非均相电芬顿法处理制药废水的研究

发布时间：2018-01-29 09:32

本文关键词： 电芬顿阴极阳极非均相催化剂制药废水　出处：《中国科学院大学(中国科学院过程工程研究所)》2017年硕士论文　论文类型：学位论文

【摘要】：制药废水具有可生化性差、体量大和有机物浓度高等特点,传统的水处理技术不能有效地将其中的难降解有机物去除。近年来,非均相电芬顿技术由于具有氧化能力强、无选择性氧化和处理效率高等特点,受到了广泛关注。本论文以非均相电芬顿技术为基础,首先以罗丹明B(RhB)溶液为模拟废水,从阴极、阳极和非均相催化剂三个角度展开研究。最后利用自制的非均相电芬顿体系降解真实的制药废水,并利用响应面法对实验条件进行优化。旨在提升非均相电芬顿体系的处理效率,帮助企业实现"零排放"的目标。具体摘要如下:为了制备电芬顿体系的阴极,比较了三种阴极材料:石墨毡(GF)、石墨片(graphite sheet)和热解石墨片(pyrolytic graphite sheet)的电化学性能和降解性能,确定石墨毡为最优的阴极材料。分别用烧结法和电沉积法对石墨毡进行修饰,通过降解RhB模拟废水和进行电化学测试实验,本论文认为聚四氟乙烯-碳黑烧结法(PTFE-CB)制备的阴极具有最优良的降解性能和电催化性能。然后利用SEM、BET和接触角等方式对PTFE-CB的表面特性进行了表征,对PTFE-CB的连续运行稳定性进行了考察。最后,通过GC-MS分析RhB模拟废水降解的中间产物提出了一条分解路线图。为了提升阳极的性能,并降低其成本。制备了钛基二氧化铅阳极(PbO2-Ti)和钛基锡锑氧化物阳极(SnO2/Sb-Ti),并对非均相电化学体系的工艺条件进行了研究。通过线性扫描伏安曲线(LSV)、循环伏安曲线(CV)、塔菲尔曲线(Tafel)和交流阻抗图谱(EIS)对几种阳极(PbO2-Ti、SnO2/Sb-Ti、Pt和Ti)的分析可知PbO2-Ti具有最高的导电性和电催化活性。通过表面形貌分析测试发现PbO2-Ti具有较平整的表面。接着利用PbO2-Ti对电解质类型、电流密度进行了研究,最后通过加速寿命实验证明PbO2-Ti具有良好的稳定性(实际寿命约4000h)。为了制备合适的非均相电芬顿催化剂,首先选用Fe-C、零价铁、海绵铁、黄铁矿、钒钛磁铁矿和磁铁矿作为非均相电芬顿催化剂来降解20 mg/L的RhB溶液,发现Fe-C、零价铁和海绵铁三种催化剂具有比较好的催化效果。随后利用XRD、EDX和SEM对三种催化剂的物相、表面元素和形貌进行了研究,结果表明三种催化剂的主要成分为Fe,并含有少量其他元素。分析三种催化剂对RhB溶液降解过程中的铁浸出量,可得海绵铁具有最好的稳定性。为了进一步提升海绵铁的稳定性,在其表面修饰了PTFE。这种方式可对铁起到缓释的作用,同时也提高了 RhB处理效率。最后对工艺条件进行了优化,并证明了修饰后的海绵铁具有较高的稳定性。为了验证自制的非均相电芬顿体系对真实制药废水的处理效果,采用自制的非均相电芬顿体系对华北制药公司的制药废水进行处理。首先应用正交试验和响应面分析法对催化剂量、电流密度、pH和降解时间进行了优化,并提出了 COD的去除率与各项参数之间的二次多项式回归模型。各因素对COD去除率的影响由大到小的顺序为时间电流密度催化剂量pH。在电流密度50A/m2,催化剂量0.5g/L,pH为中性的条件下处理100 min,制药废水的COD的去除率可达到80%以上。建立了电芬顿处理制药废水的关于COD去除率的一级反应动力学方程,结果表明制药废水COD的去除率基本符合一级反应动力学特征。通过GC-MS分析处理前后制药废水中有机物含量可知,经过非均相电芬顿的降解,大部分有机物可被去除。
[Abstract]:Pharmaceutical wastewater has poor biodegradability, high volume and high concentration of organic matter, the traditional water treatment technology can not effectively remove the refractory organics. In recent years, the heterogeneous Fenton electric technology has strong oxidation, no selective oxidation and higher processing efficiency, this has attracted widespread attention. Based on the heterogeneous Fenton electric technology as the foundation, the Luo Danming B (RhB) solution as simulated wastewater from the cathode, anode and three angles of homogeneous catalyst is studied. Finally, the heterogeneous degradation of pharmaceutical wastewater by electro Fenton system of real self, and the use of the experimental conditions were optimized by response in order to improve the efficiency of processing surface method. Heterogeneous electro Fenton system, help the enterprise to realize the target of "zero emissions". The specific as follows: in order to prepare cathode electro Fenton system, compares the three kinds of cathode materials: graphite felt (GF), stone Ink film (graphite sheet) and graphite (pyrolytic graphite sheet) film electrochemical properties and degradation properties, determine the graphite felt as cathode material. The optimal of graphite felt modified by sintering method and electrodeposition method, and electrochemical experiments through the degradation of RhB wastewater, this paper believes that the PTFE - carbon sintering method for preparing cathode (PTFE-CB) has excellent biodegradability and electrocatalytic properties. Then using SEM, BET and contact angle of the surface properties of PTFE-CB were characterized by the continuous operation stability of PTFE-CB were investigated. Finally, through the GC-MS analysis of the intermediate product of RhB degradation is proposed a decomposition map. In order to improve the anode performance, and reduce the cost. Two titanium based lead dioxide anode was prepared (PbO2-Ti) and titanium based anode tin antimony oxide (SnO2/Sb-Ti), and the heterogeneous power The process conditions of chemical system was studied. By linear sweep voltammetry (LSV), cyclic voltammetry (CV), Tafel curve (Tafel) and electrochemical impedance spectroscopy (EIS) of the anode (PbO2-Ti, SnO2/Sb-Ti, Pt and Ti) analysis shows that PbO2-Ti has the highest conductivity and electrocatalytic activity through. The analysis of surface morphology test found that PbO2-Ti has a smooth surface. Then using the PbO2-Ti of electrolyte type, current density are studied, finally through the accelerated life experiments show that PbO2-Ti has good stability (the actual life of about 4000H). In order to heterogeneous electric Fenton catalyst preparation right, first choose Fe-C, zero valent iron sponge. Iron, pyrite, magnetite and titanomagnetite as heterogeneous RhB solution, Fenton catalyst to degrade 20 mg/L Fe-C, zero valent iron and sponge iron three catalyst has better catalytic effect with. After using XRD, EDX and SEM of three kinds of catalysts, elements and surface morphology were studied. The results show that the main components of the three catalysts for Fe, and contains a small amount of other elements. Analysis of three kinds of catalysts on the iron leaching amount of RhB solution in the degradation process, can get out of sponge iron has the best stability in order to further enhance the stability of sponge iron, coated on the surface of PTFE. in this way can be sustained release effect on iron, but also improve the processing efficiency of RhB. Finally, the process conditions were optimized, and it is proved that the sponge iron modified with higher stability. In order to verify the self-made heterogeneous electric Fenton of the real system of pharmaceutical wastewater treatment effect, using the self-made heterogeneous electro Fenton system for pharmaceutical wastewater in North China pharmaceutical company. Firstly, the application of orthogonal experiment and the response surface analysis of the amount of catalyst, the electric current. The degree of pH, and degradation time were optimized, and put forward the parameters and the removal rate of COD regression model of two order polynomial. The factors affecting the removal efficiency of COD from large to small order of the time the amount of catalyst pH. in current density, current density 50A/m2, the amount of catalyst 0.5g/L, pH 100 min neutral under the condition of the pharmaceutical wastewater COD removal rate can reach more than 80%. The Fenton pharmaceutical wastewater treatment on the kinetic equation of COD removal rate, results show that the pharmaceutical wastewater COD removal rate basically conforms to the first-order reaction kinetic characteristics. Through the analysis of GC-MS organic matter content before and after the treatment of pharmaceutical wastewater after degradation, heterogeneous electric Fenton, most of the organic material can be removed.

【学位授予单位】：中国科学院大学(中国科学院过程工程研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X787

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