Study On Preparation And Adsorption Performance Of Activated Carbon From Caragana Microphylla

The caragana microphylla is sand plant which is grown in Northwest Territories and west of Inner Mongolia.The caragana microphylla resources are plentiful and contain plentiful’ fixed carbon.It is significant to exploit the application of salix.The activated carbon is prepared from caragana microphylla by chemical activation in the protection of N2.The studies were carried out on the preparation of caragana microphylla activated carbon with ZnCl2,H3PO4 and KOH as activator,orthogonal test determined the optimum conditions and the ratio,activator concentration,the activate time,the activate temperature and carbonization temperature have been investigated.Under the optimum conditions,the adsorption kinetics and adsorption thermodynamics which three different kinds of salix adsorption capacity on methylene blue have been studied.The degree of crystallinity,surface chemical state and surface structural features of caragana microphylla activated carbon were determined by XRD,FTIR and BET specific surface area.The results are follows:(1)The processing optimum conditions on preparation for activated carbon from caragana microphylla with ZnCl2 were obtained,which was the ratio of 2.5:1,activator concentration of 65%,activation temperature of 800℃ and time of 90 min.The processing optimum conditions on preparation for activated carbon with H3PO4 were obtained,which was the ratio of 2:1,activator concentration of 90%,activation temperature of 800℃ and time of 120 min.(2)The degree of graphitization of caragana microphylla activated carbon was low,the structure is consist of amorphous carbon and a small amount of graphite crystallites.Three different kinds of activated carbon contained functional groups which are hydroxyl,carboxide,lactone-based etc.Specific surface area on the preparation of caragana microphylla activated carbon with ZnCl2 is 1493.79m2/g.Specific surface area on the preparation of caragana microphylla activated carbon with H3PO4 is 1543.76 m2/g.(3)The adsorption capacity of caragana microphylla activated carbon was increased with increasing adsorption temperature,adsorption time and pH value.The adsorption kinetics obeys the pseudo-second-order model,and the isotherm follows the Langmuir monolayer model.(4)Desorption results showed that the desorption efficiency of activated carbon from caragana microphylla with ZnCl2 and with H3PO4 was 60.91%and 32.65%.the desorption efficiency after three cyclic adsorption desorption was 78.04%and 43.82%.As a result,the activated carbon from caragana microphylla possessed of the potential of certain regeneration and reuse.