用超重力技术强化O_3/Fe(Ⅱ)工艺深度氧化降解苯胺废水

Deep Oxidation Degradation of Aniline Wastewater by O_3/Fe(Ⅱ) Process Enhanced Using High-Gravity Technology

针对传统反应器存在臭氧传质效率低的问题,将旋转填料床(RPB)的超重力技术与O_3/Fe(Ⅱ)高级氧化法相耦合(RPB-O_3/Fe(Ⅱ))用于含苯胺(AN)废水的深度氧化降解,考察了超重力因子β、催化剂Fe(Ⅱ)投加量、O_3浓度,体系pH值及苯胺初始浓度对AN降解率和TOC去除率的影响,用液相色谱-质谱联用仪分析了AN降解过程的中间产物,探讨了AN的降解机理。结果表明,超重力因子的提高有利于AN的深度降解;体系pH值会影响臭氧化直接与间接反应以及催化剂Fe(Ⅱ)的存在形式,RPB-O_3/Fe(Ⅱ)体系拓宽了臭氧使用的pH范围;O_3浓度增加有利于提高AN降解效能,但臭氧利用效率降低。在超重力因子β为100,Fe(Ⅱ)浓度为0.8 mmol·L^(-1),O_3浓度为36 mg·L^(-1),pH值为3,AN初始浓度为200 mg·L^(-1)时,12 min苯胺去除率达100%,60min时TOC去除率可达73%。氧化降解苯胺过程的中间产物主要有硝基苯、对苯醌、马来酸和草酸,并推断了臭氧催化氧化降解苯胺的可能途径。

Aiming at the problem of low mass transfer efficiency of ozone existed in traditional reactor,the high gravity technology of rotating packed bed（RPB） coupled with advanced oxidation method of O3/Fe（Ⅱ）,（RPB-O3/Fe（Ⅱ）） was used for deep oxidation degradation of aniline（AN） wastewater. The effects of high gravity factor β,dosage of catalyst Fe（Ⅱ）,concentration of O3,pH value of system and initial concentration of AN on the degradation rate of AN and removal efficiency of total organic carbon（TOC） were studied. The intermediates of AN degradation process were analyzed by liquid chromatograph-mass spectrometer（LC-MS）. The degradation mechanism of AN was investigated. Results show that increasing of high gravity factor is beneficial to the deep degradation of AN wastewater. The pH value of the system can affect the direct and indirect reactions of ozonation and the existence form of catalyst Fe（Ⅱ）. and the RPB-O3/Fe（Ⅱ） system broadens the pH range for O3 use. The increase of ozone concentration is beneficial to improving the efficiency of AN degradation but the utilization efficiency of ozone decreases. When high gravity factor is 100,Fe（Ⅱ） concentration 0.8 mmol·L^-1,O3 concentration 36 mg·L^-1,pH 3 and initial concentration of AN 200 mg·L^-1,the AN removal efficiency reaches 100% in 12 min,and TOC removal efficiency is 73% in 60 min.The intermediates of AN oxidation degradation process mainly are nitrobenzene,p-benzoquinone,maleic acid and oxalic acid. The possible pathway to deduce the catalytic oxidation degradation of AN by O3 is described.