Research On Cellulose Loaded TiO₂ Spherical Catalyst And Reactor

Titanium dioxide?TiO₂?,as an excellent semiconductor photocatalyst,has a good application prospect.In particular,TiO₂ is able to degrade organic matter into non-toxic carbon dioxide and water,making it a hot topic for researchers.The traditional method is to put the catalyst directly into the liquid to be treated,under ultraviolet light,to treat the organic matter in the water.However,this method not only causes the waste of the catalyst which is difficult to recover,but also causes secondary pollution when the catalyst is dispersed in the waste water.In this paper,the properties of calcium alginate gel formed by the crosslinking calcification of sodium alginate with calcium ions were utilized,and the photocatalyst TiO₂ was supported on this gel to form a catalyst gel.At the process of loading,biomass such as cellulose,lignin and xylose residue were added creatively.The treatment effect of spherical catalyst on wastewater was studied by using wastewater as photocatalytic model.Finally,the spherical catalyst was put into use in a self-made reactor to observe the treatment effect of the catalyst.Firstly,during the preparation of the spherical catalyst,the ratio of different substances,soaking time,stirring and other factors were changed.Taking the methylene blue dye solution as the target material,the material ratio of the catalyst gel with the best treatment effect was obtained:sodium alginate 2.00 g/100m L,TiO₂ 0.25g/100m L,calcium chloride 1.00 g/100m L in the solution of calcium chloride.Different biomass additives such as cellulose,lignin and xylose residue were added to observe the changes of the removal effect of different additives on the solution of methylene blue dye.Finally,microcrystalline cellulose was determined to be the most appropriate additive,and the amount of addition was 4.00 g/100m L.The prepared catalyst gel was tested repeatedly for 5 times in a row.After the first test,the treatment effect of the spherical catalyst on the solution methylene blue dye reached 88.7%,while the treatment effect of the spherical catalyst on the solution methylene blue dye still reached 68.7%in the fifth test.Secondly,the cellulose-based spherical catalyst was treated with ultraviolet light in laboratory water treated wastewater and high chemical oxygen demand?COD?wastewater.The results showed that the adsorption and illumination combined treatment were the best in three ways:pure adsorption,pure illumination,adsorption and illumination,water heat treatment wastewater COD decreased from 7530 mg/L to5404 mg/L,chromaticity value dropped from 2018 to 1319,pharmaceutical wastewater after the 20 times diluted,COD dropped from 1506 mg/L to 1146 mg/L,chromaticity value dropped from 80 to 29.Finally,the cellulose based spherical catalyst was applied to a self-made reactor for amplification test.The center of the reactor was provided with an ultraviolet lamp as the light source.The results showed that the spherical catalyst still had good treatment effect on methylene blue dye solutions with different concentrations?10,20,30mg/L?in the reactor,and different from the test tube,the spherical catalyst could return to its original white color after treatment in the reactor.Adding gas in the reactor can effectively speed up the treatment of dyes in the solution by spherical catalyst,but when the added gas is too large,it will speed up the decomposition of spherical catalyst,resulting in more powder in the solution and make the solution cloudy.