Weathering of phosphorus-bearing mineral powder and calcium phosphate by Aspergillus niger  

作　　者：QIU Shuangshuang LIAN Bin 

机构地区：[1]State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,China [2]Graduate University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Journal Of Geochemistry》2012年第4期390-397,共8页中国地球化学学报

基　　金：the National Natural Science Foundation of China for Creative Research Groups (Grant No. 41021062);the "Hundred Talents" Program of the Chinese Academy of Sciences for their financial support

摘　　要：The weathering of phosphorus-bearing mineral powder(PBMP) and calcium phosphate(CP) by Aspergillus niger was compared,and the mechanism involved was analyzed for the comprehensive utilization of PBMP.The concentration of water-soluble phosphorus(WSP),Mg2+,and Ca2+at different culture times,microstructures of particles,and mineral compositions was examined by ultraviolet-visible spectrometer(UV),atomic absorption spectrometry(AAS),scanning electron microscopy(SEM),and X-ray diffraction(XRD).Results showed that the change in the concentrations of WSP,Mg2+,and Ca2+were related to the growth of A.niger and the different mineral compositions.Compared with CP,PBMP was weathered harder by fungi.Traces of the weathered mineral were found through SEM.CP not only showed traces of erosion damage but also appeared as a rhombohedron-like substance.The XRD test indicated that the weathering minerals can form water calcium oxalate.Further analysis revealed that the mechanism of PBMP and CP weathering by A.niger was the collaborative result of mycelium biomechanical effects and the acid-soluble role of acidic metabolites.The phosphorus dissolution rate of PBMP after 20 d was 46.83%,whereas that of CP after 12 d was 91.01%.The findings of this study are significant to the effective use of waste PBMP and to the exploitation of low-grade phosphate rock resources.The weathering of phosphorus-bearing mineral powder （PBMP） and calcium phosphate （CP） by Asper- gillus niger was compared, and the mechanism involved was analyzed for the comprehensive utilization of PBMP. The concentration of water-soluble phosphorus （WSP）, Mg2＋, and Ca2＋ at different culture times, microstructures of particles, and mineral compositions was examined by ultraviolet-visible spectrometer （UV）, atomic absorption spec- trometry （AAS）, scanning electron microscopy （SEM）, and X-ray diffraction （XRD）. Results showed that the change in the concentrations of WSP, Mg2＋, and Ca2＋ were related to the growth of A. niger and the different mineral com- positions. Compared with CP, PBMP was weathered harder by fungi. Traces of the weathered mineral were found through SEM. CP not only showed traces of erosion damage but also appeared as a rhombohedron-like substance. The XRD test indicated that the weathering minerals can form water calcium oxalate. Further analysis revealed that the mechanism of PBMP and CP weathering by A. niger was the collaborative result of mycelium biomechanical effects and the acid-soluble role of acidic metabolites. The phosphorus dissolution rate of PBMP after 20 d was 46.83%, whereas that of CP after 12 d was 91.01%. The findings of this study are significant to the effective use of waste PBMP and to the exploitation of low-grade phosphate rock resources.

关 键 词：磷酸钙 磷矿物 黑曲霉 紫外可见分光光度计 原子吸收光谱仪 XRD测试 老化 X-射线衍射 

分 类 号：TQ132.32[化学工程—无机化工] TQ442