVATION ONPERSULFATE TO DEGRADE TETRACYCLINE HYDROCHLORIDE

铁基催化剂具有优良的活化过硫酸盐的性能,且价廉易得,受到研究者的广泛关注,然而在现阶段研究铁基催化剂多为粉末材料,存在易团聚、回收困难等问题,制约其实际应用。以醋酸纤维素(CA)为载体,采用液滴微流控技术制备了一种具有较高催化活性的微球催化剂(CA-Fe微球)。采用扫描电镜-能谱仪(SEM-EDS)、傅里叶红外变换光谱仪(FTIR)和比表面积分析仪(BET)对催化剂的形貌、结构和组成进行分析。以CA-Fe微球为催化剂活化过二硫酸盐(PS)降解盐酸四环素(TCH)废水,考察初始TCH浓度、CA-Fe微球投加量和PS投加量等操作条件对TCH去除效果的影响。结果表明:CA-Fe微球对PS具有良好的活化性能,CA-Fe/PS体系能够有效去除TCH。在TCH初始浓度为20 mg/L、PS浓度为2 mmol/L、CA-Fe微球投加量为4 g/L条件下,TCH去除率在85%左右。自由基捕获(EPR)和自由基猝灭实验结果揭示,CA-Fe微球/PS体系中存在的活性自由基为·OH和SO_(4)^(-)·,且SO_(4)^(-)·在TCH降解中起主要作用。循环利用实验表明,CA-Fe微球具有良好的结构稳定性和循环利用性能,3次循环使用后TCH去除率仍保持在80%左右。研究结果可为铁基纤维素微球/PS催化体系在去除抗生素废水领域的应用提供科学依据。

Iron-based catalysts have excellent performance in activating persulfate(PS)and are readily available,attracting extensive attention from researchers.However,most of the iron-based catalysts studied at the current stage are powder materials,and there are problems such as easy agglomeration and difficulty in recycling,which restrict their practical application.In this study,a microsphere catalyst(CA-Fe microspheres)with high catalytic activity was prepared using cellulose acetate(CA)as a carrier by droplet microfluidic technology.The morphology,structure and composition of the catalysts were characterized by SEM-EDS,FTIR and BET.The high catalytic degradation of tetracycline hydrochloride(TCH)in aqueous solution was tested by catalytic activation of PS.The effects of initial TCH concentration,the dosage of CA-Fe microspheres and the dosage of PS on TCH degradation were also investigated.The results showed that the CA-Fe microspheres had good activation performance for PS,and TCH could be effectively degraded in the CA-Fe/PS system.In the condition of the initial TCH concentration of 20 mg/L,the PS concentration of 2 mmol/L,and the CA-Fe microspheres dosage of 4 g/L,the degradation rate of TCH was about 85%.The electron paramagnetic resonance(EPR)and free radical quenching studies revealed that both SO_(4)^(-)·and·OH radicals were found in the CA-Fe microspheres/PS system,and the SO_(4)^(-)·radical played a major role in the degradation of TCH.Furthermore,the CA-Fe microspheres exhibited excellent structural stability and recycling performance,and the TCH degradation rate remained 80%above after three cycles.The results can provide a scientific basis for the application of cellulose-based magnetic microspheres/PS catalytic systems in the field of removing antibiotic wastewater.