Pure nano-All3 and aggregates at various concentrations were prepared to examine the particle size effect of coagulation with inorganic polymer flocculant. The property and stability of various species formed were cha...Pure nano-All3 and aggregates at various concentrations were prepared to examine the particle size effect of coagulation with inorganic polymer flocculant. The property and stability of various species formed were characterized using Infrared, 27Al-NMR, photo correlation spectroscopy （PCS）, and Ferron assay. Results showed that concentration and temperature exhibited different roles on the stability of Al13. The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1-2 nm by PCS. Al13 solutions at high concentrations （0.5-2.11 tool/L） were observed to undergo further aggregation with aging. The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the eTA1-NMR spectrum, whereas a part of Al13 would still remain as Alb. At low concentrations, All3 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90~C.展开更多
In spite of increasing attention on Chinese aerosol, there has never been a country-wide survey of its general characteristics. This paper presents elemental data for aerosol at 23 sites in and around China, mostly dr...In spite of increasing attention on Chinese aerosol, there has never been a country-wide survey of its general characteristics. This paper presents elemental data for aerosol at 23 sites in and around China, mostly drawn from the literature, and shows some of the large-scale patterns. Al, Na, and Se are used to represent the crustal, marine, and pollution components, respectively. Most of the patterns are aligned in SW-NE. Al and Na are highest to the NW and the SE, respectively, and their ratio changes rapidly near the coast. Se has a broad maximum over Central China, and the Se/Al ratio （an indicator of pollution vs. crustal aerosol） increases progressively from the NW to the SE. A simple index for simulating pollution aerosol, which uses population density, annual precipitation, and mean wind speed, adequately reproduces the large-scale pattern of pollution aerosol and shows how crustal Al in the NW gradually gives way to flyash Al toward the SE.展开更多
基金supported by the National Natural Science Foundation of China (No. 51025830, 50921064)the National Hi-Tech Research and Development Program(863) of China (No. 2008AA06A414)
文摘Pure nano-All3 and aggregates at various concentrations were prepared to examine the particle size effect of coagulation with inorganic polymer flocculant. The property and stability of various species formed were characterized using Infrared, 27Al-NMR, photo correlation spectroscopy （PCS）, and Ferron assay. Results showed that concentration and temperature exhibited different roles on the stability of Al13. The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1-2 nm by PCS. Al13 solutions at high concentrations （0.5-2.11 tool/L） were observed to undergo further aggregation with aging. The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the eTA1-NMR spectrum, whereas a part of Al13 would still remain as Alb. At low concentrations, All3 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90~C.
基金the National Natural Science Foundation of China （Grant Nos. 29837190, 20077004, and 30230310）.
文摘In spite of increasing attention on Chinese aerosol, there has never been a country-wide survey of its general characteristics. This paper presents elemental data for aerosol at 23 sites in and around China, mostly drawn from the literature, and shows some of the large-scale patterns. Al, Na, and Se are used to represent the crustal, marine, and pollution components, respectively. Most of the patterns are aligned in SW-NE. Al and Na are highest to the NW and the SE, respectively, and their ratio changes rapidly near the coast. Se has a broad maximum over Central China, and the Se/Al ratio （an indicator of pollution vs. crustal aerosol） increases progressively from the NW to the SE. A simple index for simulating pollution aerosol, which uses population density, annual precipitation, and mean wind speed, adequately reproduces the large-scale pattern of pollution aerosol and shows how crustal Al in the NW gradually gives way to flyash Al toward the SE.
