Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples w...Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples were determined in a range of relative humidity.The ion-exchange process was characterized by FT-IR,ash content,and p H value.A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities.The extent of ion-exchange reaction between Mg2+and lignite is controlled by the concentration of Mg2+in Mg SO4solution.The effect of Mg2+on equilibrium adsorption water content varies with relative humidity and content of Mg2+.The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites,which are Mg2+–carboxyl group complex.At middle relative humidity capillary force between Mg2+–water clusters Mg+(H2O)nand capillary is more important.At high relative humidity,free water–free water interactions are more significant.展开更多
Experiment was designed under different pH and temperature conditions to analysis the NH4+ exchange capacity of Na+-vermiculite,Ca2+-vermiculite and Mg2+-vermiculite clay minerals pre-treated using NaCl,CaCl2 and MgCl...Experiment was designed under different pH and temperature conditions to analysis the NH4+ exchange capacity of Na+-vermiculite,Ca2+-vermiculite and Mg2+-vermiculite clay minerals pre-treated using NaCl,CaCl2 and MgCl2 solutions respectively.The results indicated that the exchange reactions occurred most rapidly at the proceeding 80 minutes and approached to equilibrium by about 120 minutes.The exchange quantity of ammonium on the vermiculite(at initial ammonium concentration of 673mg/L)varied with pH with a peak value of 28.36mg/g on Na+-vermiculite,23.01mg/g on Ca2+-vermiculite,20.14mg/g on Mg2+-vermiculite,18.04mg/g on natural vermiculite at pH 7.The exchange and adsorption isotherm of NH4+ on cation-vermiculite can be described by Langmuir equation.展开更多
Silk is made of sericin and fibroin proteins. The sericin constitutes 20%- 30% of silk proteins and it covers the fibmin. Sericin is usually treated as impurity and removed during the process of degumming in dyeing an...Silk is made of sericin and fibroin proteins. The sericin constitutes 20%- 30% of silk proteins and it covers the fibmin. Sericin is usually treated as impurity and removed during the process of degumming in dyeing and printing factories. However, sericin is a useful natural protein. In this paper, viscose auion-exchange fibers have been used to absorb seriein from waste water. The amount of adsorbed sericin into the viscose anion-exchange fibers at different temperatures and times has been studied. The study show that the anion-exchange fibers can adsorb sericin from the waste water. Furthermore, the equilibrium adsorption data show that the adsorption of sericin onto anion-exchange fiber fit the Freundlich isotherm at 25 1C and 50 ℃, and fit the Langmuir isotherm at 75 ℃.展开更多
基金Supported by the National Basic Research Program of China(2012CB214900)the National Natural Science Foundation of China(51274197)+1 种基金the 111 Project(B12030)the Fundamental Research Funds for the Central Universities(2014XT05)
文摘Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples were determined in a range of relative humidity.The ion-exchange process was characterized by FT-IR,ash content,and p H value.A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities.The extent of ion-exchange reaction between Mg2+and lignite is controlled by the concentration of Mg2+in Mg SO4solution.The effect of Mg2+on equilibrium adsorption water content varies with relative humidity and content of Mg2+.The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites,which are Mg2+–carboxyl group complex.At middle relative humidity capillary force between Mg2+–water clusters Mg+(H2O)nand capillary is more important.At high relative humidity,free water–free water interactions are more significant.
文摘Experiment was designed under different pH and temperature conditions to analysis the NH4+ exchange capacity of Na+-vermiculite,Ca2+-vermiculite and Mg2+-vermiculite clay minerals pre-treated using NaCl,CaCl2 and MgCl2 solutions respectively.The results indicated that the exchange reactions occurred most rapidly at the proceeding 80 minutes and approached to equilibrium by about 120 minutes.The exchange quantity of ammonium on the vermiculite(at initial ammonium concentration of 673mg/L)varied with pH with a peak value of 28.36mg/g on Na+-vermiculite,23.01mg/g on Ca2+-vermiculite,20.14mg/g on Mg2+-vermiculite,18.04mg/g on natural vermiculite at pH 7.The exchange and adsorption isotherm of NH4+ on cation-vermiculite can be described by Langmuir equation.
文摘Silk is made of sericin and fibroin proteins. The sericin constitutes 20%- 30% of silk proteins and it covers the fibmin. Sericin is usually treated as impurity and removed during the process of degumming in dyeing and printing factories. However, sericin is a useful natural protein. In this paper, viscose auion-exchange fibers have been used to absorb seriein from waste water. The amount of adsorbed sericin into the viscose anion-exchange fibers at different temperatures and times has been studied. The study show that the anion-exchange fibers can adsorb sericin from the waste water. Furthermore, the equilibrium adsorption data show that the adsorption of sericin onto anion-exchange fiber fit the Freundlich isotherm at 25 1C and 50 ℃, and fit the Langmuir isotherm at 75 ℃.
