PDF(Pubmed)
Abstract：
Fly ash, a type of solid waste generated in power plants, can be utilized as a catalyst carrier to enhance its value-added potential. Common methods often involve using a large amount of alkali for preprocessing, resulting in stable quartz and mullite forming silicate dissolution. This leads to an increased specific surface area and pore structure. In this study, we produced a catalyst composed of MnOx/NiOOH supported on fly ash by directly employing nickel hydroxide and potassium permanganate to generate metal active sites over the fly ash surface while simultaneously creating a larger specific surface area and pore structure. The ozone catalytic oxidation performance of this catalyst was evaluated using sodium acetate as the target organic matter. The experimental results demonstrated that an optimal removal efficiency of 57.5% for sodium acetate was achieved, surpassing even that of MnOx/NiOOH supported catalyst by using γ-Al2O3. After loading of MnOx/NiOOH, an oxygen vacancy is formed on the surface of fly ash, which plays an indirect oxidation effect on sodium acetate due to the transformation of ozone to •O2- and •OH over this oxygen vacancy. The reaction process parameters, including varying concentrations of ozone, sodium acetate, and catalyst dosage, as well as pH value and the quantitative analysis of formed free radicals, were examined in detail. This work demonstrated that fly ash could be used as a viable catalytic material for wastewater treatment and provided a new solution to the added value of fly ash.
摘要：
粉煤灰,发电厂产生的一种固体废物，可用作催化剂载体以增强其增值潜力。常见的方法通常涉及使用大量的碱进行预处理，导致稳定的石英和莫来石形成硅酸盐溶解。这导致比表面积和孔结构增加。在这项研究中,我们通过直接使用氢氧化镍和高锰酸钾在粉煤灰表面上产生金属活性位点，同时产生更大的比表面积和孔结构，从而生产了由MnOx/NiOOH负载在粉煤灰上的催化剂。使用乙酸钠作为目标有机物评价该催化剂的臭氧催化氧化性能。实验结果表明，乙酸钠的最佳去除率为57.5%。通过使用γ-Al2O3，甚至超过MnOx/NiOOH负载催化剂。负载MnOx/NiOOH后，在粉煤灰表面形成氧空位,由于臭氧在该氧空位上转化为•O2-和•OH，因此对乙酸钠起间接氧化作用。反应过程参数,包括不同浓度的臭氧，乙酸钠,和催化剂用量，以及pH值和形成的自由基的定量分析，进行了详细的检查。这项工作表明，粉煤灰可以作为一种可行的催化材料用于废水处理，并为粉煤灰的附加值提供了新的解决方案。
