缺氧-好氧膜生物反应器处理高浓度氨氮废水

采用前置缺氧/好氧膜生物反应器处理高浓度氨氮废水,对反应器的硝化和反硝化性能以及污泥特性进行了研究.研究结果表明:适宜的pH、DO、T下,在容积负荷1.5kgNH4 -N/(m3·d)以下时,出水平均NH4 -N值在1 mg/L左右,硝化率保持在99%以上;在容积负荷为1.0 kgNH4 -N/(m3·d),C/N为3.2,回流比为3时,硝化率为99%,总氮去除率达到83.34%.缺氧池与好氧池的污泥浓度后期分别稳定在6.5～7.0 g/L和9.5～10.0 g/L,两池污泥VSS/SS长期稳定在89%左右,说明污泥没有无机成分的积累.     

两相厌氧工艺处理化学合成类制药废水试验研究

采用两相厌氧工艺处理化学合成类制药废水,实验结果表明:产酸相进水COD多在14000～20000mg/L之间(平均为17883mg/L),容积负荷在30～42kgCOD/m3·d之间,pH值为4.8～5.2,COD去除率为32%～52%,挥发酸含量从4.12%提高到22.54%,为产甲烷相的进一步处理提供了有利条件。经过产酸相后,UASB进水COD浓度在10000mg/L左右,COD平均去除率为86.7%,出水COD浓度为1240～1550mg/L,平均容积负荷为4.5kgCOD/(m3·d),产甲烷相出水pH值在6.5～7.0左右。     

厌氧颗粒污泥膨胀床（EGSB）-接触氧化工艺处理可乐废水

介绍采用EGSB-接触氧化工艺处理可乐生产废水的工程实例。EC,SB反应器的颗粒污泥由城市消化污泥接种,运行温度33—35℃,停留时间为12h,有机负荷14KgCOD／（m3·d）,接触氧化停留时间10h。当进水COD浓度为3000mg／L时,厌氧段COD去除率可达到80％以上,厌氧出水经接触氧化工艺处理后,COD去除率可达95％以上,出水COD≤150mg／L,达到国家二级排放标准。     

低氧下膜生物反应器强化脱氮除磷

利用城市污水对一体化膜生物反应器脱氮除磷的特性进行研究,研究结果表明,当控制反应器内溶解氧浓度为0.5 mg/L左右时,系统在有效地去除有机污染物的同时,可达到较高的氮、磷去除率.CODcr进水为342～1 500 mg/L,出水均在40 mg/L以下,去除率在90%以上;总磷(TP)进水为4.08～31.45 mg/L,出水均在0.5 mg/L以下,去除率平均为96%;进水总氮(TN)为30.55～91.34 mg/L,去除率平均在70%以上.     

HLS-无机膜生物反应器的制备与应用

采用接触氧化法和陶瓷膜相结合设计制备了无机膜生物反应器.在温度10～28℃、pH>6.5、HRT(水力停留时间)8 h、SRT(污泥停留时间)130 h、MLSS(混合液悬浮固体浓度)10.2 g/L、膜面流速5.0～7.0 m/s,膜操作压力0.20 MPa的条件下处理生活污水,膜通量为:130～170 L/(h·m2),HLS-无机膜生物反应器对COD的去除率可达99%以上.出水NH3-N为3～6 mg/L.浊度为3～8 NTU.     

外置式中空纤维膜-生物反应器处理污水的研究

设计了可正/反运行的外置式膜-生物反应器(RMBR),研究了RMBR处理污水的工艺条件,讨论了膜面流速、添加粉末活性炭(PAC)等因素对临界膜通量、CODcr脱除率的影响.结果表明:在进水水质CODcr为312~584 mg/L,NH3-N为16~40 mg/L时,RMBR的出水水质达到CODcr<15 mg/L(脱除率>96.5%),NH3-N<1.53 mg/L(平均去除率>80%),浊度<0.17 NTU;添加PAC后出水水质CODcr<4.22 mg/L,临界循环比降低了10%~20%;对于已污染的膜,水反冲洗、碱浸泡后水反冲洗、碱浸泡 酸浸泡后水反冲洗可使膜通量恢复至新膜的47%,83%,94%;组件反置运行可使膜通量恢复约10%.     

一种新型好氧颗粒污泥反应器的试验研究概述

该反应器在直接投加高浓度的二次沉淀池回流污泥、0.3-0.5kgCODCr/(m3·d)的容积负荷、24h的水力停留时间的条件下,在15天内启动驯化,成功培养出颗粒污泥;该反应器对CODCr的去除能力较强,同时又具有较好的脱除氨氮的效能。12-24h的水力停留时间3内、0.65-5.0kgCODCr/(m3·d)的容积负荷条件下,CODCr去除率稳定高达98%以上,氨氮去除率80%以上。出水水质较好,CODCr最低达20mg/L以下,氨氮5mg/L以下,为中水回用提供条件。     

膜法富氧曝气和粗内径对外置式中空纤维膜生物反应器性能的影响

膜法富氧曝气可以提高外置式膜生物反应器(RMBR)污水处理负荷,处理效果好,出水无色无味,固体悬浮物(SS)未检出,浊度小于0.1NTU,COD去除率大于95%,氨氮去除率大于98%,满足中水回用标准.试验结果表明,用内径为2 mm聚醚砜(PES)中空纤维膜制作的RM-BR,长期稳定运行而未出现堵塞.增加跨膜压差(TMP)可以增加膜通量,当TMP超过适宜值后表现为通量与TMP无关的特性.提高膜面流速可以削弱污染层的形成,当超过适宜流速后也表现出通量与流速无关的特性.不同的污泥浓度(MLSS)存在适宜的TMP和适宜膜面流速:当MLSS为2.2 g/L、3.1 g/L、4.6 g/L时,适宜的TMP为100 kPa、80 kPa、60 kPa,膜面流速为0.6～0.9m/s.合适的反冲洗周期为40 min,较佳的反冲洗程序为60 s反洗 15 s正向冲洗.反冲洗和化学清洗可分别使膜的通量恢复至新膜的78%和89%.300h的运行表现出较好的稳定性.     

A/O MBR处理城市污水回用的中试研究

采用中试规模(36 m3/d)的缺氧-好氧膜生物反应器(A/O MBR)对城市污水处理回用进行了试验研究.试验结果表明,该工艺处理效果优良,系统对COD、氨氮、浊度、细菌的平均去除率分别为94%,98.3%,99.6%,lg6,出水浓度分别为18 mg/L,0.65 mg/L,0.06 NTU,4个/mL.出水水质优于城市杂用水水质标准(GB/T 18920-2002).该系统具有较强的抗冲击负荷能力.     

颗粒填料复合式膜生物反应器运行参数对膜污染的影响

为了探讨颗粒填料在减缓膜污染方面的作用,通过正交实验,研究了颗粒填料复合式膜生物反应器(HMBR)中膜通量、悬浮污泥浓度、颗粒填料体积三个运行参数对膜污染的影响.在实验过程中用平均膜过滤阻力的上升速率(K)来表征膜污染速率.结果表明,膜污染速率与膜通量、悬浮污泥浓度成正比,与填料体积成反比,填料颗粒能够有效地减缓膜污染和提高膜生物反应器的运行稳定性.各运行参数对膜污染速率的影响次序为:膜通量>悬浮污泥浓度>填料体积.在本实验条件下HMBR的最佳操作参数是:X=4g MLSS/L,C=20%,J=4.5L/(m2·h).     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from