Chemical precipitation to form magnesium ammonium phosphate（MAP） is an effective technology for recovering ammonium nitrogen（NH4＋-N）.In the present research,we investigated the thermodynamic modeling of the PHREE...Chemical precipitation to form magnesium ammonium phosphate（MAP） is an effective technology for recovering ammonium nitrogen（NH4＋-N）.In the present research,we investigated the thermodynamic modeling of the PHREEQC program for NH4＋-N recovery to evaluate the effect of reaction factors on MAP precipitation.The case study of NH4＋-N recovery from coking wastewater was conducted to provide a comparison.Response surface methodology（RSM） was applied to assist in understanding the relative significance of reaction factors and the interactive effects of solution conditions.Thermodynamic modeling indicated that the saturation index（SI） of MAP followed a polynomial function of pH.The SI of MAP increased logarithmically with the Mg2＋/NH4＋ molar ratio（Mg/N） and the initial NH4＋-N concentration（CN）,respectively,while it decreased with an increase in Ca2＋/NH4＋ and CO32？/NH4＋ molar ratios（Ca/N and CO32？/N）,respectively.The trends for NH4＋-N removal at different pH and Mg/N levels were similar to the thermodynamic modeling predictions.The RSM analysis indicated that the factors including pH,Mg/N,CN,Ca/N,（Mg/N）×（CO32？/N）,（pH）2,（Mg/N）2,and（CN）2 were significant.Response surface plots were useful for understanding the interaction effects on NH4＋-N recovery.展开更多
The magnetic and structural properties of 2% Ni-doped ZnO powers prepared by sol-gel method were studied. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) of the sample do not show ...The magnetic and structural properties of 2% Ni-doped ZnO powers prepared by sol-gel method were studied. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) of the sample do not show existence of any signal of second phase. The X-photoelectron spectroscopy (XPS) of the sample shows the chemical valence of Ni is +2 and the real Ni concentration is 2.19% determined by X-ray fluorescence spectra (XRFS). The magnetic property performed with superconducting quantum interference device (SQUID) shows that the sample exhibits ferromagnetism above room temperature and the Curie temperature (TC) is about 600 K.展开更多
There exists an E-W trending Middle Jurassic volcanic zone in southern China.The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example.The Fankeng basalts have TiO2 contents i...There exists an E-W trending Middle Jurassic volcanic zone in southern China.The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example.The Fankeng basalts have TiO2 contents in the range of 1.92%-3.21%.They are classified as high-Ti basalts.They also have higher total Fe(averaging FeO*=11.09%).The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cre-taceous basalts from southeastern coast of China.They have higher HFSE,such as Th,Nb,Ta,Zr and Ti.Their element ratios related with HFSE,such as Zr/Ba,La/Nb,La/Ta,Zr/Y,Ti/Y,Ba/Nb,K/Ti and Rb/Zr are similar to those of OIB.The most samples haveεNd(T)of-0.70-0.24,which are near chondrite.Some samples have higherεNd(T)of 1.87-3.55.Therefore,these basaltic magmas might be derived from depleted asthenospheric mantle.The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time.The(Early-)Middle Jurassic basalts and gabbros from southeastern Hunan,southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian.Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time.Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.展开更多
The Xihuashan granite, famous for the production of large tungsten mine, liesabout 8 km to the northwest of Dayu County, Jiangxi Province. The emergencearea of the granite is about 20 km^2. It is intruded as a stock i...The Xihuashan granite, famous for the production of large tungsten mine, liesabout 8 km to the northwest of Dayu County, Jiangxi Province. The emergencearea of the granite is about 20 km^2. It is intruded as a stock into the展开更多
基金supported by the National High Technology Research and Development Program(863) of China(No.2009AA033003)the National Water Pollution Control and Management Science and Technology Breakthrough Program(No.2009ZX07106-004)+2 种基金the Scientific Research Foundation of Graduate School of Jiangsu Province(No.CX09B 013Z)the Key Technology Research and Development Program of Jiangsu Province (No.BE2008668)the Ph.D Candidate Academic Foundation of Ministry of Education of China
文摘Chemical precipitation to form magnesium ammonium phosphate（MAP） is an effective technology for recovering ammonium nitrogen（NH4＋-N）.In the present research,we investigated the thermodynamic modeling of the PHREEQC program for NH4＋-N recovery to evaluate the effect of reaction factors on MAP precipitation.The case study of NH4＋-N recovery from coking wastewater was conducted to provide a comparison.Response surface methodology（RSM） was applied to assist in understanding the relative significance of reaction factors and the interactive effects of solution conditions.Thermodynamic modeling indicated that the saturation index（SI） of MAP followed a polynomial function of pH.The SI of MAP increased logarithmically with the Mg2＋/NH4＋ molar ratio（Mg/N） and the initial NH4＋-N concentration（CN）,respectively,while it decreased with an increase in Ca2＋/NH4＋ and CO32？/NH4＋ molar ratios（Ca/N and CO32？/N）,respectively.The trends for NH4＋-N removal at different pH and Mg/N levels were similar to the thermodynamic modeling predictions.The RSM analysis indicated that the factors including pH,Mg/N,CN,Ca/N,（Mg/N）×（CO32？/N）,（pH）2,（Mg/N）2,and（CN）2 were significant.Response surface plots were useful for understanding the interaction effects on NH4＋-N recovery.
基金Project supported by the Special Fund for Major State Basic Research Project (G2000068305), the Hi-Tech Research Project (2004AA31G050), and the National Natural Science Foundation of China (60390072)
文摘The magnetic and structural properties of 2% Ni-doped ZnO powers prepared by sol-gel method were studied. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) of the sample do not show existence of any signal of second phase. The X-photoelectron spectroscopy (XPS) of the sample shows the chemical valence of Ni is +2 and the real Ni concentration is 2.19% determined by X-ray fluorescence spectra (XRFS). The magnetic property performed with superconducting quantum interference device (SQUID) shows that the sample exhibits ferromagnetism above room temperature and the Curie temperature (TC) is about 600 K.
基金This research was supported by the National Natural Science Foundation of China(Grant Nos.40273017and 40221301)the State Key Laboratory of Mineral Deposit Research,Nanjing University.
文摘There exists an E-W trending Middle Jurassic volcanic zone in southern China.The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example.The Fankeng basalts have TiO2 contents in the range of 1.92%-3.21%.They are classified as high-Ti basalts.They also have higher total Fe(averaging FeO*=11.09%).The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cre-taceous basalts from southeastern coast of China.They have higher HFSE,such as Th,Nb,Ta,Zr and Ti.Their element ratios related with HFSE,such as Zr/Ba,La/Nb,La/Ta,Zr/Y,Ti/Y,Ba/Nb,K/Ti and Rb/Zr are similar to those of OIB.The most samples haveεNd(T)of-0.70-0.24,which are near chondrite.Some samples have higherεNd(T)of 1.87-3.55.Therefore,these basaltic magmas might be derived from depleted asthenospheric mantle.The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time.The(Early-)Middle Jurassic basalts and gabbros from southeastern Hunan,southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian.Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time.Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.
基金Project supported by the National Natural Science Foundation of China, and Doctor Subject Foundation of National Education Commission.
文摘The Xihuashan granite, famous for the production of large tungsten mine, liesabout 8 km to the northwest of Dayu County, Jiangxi Province. The emergencearea of the granite is about 20 km^2. It is intruded as a stock into the
