Intensification Of Micromixing And Photo-Fenton Reaction In A Spinning Disk Reactor

The micromixing performance of the reactor has a significant influence on the selectivity and yield of chemical reactions.In this study,three different enhancement strategies were firstly proposed for the micromixing performance of Spinning Disk Reactor(shorthand SDR).The effects of the baffle structure of the disk surface,the pre-mixer and heterogeneous surface wettability regulation of the disk surface on the micromixing performance of SDR were investigated by using the iodide-iodate system,and the segregation index Xs was obtained.The micromixing time tm was determined based on incorporation model and compared with other reactors.Then the application research on the degradation of rhodamine B by photo-Fenton was carried out.The effects of different conditions on degradation efficiency,apparent reaction rate constant and mineralization efficiency were investigated.The main results were as follows:(1)The micromixing efficiency of SDR could be intensified by setting radial baffles on the disk surface.Micromixing performance could be improved to a certain extent by increasing the height of the baffle on the surface of the disk.Increasing rotational speed,flowrate and liquid flow ratio could effectively reduce the value of Xs,and the micromixing performance was steadily intensified.By increasing the liquid viscosity and hydrogen ion concentration,the value of Xs gradually increased and the micromixing became worse.The micromixing performance of the cross-flow pre-mixer for SDR was improved obviously at a lower rotational speed and the average decline in the value of XS was 36.0%.The micromixing efficiency of SDR could be effectively intensified by heterogeneous surface wettability regulation of the disk surface.When the inlet area was hydrophobic,the micromixing was favorable and the average decline in the value of Xs was as high as 46.7%.The tm range was calculated to be 0.13-0.50 ms.(2)The process of photo-Fenton degradation of rhodamine B wastewater could be enhanced by SDR’s excellent micromixing and the characteristics of flow film.It was found that the degradation efficiency could be influenced either by setting baffles on the disk surface or by heterogeneous surface wettability regulation.The degradation efficiency increased first and then decreased with the increase of rotational speed.Increasing the initial pH of the solution would lead to a decrease in degradation efficiency.Under UV irradiation,the degradation rate and mineralization efficiency could be improved effectively.The oxidation degradation efficiency and mineralization efficiency of rhodamine B reached the highest 94%and 37%,respectively.