Iron-based biochar as efficient persulfate activation catalyst for emerging pollutants removal:A review

In recent years,biochar(BC)as a low-cost,easily available biomass product,is widely applied in sulfate radical-based advanced oxidation processes(SR-AOPs)for emerging pollutants remediation.Herein,a state-of-art review of iron-based biochar catalysts is currently available in SR-AOPs application.A general summary of the development of biochar and the catalytic properties of biochar is presented.Especially,the synthetic strategies of different types of iron-based biochar catalysts are discussed.Moreover,the theoretical calculation to interpret the interaction between biochar and iron species is discussed to explore the activation mechanisms.And the regeneration methods of biochar-based catalyst are presented.The unresolved challenges of the existent biochar-based SR-AOPs are pointed out,and the outlooks of future research directions are proposed.

基于光学测量的异形纤维润湿性差异研究

气液聚结过滤在过程工业领域具有广泛应用,纤维材料润湿性是影响聚结元件过滤性能的关键因素。基于光学测量法,本工作开展了单根三角形、三叶形和十字形纤维表面的液体润湿性差异研究,分析了液体接触角及体积的变化过程,考察了液体类型、纤维倾斜角度及异形度对润湿性的影响。结果表明,液体表面张力越小,接触角越小,润湿性越强,但液体的挥发性易导致实际接触角大于理论接触角。三甘醇、癸二酸二辛酯和硅油的接触角基本不随时间发生变化,水和乙醇的接触角随时间逐渐减小且由于乙醇挥发速率较高,导致减小速率更大。液体接触角随异形纤维的倾斜角度呈"V"形分布,即存在极小值点(倾斜角度为30°),使纤维润湿性达到最佳。当纤维异形度增大时,不同液体间的接触角差异缩小、整体润湿性提高,表明在制备预过滤层或排液层材料时,宜选择异形度较高的纤维。

表面润湿性对梯形除雾器分离性能的影响

为解决实际工业中除雾器在高气速时分离效率明显降低的问题,利用除雾器分离实验装置,以水为实验介质,采用电火花线切割技术在叶片表面构建仿生微结构实现表面疏水化,考察了表面润湿性对除雾器分离效率和压降的影响。结果表明,仿生微结构的疏水功能和减阻效应良好,表面液膜的排液速率明显加快。当气速超过5m/s时,其液膜厚度相对较薄,可有效抑制液滴的二次夹带,提升分离效率。同时,疏水型梯形除雾器内的流场分布较平缓,流动阻力小,总压降约为带钩型梯形除雾器的一半。因此,疏水型梯形除雾器兼具高效率和低阻力特性,综合分离性能最佳。