T-FMSAC制备及其催化臭氧氧化去除p-CBA效能研究

摘要

Basing on the activated carbon prepared from sludge, different transition metals (Mn, Co, and Cu) doped ferromagnetic sludge-based activated carbons (T-FMSAC, T= Mn, Co, and Cu) were prepared by chemical coprecipitation method. The effects of metal species and doping ratio on the removal efficiency of p-chlorobenzoic acid (p-CBA) in water by T-FMSAC catalytic ozonation were investigated, and the optimal dosages of initial ozone and T-FMSAC catalyst were further determined. Experimental results showed that, after 40minutes of ozonation, Mn-FMSAC exhibited the highest catalytic activity under the initial ozone and catalyst dosage of 1mg/L and 40mg/L respectively, and the removal efficiency was 76%, higher than that for Co-FMSAC (72%) or Cu-FMSAC (65%). In addition, the removal efficiency of p-CBA decreased with the increase in the doping ratio from SAC: metal=100:1 to 10:1. With the doping ratio of 100:1, the T-FMSAC exhibited the optimal magnetic separation property and catalytic activity. The optimal condition for 100:1Mn-FMSAC catalytic ozonation was determined to be [O3]0= 1mg/L and [FMSAC]0= 40mg/L. Besides, the inhibition of p-CBA degradation by tertiary butyl alcohol (TBA) indicated that this process followed the hydroxyl radical reaction mechanism.%以污泥基活性炭为基质,采用化学共沉淀法制备了不同过渡金属(Mn、Co和Cu)掺杂的铁磁污泥基活性炭(T-FMSAC,T=Mn、Co、Cu),重点考察了过渡金属种类及其掺杂比例对T-FMSAC催化臭氧氧化去除水中对氯苯甲酸(p-CBA)效能的影响,并对臭氧与T-FMSAC催化剂的最佳投量进行了研究确定.结果表明,在臭氧投加量为1mg/L,催化剂投加量为40mg/L条件下,反应进行40min后,Mn-FMSAC的催化活性最高,其催化臭氧氧化对p-CBA的去除率为76%,高于Co-FMSAC(72%)及Cu-FMSAC(65%).并且,随着金属掺杂比例的增加(100:1,50:1,25:1,10:1(污泥量:金属掺杂量,W:W)),T-FMSAC催化臭氧氧化对p-CBA的去除率逐渐降低.在100:1掺杂比例下,催化剂不仅能够简单地通过磁铁分离,且具备最佳催化活性.100:1Mn-FMSAC催化臭氧氧化工艺对p-CBA的去除率随臭氧浓度的增加而增加;当臭氧投加量为1mg/L时,100:1Mn-FMSAC催化剂的最佳投量为40mg/L.叔丁醇的加入显著抑制了100:1Mn-FMSAC催化臭氧氧化降解p-CBA的效能,表明该反应过程遵循羟基自由基反应机制.