磁改性羊粪衍生ZVI-生物炭的制备及其活化过一硫酸盐降解AO7特性研究

Preparation of ZVI-biochar derived from magnetically modified sheep manure and its activation of peroxymonosulfate to degrade AO7

以羊粪为原料,制备磁改性羊粪衍生ZVI-生物炭复合材料(SMF_(800)),通过BET、SEM、XRD、N2吸附-脱附等温线等对其表面形貌及晶体结构进行表征,并采用序批实验考查活化剂和过一硫酸盐(PMS)投加量、温度、溶液初始pH、无机阴离子等因素对AO7降解效率影响.结果表明,SMF_(800)拥有高度石墨化及多孔结构,在最佳条件下(PMS=0.8 g·L^(-1)、SMF_(800)=0.5 g·L^(-1)、AO7=20 mg·L^(-1)、T=25℃),40 min内AO7能被完全降解,在弱酸条件下有利于脱色,且活化剂经过3次循环使用后仍具有良好的活化效率.猝灭实验和XPS测试结果表明,自由基(SO_(4)^(-)∙、·OH、O_(2)^(-)·)和非自由基途径((1)^O_(2))协同作用于AO7的降解,其中以Fe^(0)还原PMS产生SO_(4)^(-)∙的自由基途径占主导地位,以Fe^(0)诱导碳电子、生物炭表面含氧官能团(C-OH和COOH)激活PMS产生(1)^O_(2)为辅,而SMF_(800)石墨化及大量的sp^(2)-C结构为电子转移提供良好的场所.综上,本研究设计制备了一种新型的生物炭基ZVI活化剂,以期为有机废水高效、低成本的处理方法提供新的技术支撑,同时也为粪源资源化利用提供新的途径.

The magnetically modified sheep manure-derived ZVI-biochar composite(SMF_(800))was prepared from sheep manure,and its surface morphology and crystal structure were characterized by BET,SEM,XRD,N_(2) adsorption-desorption isotherms,and sequential batch experiments were used to investigate the effects of activator and peroxymonosulfate(PMS)dosing,temperature,solution initial pH and inorganic anions on the degradation efficiency of AO7.The results showed that SMF_(800)possessed a highly graphitized and porous structure.Under the optimal conditions(PMS=0.8 g·L^(-1),SMF_(800)=0.5 g·L^(-1),AO7=20 mg·L^(-1),T=25℃),AO7 could be completely degraded in 40 minutes,the decolorization was facilitated under weak acid conditions,and the activator still showed good activation efficiency after three cycles of experiments.The results of the radical quenching experiment and XPS tests analysis showed that the radical(SO_(4)^(-)∙,·OH,O_(2)^(-)·)and nonradical pathways((1)^O_(2))acted synergistically in the degradation of AO7,in which the free radical pathway was dominated by SO_(4)^(-)∙produced by Fe0-activated PMS,and the nonradical pathway of(1)^O_(2)generated by Fe0 and oxygen-containing functional groups(C-OH and COOH)on the surface of biochar played a subordinate role,while the graphitization of SMF_(800)and the large number of sp2-C structures provide good sites for electron transfer.In summary,a novel biochar-based ZVI activator was designed and prepared in this study to provide a new technical support for an efficient and low-cost treatment method for organic wastewater,as well as providing a new way for the resource utilization of manure sources.