Goethite, a typical iron-containing monomineral in red mud, was synthesized under the simulated Bayer digestion condition during the alumina production. The effects of dissolved organic compounds including sodium ...Goethite, a typical iron-containing monomineral in red mud, was synthesized under the simulated Bayer digestion condition during the alumina production. The effects of dissolved organic compounds including sodium formate, sodium acetate, sodium oxalate, sodium salicylate and disodium phthalate on the settling performance of goethite slurries were studied. The settling performance of the slurries was also investigated with the addition of self-made hydroxamated polyacrylamide flocculant （HCPAM）. The adsorption mechanism of dissolved organic compounds on the goethite surfaces was studied by FT-IR and XPS, respectively. The results show that the addition of organic compounds lowers the settling performance of the slurries and a deterioration in settling performance is observed in the order of sodium oxalate 〉 sodium salicylate （~ disodium phthalate） 〉 sodium formate 〉 sodium acetate. Moreover, HCPAM can efficiently eliminate the negative effects of sodium formate, sodium acetate and sodium oxalate on the settling performance of the goethite slurries, but it can only partially improve the settling performance of the goethite slurries containing sodium salicylate or disodium phthalate. FT-IR and XPS results show that these organic compounds are chemically adsorbed on the goethite surface.展开更多
Solar energy is the radiant light and heat from the Sun that has been harnessed by human since ancient times. Also secondary solar resources such as wind and wave power, hydroelectric power and biomass account for mos...Solar energy is the radiant light and heat from the Sun that has been harnessed by human since ancient times. Also secondary solar resources such as wind and wave power, hydroelectric power and biomass account for most of the available renewable energy on Earth, which can be used by human. Architects since alacient times have used various methods to hamesse and employ the solar energy for lighting, cooling and heating and etc. Meanwhile, Iran＇s ancient architecture, as an adaptive one, which consists of various climatic reigns, is filled with abounding examples of using sun energy in buildings. But, unfortunately despite these ancient methods, our modern architects mostly tend to provide energy of buildings with fossil fuels. This increases energy costs of the building＇s and also pollutes the environment. In this article it is intended to consider the ancient ways of using solar energy in Iran, and then suggest new methods for applying in modem buildings. The results of consideration show that among Solar technologies, passive and active methods, Iran＇s ancient architects have used passive methods, for example in mass and space, orientation and settlement of building. The idea of passive methods can be used in new shapes in current buildings, for instance by using solar space, central yard and etc. The suggestive method in this paper is combining the passive methods with the active ones.展开更多
基金Projects(51174231,51134007)supported by the National Natural Science Foundation of China
文摘Goethite, a typical iron-containing monomineral in red mud, was synthesized under the simulated Bayer digestion condition during the alumina production. The effects of dissolved organic compounds including sodium formate, sodium acetate, sodium oxalate, sodium salicylate and disodium phthalate on the settling performance of goethite slurries were studied. The settling performance of the slurries was also investigated with the addition of self-made hydroxamated polyacrylamide flocculant （HCPAM）. The adsorption mechanism of dissolved organic compounds on the goethite surfaces was studied by FT-IR and XPS, respectively. The results show that the addition of organic compounds lowers the settling performance of the slurries and a deterioration in settling performance is observed in the order of sodium oxalate 〉 sodium salicylate （~ disodium phthalate） 〉 sodium formate 〉 sodium acetate. Moreover, HCPAM can efficiently eliminate the negative effects of sodium formate, sodium acetate and sodium oxalate on the settling performance of the goethite slurries, but it can only partially improve the settling performance of the goethite slurries containing sodium salicylate or disodium phthalate. FT-IR and XPS results show that these organic compounds are chemically adsorbed on the goethite surface.
文摘Solar energy is the radiant light and heat from the Sun that has been harnessed by human since ancient times. Also secondary solar resources such as wind and wave power, hydroelectric power and biomass account for most of the available renewable energy on Earth, which can be used by human. Architects since alacient times have used various methods to hamesse and employ the solar energy for lighting, cooling and heating and etc. Meanwhile, Iran＇s ancient architecture, as an adaptive one, which consists of various climatic reigns, is filled with abounding examples of using sun energy in buildings. But, unfortunately despite these ancient methods, our modern architects mostly tend to provide energy of buildings with fossil fuels. This increases energy costs of the building＇s and also pollutes the environment. In this article it is intended to consider the ancient ways of using solar energy in Iran, and then suggest new methods for applying in modem buildings. The results of consideration show that among Solar technologies, passive and active methods, Iran＇s ancient architects have used passive methods, for example in mass and space, orientation and settlement of building. The idea of passive methods can be used in new shapes in current buildings, for instance by using solar space, central yard and etc. The suggestive method in this paper is combining the passive methods with the active ones.
