高氯介质下催化湿式氧化降解高浓高盐有机废水新型钙钛矿催化剂的开发及催化机制的研究

The rapid development of the national economy has led to the rapid development of petroleum, chemical, pharmaceutical, paper, food and other industries, while high concentration of refractory biodegradable organic wastewater emissions also increased at a faster rate. Particularly, due to the limitation of the chemical production process, the wastewater of chemical production not only has high organic content but also high salt content, which will lead to serious pollution of water body, deterioration of ecological environment and threat to human health..The key to solve this problem is to develop a new type of catalyst for wet oxidation of high concentration organic wastewater under high chlorine medium, based on several major methods of desalination and the cost and environmental impact of catalytic wet oxidation. In this study, the influence of Cl- on degradation of organic compounds in WAO and CWAO was studied and non-stoichiometric perovskite-based precious metal catalyst was firstly proposed and designed to develop a new type of the integration of support and active component. Using self-designed catalytic wet air oxidation experimental device, the toxicity of chloride ions to different perovskite-type catalysts was investigated under different process conditions. A mathematical model was established to predict the anti-Cl-activity of different catalysts under different reaction conditions. The control mechanism of the amplification process of perovskite base catalyst was discussed. And finally to provide an effective solution for high chlorine and high concentration organic wastewater treatment during the chemical production process in our country.

国民经济的高速发展带动了石油、化工、制药、造纸、食品等行业的飞速发展，与此同时也造成了高浓有机废水的排放量极速增多。并且受化工生产领域工艺技术的限制，化工生产所排放的废水不仅有机物含量高，盐含量也很高。这些会导致水体重度污染、生态环境恶化进而威胁人体健康。.综合几种主要的除盐方法及催化湿式氧化法的成本及对环境影响，开发高氯介质下催化湿式氧化高浓度有机废水新型催化剂成为解决此问题的关键。本研究在分析Cl-在WAO和CWAO下对有机物降解的影响的基础上，首次提出并设计开发新型的载体及活性组分一体的非化学计量钙钛矿基贵金属催化剂；利用自主设计的催化湿式氧化实验装置，考察不同工艺条件下氯离子对不同成分钙钛矿型催化剂的毒害情况；建立数学模型，对不同催化剂在不同反应条件下的抗Cl-情况进行预测，并对钙钛矿基催化剂放大过程控制机制进行探讨。最终为我国化工生产中高氯高浓有机废水的治理提供有效解决途径。

高浓度的Cl-对目前CWAO技术中的常规催化剂有毒害作用，这极大限制了该项技术的推广应用。本申请人以钙钛矿型氧化物为骨架，将活性组分固溶于钙钛矿结构中，制备了载体活性组分一体的钙钛矿基催化剂。.目前在国家面上基金（51878643）的支持下，已经开发出高稳定性CWAO用Ce改性LaFeO3钙钛矿型催化剂，该催化剂拥有大量氧空位，且高效的Ce3+/Ce4+电子转移，使得该催化剂拥有常规氧化钛系催化剂没有的独特活性位点。Cl离子与羟基自由基反应生成次氯酸根，把活性组分钌氧化为易挥发的四氧化钌，造成钌流失。本项目在阐明氯毒害机理的基础上，提出钙钛矿骨架稳定策略，成功解决高氯介质下催化剂表面贵金属易流失科学难题，该项理论研究为CWAO资源化项目奠定了基础。所开发出的B位Ru掺杂钙钛矿催化剂和Ru/TiO2商业化催化剂均用于高氯环境下CWAO降解丙烯酸，研究结果表明，氯离子对钙钛矿催化剂活性无影响，但是会抑制负载型Ru/TiO2商业化催化剂的活性。.利民化工股份有限公司在霜脲氰废水及氰乙酰乙基脲废水处理项目中采用了我们团队研发的CWAO技术。废水中氯离子含量高达20000 mg/L，处理规模为264 t/d (80000吨/年)，自运行以来，系统运行稳定，自动化程度高，在钙钛矿催化剂的高效处理下，实现了COD去除率90%以上，出水BOD5/COD > 0.3，投资仅为进口的1/3~1/2，为利民化工创造了良好的经济效益。