Design And Treatment Of Aquaculture Wastewater With Fixed-bed Photocatalytic Reactor

Semiconductor photocatalysis has been considered as an important environmental management technology,the use of nano-degradation of organic pollutants in water by the widespread concern.In this paper,a supported photocatalytic material based on titanium dioxide nanoparticles was prepared.Three types of stationary phase photocatalytic reactors,flat-plate,barrel,and pyramid,were designed and developed.In addition,three photocatalytic reactors were tested for the treatment of aquaculture wastewater.This paper specifically obtained the following conclusions:(1)Surface micro-morphology analysis of the prepared catalyst.Before the finishing,the surface of the fiber was smooth,and there was a small amount of impurities.After finishing,the surface of the polyester fiber was rough,and there were a lot of granules attached,indicating that the TiO2 particles had been loaded on the fiber surface.The surface elements of the catalyst were analyzed and the main characteristic peaks of Si and Ti were evident on the X-ray energy spectrum.An obvious characteristic peak of the anatase phase appears again on the X-ray diffraction pattern,indicating that the TiO2@SiO2 particles have been well loaded onto the fiber material.(2)The structural parameters of the three photocatalytic reactors were systematically designed.Taking the photocatalytic reactor's ratio of the irradiated area to the volume of the reactants(A/V value)as a calculation basis,it was found that the maximum size of the cartridge type photocatalytic reactor(A/V value)was 66.7.Therefore,the cartridge photocatalytic reactor more meets the design requirements.(3)Taking the tube photocatalytic reactor as the reaction system,the factors influencing the photocatalytic reaction were studied and discussed.The effects of photocatalyst dosage,aeration rate,wastewater pH and initial concentration on the ammonia nitrogen and COD degradation rates in aquaculture wastewater were analyzed.It can be seen that when the aeration rate is 1.0L/min,the amount of catalyst is 12.5g,the basic conditions and the initial concentration of ammonia nitrogen and COD are about 90mg/L and 120mg/L respectively,the degradation rates of ammonia nitrogen and COD are up to 83.4%and 85.7%.Select the best test conditions in a simulated breeding tank for continuous experiments,ammonia nitrogen and COD concentrations can be reduced quickly to achieve China's second grade standard of sewage discharge,and to keep the water quality and reduce water change frequency.