污泥基活性炭催化臭氧氧化降解水中微量布洛芬的效能研究

Catalytic Ozonation of Ibuprofen in Aqueous Solution by Activated Carbon Made from Sludge and Corn Cob

以城市污水处理厂脱水污泥和玉米芯为原料,氯化锌为活化剂制备污泥基活性炭(SAC),考察其催化臭氧氧化去除水中稳定性药物布洛芬(IBP)的效能.试验中对比考察了单独臭氧氧化、单独SAC吸附、SAC催化臭氧氧化这3种工艺对水中IBP(初始浓度为500μg.L-1)的去除效果,同时研究了臭氧与SAC投加量对催化效果的影响.结果表明,单独臭氧氧化对IBP的去除率随臭氧浓度的增加而增加,当臭氧浓度由0.75 mg.L-1增加至3.0 mg.L-1时,IBP的去除率由44.4%提高到100%;单独SAC对IBP的吸附去除效果较差,即使SAC投加量增至100 mg.L-1,吸附时间为40 min时,IBP的吸附去除率仅为44.56%;SAC催化臭氧氧化工艺中,IBP去除速率大大加快,在反应的初始阶段(0～5 min)SAC催化臭氧氧化对IBP的去除率要远远高于单独臭氧氧化和单独SAC吸附二者作用之和.臭氧与SAC的投加量对IBP的催化氧化去除效果具有较大影响.SAC催化臭氧氧化IBP分为瞬时需氧阶段反应(0～5 min)和慢速反应(5～40 min)两阶段.快速反应阶段以.OH与IBP反应为主,慢速反应阶段残余臭氧浓度很低,此时主要以SAC吸附去除IBP为主.

Catalytic ozonation of ibuprofen（IBP） from aqueous solution in the presence of sludge-based activated carbon（SAC） prepared from sewage sludge and corn cob was studied.For comparative purposes,experiments of adsorption on SAC,single ozonation,and ozonation in the presence of SAC were carried out and the effects of the amount of SAC and O3 on the treatment of IBP were studied.There was an increase in the degradation efficiency of IBP with the increasing ozone concentration in the process of ozonation alone.After 40 min for ozonation,the degradation efficiency of IBP was nearly 44.4% with the ozone dosage of 0.75 mg·L-1.Compared with the ozone dosage of 3 mg·L-1,IBP entirely degraded after 40 min.The property of SAC for IBP is not excellent,approximately 44.56% of the IBP is adsorbed on 100 mg·L-1 SAC after 40 min.The presence of SAC during ozonation increased the rate of degradation of IBP.In the first stage of the reaction（0-5 min）,the simultaneous combination of ozone and SAC leads to degradation rates slightly higher than the sum of single ozonation and single adsorption.The degradation of IBP was influenced by the amount of SAC and O3 in the SAC catalytic ozonation system.When the concentration of O3 was 1 mg·L-1,100 mg·L-1,SAC needed to be added in the reaction to a complete conversion of IBP.When the concentration of ozone increased to 3 mg·L-1,IBP was completely removed at 25 mg·L-1 SAC in approximately 20 min.The removal of IBP can be divided into two-phases,an initial rapid removal phase of IBP called instantaneous ozone demand（IOD）（Phase Ⅰ）,followed by a rather slow decomposition phase（phase Ⅱ）.In the Phase Ⅰ,·OH was responsible for the improvement of IBP removal effectiveness.In the Phase Ⅱ,since the low ozone concentration,the removal of IBP mainly due to the adsorption effect on SAC.