Study On The Adsorption Properties Of Activated Carbon And Lotus Seeds By Alternanthera Philoxeroides

Low-cost and effective alligator weed activated carbon(AWAC)was prepared from perennial herbs aquatic plants by phosphoric acid activation.AWAC revealed a highly porous structure with a rough surface.It was used to adsorb cephalexin(CEX)?sunset yellow dye(SYD)and Rhodamine B(RB)from aqueous solution.Brunauer–Emmett–Teller(BET)surface area,Scanning electron microscopy(SEM),porosity analyzer and fourier transform infrared(FTIR)was applied to characterize the physical and chemical properties.Investigated the adsorption capacity of CEX?SYD and RB adsorbed by AWAC.The adsorption performance of AWAC was examined by assessing the effects of various parameters,i.e.contact time,initial solution concentration,adsorbent dosage,temperature and p H on the adsorption properties of AWAC.Kinetic and thermodynamic models of adsorption and applicable adsorption isotherms are determined for these adsorbents.The orthogonal experiment was used to get the optimal conditions,and the order of the effect on the removal and equilibrium adsorption amount is important of the four factors with the range analysis.The main conclusions are as follows:(1)A rough structure in terms of both size and shape was highly developed and widely distributed on the surface of AWAC.The AWAC features a high surface area(736.3 m2/g)and has an abundant array of microvoids and mesopores with an average pore size of 4.05 nm,which would improve the activated carbon adsorption performance of macromolecules and small molecules particles.respectively.The presence of phosphorus-containing groups,C–H,C–O,and C=C moieties on the surface of AWAC combined or reacted with the solution molecular would increase the adsorption property.(2)AWAC has the great adsorption effect on adsorbing the three kinds of pollutants.A 1.6 g/L dose of AWAC adsorbed about 93 % of CEX at a concentration of 35 mg/L,the maximum adsorption was about 45 mg/g at 308 K;A 0.8 g/L does of AWAC adsorbed about 96% of sunset yellow dye(SYD)at a concentration of 150 mg/L,the maximum adsorption was about 271 mg/g at 308 K;A 0.8g/L dose of AWAC adsorbed about 96% of RB at a concentration of 100mg/L,the maximum RB adsorption capacity of AWAC was about 286 mg/g.The kinetic data of the three pollutants adsorbed by AWAC were agreed with the pseudo-second-order kinetic model well,which was considered as the rate-limiting factor.The batch equilibrium data fitted well to the Langmuir isotherm,which indicated monolayer adsorption.The negative ?G values confirmed the spontaneity of the adsorption process.Positive ?H and ?S values indicated endothermic and irreversible adsorption.