Zhejiang Daxue xuebao. Lixue ban (May 2024)
Removal of norfloxacin by ZnCl2-modified biochar-activated sulfate and investigation of its loadability on geopolymers(ZnCl2改性海藻基生物炭去除水体中诺氟沙星的性能及循环利用性研究)
Abstract
Advanced oxidative processes of persulfate (PS-AOPs) have promising applications in antibiotic wastewater treatment due to their strong oxidation capacity and good selectivity. In this study, Sargassum fusiforme was selected as a raw biomass, and ZnCl2 carbonation-pyrolysis was adopted to prepare zinc chloride modified sheep sorrel biochar which was used as a catalyst to catalyze persulfate (PDS) to degrade the norfloxacin (NOR) in the water. The results showed that different ratios of ZnCl2 doping would significantly affect the performance of biochar, and the catalytic efficiency of the prepared biochar was optimal when the ratio of algal powder to ZnCl2 was 1∶1. Moreover, SEM, BET, XRD characterizations were employed to investigate the physical and chemical properties of YQZn in order to further explore the modification mechanism of ZnCl2. The catalytic efficiency result of YQZn under different conditions showed that the biochar had the best NOR removal rate of 95.09% under the conditions of PDS concentration was 1 mmol·L-1, modified biochar addition was 0.3 g·L-1, pH=9 and NOR concentration was 10 mg·L-1. SO4·-, HO· radicals, and 1O2 played a leading role in activating PDS in the system by free radical quenching. To solve the difficulties in biochar powder recovery YQZn geopolymer composite catalyst (GB) was prepared by using biochar loaded on porous geopolymer. The results showed that GB had excellent degradation activity and reuse performance, which successfully realized the loading and recycling of biochar, and thus had great potential for continuous treatment of norfloxacin in water.(过硫酸盐高级氧化工艺（PS-AOPs）因具有氧化能力强、选择性高等优点在抗生素废水处理方面具有广阔的应用前景。选取羊栖菜为研究对象，采用氯化锌（ZnCl2）共热裂解法，制备了ZnCl2改性羊栖菜生物炭（YQZn），并将其作为催化剂活化过二硫酸盐（PDS），降解水体中的诺氟沙星（NOR）。结果显示，不同的ZnCl2添加量对生物炭催化活性的影响不同，当ZnCl2与羊栖菜的质量比为1∶1时，催化活性最佳。采用扫描电镜（SEM）、Brunauer-Emmet-Teller（BET）方法、X射线衍射（XRD）分析等表征YQZn的理化性质，探究了ZnCl2的改性机理，同时研究了不同反应条件对YQZn催化活性的影响。结果表明，在PDS浓度为1 mmol·L-1、改性生物炭添加量为0.3 g·L-1、pH为9、NOR浓度为10 mg·L-1的条件下，NOR的去除率最高，可达95.09%。自由基淬灭实验结果表明，SO4·-和HO∙自由基在氧化作用中占主导地位，1O2的作用较为有限。针对粉末生物炭回收困难的问题，将YQZn负载至多孔地质聚合物上，制备了复合物GB。重复利用性实验表明，GB具有良好的降解活性和优良的重复利用性，可有效去除96.68%的NOR。)
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