非均相催化硫酸根自由基处理废水的研究

发布时间：2018-04-23 13:57

  本文选题：非均相 + 过硫酸盐　； 参考：《大连工业大学》2016年硕士论文

【摘要】：本实验选取罗丹明B为目标污染物,选择罗丹明B(Rh B)染料废水作为目标污染物是由于据资料显示,在全国工业废水排放中,纺织废水年排放量可达23亿吨,其占总废水排放量的10.6%,排位第三。而在庞大的纺织废水中,染料废水占其总排放量的80%,所以对染料废水相关处理方式的研究十分有意义。高级氧化技术大体可分为两大类:均相反应和非均相反应。本实验采取非均相反应,在催化剂的制备中以活性炭作为载体,为了将过渡金属铁负载在活性炭上,采用了老化-煅烧的方法制备催化剂(Fe/AC),并通过XRD对制备的催化剂进行表征,结果显示铁以氧化物的方式负载在活性炭上。本研究采用Fe/AC催化过硫酸盐(K2S2O8)产生氧化能力较强的硫酸根自由基(·SO4-)对罗丹明B溶液进行处理。首先确定出制备催化剂的最佳条件,然后,改变催化剂投加量、氧化剂投加量、反应溶液初始浓度、反应溶液初始p H和温度等变量,得出脱色罗丹明B的最佳实验条件。由于微波、超声、紫外光照可以协同促进·SO4-的产生,所以考察了在微波体系中、超声体系中以及紫外光照体系中,不同变量对实验的影响,并得出脱色罗丹明B最佳反应条件。在以上四大反应体系中,分别对反应过程中产生的自由基加以验证,并对其紫外-可见吸收谱图进行分析。所得到的实验结论如下:(1)在室温时,Fe/AC的投加量为1.5g/L,K2S2O8投加量为0.6g/L,在溶液初始p H的条件下,对100mg/L的Rh B溶液进行脱色,2.5h后其脱色率可达80%以上;升高温度有利于罗丹明B的脱色,65℃时罗丹明B的脱色率达99%。(2)在微波辅助条件下,Fe/AC的投加量为0.8g/L,K2S2O8投加量为0.4g/L,在溶液初始p H的条件下,对100mg/L的Rh B溶液进行脱色,40s后其脱色率可达76%。与室温条件相比,微波辅助大大缩短了罗丹明B脱色所需的时间。(3)在超声辅助条件下,Fe/AC的投加量为1.2g/L,K2S2O8投加量为0.8g/L,在溶液初始p H的条件下,对100mg/L的Rh B溶液进行脱色,40min后其脱色率可达70%。与不加超声相比,罗丹明B脱色率增加27%。(4)在紫外光照辅助条件下,Fe/AC的投加量为1.5g/L,K2S2O8投加量为0.4g/L,在溶液初始p H的条件下,对100mg/L的Rh B溶液进行脱色,50min后其脱色率可达73%。与Fe/AC-K2S2O8相比,罗丹明B脱色率增加15%。上述四种体系中,通过自由基的验证实验可知,存在·SO4-和·OH共同作用脱色Rh B溶液。
[Abstract]:In this experiment, Rhodamine B was chosen as the target pollutant and Rhodamine B(Rh B) dye wastewater as the target pollutant because according to the data, the annual discharge of textile wastewater could reach 2.3 billion tons in the national industrial wastewater discharge. It accounts for 10.6% of the total waste water discharge, ranked third. Among the huge textile wastewater, the dye wastewater accounts for 80% of the total discharge, so it is very meaningful to study the treatment methods of dye wastewater. Advanced oxidation technology can be divided into two broad categories: homogeneous reaction and heterogeneous reaction. In this experiment, the catalyst was prepared by heterogeneous reaction, the active carbon was used as the carrier in the preparation of the catalyst, in order to support the transition metal iron on the activated carbon, the catalyst was prepared by the method of aging and calcination, and the catalyst was characterized by XRD. The results show that iron is loaded on the activated carbon in the form of oxides. In this study, Rhodamine B solution was treated by Fe/AC catalyzed persulfate K2S2O8) to produce sulfate radical (SO4) with strong oxidation ability. The optimum conditions for the preparation of the catalyst were determined, and the optimal conditions for decolorizing Rhodamine B were obtained by changing the amount of catalyst, the amount of oxidant, the initial concentration of the reaction solution, the initial pH of the reaction solution and the temperature. Since microwave, ultrasonic and ultraviolet irradiation can promote the production of so _ 4-, the effects of different variables on the experiment in microwave system, ultrasonic system and ultraviolet radiation system are investigated, and the optimum reaction conditions for decolorization of rhodamine B are obtained. In the above four reaction systems, the free radicals produced during the reaction were verified, and the UV-Vis absorption spectra were analyzed. The experimental results are as follows: (1) at room temperature, the dosage of Fe / AC is 1.5g / L K2S2O8 = 0.6g / L, and the decolorization rate of 100mg/L RhB solution can reach more than 80% after 2.5 h decolorization at initial pH; The decolorization rate of Rhodamine B reaches 99g / L at 65 鈩，

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