Preparation Of Activated Carbon By Organic Potassium Salt Activation For Adsorption Of Chloramphenicol

Potassium tartrate and Potassium sorbate as novel activating agents was used to prepare activated carbon by activating biomass solid wastes aim to solve the shortage of coal resources and the strong causticity of activators which were used to prepare high specific surface area activated carbon.The influences of prepapation conditions and raw material types on activated carbon pore size structure and chemical composition were investigated,meanwhile,the activation mechanism was discussed.The modern analytical techniques of specific surface area instrument,scanning electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy were utilized to analyze the porous structure,surface morphology and chemical composition of activated carbon.The adsorption properties of biomass activated carbons and the corresponding adsorption mechanism were investigated by selecting chloramphenicol as a target adsorbate.The main research contents and related conclusions were as follows:1.Potassium tartrate as a novel activating agent,was utilized to prepare activated carbon with relatively high specific surface area by using less activating agent and activation time from marine waste-green alga(Enteromorpha prolifera)for the first time.The influences of activation temperature,impregnation ratio and activation time on the pore structure were investigated to obtain the optimum conditions(700 ?,1:1,30 min).The activated carbon under optimum conditions(AC-PT)had a relateively well-developed pore structure with a high surface area of 1692 m~2/g,1.22 cm3/g total pore volume and 2.88 nm average pore size.The influences of preparation parameters on the specific surface area were in the order of activation temperature>impregnation ratio>activation time.In the activation process,potassium tartrate can activate additional carbon resources,can also be self-activated to facilely synthesize activated carbon simultaneously.AC-PT showed high adsorption capacity of 729.9 mg/g towards chloramphenicol.Compared with Freundlich and Dubinin-Radushkevich model,the thermodynamic data conformed the Langmuir isotherm model.2.The single factor experiment was employed to prepare activated carbon by potassium sorbate(a novel activator)activating fallen leaves.The processing parameters of activation temperature,impregnation ratio and activation time were investigated to obtain the optimum preparation conditions.The effects of three process pararneters on the specific surface are were in an order of activation temperature>impregnation ratio>activation time.Meanwhile,the optimum preparation conditions were activation temperature 700 ?,impregnation ratio3:1,activation time 30 min.The specific surface area,pore volume and mean pore size of the prepared activated carbon under the optimum preparation conditions(AC-PS)were 1627 m~2/g,0.757 cm3/g and 1.86 nm,respectively.In the synthesis process,potassium sorbate could activate external carbon source,and also could be self-activated to facilely synthesize activated carbon,simultaneously.The data of kinetics and thermodynamics could be well fitted by Pseudo-second-order and Langmuir equation respectively.Meanwhile,AC-PS exhibited high adsorption capacity of 540.5 mg/g.3.Potassium tartrate as activator was used to produce activated carbon(AC)by activating petroleum cokes(PC),fallen leaves(FL),chicken feathers(CF)and enteromorpha prolifera(EP)under the identical conditions(activation temperature of 750 ?,impregnnation ratio of 2.5:1 and activation time of 1 h).The ACs synthesized through various precursors showed significant discrepancies in morphologies and the porous structure was characterized by SEM and N2 adsorption-desorption isotherm.The BET surface area of FL-AC(1721 m~2/g),CF-AC(1819 m~2/g),and EP-AC(2151 m~2/g)were larger than that of PC-AC(256 m~2/g).Compared to petroleum coke,fallen leaves,chicken feathers and enteromorpha prolifera were more suitable as raw materials for producing high surface area activated carbon.In addition,the adsorption properties of the four ACs under various conditions were detected by selecting chloramphenicol(CAP)as a target adsorbate.The kinetics and isotherms of adsorption processes were well fitted by pseudo-second-order and Langmuir model for four ACs.Meanwhile,EP-AC exhibited high adsorption capacity of 892.86 mg/g.