Photocatalytic reduction method using TiO2 suspension for removal as well as possibly recovery of silver （Ag（I）） in the presence of Cu（II） is examined. The photocatalytic reduction was performed by batch techniq...Photocatalytic reduction method using TiO2 suspension for removal as well as possibly recovery of silver （Ag（I）） in the presence of Cu（II） is examined. The photocatalytic reduction was performed by batch technique in a closed reactor equipped with UV lamp. The concentration of unreduced Ag（I） was analyzed by atomic absorption spectrophotometry method. The research results indicate that Ag（I） in the solution can be removed and recovered effectively as silver metal Ag（0） deposited on the surface of TiO2 for photocatalytic reduction. In addition, the presence of Cu（II） ion with increasing concentration leads to a proportional decline in Ag（I） photoreduction due to the prominent competition in the adsorption on the surface of TiO2. The effectiveness of Ag（I） ion photoreduction in the presence of Cu（II） ion is strongly influenced by solution pH and the highest photoreduction is obtained at pH 5 - 8, which is related with the speciation ofAg（I）, TiO2 surface as well as Cu（II） in the solution.展开更多
Two methods for particulate pigments(i.e.,quantitative filter technique,QFT,and in vivo measurement,InVivo,respectively)and two methods for dissolved pigments(i.e.,Acetone Extracts,AceEx,and high-performance liquid ch...Two methods for particulate pigments(i.e.,quantitative filter technique,QFT,and in vivo measurement,InVivo,respectively)and two methods for dissolved pigments(i.e.,Acetone Extracts,AceEx,and high-performance liquid chromatography,HPLC,respectively) were used to obtain the optical absorption coefficient spectra for cultures of four typical algal species.Through normalization and analysis of the spectra,it is shown that(1) the four methods are able to measure optical absorption spectra of particulate and/or dissolved pigments;(2)that the optical absorption spectra of particulate and dissolved pigments were consistent in terms of the peak position in the blue wavelength,and the difference of the peak position in the near infrared wavelength was ~10nm between each other;and(3)that the leveling effect of the absorption spectra of particulate pigments was significant.These four methods can all effectively measure the absorption coefficients of phytoplankton pigments,while each one has its unique advantages in different applications.Therefore,appropriate method should be carefully selected for various application due to their intrinsic difference.展开更多
文摘Photocatalytic reduction method using TiO2 suspension for removal as well as possibly recovery of silver （Ag（I）） in the presence of Cu（II） is examined. The photocatalytic reduction was performed by batch technique in a closed reactor equipped with UV lamp. The concentration of unreduced Ag（I） was analyzed by atomic absorption spectrophotometry method. The research results indicate that Ag（I） in the solution can be removed and recovered effectively as silver metal Ag（0） deposited on the surface of TiO2 for photocatalytic reduction. In addition, the presence of Cu（II） ion with increasing concentration leads to a proportional decline in Ag（I） photoreduction due to the prominent competition in the adsorption on the surface of TiO2. The effectiveness of Ag（I） ion photoreduction in the presence of Cu（II） ion is strongly influenced by solution pH and the highest photoreduction is obtained at pH 5 - 8, which is related with the speciation ofAg（I）, TiO2 surface as well as Cu（II） in the solution.
基金Supported by the National Natural Science Foundation of China(No.41276184)the Key Laboratory of Marine Remote Sensing and Acoustics(Nanjing University of Information Science and Technology),Jiangsu Province,China(No.KHYS1404)
文摘Two methods for particulate pigments(i.e.,quantitative filter technique,QFT,and in vivo measurement,InVivo,respectively)and two methods for dissolved pigments(i.e.,Acetone Extracts,AceEx,and high-performance liquid chromatography,HPLC,respectively) were used to obtain the optical absorption coefficient spectra for cultures of four typical algal species.Through normalization and analysis of the spectra,it is shown that(1) the four methods are able to measure optical absorption spectra of particulate and/or dissolved pigments;(2)that the optical absorption spectra of particulate and dissolved pigments were consistent in terms of the peak position in the blue wavelength,and the difference of the peak position in the near infrared wavelength was ~10nm between each other;and(3)that the leveling effect of the absorption spectra of particulate pigments was significant.These four methods can all effectively measure the absorption coefficients of phytoplankton pigments,while each one has its unique advantages in different applications.Therefore,appropriate method should be carefully selected for various application due to their intrinsic difference.
