双包覆型过硫酸盐缓释材料的制备及其对地下水中磺胺甲恶唑的去除  

Preparation of a double-coated persulfate slow-release material for sulfamethoxazole removal from groundwater

作　　者：夏玉瑾 胡志欣 董鲁钰 张渺 杨胜科[1,2] 王雪丽 XIA Yujin;HU Zhixin;DONG Luyu;ZHANG Miao;YANG Shengke;WANG Xueli(School of Water and Environment,Chang′an University,Xi′an 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region,Ministry of Education,Chang′an University,Xi′an 710054,China)

机构地区：[1]长安大学水利与环境学院,西安710054 [2]长安大学,旱区地下水文与生态效应教育部重点实验室,西安710054

出　　处：《环境工程学报》2025年第3期568-577,共10页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划资助项目(2020YFC1808300);陕西省自然科学基金资助项目(2022JQ-081)。

摘　　要：针对单层过硫酸盐缓释材料前期释放过快导致的缓释材料使用寿命缩短的问题,采用聚已内酯-硅砂为外层材料,对聚已内酯-硅砂-过硫酸钠组成的内层缓释材料进行包覆,制备了双包覆型过硫酸盐缓释材料。通过静态释放实验评估过硫酸盐缓释材料在有无外层材料包覆条件下的释放行为与机制;通过铁氮共掺杂生物炭(Fe@N-BC)活化释放的过硫酸盐考察其对地下水中的磺胺甲恶唑(SMZ)的降解效果。结果表明:双包覆型缓释材料与单层材料相比在释放周期内释放速率较稳定,且与单层缓释材料相比更符合零级释放动力学特征;在外层厚度为0.25 cm条件下,2<硅砂/聚已内酯(PCL)<5时,双包覆型缓释材料释放速率较稳定且释放性能较好,在缓释21 d之后,硅砂/PCL=3和4的双包覆型缓释材料缓释率分别为35.52%和47.27%;在外层硅砂/PCL相同条件下,双包覆型缓释材料的释放速率随着外层厚度的减小而增大,且最少可以保持21 d的稳定释放;降解实验结果显示,在pH=3的条件下SMZ去除速率最快,12 h内1 mg·L^(−1)的SMZ去除率可达到100%,随着SMZ初始浓度的提高,降解完全所需时间增长。以上研究结果可为实现过硫酸盐持续稳定释放及去除实际地下水中SMZ提供参考依据。To address the issue of shortened lifespan in single-layer persulfate slow-release materials due to rapid initial release,polycaprolactone-silica sand was taken as the outer-layer material,which covered on the inner-layer with a combination of sodium persulfate and polycaprolactone-silica sand,to synthesize a double-coated persulfate slow-release material.The static release experiments were used to evaluate the release behavior and mechanism of persulfate slow-release materials with or without the outer-layer material.Its performance on sulfamethoxazole(SMZ)degradation in groundwater was investigated through iron-nitrogen co-doped biochar(Fe@N-BC)activating persulfate released from the double-coated persulfate slow-release material.The results showed that the release rate of the double-coated persulfate slow-release material was more stable than that of the single-layer slow-release one over the release period,and the release kinetics of the former material were more fitted by zero-order release kinetics than the latter one.At an outer layer thickness of 0.25 cm and a silica sand/PCL ratios between 2 and 5,the release rate of the double-coated slow-release material was stable with an effective performance.After 21 days of slow release,the slow-release rates of the double-coated slow-release materials with sand/PCL ratios of 3 and 4 were 35.52%and 47.27%,respectively.At the same ratio of silica sand/PCL,the release rate of the double-coated slow-release material increased as the thickness of the outer layer decreased,and the stable release could maintain at least 21 days.At pH_(3),the highest SMZ degradation rate occurred,and the removal rate for 1 mg/L SMZ could reach 100%within 12 hours.As the initial concentration of SMZ increased,the time required for complete degradation also increased.The above study result could provide a reference for realizing the sustained and stable release of persulfate and removing SMZ in in groundwater.

关 键 词：过硫酸盐 双层缓释材料 地下水 磺胺甲恶唑 

分 类 号：X703[环境科学与工程—环境工程]