The melting characteristics and wettability of the binding phase in high basicity sinter were studied. By changing nCaO∶nFe2O3 （molar ratio of CaO to Fe2O3） as well as the percentage of MgO,SiO2,and Al2O3,the melti...The melting characteristics and wettability of the binding phase in high basicity sinter were studied. By changing nCaO∶nFe2O3 （molar ratio of CaO to Fe2O3） as well as the percentage of MgO,SiO2,and Al2O3,the melting characteristics and wettability of the binding phase were discussed. The results indicated that the characteristic melting temperature was the lowest and wettability was the best at nCaO∶nFe2O3=1∶1 （without addition）; the addition of MgO increased the characteristic melting temperature and contact angles; when the percentage of SiO2 or Al2O3 was 3%,the characteristic melting temperature was the lowest,whereas the contact angles increased with an increase in SiO2 and Al2O3 contents.展开更多
The unexpected emergent discharge of high- arsenic wastewater into water environments results in significantly increased levels of arsenic in water; however, the species distribution of arsenic in sediments has never ...The unexpected emergent discharge of high- arsenic wastewater into water environments results in significantly increased levels of arsenic in water; however, the species distribution of arsenic in sediments has never been reported before for such cases. This study focuses on an As pollution accident in the Dasha River, and uses sequential extraction procedures with deionized water, l mol-L-1 MgC12 at pH = 8, 1 mol.L-1 NaH2PO4 at pH = 5, and 1 mol. L-1 HC1 to investigate four binding phases of arsenic （i.e., water soluble, ion-exchangeable, strongly- bound, and precipitates） in sediments at different layers in different cross-sections along the fiver. The average ratio of arsenite （As（III）） to arsenate （As（V）） was found to decrease from 0.74：1 in fiver water to 0.48：1 in sediment, owing to its higher affinity toward As（V） than As（III）. The content of arsenic in the sediments was relatively low and the maximum content was observed to be 36.3 mg-kg1 for As（IID and 97.5 mg.kg1 for As（V）. As（III） and As（V） showed different binding phases in sediments, and the average fractions of these four species were determined to be 0.09, 0.11, 0.17, and 0.63 for As（III） and 0.03, 0.14, 0.63, and 0.20 for As（V）, respectively. For all the sediment samples, the content of arsenic showed no relationship with the characteristics of the sediments such as the particle diameter, the content of organic carbon, Fe, and Mn, although a negative correlation with particle diameter was observed for the sediments in the uppermost 2-cm layer. The unexpected emergent As incident results in the high content of total arsenic in the surface sediment, which may be potential secondary source to the elevated As levels in surface water.展开更多
基金Sponsored by National Natural Science Foundation of China (50474014)
文摘The melting characteristics and wettability of the binding phase in high basicity sinter were studied. By changing nCaO∶nFe2O3 （molar ratio of CaO to Fe2O3） as well as the percentage of MgO,SiO2,and Al2O3,the melting characteristics and wettability of the binding phase were discussed. The results indicated that the characteristic melting temperature was the lowest and wettability was the best at nCaO∶nFe2O3=1∶1 （without addition）; the addition of MgO increased the characteristic melting temperature and contact angles; when the percentage of SiO2 or Al2O3 was 3%,the characteristic melting temperature was the lowest,whereas the contact angles increased with an increase in SiO2 and Al2O3 contents.
文摘The unexpected emergent discharge of high- arsenic wastewater into water environments results in significantly increased levels of arsenic in water; however, the species distribution of arsenic in sediments has never been reported before for such cases. This study focuses on an As pollution accident in the Dasha River, and uses sequential extraction procedures with deionized water, l mol-L-1 MgC12 at pH = 8, 1 mol.L-1 NaH2PO4 at pH = 5, and 1 mol. L-1 HC1 to investigate four binding phases of arsenic （i.e., water soluble, ion-exchangeable, strongly- bound, and precipitates） in sediments at different layers in different cross-sections along the fiver. The average ratio of arsenite （As（III）） to arsenate （As（V）） was found to decrease from 0.74：1 in fiver water to 0.48：1 in sediment, owing to its higher affinity toward As（V） than As（III）. The content of arsenic in the sediments was relatively low and the maximum content was observed to be 36.3 mg-kg1 for As（IID and 97.5 mg.kg1 for As（V）. As（III） and As（V） showed different binding phases in sediments, and the average fractions of these four species were determined to be 0.09, 0.11, 0.17, and 0.63 for As（III） and 0.03, 0.14, 0.63, and 0.20 for As（V）, respectively. For all the sediment samples, the content of arsenic showed no relationship with the characteristics of the sediments such as the particle diameter, the content of organic carbon, Fe, and Mn, although a negative correlation with particle diameter was observed for the sediments in the uppermost 2-cm layer. The unexpected emergent As incident results in the high content of total arsenic in the surface sediment, which may be potential secondary source to the elevated As levels in surface water.
