Preparation Of Biomass Modified Materials And Study On The Treatment Performance Of High Fluorine Water

High fluorine is widely distributed worldwide,and has also suffered from high fluorine in my country,the pollution problem of high-fluorine water is also quite serious,in a country with severe water shortage like our country,how to solve the question of high-fluorine water and use the limited water resources is the urgent problem we are facing.Therefore,the research on the treatment of high-fluorine water and the development of high-efficiency,low-cost,reproducible,economic and environmentally-friendly high-fluorine water treatment materials have important economic and social significance.In this paper,three kinds of biomass materials are selected and modified to obtain three kinds of high-fluorine water treatment materials,which are applied to high-fluorine water treatment.And use SEM,XRD,FTIR and other methods to characterize and analyze the structural changes,surface morphology,and functional groups of the modified materials,at the same time,a preliminary exploration was made on the mechanism of fluorine removal from the treated materials.The results of the study are as follows:（1）In the experiment,peanut shell biochar was first prepared,and using this as a carrier,ferro-zirconium was loaded on the biochar by co-precipitation method to prepare a high-efficiency defluorinating agent-loaded zirconium-iron modified biological activated carbon（ZrFe-BC）.Characterization results show that the zirconium iron is successful loaded into the surface and pores of the biocarbon,and the distribution is uniform.Discuss the preparation conditions of ZrFe-BC and the adsorption conditions of high-fluorine water.When the total concentration of Zr-Fe in the impregnation liquid is 0.4mol/L,Zr-Fe molar ratio is 7:3,the dosage is 0.2g,and the pH is 7 The fluorine removal performance is the best,the adsorption is saturated after 2h.ZrFe-BC adsorption fluoride ions are mainly chemically adsorbed,and physical adsorption synergies.Langmuir isothermal models can better describe this reaction process,and dynamic fitting results quasi-secondary dynamic model is similar.（2）In the experiment,polyacrylonitrile fiber was used as the carrier,and the amidoxime group was introduced by chemical grafting method to prepare the amidoxime fiber.Then,the zirconium iron is loaded on the amidoxime fiber by the co-precipitation method to prepare high-efficiency fluoride removal agent-carrying zirconium-iron modified amidoxime ion exchange fiber（ZrFe-AOPAN）.The characterization results show that in the amidoximation reaction,the nitrile group of the polyacrylonitrile fiber is successfully converted into the amidoxime group;during the process of loading zirconium iron,both-NH₂and-OH participate in the coordination reaction.The preparation conditions of ZrFe-AOPAN and the adsorption conditions for high-fluorine water were discussed,when the concentration of hydroxylamine hydrochloride is 15g/L,the amidoximation reaction temperature is 70℃,the amidoximation reaction time is 5h,and the dosage of ZrFe-AOPAN is 0.15g,the prepared modified material has a good fluorine removal effect.The degree of influence of common anions on the fluoride removal performance of ZrFe-AOPAN is CO₃^2->HCO₃^->SO₄^2->Cl^-.The desorption experiment shows that the adsorbent ZrFe-AOPAN has good reusability.Designing three-level four-factor orthogonal test,resulting in the maximum effect of the fluorine fluoromer in ZrFe-AOPAN,and the pH has the smallest..The best adsorption condition is that the initial concentration of the fluorine solution is 10mg/L,the time is 80min,the dosage is 0.1g,the pH is 7,and the adsorption capacity reaches 1.71mg/g.（3）In the experiment,chitosan was used as a carrier,ferro-zirconium was loaded on chitosan molecules,zeolite was added to improve its mechanical strength,and a small amount of kaolin was added to act as a binder.Finally,it was chemically crosslinked with glutaraldehyde to reduce the composite adsorbent’s Fluidity,and finally prepared zirconium-iron modified chitosan-zeolite composite adsorbent（ZrFe-CZ）.Combined with the characterization results,it can be seen that the-NH₂,-OH groups of the chitosan molecule participate in the chelation with Zr and Fe,and the coordination of Zr,Fe and F is successful.The preparation conditions of ZrFe-CZ were discussed,and the results showed that when the amount of acetic acid was 40mL,the mass ratio of chitosan-zeolite was 0.8/0.2,and the oscillation frequency was 120rpm,the modified material had the best fluoride removal effect,and the best adsorption conditions were the dosage of ZrFe-CZ is 0.1g,pH=7,t=80min.Further exploration of its reaction mechanism,the ratio of the secondary dynamic model is higher than the experimental data of ZrFe-CZ absorbent fluoride ion,which is chemically adsorbed by multi-step control,diffused by liquid film diffusion and particles.Waiting for a comprehensive role.Adsorption process is closer to Langmuir isothermal model,which indicates the uniformity of the ZrFe-CZ surface.The adsorption of fluoride ions by ZrFe-CZ is a single-layer adsorption and can proceed spontaneously.