| In this paper,alkali lignin and sodium lignosulfonate were used as raw mater:ials,and potassium tartrate was used as a novel activator to prepare porous carbon materials.Through single factor method,the specific surface area,pore size distribution,surface morphology,microcrystalline structure,and surface functional groups of porous carbon materials were analyzed by specific surface area and pore analyzer(BET),field emission scanning electron microscope(SEM),X-ray diffractometer(XRD),Fourier infrared spectrometer(FTIR),and the optimal preparation process conditions were determined.Methyl orange was used to simulate the printing and dyeing wastewater,and the porous carbon material with the optimal preparation process conditions was used in the adsorption treatment.The adsorption performance and corresponding adsorption mechanism of the porous carbon material were investigated.The main research contents and conclusions are as follows:The base lignin-based porous carbon material was prepared by using alkali lignin as raw material,potassium hydroxide,sodium hydroxide and potassium tartrate as activator.Structure and properties were analyzed by BET,SEM,XRD,FTIR and other methods.The results show that the order of specific surface area of three alkali lignin-based porous carbon materials were APC-K(1113 m2/g)>APC-J(947 m2/g)>APC-Na(762 m2/g);the activation ability of potassium tartrate to alkali lignin was between KOH and NaOH;the degree of disorder and graphitization of APC-K was lower than that of APC-Na and APC-J.Using alkali lignin as raw material and potassium tartrate as activating agent,the process of preparing alkali lignin based porous carbon materials by potassium tartrate activation was studied.The effects of mass ratio(potassium tartrate/alkali lignin)and activation temperature on the specific surface area and pore size distribution,surface morphology,microcrystalline structure,and surface functional groups of alkali lignin based porous carbon materials were systematically investigated through a single factor test.The optimum preparation process conditions were as follows:the mass ratio was 2:1,the activation temperature was 800?,the activation time was 90 minutes,the specific surface area was 1911 m2/g,the total pore volume was 1.06 cm3/g,and the average pore diameter was 2.37 nm.The pore size distribution was composed of micro-pores and a partial mesopore structures,and all contain a very microporous structures.The effects of mass ratio and activation temperature on the specific surface area and pore size distribution,surface morphology,microcrystal structure and surface functional groups of sodium lignosulfonate based porous carbon materials were studied by single factor method.The optimum preparation conditions were determined:the mass ratio was 2:1,the activation temperature was 800?,the activation time was 90 min,the specific surface area was 1817 m2/g,the total pore volume was 0.90 cm3/g,and the average pore diameter was 2.71 nm.The pore size distribution was dominated by micropores-mesopores.Using alkali lignin based porous carbon materials APC-2-8 and sodium lignosulfonate based porous carbon materials SPC-3-8 as adsorbents,methyl orange simulated dye wastewater,and the adsorption characteristics of two activating agents for methyl orange were investigated.The effects of initial concentration,adsorption temperature,adsorbent dosage and adsorption time on the adsorption of methyl orange were studied,and the adsorption kinetics and isothermal adsorption lines were studied.The results show that the unit adsorption amount of APC-2-8 and SPC-3-8 were positively correlated with the initial concentration,system temperature,and adsorption time and has an equilibrium value.The removal rate of methyl orange by APC-2-8 at the initial concentration of 25?,was 0.05 g,the removal rate of methyl orange by adsorption time of 60 min,was as high as that of 99.04%.SPC-3-8 at the initial concentration of 25?,and the removal rate of methyl orange by adsorption time of 60 min,was as high as 98.17%.The adsorption kinetics of APC-2-8 and SPC-3-8 on methyl orange conform to the quasi-second-order kinetic model,and the adsorption process was mainly chemical adsorption The isotherm adsorption process accords with Langmuir adsorption isotherm model,and the adsorption process was monolayer adsorption.The maximum adsorption capacity was 526.316?476.191 mg/g,which were close to the actual values and higher than the adsorption amounts calculated by other models... |
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