Preparation And Adsorption Performance Of Microwave Assisted Cellulose-based Materials

In recent years,the development of industry has produced a lot of potential dangers to the environment,dye wastewater emissions have great influence and damage on industry and the environment.Dye wastewater treatment,therefore,has caused the attention of many researchers.Adsorption is one of the most economic and effective method to remove dye in wastewater.The most commonly used at present are natural polymer materials and synthetic polymer adsorption materials,but those materials have some disadvantages such as low adsorption quantities and high costs.In order to solve the problems above,first,we prepared modified microcrystalline cellulose material,microwave assisted modified microcrystalline cellulose material and modified microcrystalline cellulose/montmorillonite composite material in this paper;Then,we studied their adsorption performance on anionic dye congo red(CR)and cationic dye methylene blue(MB).We characterize the prepared adsorbents using X-ray diffraction(XRD),infrared spectrum(FTIR),scanning electron microscope(SEM),and elemental analysis;Finally,we used the adsorption kinetics and isothermal adsorption model to describe the adsorption behavior.The results showed:(1)The modified microcrystalline cellulose adsorbent was prepared.Under the condition of the preparation of the CHPTAC/MCC mass ratio of 1:1,2.5h reaction time,reaction temperature 50?,40%NaOH concentration,the adsorption material of congo red can achieve maximum adsorption capacity up to 274 mg/g.The adsorption process meets the pseudo-second-order kinetics model.The isothermal adsorption of congo red corresponded to the Langmuir isotherm model,which belonged to the monolayer adsorption.(2)The modified microcrystalline cellulose using microwave was prepared,and under the condition of the optimum preparation process for CHPTAC/MCC mass ratio is 1:1,microwave radiation time 50s,power 280W,NaOH concentration is 40%,congo red maximum adsorption capacity can reach 358mg/g.The adsorption process meeted the pseudo-second-order kinetics model well,and the isothermal adsorption of congo red corresponded to the Langmuir isotherm model,which belonged to the monolayer adsorption.As the desorption effect of congo red was not ideal,this paper investigated the secondary cumulative adsorption effect of the material,and the results showed that the secondary cumulative adsorption capacity can reach 92.3%of the first time.(3)We prepared microwave assisted composite adsorbent with modified MCC and MMT.When the quality ratio was 1:1,CTBA quality 0.5g,microwave radiation time of 120s,power 360W,the maximum adsorption capacity of methylene blue and congo red were 340mg/g and 139mg/g respectively.The adsorption process of composite materials onto congo red and methylene blue meeted the pseudo-second-order kinetics model well.The adsorption of congo red can be described using the Langmuir adsorption isotherm model,which belonged to the monolayer adsorption.And it also meted the Freundlich adsorption isotherm model well for methylene blue,which belonged to the multilayer adsorption.For the desorption performance of composite materials was not ideal,this paper examineed the secondary cumulative adsorption effect,the results showed that the secondary accumulation of congo red and methylene blue adsorption capacity can reach 423mg/g and 239mg/g.