磁性铋系光催化剂的制备及其降解丁基黄药废水的研究

发布时间：2018-04-28 00:16

本文选题：丁基黄药 + 光催化　；参考：《吉林大学》2017年硕士论文

【摘要】：随着工业的发展,矿山开采的规模逐渐扩大,浮选药剂的使用量随之增加,浮选废水中有高毒、高污染性的药剂残留量也逐渐增大,导致矿区生态环境不断恶化。黄药是最常用的和最为有效的硫化矿捕收剂,所以研究黄药的处理方法对矿区环境保护具有积极意义。光催化氧化法在有机废水处理方面具有较好的处理效果,研究备受关注,然而光催化剂存在难重复再利用和易流失等问题,限制了其实际应用。磁性复合光催化剂因引入了磁性物质,使其既具有磁性又有光催化活性,在应用时便于与反应体系分离,能提高重复利用率,降低处理废水的成本,因此具有良好的应用前景。本论文以制备新型磁性光催化剂,解决光催化剂难以回收的问题以及光催化反应器中的实际应用为研究目的,制备了MgFe_2O_4/Bi_2WO_6和MgFe_2O_4/Bi_2MoO_6磁性复合光催化剂,对其进行了丁基黄药的光催化效果研究,并将制备的MgFe_2O_4/Bi_2WO_6应用于改进的磁性固定膜式的光催化反应器中,主要内容及结果如下:(1)通过水热法成功制备了花状MgFe_2O_4/Bi_2WO_6,其中掺杂比例为10 wt%MgFe_2O_4/Bi_2WO_6的光降解效果最好,说明适量的掺杂MgFe_2O_4能改善Bi_2WO_6的光催化活性;并考察了光催化剂投加量、丁基黄药的初始浓度和p H值对光催化降解效果的影响,结果表明光催化剂投加量和丁基黄药初始浓度对光降解影响较大,p H值的影响较小;当丁基黄药的初始浓度为50 mg/L,光催化剂投加量为0.5 g/L时,经过120 min光照,丁基黄药的降解率能达到96%,并对其进行重复使用实验,重复使用5次后对丁基黄药的降解率仍有92%,说明MgFe_2O_4/Bi_2WO_6具有较好的稳定性,能回收再利用。(2)通过水热法成功制备了MgFe_2O_4/Bi_2MoO_6,结果表明掺杂比例为10 wt%MgFe_2O_4/Bi_2MoO_6的光降解效果最好,说明适量的掺杂MgFe_2O_4能改善Bi_2MoO_6的光催化活性;当丁基黄药的初始浓度为50 mg/L,光催化剂投加量为0.2 g/L时,经过120 min光照,丁基黄药的降解率能达到80%以上,并考察了光催化剂投加量、丁基黄药的初始浓度和p H对光催化降解效果的影响,结果表明光催化剂投加量和丁基黄药初始浓度对光降解影响较大,p H值的影响较小;并对其进行重复使用实验,发现重复使用5次后对丁基黄药的降解率仍有80%,说明MgFe_2O_4/Bi_2MoO_6具有较好的稳定性,能回收再利用。(3)研究表明MgFe_2O_4/Bi_2WO_6的光催化性能好于MgFe_2O_4/Bi_2MoO_6,将MgFe_2O_4/Bi_2WO_6应用在磁性固定膜式的光催化反应器中,以丁基黄药为目标降解物,通过连续进出水的方式分别考察水力停留时间、光源强度和丁基黄药初始浓度对反应器光催化效果的影响;结果表明水力停留时间对丁基黄药的降解效果影响最大。该反应器对丁基黄药有较好的降解效果,当丁基黄药的初始浓度为50 mg/L,水力停留时间为49 min,光源强度为2.2×105 lux时,对丁基黄药的降解率能达到98%。
[Abstract]:With the development of industry, the scale of mining is gradually expanding, the use of flotation reagents is increasing, flotation wastewater has high toxicity, and the residue of high pollution chemicals is gradually increasing, which leads to the deterioration of ecological environment in mining areas. Xanthate is the most commonly used and most effective sulphide collector, so it is of great significance to study the treatment of xanthate for environmental protection of mining area. Photocatalytic oxidation has a good effect on the treatment of organic wastewater, and has attracted much attention. However, the photocatalyst is difficult to reuse and easy to run off, which limits its practical application. Magnetic composite photocatalyst has good application prospect because of its magnetic material and photocatalytic activity, which can be easily separated from the reaction system in application, and can improve the reuse efficiency and reduce the cost of wastewater treatment. In order to prepare new magnetic photocatalyst, solve the problem of difficult recovery of photocatalyst and practical application in photocatalytic reactor, the magnetic composite photocatalyst of MgFe_2O_4/Bi_2WO_6 and MgFe_2O_4/Bi_2MoO_6 was prepared in this paper. The photocatalytic effect of Ding Ji xanthate was studied, and the MgFe_2O_4/Bi_2WO_6 was applied to the improved magnetic fixed film photocatalytic reactor. The main contents and results are as follows: (1) Flower MgFe _ 2O _ 2O _ 4 / T _ 2W _ 6 was successfully prepared by hydrothermal method, among which the photodegradation effect of 10 wt%MgFe_2O_4/Bi_2WO_6 doped MgFe_2O_4 was the best, indicating that the appropriate amount of doped MgFe_2O_4 could improve the photocatalytic activity of Bi_2WO_6, and the dosage of photocatalyst was investigated. The effect of initial concentration and pH value of Ding Ji xanthate on photocatalytic degradation was studied. The results showed that the dosage of photocatalyst and initial concentration of Ding Ji xanthate had little effect on photodegradation. When the initial concentration of Ding Ji xanthate is 50 mg / L and the amount of photocatalyst is 0.5 g / L, the degradation rate of Ding Ji xanthate can reach 96g / L after 120 min illumination, and the repeated use experiment is carried out. The degradation rate of Ding Ji xanthate is still 92% after repeated use for 5 times, indicating that MgFe_2O_4/Bi_2WO_6 has good stability and can be recovered and reused.) MgFe _ 2O _ 2O _ 4 / Bi2MoO _ 6 has been successfully prepared by hydrothermal method. The results show that the photodegradation effect is the best when the doping ratio is 10 wt%MgFe_2O_4/Bi_2MoO_6. When the initial concentration of Ding Ji xanthate is 50 mg / L and the dosage of photocatalyst is 0.2 g / L, the degradation rate of Ding Ji xanthate can reach more than 80% after 120 min illumination. The effects of the dosage of photocatalyst, the initial concentration of Ding Ji xanthate and pH on photocatalytic degradation were investigated. The results showed that the amount of photocatalyst and the initial concentration of Ding Ji xanthate had little effect on photodegradation. It was found that the degradation rate of Ding Ji xanthate was still 80% after repeated use for 5 times, which indicated that MgFe_2O_4/Bi_2MoO_6 had good stability. The study of recovery and reuse showed that the photocatalytic performance of MgFe_2O_4/Bi_2WO_6 was better than that of MgFe2O4 / Biti2MoO6.The MgFe_2O_4/Bi_2WO_6 was applied to the magnetic fixed membrane photocatalytic reactor, and the degradation of Ding Ji xanthate was taken as the target. The HRT was investigated by means of continuous water access. The effect of light source intensity and initial concentration of Ding Ji xanthate on the photocatalytic effect of the reactor was studied. The results showed that HRT had the greatest effect on the degradation of Ding Ji xanthate. When the initial concentration of Ding Ji xanthate is 50 mg / L, the HRT is 49 min and the intensity of light source is 2.2 脳 10 ~ 5 lux, the degradation rate of Ding Ji xanthate can reach 98%.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X751;O643.36

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