Preparation And Performance Study Of Zeolite/Cellulose Composites

With the rapid development of industrialization,a large number of industrial pollutants are discharged into water sources.These pollutants contain a large number of heavy metal ions,organic micromolecules,bacterial pathogens and other substances,which seriously contaminate water sources and cause harm to the environment and human health.Therefore,there is an urgent need for a material that is environmentally friendly,inexpensive,efficient,and easy to recycle for water purification.Adsorption is the most commonly used experimental method to treat pollutants.Faujasite zeolite and cellulose are often used as adsorbents due to their unique pore structure and high specific surface energy.Natural cellulose porous network topography with a nanoscale layer can be used as a template to prepare novel functional composites.Therefore,Faujasite zeolite(Na Y)was synthesized in-situ on the surface of cellulose fiber by immersion-hydrothermal method,and zeolite/cellulose composite(Na Y/FP)is obtained as adsorbent for wastewater treatment;ion exchange method was used to prepare antibacterial agent Zn Y&Cu Y/FP.The main research contents of this paper were as follows:1.Preparation of zeolite/cellulose composites(Na Y/FP)The zeolite precursors were:12 Na₂O:Al₂O₃:7 Si O₂:515 H₂O,aged for 1 h,reacted at 70?for 10 h,zeolite/cellulose composites(Na Y/FP)were synthesized by impregnation-hydrothermal method with cellulose,and analyzed for alkalinity,water amount,crystallization temperature,and aging time.The prepared materials were characterized by X-ray powder diffraction(XRD),X-ray fluorescence spectrum(XRF),scanning electron microscope(SEM),and thermogravimetric analyzer(TGA).The results showed that zeolite and filter paper were successfully compounded.The diameter of zeolite is less than 500 nm,accounting for about 20 wt%.2.Studying the adsorption performance of Na Y/FPThe copper(?)-lead(?)mixed solution,methylene blue(MB)and rhodamine B(Rh B)were adsorbed respectively by Na Y/FP.The highest removal of Cu²⁺and Pb²⁺occurred when the adsorbent was 45 mg and p H of 6 for 30 min adsorption.The adsorption process was fitted with the Freundlich adsorption isotherm model and the pseudo second order kinetic model.The theoretical equilibrium adsorption capacity of Cu²⁺was 61.52 mg/g,and of Pb²⁺was 49.5 mg/g.Order of selective adsorption of adsorbents is:Cu²⁺>Pb²⁺.The removal efficiency of 75%remained after Na Y/FP was cyclically adsorbed with copper ions for three times,which indicated that the composites had better recyclability.The optimal adsorption conditions for MB were as follows:p H of 7,solution initial concentration of 140 mg/L,feed amount of 0.20 g,adsorption for 1 h and removal efficiency of 98.2%;for Rh B were as follows:p H of 9,solution initial concentration of 140 mg/L,feed amount of 0.30 g,adsorption for 2.5 h,and removal efficiency of 93.4%.The optimal adsorption conditions for RHB were as follows:p H of 9,solution initial concentration of 140 mg/L,feed amount of 0.30 g,adsorption for 2.5 h,and removal efficiency of 93.4%.The adsorption processes all conformed to the Langmuir isotherm model and the pseudo second order kinetic model.The maximum adsorption capacity of Na Y/FP for MB reached 46.78 mg/g,and for Rh B reached 23.33 mg/g.3.Preparation of antibacterial agent Zn Y&Cu Y/FP and research on antibacterial abilityThe antibacterial agent Zn Y&Cu Y/FP was obtained by exchanging Na⁺for Zn²⁺,Cu²⁺through ion exchange.The loading of Zn²⁺,Cu²⁺on zeolites was verified to be relatively stable with a slow-release property by flow-through tests.It was experimentally demonstrated that Zn Y&Cu Y/FP exhibited a high antibacterial capacity with a Log removal ratio close to Log 6 and a bactericidal percentage of 99.99%.Zn Y&Cu Y/FP was proved to still have effective bactericidal capacity after cyclic filtration experiments on natural water from Shihu,Suzhou.Zn Y&Cu Y/FP is a kind material for water purification,environmentally friendly and inexpensive.