In chloride system, thermodynamic analysis is a useful guide to separate lead and antimony as well as to understand the separation mechanism. An efficient and feasible way for separating lead and antimony was discusse...In chloride system, thermodynamic analysis is a useful guide to separate lead and antimony as well as to understand the separation mechanism. An efficient and feasible way for separating lead and antimony was discussed. The relationships of [Pb2+][Cl-]2—lg[Cl]T and E—lg[Cl]T in Pb-Sb-Cl-H2O system were studied, and the solubilities of lead chloride at different antimony concentrations were calculated based on principle of simultaneous equilibrium. The results show that insoluble salt PbCl2 will only exist stably in a certain concentration range of chlorine ion. This concentration range of chlorine ion expands a little with increasing the concentration of antimony in the system while narrows as the system acidity increases. The solubility of Pb2+ in solution decreases with increasing the concentration of antimony in the system, whereas increases with increasing the concentration of total chlorine. The concentration range of total chlorine causing lead solubility less than 0.005 mol/L increases monotonically.展开更多
Chloroplasts were isolated from spinach cultured in lead chloride-present, Ce3+-administered, cerium chloride-administered lead chloride-present Hoagland’s media or that of Hoagland’s media. The experimental study d...Chloroplasts were isolated from spinach cultured in lead chloride-present, Ce3+-administered, cerium chloride-administered lead chloride-present Hoagland’s media or that of Hoagland’s media. The experimental study demonstrated the effects of cerium (Ce) on distribution of light energy and photochemical activities of spinach chloroplast grown in lead (Pb)-present media. It was observed that Pb2+ significantly inhibited photosynthesis in spinach, including light absorption, energy transfer from LHCⅡ to photosystem Ⅱ, excitation energy distribution from photosystem I to photosystem Ⅱ, and transformation from light energy to electron energy and oxygen evolution of chloroplasts, and decreased spinach growth. However, Ce3+ treatment to Pb2+-present chloroplasts could obviously improve light absorption and excitation energy distribution in both photosystems and increase activity of photochemical reaction and oxygen evolution of chloroplasts. The results suggested that Ce3+ under Pb2+ stress could maintain the stability of chloroplast membrane, and improve photosynthesis of spinach chloroplast, thus promote spinach growth.展开更多
The behaviours of complexation and dissolution of PbCl2 on the surface of galena were investigated to explore the process of hydro-chemical conversion of galena(PbS)in chloride media.By means of solution chemistry cal...The behaviours of complexation and dissolution of PbCl2 on the surface of galena were investigated to explore the process of hydro-chemical conversion of galena(PbS)in chloride media.By means of solution chemistry calculation,the production and dissolution of the products PbCl2 were studied.And the passivation of the galena was studied by Tafel curve.The results show that PbCl4 2-is the main form of PbCl2 presented in the saturated potassium chloride(KCl)solution.The PbCl2 crystal is easy to precipitate when the total concentration of chloride ion([Cl -]T)is equal to 0.92 mol/L,and it is inclined to dissolve when[Cl -]T is more than 0.92 mol/L.The chloride complexing reaction rate strongly depends on the Fe3 +ion concentration when it is less than 6× 10-4mol/L,while passivation occurs on the surface of the electrode when Fe 3+concentration is larger than 6×10 -4mol/L.The reaction rate increases obviously when KCl is added,since the activity of Cl-increases;thus accelerates the dissolution of PbCl2.展开更多
基金Project(2006BAB02B04-4-1)supported by the National Key Technology R&D Program of China
文摘In chloride system, thermodynamic analysis is a useful guide to separate lead and antimony as well as to understand the separation mechanism. An efficient and feasible way for separating lead and antimony was discussed. The relationships of [Pb2+][Cl-]2—lg[Cl]T and E—lg[Cl]T in Pb-Sb-Cl-H2O system were studied, and the solubilities of lead chloride at different antimony concentrations were calculated based on principle of simultaneous equilibrium. The results show that insoluble salt PbCl2 will only exist stably in a certain concentration range of chlorine ion. This concentration range of chlorine ion expands a little with increasing the concentration of antimony in the system while narrows as the system acidity increases. The solubility of Pb2+ in solution decreases with increasing the concentration of antimony in the system, whereas increases with increasing the concentration of total chlorine. The concentration range of total chlorine causing lead solubility less than 0.005 mol/L increases monotonically.
基金Project supported by the National Natural Science Foundation of China (30470150,30800068)
文摘Chloroplasts were isolated from spinach cultured in lead chloride-present, Ce3+-administered, cerium chloride-administered lead chloride-present Hoagland’s media or that of Hoagland’s media. The experimental study demonstrated the effects of cerium (Ce) on distribution of light energy and photochemical activities of spinach chloroplast grown in lead (Pb)-present media. It was observed that Pb2+ significantly inhibited photosynthesis in spinach, including light absorption, energy transfer from LHCⅡ to photosystem Ⅱ, excitation energy distribution from photosystem I to photosystem Ⅱ, and transformation from light energy to electron energy and oxygen evolution of chloroplasts, and decreased spinach growth. However, Ce3+ treatment to Pb2+-present chloroplasts could obviously improve light absorption and excitation energy distribution in both photosystems and increase activity of photochemical reaction and oxygen evolution of chloroplasts. The results suggested that Ce3+ under Pb2+ stress could maintain the stability of chloroplast membrane, and improve photosynthesis of spinach chloroplast, thus promote spinach growth.
基金Project(50774094)supported by the National Natural Science Foundation of China
文摘The behaviours of complexation and dissolution of PbCl2 on the surface of galena were investigated to explore the process of hydro-chemical conversion of galena(PbS)in chloride media.By means of solution chemistry calculation,the production and dissolution of the products PbCl2 were studied.And the passivation of the galena was studied by Tafel curve.The results show that PbCl4 2-is the main form of PbCl2 presented in the saturated potassium chloride(KCl)solution.The PbCl2 crystal is easy to precipitate when the total concentration of chloride ion([Cl -]T)is equal to 0.92 mol/L,and it is inclined to dissolve when[Cl -]T is more than 0.92 mol/L.The chloride complexing reaction rate strongly depends on the Fe3 +ion concentration when it is less than 6× 10-4mol/L,while passivation occurs on the surface of the electrode when Fe 3+concentration is larger than 6×10 -4mol/L.The reaction rate increases obviously when KCl is added,since the activity of Cl-increases;thus accelerates the dissolution of PbCl2.
