Understanding the effects of organic acids （OA） on the transformation of Fe and Mn to surface water from the weathering coal gangue is of great benefit to risk assessment and remediation strategies for contaminated ...Understanding the effects of organic acids （OA） on the transformation of Fe and Mn to surface water from the weathering coal gangue is of great benefit to risk assessment and remediation strategies for contaminated water and soil. Based on the investigation on surface water in the central coal districts of the Guizhou Province, 18 water samples were collected for heavy metal analysis. The results indicated that the pH value of surface water is low （3.11-4.92）, and Fe concentration （1.31-5.55 mg L-1） and Mn concentration （1.90-5.71 mg L^-1） were, on average, 10.86 and 34.33 times the limit of Surface Water Quality Standards, respectively. In order to evaluate the effects of the OA on the dissolution of Fe and Mn from the weath- ering coal gangue, column elution and batch leaching experiments were conducted. The results show that the low molecular weight of organic acids （LMWOAs, i.e., oxalic, tartaric, malic and citric acids） and fulvic acids signifi- cantly accelerated the dissolution of Fe and Mn; in addi- tion, when the concentration of OA reached 25 mmol L-1, the concentrations of Fe, and Mn were 1.14-67.08 and 1.11-2.32 times as high as those in 0.5 mmol L-1OA, respectively. Furthermore, the migration of Fe and Mn was significantly influenced by the pH and Eh, especially for Fe; the ion Mn was dissolved from the gangue more easily than the ion Fe in the column leaching, which was contrary to the results of batch leaching.展开更多
Deliquescence and efflorescence are the two most important physicochemical processes of aerosol particles. In deliquescence and efflorescence cycles of aerosol particles, many fundamental problems need to be investiga...Deliquescence and efflorescence are the two most important physicochemical processes of aerosol particles. In deliquescence and efflorescence cycles of aerosol particles, many fundamental problems need to be investigated in detail on the molecular level, including ion and molecule interactions in supersaturated aerosols, metastable solid phases that may be formed, and microscopic structures and deliquescence mechanisms of aerosol particles. This paper presents a summary of the progress made in recent investigations of deliquescence and efflorescence processes of aerosol particles by four common spectral techniques, which are known as Raman/electrodynamic balance, Fourier transform infrared/aerosol flow tube, Fourier transform infrared/attenuated total reftection, and confocal Raman on a quartz substrate.展开更多
基金sponsored by The Innovative Talent Team Construction Project for Science and Technology of Guizhou Province (Project Number [2012]4005)
文摘Understanding the effects of organic acids （OA） on the transformation of Fe and Mn to surface water from the weathering coal gangue is of great benefit to risk assessment and remediation strategies for contaminated water and soil. Based on the investigation on surface water in the central coal districts of the Guizhou Province, 18 water samples were collected for heavy metal analysis. The results indicated that the pH value of surface water is low （3.11-4.92）, and Fe concentration （1.31-5.55 mg L-1） and Mn concentration （1.90-5.71 mg L^-1） were, on average, 10.86 and 34.33 times the limit of Surface Water Quality Standards, respectively. In order to evaluate the effects of the OA on the dissolution of Fe and Mn from the weath- ering coal gangue, column elution and batch leaching experiments were conducted. The results show that the low molecular weight of organic acids （LMWOAs, i.e., oxalic, tartaric, malic and citric acids） and fulvic acids signifi- cantly accelerated the dissolution of Fe and Mn; in addi- tion, when the concentration of OA reached 25 mmol L-1, the concentrations of Fe, and Mn were 1.14-67.08 and 1.11-2.32 times as high as those in 0.5 mmol L-1OA, respectively. Furthermore, the migration of Fe and Mn was significantly influenced by the pH and Eh, especially for Fe; the ion Mn was dissolved from the gangue more easily than the ion Fe in the column leaching, which was contrary to the results of batch leaching.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20073004, No.20473012, No.20673010, and No.20640420450）, the 111 Project B07012, and the China Postdoctoral Science Foundation （No.20070410466）. The Trans-Century Training Program Foundation for the Talents by the Ministry of Education of China was also gratefully acknowledged.
文摘Deliquescence and efflorescence are the two most important physicochemical processes of aerosol particles. In deliquescence and efflorescence cycles of aerosol particles, many fundamental problems need to be investigated in detail on the molecular level, including ion and molecule interactions in supersaturated aerosols, metastable solid phases that may be formed, and microscopic structures and deliquescence mechanisms of aerosol particles. This paper presents a summary of the progress made in recent investigations of deliquescence and efflorescence processes of aerosol particles by four common spectral techniques, which are known as Raman/electrodynamic balance, Fourier transform infrared/aerosol flow tube, Fourier transform infrared/attenuated total reftection, and confocal Raman on a quartz substrate.
