基于钽酸盐的光催化-硫酸根自由基协同氧化体系深度处理煤气化废水的研究

In order to solve the problems of need strict reaction condition, high energy consumption, produce toxic by-products in advanced oxidation process (AOPs), this project aim to design and synthesize a novel "bifunctional catalyst" based on tantalate through doping the transition metal elements, catalyst surface construction using heteropoly acid. The crystallinity, specific surface area, micro, band structure and stability of catalyst are optimized. A sulfate radical-photocatalytic synergistic catalytic oxidation system are built with loaded bifunctional catalyst on molecular sieve and peroxymonosulfate, which characteristic with synergistic catalytic effect, pH independence, easy recovery and process controllable. By optimizing the reaction parameters and adjusting the use amount of catalyst and persulfate, the refractory organics in coal gasification wastewater can be treated effectively in advanced treatment process. In addition, through a variety of modern test methods and numerical simulation to identify the activity level of catalyst, optical electronic interface migration patterns, catalytic mechanism, coordination mechanism, reveal the characteristics of coal gasification wastewater pollutants degradation mechanism and reaction kinetics. This project not only opens up a new way for the comprehensive utilization of tantalum resource in Inner Mongolia, but also provides technical support for the green sustainable development of coal chemical industry.

为解决高级氧化工艺反应条件苛刻、能耗高、产生有毒副产物等问题，本项目以煤气化废水为研究对象，通过过渡金属元素掺杂、杂多酸表面构筑等手段，探寻设计、合成一种基于钽酸盐的能同时实现光催化和硫酸根自由基催化的新型“双效催化剂”，优化催化剂结晶度、比表面积、微观结构、能带结构及稳定性；利用分子筛负载合成的催化剂并投加过硫酸盐，构建具有协同催化效果、pH适应性强、催化剂易回收、催化过程可控的光催化-硫酸根自由基协同催化氧化非均相体系；通过优化反应参数、调整催化剂和过硫酸盐的使用量、投配比，实现煤气化废水中难生物降解有机物的高效深度处理。另外，通过多种现代测试手段和模拟计算辨识催化剂的活性点位、光生电子界面迁移规律、催化机理、协同作用机制，揭示煤气化废水特征污染物的降解机理及反应动力学。本项目的开展可为内蒙古自治区钽资源的综合利用开辟新的途径，为煤化工行业绿色可持续发展提供技术支撑。

为解决高级氧化工艺反应条件苛刻、能耗高、产生有毒副产物等问题，本项目以煤气化废水为研究对象，采用水热法成功设计、合成了具有较高比表面积、高度晶化的钽酸钠光催化剂，分别通过金属元素钴离子和铁离子及非金属元素硫的掺杂改性，提高了光催化剂的催化活性及可见光响应度。然后，将优选的催化剂与过硫酸盐（PMS）掺混，构建了硫酸根自由基/光催化双效催化体系，在亚甲基蓝及煤气化废水特征污染物苯酚的降解实验中均表现出优异的催化性能。最后，在煤气化模拟废水实验中，通过优化反应参数、调整催化剂和过硫酸盐的使用量、投配比，实现该催化体系成功将难降解有机物高效深度处理，达到后续处理工艺的要求。另外，通过多种现代测试手段和模拟计算辨识了催化剂的活性点位、光生电子界面迁移规律、催化机理、协同作用机制。依托上述成果发表论文11篇，授权专利2项，培养博士研究生1名，硕士研究生7名。