Anodic behavior and microstructure of Al/Pb-Ag-Co anode during zinc electrowinning简

In order to study the anodic behavior and microstmctures of A1/Pb-Ag-Co anode during zinc electrowinning, by means of potentiodynamic investigations, scanning electron microscopy （SEM） and X-ray diffraction （XRD） analyses, the mechanism of the anodic processes playing on the surface of A1/Pb-0.8%Ag and A1/Pb-0.75%Ag-0.03%Co anodes prepared by electro-deposition from methyl sulfonic acid bath for zinc electrowinning from model sulphate electrolytes have been measured. On the basis of the cyclic voltammograms obtained, information about the corrosion rate of the composite in PbO2 region has been concluded. The microstructures were also observed by means of SEM and XRD which showed Pb-0.75%Ag-0.03%Co alloy composite coating has uniform and chaotic orientation tetragonal symmetry crystallites of PbSO4, but Pb-0.8%Ag alloy composite coating has well-organized orientation crystallites of PbSO4 concentrated in the certain zones after 24 h of anodic polarization. It is important that Al/Pb-0.75%Ag-0.03%Co anode oxide film consists of non-conductive dense MnO2 and PbSO4 and a, fl-PbO2 penetrated into which, in fact, are the active centers of the oxygen evolution after 24 h of anodic polarization.     

Dye removal using some surface modi?ed silicate minerals简

The objective of this work is to study the efficiency of some surface modified phyllosilicate minerals (bentonite and glauconite) in the removal of dyes from textile waste water. It is found that complete dye removal was achieved by using 10–25 g modified glauconite from solutions having a dye concentration of 10–50 mg/L. Adsorption data were modeled using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. Adsorption capacities and optimum adsorption isotherms were predicted by linear regression method. The analysis of experimental isotherms showed that Langmuir isotherm reasonably fit the experimental data in the studied concentration range for the adsorption of dye onto glauconite mineral surface where Freundlich isotherm fit the experimental data for the adsorption of dye onto bentonite mineral surface.     

Corrosion detection of tinplate cans containing coffee using EIS/EN sensor简

The corrosion behavior of tinplate cans containing coffee was investigated using novel electrochemical impedance spectroscopy （EIS） and electrochemical noise （EN） sensors. The contents of iron and tin dissolved in cans were detected by inductively coupled plasma mass spectrometer （ICP-MS）, and the morphology of corroded surface was observed by optical microscopy and scanning probe microscopy （SPM）. The results reveal that the coating resistance, charge transfer resistance and noise resistance decrease with the prolongation of storage time. The iron and tin contents in cans increase with the storage time, while the bump height of coating surface increases from 30 nm to 80 nm during the corrosion of twelve months. The existence of deformation would enhance the corrosion process of tinplate cans. Finally, the corrosion mechanism of tinplate cans in coffee was proposed.     

Experimental research on electromagnetic continuous casting high-speed steel composite roll简

A high speed steel composite roll billet was fabricated, which is regular in shape, smooth in surface, slight in trace, compact in internal structure, free of slag inclusion, shrinkage cavity, cracks and other flaws, and good in macro quality of junction surface using a vertical continuous casting machine. The interface zone microstructure of bimetallic in billet of high speed steel composite roll was analyzed by metallurgical microscope （OM）, X-ray diffractmeter （XRD）, scanning electron microscopy （SEM） and energy-dispersive X-ray analysis （EDS）. The results indicate that the microstructure of roll billet is composed of chilled solidified layer, dendrite zone, interfacial zone of bimetal and core material zone. The microstructure of outer shell material is composed of martensite ＋ bainite ~ residual austenite ＋ some small labyrinth-shape, small-short lath-shape, or dollop-shape eutectic carbides. The microstructure of core material is slice-shape pearlite and a little ferrite along boundary of cells. The interface region microstructure of bimetallic composite roll consists of diffusion region, chilled solidified layer and columnar grain region.     

Microstructure and electrical properties of La2O3-doped ZnO-based varistor thin films by sol-gel process简

Microstructure and electrical properties of La2O3-doped ZnO-Bi2O3 thin films prepared by sol-gel process have been investigated. X-ray diffraction shows that most diffraction peaks of ZnO are equal, and the crystals of ZnO grow well. Scanning electron microscopy and atomic force microscopy results indicate that the samples have a good structure and lower surface roughness. The nonlinear V-I characteristics of the films show that La2O3 develops the electrical properties largely and the best doped content is 0.3% lanthanum ion, with the leakage current of 0.25 mA, the threshold field of 150 V/mm and the nonlinear coefficient of 4.0 in detail.     

重量法标定流量计简

在利用太阳能热泵供热实验台对系统的供热性能进行实验研究时,流量计因被测介质不同及长期使用会产生实验误差.为了提高测量水平,减少误差对实验的影响,本文中的实验采用重量法,分别对室内、外管路上的LZB型玻璃转子流量计和MCE08-787型累积式流量计进行了标定,并求出了各自的流量修正系数,以此来提高实验台的测量精度,从而保证实验结果的可靠性和准确性.     

Characteristics and formation of high quality reservoirs in sediment gravity flows of Gangzhong area,Huanghuadepression简

Reservoirs can be developed in the sediment gravity flows.However,high quality reservoirs are found widespread in sediment gravity flows of Gangzhong area,Huanghua depression,Bohai Bay Basin,East China.Characteristics and formation of these reservoirs are key problems to be solved.Through comprehensive analysis of thin section petrography,scanning electron microscopy and X-ray diffraction,two distinct rules were obtained.1） These high quality reservoirs have apparent characteristics：lithology consists mainly of medium-fine grained sands; moderately-well sorted and rounded; intergranular pores dominating 70% of the entire pores,surface per unit pore volume reaches 15%; average porosity is 21% and average permeability is 55×10-3 μm2.2） Types of sedimentary microfacies and dissolution strongly control on the formation of high quality reservoirs.Main channels and sandy braided bars have the best reservoir properties.Because that sediments are mainly medium-fine grained sands in high-energy environments.The favorable primary porosity and permeability may promote calcite cementation and help to produce more secondary pores.Besides,at the depth of 2500-3200 m,basically matching threshold of oil generation,organic acid expelled when organic matter became mature,and H＋ released during clay mineral transformation.These both result in the dissolution of calcite cements and create large volume pores,then physical properties improve correspondingly.Moreover,deep hydrothermal fluid intrusion may also have impacts on the development of secondary pores.     

Propagation simulation and dilatancy analysis of rock joint using displacement discontinuity method简

A revised displacement discontinuity method （DDM） program is developed for the simulation of rock joint propagation and dilatancy analysis. The non-linear joint model used in the program adopts Barton-Bandis normal deformation model, Kulhaway shear deformation model and Mohr-Coulomb criterion. The joint propagation criterion is based on the equivalent stress intensity factor which can be obtained by regression analysis. The simulated rock joint propagation accords well with the existing knowledge. The closure and opening ofj oint is investigated by DDM, and it is shown that if the opening volume of propagated joint is larger than closure volume of the old joint, the joint dilatancy occurs. The dilatancy condition is mainly controlled by the normal stiffness of the rock joint. When the normal stiffness is larger than the critical value, joint dilatancy occurs. The critical normal stiffness of rock joint changes with the joint-load angle, and joint dilatancy is most possible to occur at 30°.     

Kinematical analysis of highway tunnel collapse using nonlinear failure criterion简

For different kinds of rocks, the collapse range of tunnel was studied in the previously published literature. However, some tunnels were buried in soils, and test data showed that the strength envelopes of the soils followed power-law failure criterion. In this work, deep buried highway tunnel with large section was taken as objective, and the basic expressions of collapse shape and region were deduced for the highway tunnels in soils, based on kinematical approach and power-law failure criterion. In order to see the effectiveness of the proposed expressions, the solutions presented in this work agree well with previous results if the nonlinear failure criterion is reduced to a linear Mohr-Coulomb failure criterion. The present results are compared with practical projects and tunnel design code. The numerical results show that the height and width of tunnel collapse are greatly affected by the nonlinear criterion for the tunnel in soil.     

Suspension principle of deep-ocean nodule collector简

To make sure that the nodule collector can walk on the soft sediments of seafloor effectively, suspension principle of deep-ocean nodule collector is proposed. The supporting and driving mechanisms are separated to avoid collector sinking. The supporting mechanism is a streamlined body with large and smooth supporting area. The grounding pressure is reduced to 0.5-1 N/cm^2 to make sure that the sinkage is limited. The impellers serve as the driving mechanism to supply enough driving power. The position between the supporting mechanism and the driving mechanism can be adjusted according to the operating condition to decrease the walking resistance and to increase driving efficiency. The test results indicate that the collector can walk on the surface of the soft sediments with the limited sinkage. The traction forces were up to 800 kg and the sinkage of the impeller was under the limitation.     

Study on the removal of urea in wastewater using Fenton reagent

The great amount of NH3-N produced in biological hydrolysis process of high concentration urea can inhibit the growth of microorganisms. In allusion to this problem,the Fenton reagent was used to treat high concentration urea wastewater. And the optimum conditions of this experiment were employed as follows: Fe(Ⅱ)-H2O2mole ratio was 1/3.53,H2O2 was 4 mL (corresponding to 35.30 mmol),pH was 3.0-3.5. Then the experiment shows that the urea concentration decreases from 500 mg/L to less than 2 mg/L,or is even not detected; under the same dose of H2O2,repetitious addition does better than one-off addition; the reaction time within one minute or to be prolonged has little influence on removal effect. The results verify feasibility of this method.     

改性膨润土在有机废水处理中的应用现状

文章介绍了膨润土的性能及其活化改性处理的方式和应用现状.     

膨润土在污水处理中的应用研究与展望

膨润土在污水处理中的应用研究已经受到人们的广泛关注。膨润土在造纸废水、有机废水和重金属废水处理的应用研究中取得良好的效果,其中用添加助剂的膨润土处理造纸废水,COD去除率可达近80%;用阴-阳离子表面活性剂改性的膨润土成功地应用于有机废水处理;对于含重金属离子的废水的处理,膨润土也有很大的应用空间。总之,膨润土作为一种环境矿物材料研究还处于起步阶段,可以预见,随着对膨润土及其深加工产品开发,它在污水处理领域的应用将越来越广泛。     

光催化-Fenton工艺处理废纸制浆废水

为有效处理废纸制浆废水,采用氙灯照射下的光催化-Fenton技术,研究不同反应器、曝气、草酸钾、H2O2投加方式和废水质量浓度对光-Fenton工艺去除废水中TOC或吸光度的影响.结果表明,提高光照强度可提高TOC去除率;添加适量的草酸钾可提高处理效果;H2O2分两次投加可取得较好的处理效果,大大减少对催化剂的需求;在处理过程中使废水暴露于空气可提高有机物的脱氯效果,但曝气对处理效果并无益处.对于TOC为185 mg/L左右的废纸制浆废水,在[H2O2]=1000 mg/L、[Fe(Ⅱ)]=100 mg/L、pH=3.0、温度为30℃的条件下,经过30 min处理,废水的TOC可去除63%以上.     

Decoloration and mineralization of yeast wastewater by using Ce-Fe/Al_2O_3 as heterogeneous photo-Fenton catalyst

1 INTRODUCTIONIn the yeast manufacturingindustry ,there ex-ists an environmental problem that yeastwastewater discharge can not meet emission con-trol regulations .For yeast wastewater ,the reduc-tion of the organic load by biological process is ahard task due to the effluent s toxicity[1]. Apossi-ble strategy for overcoming this problemshould bethe use of chemical oxidation as a pre-treat mentstepin order toi mprove wastewater biodegradabili-ty .Such processes prove to be particularly ef…     

UV/Fenton法降解四环素废水的试验研究

分析了FeSO4和H2O2的初始浓度及溶液pH值对UV/Fenton法降解四环素废水的影响.结果表明四环素的初始浓度为25,mg/L时,降解四环素的最佳工况:FeSO4的初始浓度为0.05mmol/L,H2O2的初始浓度为10,mmol/L,pH值为2.5,在反应时间为60,min时,对四环素的去除率可达93.14%.另外,对自然光、太阳光、紫外光三种不同光照条件进行了对比试验,得出紫外光辐照下的四环素去除率最高,太阳光次之,自然光最小.     

Decoioration and mineralization of yeast wastewater by using Ce-Fe/Al2O3 as heterogeneous photo-Fenton catalyst

Decoloration and mineralization of yeast wastewater were investigated by using Ce-Fe/Al2O3 as a heterogeneous photo-Fenton catalyst in fluidized bed reactor in order to solve the problem of yeast wastewater discharge. The experimental results were assessed in terms of total organic carbon（TOC） reduction. The operational and reaction conditions affecting the efficiencies of TOC removal such as initial pH value, H2O2 concentration, catalyst loading and UV power were studied. The results show that TOC is reduced from 347.6 mg/L to 10.8 mg/L, color is changed from 500 units to 0 under the conditions as follows： initial pH value 6. 0, H2O2 concentration of 1. 000 g/L, catalyst loading of 5 g/L, reaction duration of 120 rain and reaction temperature of 30 ℃. The irradiated Ce-Fe/Al2O3 catalyst was complexed with 1,10-phenanthroline and then it was subjected to Fourier transform infrared spectroscopy and diffuse reflectance spectroscopy to confirm the formation of Fe（Ⅱ） in the solid state. Heterogeneous photo-Fenton reaction proves to be effective for the treatment of yeast wastewater.     

污水土地处理除磷脱氮原理探讨

在阐述上壤－微生物－植物系统特性的基础上，探讨和分析其对污水的净化功能和除磷脱氮的过程与机理．     

A~2O工艺中的反硝化除磷及其强化

为研究A2O工艺中的反硝化除磷现象及影响因素,采用52.5L的A2O反应器处理实际污水.结果表明:正常运行的A2O工艺中存在反硝化除磷现象,在系统HRT为8h,污泥回流比为70%和内回流比为250%的情况下,A2O系统中缺氧区吸磷占总吸磷量的36%左右,序批试验表明,此时反硝化除磷菌占总除磷菌的35.4%.原水的C/N比越低,反硝化除磷的比例越高,但是过低的C/N比会导致TN去除率低下.将缺氧区和好氧区的容积比从1/1扩大到5/8,延长反硝化除磷反应的时间,TN去除率可从62%提高到70%左右,相比单纯提高内回流比更节能.强化A2O工艺中的反硝化除磷,为传统A2O工艺在处理低C/N比污水时提高脱氮除磷效率提供了一个新思路.     

PACT法去除维生素B1制药废水中有机物的试验研究

PACT法(powdered aetivated earbon treatment process)是指将粉末活性炭(PAC)加人活性污泥中的 一种污水处理工艺.该工艺产生于20世纪70年代早 期，目前已被广泛用于处理印染、化工、焦化、炼油、制 药等工业废水.PACT工艺的特点是PAC颗粒包裹在 活性污泥絮体中，通过活性炭吸