摘要
由于TiO_(2)掺入Ag可提高光催化去除氨氮的气体产物比例,从而实现水中氨氮和总氮的同步去除,采用光还原法制备了掺Ag改性TiO_(2),借助XRF、XRD、SEM和XPS研究了Ag-TiO_(2)的Ag掺量、晶体结构、粒径大小及元素组成等,并考察了Ag掺量、催化剂投加量、初始pH值等影响因素.结果表明:TiO_(2)经Ag掺入后以锐钛矿为主导,粒径缩小至23.63 nm,排列紧密,且同时存在O、Ti、Ag元素,氨氮及总氮去除率均随Ag掺量、催化剂投加量和初始pH值的升高先上升后下降;当Ag实际质量分数为0.53%,初始pH值为10,催化剂投加量为1.0 mg/L时,经波长为365 nm的紫外光照射180 min后,氨氮和总氮去除率分别为79.8%和72.0%,产物中气体选择性为90.2%,降解过程符合一级反应动力学.掺入Ag的TiO_(2)缩小粒径或改变影响因素均可提高产物中气体选择性,有助于氨氮和总氮的去除.
Due to that Ag-doped TiO_(2)can increase the proportion of gas products for photocatalytic removal of ammonia nitrogen, so as to realize the simultaneous removal of ammonia nitrogen and total nitrogen in water, Ag-doped TiO_(2)was prepared by a photoreduction method. The Ag doping amount, crystal structure, particle size, and element composition of Ag-TiO_(2)were studied by XRF, XRD, SEM, and XPS. The influencing factors, such as Ag doping amount, catalyst dosage and initial pH value, were investigated. The results show that after Ag doping, TiO_(2)is dominated by anatase, the particle size is reduced to 23.63 nm, the arrangement is tight, and O, Ti, Ag elements are existed at the same time. The removal rates of ammonia nitrogen and total nitrogen first increase and then decrease with the increase of the Ag doping amount, the catalyst dosage and the initial pH value. When the actual mass fraction of Ag is 0.53%, the initial pH value is 10 and the catalyst dosage is 1.0 mg/L. After 180 min of UV irradiation at 365 nm, the removal rates of the ammonia nitrogen and the total nitrogen are 79.8% and 72.0%, respectively;and the gas selectivity of the product is 90.2%. The degradation process accords with the first-order reaction kinetics. Reducing the particle size of Ag-doped TiO_(2)or changing the influencing factors can improve the gas selectivity of the product and contribute to the removal of the ammonia nitrogen and the total nitrogen.
作者
姜娥梅
吴磊
林超
Jiang Emei;Wu Lei;Lin Chao(School of Energy and Environment,Southeast University,Nanjing 210096,China;Jiangsu Academy of Environmental Sciences,Nanjing 210036,China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第2期328-334,共7页
Journal of Southeast University：Natural Science Edition
基金
“十三五”国家科技重大专项资助项目(2017ZX07202-004-005)。
关键词
载银二氧化钛
光催化氧化
氨氮
总氮
同步
silver-loaded titanium dioxide
photocatalytic oxidation
ammonia nitrogen
total nitrogen
synchronization
