Study On The Process And Material Of Fluidized-adsorption For Phenol Treatment

In sudden water pollution accident, adsorption is a simple and efficient method ofemergency water treatment to remove pollutants from water. Due to the problem of bigwater resistance and samll water flux in traditional adsorption method, a liquid-solidadsorption fluidized bed, which can be used for emergency treatment is designed in thestudy. Through the investigation of the adsorption capacity of nine granular absorbentand microwave rapid modification study of activated carbon, it is determined activatedcarbon as adsorbent and phonel as adsorbates to investigate the effect offluidized-adsorption process condition on the removal of phenol from water. And theflow behavior of liquid-solid two-phase in fluidized bed is simulated by CFDsimulation.The coconut shell activated carbon had the best adsorption property of phenol witha static adsorption capacity of73.58mg/g among the selected9kinds of adsorbentmaterials in experiments. The microwave rapid modification conditions wasoptimized.The adsorption capacity of activated carbon achieved83.13mg/g after it wasmodified under the optimum conditions: microwave output power500W, irradiationtime of7min, activated carbon amount of15g. The original carbon and modified carbonwere characterized by Bohem titration, BET, SEM, XPS, and the result indicated thatthe content of impurities, acidic oxygen functional groups, inorganic elements onactivated carbon surface reduced and the pore volume increased after modification bymicrowave.In dynamic adsorption experiments, the liquid-solid adsorption fluidized bed hasbeen investigated for removal of phenol from water by using coconut-shell granularactivated carbon(GAC) as adsorbent under various operating conditions. For treating aconcentration of100mg/L of total3g phenol, the removal efficiency of phenolachieved95%under the optimum condition that water flow rate of9.8L/min,activatedcarbon of800g and particle size of0.55-1.7mm. The failure time of adsorption ofactived carbon in fluiedized is about5h with a dynamic adsorption capacity of66.42mg/g. The bed pressure drop and bed expansion characteristics were also studied.The results indicated that the pressure drop of fluidized bed tended to a stable value inthe fluidized stage and the experimental porosity values and calculation results were at agood agreement with a relative error of6.52%.The CFD simulation technology was used to study the flow of liquid-solidtwo-phase in fluiedized bed. The simulated results showed that the distribution of solidsholdup was unevenly in X-axis direction and so was the velocity of particles.The modelused in simulation could predict the flow characteristics of iquid-solid two-phase influiedized bed. The relative error between the the simulation results of bed expansion height、solids holdup、pressure drop and measured data were3.6%,1.36%and1.54%respectively.