AlCl3,NH3·H2O,HNO3 and activated carbon were used as raw materials to prepare one new type of activated alumina-activated carbon composite material.The influence of heat treatment conditions on the structure and ...AlCl3,NH3·H2O,HNO3 and activated carbon were used as raw materials to prepare one new type of activated alumina-activated carbon composite material.The influence of heat treatment conditions on the structure and property of this material was discussed;The microstructures of the composite material were characterized by XRD,SEM,BET techniques;and its formaldehyde adsorption characteristic was also tested.The results showed that the optimal heat treatment temperature of the activated alumina-activated carbon composite material was 450 ℃,iodine adsorption value was 441.40 mg/g,compressive strength was 44 N,specific surface area was 360.07 m2/g,average pore size was 2.91 nm,and pore volume was 0.26 m3/g.According to the BET pore size distribution diagram,the composite material has dual-pore size distribution structure,the micro-pore distributes in the range of 0.6-1.7 nm,and the meso-pore in the range of 3.0-8.0 nm.The formaldehyde adsorption effect of the activated alumina-activated carbon composite material was excellent,much better than that of the pure activated carbon or activated alumina,and its saturated adsorption capacity was 284.19 mg/g.展开更多
The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influenc...The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influences of experimental parameters such as pH, temperature, initial concentration and adsorption rate were investigated. The experimental results show that in the studied concentration range, 001×7 resin has a good sorption ability for Cd2+, and the equilibrium adsorption data fit to Freundlich isotherms. The adsorption is an exothermic process which runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best adsorption condition is pH 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the desorption efficiency is over 98%. The maximal static saturated adsorption capacity is 355 mg/g (wet resin) at 293 K. The adsorption mechanism of Cd2+ on 001×7 resin was discussed based on IR spectra.展开更多
The adsorption properties of a novel macroporous weak acid resin (D152) for Pb2+ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb2+ is at pH 6.00 in HAc-NaAc medium. The s...The adsorption properties of a novel macroporous weak acid resin (D152) for Pb2+ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb2+ is at pH 6.00 in HAc-NaAc medium. The statically saturated adsorption capacity is 527 mg/g at 298 K. Pb2+ adsorbed on D152 resin can be eluted with 0.05 mol/L HCl quantitatively. The adsorption rate constants determined under various temperatures are k288 K=2.22×10-5 s-1, k298 K=2.51×10-5 s-1, and k308 K= 2.95×10-5 s-1, respectively. The apparent activation energy, Ea is 10.5 kJ/mol, and the adsorption parameters of thermodynamics are -HΘ=13.3 kJ/mol, -SΘ=119 J/(mol·K), and -GΘ298 K =-22.2 kJ/mol, respectively. The adsorption behavior of D152 resin for Pb2+ follows Langmuir model.展开更多
In order to investigate the role of TiO2 during plasma treatment,the degradation of the dye AO7 has been studied by gliding arc discharge in the presence of a TiO2 catalyst(CGAD).The results revealed that the adsorpti...In order to investigate the role of TiO2 during plasma treatment,the degradation of the dye AO7 has been studied by gliding arc discharge in the presence of a TiO2 catalyst(CGAD).The results revealed that the adsorption of the dye on TiO2 is a physical adsorption in accordance with Langmuir isotherm,with a constant of adsorption KL=0.52 mg/L and a maximum adsorption capacity b=18.1 mg/g.The temperature variation of the reaction medium made it possible to consider thermodynamic parameters.Indeed,the adsorption is exothermic(enthalpy:△H< 0),and spontaneous(free enthalpy:△G< 0).The negative entropy(△S<0) confirms the afnity of the dye molecules for TiO2.20 min of CGAD treatment in the presence of an optimal quantity of TiO2(2 g/L enabled us to bleach the solution of AO7(100 μM) completely.The discoloration rate with and without the addition of TiO2 was 100% and 28%,respectively.40 additional minutes of treatment allowed a total abatement of the chemical oxygen demand.The elimination of AO7 molecules during the plasma-catalytic treatment follows Langmuir-Hinshelwood(L-H) model kinetics.According to this model,the speed constant is kr=14.97 mg · L 1· min 1and the adsorption coefcient is KL-H = 0.010 L/mg.The latter being negligible compared to kr,adsorption is therefore weakly performed during the plasma treatment.展开更多
The adsorption behaviors of rare earth elements on clay minerals would have great influence on the mineralization process and the leaching process of the ion-adsorption type rare earths ore.In this work,the adsorption...The adsorption behaviors of rare earth elements on clay minerals would have great influence on the mineralization process and the leaching process of the ion-adsorption type rare earths ore.In this work,the adsorption thermodynamics of REEs on kaolin were investigated thoroughly and systematically.The experimental results showed that the adsorption characteristics of La,Nd,Y on kaolin did fit well with the Langmuir isotherm model and their saturated adsorption capacities were 1.731,1.587 and 0.971 mg/g,respectively.The free energy change(ΔG)values were –16.91 kJ/mol(La),–16.05 kJ/mol(Nd)and –15.58 kJ/mol(Y),respectively.The negative values of ΔG demonstrated that the adsorption of rare earth on kaolin was a spontaneously physisorption process.The deposit characteristic of the volcanic ion-adsorption type rare earths ore and the behavior of the rare earth in the column leaching process were also developed here.With the increase of the ore body depth,the distribution of the LREEs decreased and the HREEs increased.And the slight differences in the adsorption ability of REEs on clay minerals led to the fractionation effect in the column leaching process.These developed more evidences and better understanding of metallogenic regularity,and provided a theoretical basis and scientific approach to separation of the HREEs and LREEs in the leaching process.展开更多
A novel sorbent for the removal of uranyl ion was prepared by expanded rice husk powder. Batch adsorption experiments were performed on factors of p H,temperature, initial uranyl ion concentration, adsorbent dosage an...A novel sorbent for the removal of uranyl ion was prepared by expanded rice husk powder. Batch adsorption experiments were performed on factors of p H,temperature, initial uranyl ion concentration, adsorbent dosage and contact time to evaluate the adsorption capacity. The results show that the saturation adsorption capacity is 5.7 mgág^(-1) using expanded rice husk powder treating uranyl ion aqueous solution(80 mgáL^(-1)) for 24 h at 25 °C with initial pH3. Adsorption process could be well described by Langmuir isotherm model. The adsorption kinetic data are fitted well with pseudo-second-order model. The results obtained show that expanded rice husk adsorbent is a promising adsorbent for the removal of uranium from aqueous solutions.展开更多
基金Sponsored by the special fund for 2010 Petty Invention and Petty Creation of Fujian Provincial Development and Reform Commission (No. MFGT[2010]1093)Natural Science Foundation of Fujian Province (No. 2011J01291)
文摘AlCl3,NH3·H2O,HNO3 and activated carbon were used as raw materials to prepare one new type of activated alumina-activated carbon composite material.The influence of heat treatment conditions on the structure and property of this material was discussed;The microstructures of the composite material were characterized by XRD,SEM,BET techniques;and its formaldehyde adsorption characteristic was also tested.The results showed that the optimal heat treatment temperature of the activated alumina-activated carbon composite material was 450 ℃,iodine adsorption value was 441.40 mg/g,compressive strength was 44 N,specific surface area was 360.07 m2/g,average pore size was 2.91 nm,and pore volume was 0.26 m3/g.According to the BET pore size distribution diagram,the composite material has dual-pore size distribution structure,the micro-pore distributes in the range of 0.6-1.7 nm,and the meso-pore in the range of 3.0-8.0 nm.The formaldehyde adsorption effect of the activated alumina-activated carbon composite material was excellent,much better than that of the pure activated carbon or activated alumina,and its saturated adsorption capacity was 284.19 mg/g.
基金Project(2005) supported by the Basic Technology Research Item of Explosive Industry, China
文摘The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influences of experimental parameters such as pH, temperature, initial concentration and adsorption rate were investigated. The experimental results show that in the studied concentration range, 001×7 resin has a good sorption ability for Cd2+, and the equilibrium adsorption data fit to Freundlich isotherms. The adsorption is an exothermic process which runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best adsorption condition is pH 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the desorption efficiency is over 98%. The maximal static saturated adsorption capacity is 355 mg/g (wet resin) at 293 K. The adsorption mechanism of Cd2+ on 001×7 resin was discussed based on IR spectra.
基金Project(2008F70059) supported by the Scientific and Technological Research Planning of Zhejiang Province, China
文摘The adsorption properties of a novel macroporous weak acid resin (D152) for Pb2+ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb2+ is at pH 6.00 in HAc-NaAc medium. The statically saturated adsorption capacity is 527 mg/g at 298 K. Pb2+ adsorbed on D152 resin can be eluted with 0.05 mol/L HCl quantitatively. The adsorption rate constants determined under various temperatures are k288 K=2.22×10-5 s-1, k298 K=2.51×10-5 s-1, and k308 K= 2.95×10-5 s-1, respectively. The apparent activation energy, Ea is 10.5 kJ/mol, and the adsorption parameters of thermodynamics are -HΘ=13.3 kJ/mol, -SΘ=119 J/(mol·K), and -GΘ298 K =-22.2 kJ/mol, respectively. The adsorption behavior of D152 resin for Pb2+ follows Langmuir model.
基金Foundation item： Project（21106188） supported by the National Natural Science Foundation of China Project（12JJ4013） supported by Htman Provincial Natural Science Foundation of China+2 种基金 Projects（2011M501299, 2012T50709） supported by China Postdoctoral Science Foundation Project（2011QNZT050） supported by the Special Fund from the Central Collegiate Basic Scientific Research Bursary of Central South University, China Project（CSUZC2012038） supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University, China
文摘In order to investigate the role of TiO2 during plasma treatment,the degradation of the dye AO7 has been studied by gliding arc discharge in the presence of a TiO2 catalyst(CGAD).The results revealed that the adsorption of the dye on TiO2 is a physical adsorption in accordance with Langmuir isotherm,with a constant of adsorption KL=0.52 mg/L and a maximum adsorption capacity b=18.1 mg/g.The temperature variation of the reaction medium made it possible to consider thermodynamic parameters.Indeed,the adsorption is exothermic(enthalpy:△H< 0),and spontaneous(free enthalpy:△G< 0).The negative entropy(△S<0) confirms the afnity of the dye molecules for TiO2.20 min of CGAD treatment in the presence of an optimal quantity of TiO2(2 g/L enabled us to bleach the solution of AO7(100 μM) completely.The discoloration rate with and without the addition of TiO2 was 100% and 28%,respectively.40 additional minutes of treatment allowed a total abatement of the chemical oxygen demand.The elimination of AO7 molecules during the plasma-catalytic treatment follows Langmuir-Hinshelwood(L-H) model kinetics.According to this model,the speed constant is kr=14.97 mg · L 1· min 1and the adsorption coefcient is KL-H = 0.010 L/mg.The latter being negligible compared to kr,adsorption is therefore weakly performed during the plasma treatment.
基金Project supported by National Science and Technology Support Program of China(2015BAB16B01)Training Program of Major Academic and Technical Leaders in Jiangxi Province(20142BCB22005)Top Youth Talent Training Program of"Gan Po 555 Talents Project"of Jiangxi Province
文摘The adsorption behaviors of rare earth elements on clay minerals would have great influence on the mineralization process and the leaching process of the ion-adsorption type rare earths ore.In this work,the adsorption thermodynamics of REEs on kaolin were investigated thoroughly and systematically.The experimental results showed that the adsorption characteristics of La,Nd,Y on kaolin did fit well with the Langmuir isotherm model and their saturated adsorption capacities were 1.731,1.587 and 0.971 mg/g,respectively.The free energy change(ΔG)values were –16.91 kJ/mol(La),–16.05 kJ/mol(Nd)and –15.58 kJ/mol(Y),respectively.The negative values of ΔG demonstrated that the adsorption of rare earth on kaolin was a spontaneously physisorption process.The deposit characteristic of the volcanic ion-adsorption type rare earths ore and the behavior of the rare earth in the column leaching process were also developed here.With the increase of the ore body depth,the distribution of the LREEs decreased and the HREEs increased.And the slight differences in the adsorption ability of REEs on clay minerals led to the fractionation effect in the column leaching process.These developed more evidences and better understanding of metallogenic regularity,and provided a theoretical basis and scientific approach to separation of the HREEs and LREEs in the leaching process.
基金Financial support from the National Natural Science Foundation of China(No:21406036)Fujian Natural Science Foundation of China(No.2014J01034)+1 种基金Project of Fujian provincial department of education(Nos.JA11044,JA10056,JB13011)the Program for Innovative Research Team in Science and Technology in Fujian Province University were greatly acknowledged
基金financially supported by the National Natural Science Foundation of China (No. 21406182)the National Decommissioning of Nuclear Facilities and Radioactive Waste Management Research Projects Focus, State Administration of Science, Technology and Industry for National Defense (SASTIND), China (No. 2014-806)the Science and Technology Project of Qinghai Province (No. 2014-GX-Q04)
文摘A novel sorbent for the removal of uranyl ion was prepared by expanded rice husk powder. Batch adsorption experiments were performed on factors of p H,temperature, initial uranyl ion concentration, adsorbent dosage and contact time to evaluate the adsorption capacity. The results show that the saturation adsorption capacity is 5.7 mgág^(-1) using expanded rice husk powder treating uranyl ion aqueous solution(80 mgáL^(-1)) for 24 h at 25 °C with initial pH3. Adsorption process could be well described by Langmuir isotherm model. The adsorption kinetic data are fitted well with pseudo-second-order model. The results obtained show that expanded rice husk adsorbent is a promising adsorbent for the removal of uranium from aqueous solutions.
