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非均相UV/Fenton反应体系处理废水中聚丙烯酰胺的研究
Degradation of Polyacrylamide in Wastewater by Heterogeneous Photo-Fenton Reaction
【作者】 李艳春;
【导师】 尤宏;
【作者基本信息】 哈尔滨工业大学 , 环境科学与工程, 2007, 硕士
【摘要】 随着各个油田相继采用聚合物驱以提高原油采收率,含聚污水的数量在逐年增加。含聚丙烯酰胺(PAM)污水是一类比较复杂、特殊的污水,其处理已经成为一个兹待解决的问题。非均相光芬顿体系(UV/Fenton)作为典型的高级氧化工艺,由于其具有光催化效率高、氧化能力强等特点,并且能避免均相芬顿(Fenton)反应产生铁泥沉淀、对体系的pH要求较为严格等缺点,而得到广泛的应用。但是利用该工艺对含聚油田废水的处理还未见报道。首先以粗孔硅胶为载体,采用浸渍法制备了载铁催化剂。对制备工艺条件进行优化,获得制备高催化活性催化剂的最优条件,并对催化剂结构进行了表征,考察了其在非均相UV/Fenton体系中的催化活性。结果表明,活性组分Fe在催化剂表面是以FeOOH和Fe2O3的形式存在的,并且在催化剂表面均匀分布;同时由于FeOOH和Fe2O3的引入,与空白载体相比,催化剂的比表面积略有增大、总孔容和平均孔径均有所减小;将该催化剂用于非均相UV/Fenton体系中处理含聚丙烯酰胺模拟油田废水,矿化度在180min时也可达80%左右,该工艺克服了常规处理方法矿化度不高的缺点。建立适合于自制三相流化床反应器的非均相UV/Fenton体系,用于废水中PAM的处理。对催化剂投加量、氧化剂投加量、光辐射强度等影响处理效果的因素进行研究,得到最优处理条件。对于非均相UV/Fenton系统处理PAM模拟废水,自制的载铁催化剂加入量为0.67g/L、双氧水初始浓度为249.75mg/L、曝气量为0.20m3/h、光辐射强度为4.4×103μw/cm2(8w紫外灯)时可取得良好的处理效果。同时我们了解到光辐射强度对去除效果影响较大,随着光强的增大,去除效果有明显的提高,当光辐射强度达到17.6×103μw/cm2(32w紫外灯)时,反应进行到60min时,PAM去除率即可达到100%。对影响非均相UV/Fenton催化氧化体系因素进行了动力学分析,得出非均相UV/Fenton体系降解PAM的光化学氧化表观速率常数与双氧水投加量、光辐射强度成正比,并且随[H2O2]0/[PAM]0增大而呈线性规律上升。
【Abstract】 Along with each oil-field successively used polymer to enhance the crude oil recovery, the quantity of wastewater contening polyacrylamide(PAM) was increasing. The water contening polyacrylamide was a class relatively complex, special wastewater, the treatment of which became a serious problem. Heterogeneous photo-Fenton reaction catalysis is one of typical advanced oxidation technique. This technique have the feature of higher efficiency and oxidation ability, can avoid precipitation of sludge contained Fe produced by Homogeneous photo-Fenton reaction catalysis, and have strict request to pH, So it was used in wastewater treating widely. But the application on oil wastewater was scarcely.An heterogeneous iron-containing catalyst carried on porous silica was prepared by the impregnation method. The manufacture process was optimized and the optimal condition of the preparation of high active catalyst was acquired. The structure of catalyst was characterized and the catalytic activity was investigated in heterogeneous photo-Fenton reaction catalysis process. The results show that the active component of Fe is exist as FeOOH and Fe2O3 which was distributed Uniformly on the surface of catalyst. As the FeOOH and Fe2O3 were carried into the porous silica, the specific surface area is bigger slightly, and the Total pore volume and average pore size is decreased. It was found that iron-containing catalyst has high catalytic activity, more than 80% TOC removal of PAM can be achieved in 180 min, the problem of TOC removal lower was overcomed.The heterogeneous photo-Fenton reaction catalysis system was builded which was suitable to the three-phase fluidized-bed reactor to treat PAM in wastewater. The optimum condition of the reactor running was accessed by studying this reaction, which the UV intensity, the volume of catalyst, the H2O2 concentration and the volume of aeration of this system to treating wastewater contained PAM respectively is 4.4×103μw/cm2(8W UV light ), 0.67g/L, 249.75mg/L, 0.20m3/h. The experimental results also showed that the UV intensity have greater effection to this system, the removal rate of PAM is increasing with the increase of UV intensity. When the UV intensity reached 17.6×103μw/cm2(32w UV light), the removal rate of PAM can reach 100% that after reaction 60 min.Sysmatical analysis for the influencing factors of heterogeneous photo-Fenton reaction catalysis was made. The result showed that the photochemically degradation apparent rate constant of PAM was proportional to hydrogen peroxide dosage and UV intensity, and linearly increased with the increase of [H2O2]0/[PAM]0.
【Key words】 heterogeneous catalysis; Fenton; Polyacrylamide(PAM); Water treatment;