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1.
氧化硫硫杆菌的培养特性及低品位磷矿浸出   总被引:3,自引:0,他引:3  
从安徽某煤矿的酸性矿坑水中分离出能有效浸出低品位磷矿的氧化硫硫杆菌菌株,对其形态特征和培养特性进行了初步的研究,并通过研究不同固体培养基成分对氧化硫硫杆菌分离纯化的影响,确定了适宜的分离条件:采用双层平板,即上层为涂布氧化硫硫杆菌的Starkey固体培养基平板,下层为涂布异养菌(红酵母菌)的琼脂平板,可显著提高菌落密度并缩短检出时间。考查了培养基、表面活性剂等因素对所选育的氧化硫硫杆菌的浸磷效果的影响,通过初步试验浸磷率可达到48.41%。  相似文献   

2.
The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can release H+ and concentrate Fe3+; Fe2+ is movable between agar-simulated EPS phase and bulk solution phase, but it is difficult for Fe3+ to move due to its hydroxylation and EPS complex action; A. ferrooxidans first prefer Fe2+ as energy to metabolize compared with chalcopyrite, and a suitable ...  相似文献   

3.
Elective culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in 9K medium modified with pyrrhotite was studied. Bioleaching of flotation concentrate of sphalerite by the selected bacteria was carried out. The results show that the microorganisms cultured by pyrrhotite are a mixture of Acidithiobacillusferrooxidans and Acidithiobacillus thiooxidans, of which the capability to oxidize ferrous to ferric irons is enhanced by the high mass ratio of Fe to S in pyrrhotite. Three pyrrhotite samples were separated into various parts with corresponding S/Fe ratios by magnetic separation and were used to culture the elective bacteria as the substrate. The association of the cultures could provide a more rapid and complete oxidation of sphalerite than that of bacteria cultivated by conventional methods.  相似文献   

4.
采用固体培养基贴片法研究了镁合金的微生物腐蚀行为。利用扫描电镜(SEM)、极化曲线研究了AZ91镁合金在无菌和有硫酸盐还原菌体系中的腐蚀行为。通过形貌对比及电化学分析发现,硫酸盐还原菌加速了镁合金的腐蚀。细菌影响下的腐蚀形貌的主要特征是点蚀。细菌的代谢过程所导致的电极的阴极去极化加速了镁合金的点蚀的形成和发展。  相似文献   

5.
A heterotrophic acidothermophilic bacterial strain, YNTC-1, was isolated from an acidic hot spring in Tengchong, Yunan, China. YNTC-1 grows at pH value of 1.5-8.0 and temperature of 40-70 ℃, with optimal pH and temperature at 3.0 and 55 ℃, respectively. The cells of the strain are in shape of short rod, with 1.0-1.2 μm in length and 0.7-0.8 μm in diameter, and with distinct spores at both poles of each cell. The predominant fatty acids in cellular membrane of the strain are C18:1 ω7c. 16s rRNA gene analysis reveals that this strain is closely related to Alicyclobacillus sendaiensis, with over 99% sequence similarity. Based on phenotypic and genotypic analyses, YNTC-1 is identified as a member ofA. sendaiensis. Considering some important morphological and biochemical differences between strain YNTC-1 and A. sendaiensis ATCC 27009T, YNTC-1 may be proposed to be a novel subspecies of A. sendaiensis. However, this viewpoint has to be confirmed by further studies. Co-bioleaching of pyrite and chalcopyrite with strain YN22, Sulfobacillus thermosulfidooxidans, shows that strain YNTC-1 has no evident influence on bioleaching rates of these two sulphide minerals.  相似文献   

6.
The experimental die apparatus of the solid granules medium forming on sheet metal was designed and manufactured.Typical parts,such as conical,parabolic,cylindrical and square-box-shaped components,were successfully trial-produced as well.According to the analysis of the changing trends of the cross-section shape and the wall thickness during the process,it can be found that the shape of the free deformation zone of the sheet metal,which is the most critical thinning area,can be described as an approximately spherical cap.According to this forming feature,back pressure deep drawing technology with solid granules medium on sheet metal was proposed to restrain drastic thinning at the bottom of the part through the joint friction effect of solid granules medium,the back pressure tringle and the sheet metal.Therefore,the deep drawing limit of the sheet metal is significantly improved.In order to fabricate thin-walled rotary parts with great drawing ratio and complex cross-sections,a finite element model based on the material property test of the solid granules medium was established to optimize the scheme of the back pressure deep drawing.The effects on the forming performance of sheet metal from back pressure load and the approach of blank holding control were analyzed through this model.  相似文献   

7.
蛹虫草胞外多糖的提取和纯化   总被引:12,自引:0,他引:12  
对蛹虫草液体深层发酵液的胞外多糖提取进行研究,确定了提取的工艺条件,并对所提取的粗多糖进行分子筛分,对主要多糖组分的糖成分进行测定。其结果为:蛹虫草液体深层发液的胞外粗多糖的提取率为10.0g/L;其粗多糖主要由4种蛹虫草多糖组成;而第4个组分占总粗多糖的32.14%,由葡萄糖构成。  相似文献   

8.
采用酶解结合醇沉法从新鲜牡蛎中提取制备牡蛎糖原(oyster glycogen,OG),经阴离子交换柱DEAE-52、葡聚糖凝胶柱Sephadex G-100分离纯化,得到纯度较高的牡蛎糖原组分OG11。其蛋白质量分数为0.33%,糖质量分数为97.77%。用气相色谱法对OG11进行单糖组成鉴定,结果表明其中只含有葡萄糖。补体实验表明,OG11对补体具有较强的抑制活性,在5.0mg/mL时补体抑制率可达到77.38%。  相似文献   

9.
10.
对白云鄂博中贫氧化矿进行了高梯度磁选试验,着重研究了磁感应强度、矿浆流速对磁选指标的影响.采用粗选(B=0.6T)-精选(B=0.15T)工艺,在矿浆流速5.6cm/s、矿浆浓度20%的条件下,选出的铁精矿品位为60.0%。回收率达到79.5%.  相似文献   

11.
分离苏云金芽孢杆菌(Bt)晶体蛋白常用的方法有液体双相法、密度梯度法、沉淀法、生物-物理分离法等,但这几种方法各有优缺点。从分离成本、仪器设备、纯度、产量、活性等方面考虑,在超声波处理、悬液制备和紫外线辐射3个方面进行了改进,提出了一种新的分离Bt晶体蛋白的方法,产品纯度可达90%以上,产率从原来的20%提高到28%。本方法成本低,产率高,操作简单,具有很强的实用价值。  相似文献   

12.
The highly-efficient dry separation technique using a gas-solid fluidized bed is very beneficial for increasing coal grade and optimizing the utilization of coal resources.The size distribution of the solid medium(e.g.,magnetite powder)used in this technique is one of key factors that influences fluidization and separation performance.It is,therefore,urgent to prepare medium in a way that operates at low cost and high efficiency.Grinding experiments were performed using a planetary ball mill equipped with a frequency convener.The effect of fed mass,rotation frequency of the mill,grinding time and the ball-size ratio on grinding performance was investigated.The grinding parameters were optimized by numerical calculations using Artificial Neural Network(ANN)in Matlab.A regression equation for predicting the yield of the desired product(i.e.,0.3~0.15 mm magnetite powder)is proposed.The maximum yield of 0.3~0.15 mm panicles was 47.24%.This lays a foundation for the industrial-scale production of the solid medium required for separation with a magnetite-powder fluidized bed.  相似文献   

13.
Elective culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in 9K medium modified with pyrrhotite was studied. Bioleaching of flotation concentrate of sphalerite by the selected bacteria was carried out. The results show that the microorganisms cultured by pyrrhotite are a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, of which the capability to oxidize ferrous to ferric irons is enhanced by the high mass ratio of Fe to S in pyrrhotite. Three pyrrhotite samples were separated into various parts with corresponding S/Fe ratios by magnetic separation and were used to culture the elective bacteria as the substrate. The association of the cultures could provide a more rapid and complete oxidation of sphalerite than that of bacteria cultivated by conventional methods.  相似文献   

14.
将固相萃取技术应用于分离纯化蔬菜中植物生长调节剂赤霉素GA3,结合液液萃取技术,该纯化方法能大部分的除去干扰GA3测定的物质,并且对GA3有很高的回收率,是一种非常有效的GA3分离纯化方法.  相似文献   

15.
The formation of jarosite in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans) was researched to ascertain the conditions of producing minimum precipitation. The effects of salt concentration and pH on the characteristics of jarosite formed in K2SO4/(NH4)2SO4-FeSO4 inorganic salt solution and 9K medium were studied by using the measurements of scanning electron microscope, X-ray diffraction, Fourierism transform infrared analysis, thermogravity/differential thermogravity analysis and particle size analysis to evaluate the product. The results indicate that the formation of jarosite begins when A. ferrooxidans reaches logarithmic growth phase in 9K medium, and a higher pH value is beneficial to the formation of jarosite. The jarosite formed in 9K medium has smaller and more concentrative particle size and smoother surface than that formed in inorganic salt solution.  相似文献   

16.
A facultative heterotrophic strain (DS-0205) was isolated from a deep-sea sediment sample collected at a depth of 5.2 km in the eastern Pacific Ocean, China. Strain DS-0205 is motile helmet-like single cell or pairs, forming hemisphere with the center sunken of variable size. It has a widespread carbon source and nitrogen source, including agarose, citric acid, salicin, D-glucitol nitrate, sodium nitrite and ethylamine. It can grow in the following environment: temperature 4–37 °C, pH 2.0–12.0, tolerance to NaCl⩽15%. Two phylogenetic trees, one based on the ITS and 5.8S rRNA sequences and the other based on the 18S rRNA sequences, unite strain DS-0205(=JCM 0205) to the type strain of Rhodosporidium diobovatum JCM 3787 through a considerable evolutionary distance. These results suggest that strain DS-0205 is a new strain of the Rhodosporidium diobovatum.  相似文献   

17.
固相萃取-分光光度法测定痕量苯酚   总被引:2,自引:0,他引:2  
在pH9.8的NH3-NH4Cl缓冲溶液中,苯酚与4-氨基安替比林和铁氰化钾反应生成红色的显色产物,该显色产物用Water Sep Park-C18固相萃取小柱萃取富集,乙醇洗脱后用分光光度测定。方法的测定范围为0.05-1.2mg/L.方法用于水中痕量苯酚的测定.结果满意。  相似文献   

18.
制备了ZrO2/SO42-型固体超强酸催化剂,在该固体超强酸的催化作用下,由乳酸和异戊醇合成了乳酸异戊酯。探讨了焙烧温度、催化剂用量、反应时间和试剂摩尔比的影响,利用IR、质谱分析表征了乳酸异戊酯的结构。  相似文献   

19.
由无定型和结晶态双酚A型聚碳酸酯(BAPC)预聚体分别固相缩聚合成高分子量BAPC,考察了缩聚时间、Nz吹扫流量、缩聚温度对产物分子量的影响.用凝胶渗透色谱(GPC)、红外光谱(FT~IR)、扫描电镜(SEM)、差示扫描量热法(DSC)表征了产物的结构和性质.结果表明反应温度为200℃,N:流速为1.5L/min,反应时间为9h时,产物的数均分子量可达71163g/mol,分子量分布指数为1.37.  相似文献   

20.
采用污泥过滤进行固液分离的试验研究   总被引:2,自引:0,他引:2  
通过水处理中慢滤池和滤饼过滤原理的借鉴,将生物滤池引入生物膜反应器,利用游离的活性污泥和部分脱落的生物膜及颗粒滤料组成污泥过滤层进行过滤出水以提高出水水质.分析了污泥滤层的过滤机理及主要影响因素,并研究了在不同污泥质量浓度、不同滤料和不同滤速下水头损失和浊度的变化情况.试验结果表明,在滤料粒径为1.0~1.6mm,滤速范围为0.3~1.0m/h,污泥质量浓度不大于1200mg/L情况下,出水浊度值均在10NTU以下,反冲洗周期长(较曝气生物滤池),证明了污泥过滤是可行的.  相似文献   

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