Study On Modification Of Mesoporous Carbon And Adsorption Of High Salinity Dye Wastewater

Common high-salinity organic wastewater often contained not only high concentration of soluble inorganic salts(SO₄^2-,Cl^-,Ca²⁺,Na⁺),organic matter,heavy metals and oils,but also a variety of refractory organic matter.This kind of wastewater was not only expensive but also difficult to be treated.Traditional physicochemical method could not reduce the concentration of organic matter in wastewater effectively,while the growth of micro organisms in biological method was limited by high concentration of salt.Therefore,how to control the pollution of high concentration saline organic wastewater effectively had become the focus of our country and even the world.In order to explore an effective method for the removal of organic matter in high-salt environment,the methylene blue simulated wastewater containing 5%Na Cl was used as the treatment object.The initial concentration of methylene blue was 100 mg/L.Choicing mesoporous carbon adsorption method,it was used to study the preparation conditions,modification methods of different mesoporous carbon and their effects on the adsorption efficiency of methylene blue solution.The thermodynamic and kinetic laws of mesoporous carbon adsorption were analyzed,combining with SEM and BE.T and other characterizations were used to explore the adsorption mechanism.The main research work and achievements are as follows:In order to explore the optimal conditions for preparing mesoporous carbon materials,soft template method was used.Glucose,sucrose,lignin and phenolic resin were selected as different carbon sources.P123 and F127 were used as single template and P123/F127as composite template.Mesoporous carbon materials were prepared by controlling the process conditions such as hydrochloric acid volume,charring temperature and time.The methylene blue simulated wastewater containing 5%Na Cl was used as the treatment object.The initial concentration of methylene blue was 100 mg/L.The results showed that pyrogallol/formaldehyde was used as carbon source.P123/F127 with mass ratio of 1:3was choiced as composite template and 0.15 m L of hydrochloric acid was choiced as catalyst.The carbonization temperature was 600℃,and charring time was 3 h.Thus the mesoporous carbon material was the best.The adsorption amount of the high-salinity methylene blue solution was 314.9 mg/g,which was 1.34 times than that of the activated carbon,and the adsorption equilibrium time was shortened.In order to explore the best method for modifying mesoporous carbon,various modified methods,such as oxidation modification method,microwave modification method,graft modification method and organic modification method,etc.,were explored.The mesoporous carbon adsorbed the high-salinity methylene blue solution.The high-salinity methylene blue solution was a solution containing 5%Na Cl with an initial concentration of methylene blue of 100 mg/L.The results showed that the solution was compared with the original mesoporous carbon.Compared with the oxidative modified adsorption treatment of high-sodium methylene blue solution,the effect of microwave modification and graft modification was better,and the effect of organic modification was the best.The removal rate of high-salt methylene blue solution could reach above 90%.In order to investigate the optimal adsorption conditions of modified mesoporous carbon for high-salinity methylene blue solution,control different influencing factors,such as adsorption time,initial methylene blue concentration,initial salt concentration,adsorbent dosage,adsorption temperature and the influence of Na₂SO₄.Single factor adsorption test.The results showed that the modified mesoporous carbon adsorption treatment of 5%Na Cl containing methylene blue concentration of 100 mg/L solution,the dosage was 0.1 g,the adsorption temperature was 40℃,the adsorption time was 180min,at this time modified mesopores The carbon adsorption capacity was 460 mg/g,and the methylene blue removal rate was 91.67%.Under the condition of constant total salinity,the removal rate and adsorption amount of modified mesoporous carbon to methylene blue solution decreased with the increase of Na₂SO₄ content,which indicated that the effect of Na₂SO₄on the modification of modified mesoporous carbon was greater than that of Na Cl.In order to investigate the adsorption mechanism of modified mesoporous carbon on high-salt methylene blue solution,the adsorption isotherm and adsorption kinetics were evaluated,and different characterization methods were used,such as SEM,BET,etc.The results showed that the high-salinity methylene blue solution was changed.The adsorption on the mesoporous carbon was monolayer adsorption.The adsorption isotherm equation could explain the adsorption process well.The K_F increases with the increase of salt concentration,indicating that the adsorption amount was positively correlated with the salt concentration.The high salt methylene blue solution The adsorption on the modified mesoporous carbon conformed to the pseudo-second-order kinetic equation,and the adsorption rate constant increased with the increase of the solution salinity;the modified mesoporous carbon had larger specific surface area and pore volume than the original mesoporous carbon.It was more conducive to the contact of pollutants to the adsorption surface and provides a larger adsorption space.In summary,it was proposed to use high-salt methylene blue simulated wastewater as adsorption target,to study the preparation of mesoporous carbon,to modify mesoporous carbon,and to optimize the adsorption effect by single factor adsorption test on simulated wastewater.Mesoporous carbon was evaluated for its performance,and its adsorption mechanism was explored by various characterization methods.It was a new method for the treatment of high-salt organic wastewater,and provided theoretical basis and technical support for the efficient treatment of high-salt organic wastewater.