改性斜发沸石处理电镀废水中的重金属离子

沸石是一族含水铝硅酸盐矿物,具有特殊的晶体化学结构,拥有离子交换、高效选择性吸附、催化、耐酸、耐辐射等优异的性能和环境属性.天然斜发沸石经改性可增强吸附性能.在静态条件和动态条件下,研究了改性斜发沸石对电镀废水中重金属离子Cu2 ,Cr6 ,Zn2 ,Cd2 ,Pb2 的吸附性.结果表明,改性斜发沸石对重金属离子有较好的吸附性,pH值是影响吸附的主要因素.本技术用于电镀废水处理,可成功地使废水中重金属离子的含量降低到国家规定的排放标准以下,处理后的废水经解吸再生后可重复使用.     

酸改性膨润土吸附去除镍镉离子的研究

在静态条件下,研究了改性膨润土对重金属离子的吸附性能和吸附机理,着重探讨了改性膨润土去除模拟水样中重金属离子Ni2 ,Cd2 的适宜条件及改性膨润土的再生方法.结果表明,改性膨润土对Ni2 ,Cd2 具有较好的吸附性能;pH值是影响改性膨润土对重金属离子吸附的重要因素,不同的金属离子都有其适宜的pH值范围.吸附的最佳条件是pH值5.0～7.0,废水中Ni2 ,Cd2 含量不大于45 mg/L,搅拌时间约60 min.利用改性膨润土吸附处理Ni2 ,Cd2 含量小于45 mg/L的模拟水样,效果很好,Ni2 ,Cd2 的去除率均可分别达到98.5%以上,出水可达到国家排放标准.     

污泥灰对Cd(Ⅱ)和Ni(Ⅱ)的吸附作用研究

在静态条件下,以改性城市污泥为吸附剂,研究了污泥灰(MSSA)对重金属离子的吸附性能,着重探讨了改性污泥灰去除工业电镀废水中重金属离子Cd(Ⅱ)、Ni(Ⅱ)的适宜条件.结果表明,pH值是影响污泥灰对重金属离子吸附的重要因素,镉(Ⅱ)、镍(Ⅱ)吸附的最佳pH值为6.0和6.5;当吸附剂最佳用量为10g/L时,Cd(Ⅲ)、Ni(Ⅱ)的吸附容量分别达到1.21mg/g和1.02mg/g;吸附等温线可以用Freundilich和Langmuir模型描述,吸附过程基本符合Langmuir和Freundilich吸附等温式.该吸附剂吸附性能优越,可有效地去除废水中的相关金属离子.     

改性海泡石对电镀废水中Pb2+、Cu2+、Cd2+的吸附

用盐酸溶液对海泡石处理后在 4 5 0℃下灼烧 ,制备出改性海泡石。在动态条件下 ,研究了改性海泡石对重金属离子Pb2 +、Cu2 +、Cd2 +的吸附效果及条件。探讨了改性海泡石对重金属离子Pb2 +、Cu2 +、Cd2 +的吸附机理。含Pb2 +、Cu2 +、Cd2 +的电镀废水经改性海泡石吸附后 ,重金属离子含量显著低于国家排放标准     

壳聚糖插层高岭土吸附处理电镀废水中的重金属离子

利用壳聚糖插层天然高岭土制备复合吸附剂去除电镀废水中重金属离子的相关研究不多。将天然高岭土活化处理后置于经乙酸溶解的壳聚糖溶胶中,制得壳聚糖插层高岭土复合吸附剂;优化了复合吸附剂的制备条件,考察了pH值、吸附时间以及复合吸附剂的投加量对电镀废水中Cr~(6+)、Ni~(2+)、Cd~(2+)、Pb~(2+)4种重金属离子吸附效果的影响;确定了复合吸附剂的最优制备条件:高岭土预处理温度为700℃,壳聚糖与高岭土的质量比为1∶5。电镀废水中重金属离子最佳脱除条件:pH值为5.0~6.0,吸附时间为60min,投加量为6.0g/L。常温下Cr、Ni、Cd、Pb4种重金属的去除率分别为94.76%、98.58%、92.47%、99.30%。连续5次吸附-解吸循环结果表明,插层复合吸附剂的去除率均大于90%,适用于去除电镀废水中的重金属离子。     

改性聚丙烯腈纤维对电镀废水中重金属离子吸附的研究

为了有效地处理含重金属离子的废水,制备了改性聚丙烯腈纤维吸附剂.在静态条件下,研究了改性聚丙烯腈纤维对重金属离子Cu2 ,Ni2 ,Zn2 的吸附效果及吸附条件.含Cu2 ,Ni2 ,Zn2 的电镀废水经改性聚丙烯腈纤维吸附后,废水中Cu2 ,Ni2 ,Zn2 的含量显著低于国家排放标准,获得了满意的结果.     

改性海泡石对电镀废水中Pb^2＋、Cu^2＋、Cd^2＋的吸咐

用盐酸溶液对海泡石处理后在450℃下灼烧，制备出改性海泡石。在动态条件下，研究了改性海泡石对重金属离子Pb^2 、Cu^2 、Cd^2 的吸咐效果及条件。探讨了改性海泡石对重金属离子Pb^2 、Cu^2 、Cd^2 的吸咐机理。含Pb^2 、Cu^2 、Cd^2 的电镀废水经改性海泡石吸附后，重金属离子含量显著低于国家排放标准。     

粉煤灰活性炭处理含铬电镀废水

为了消除电镀废水中的金属离子等的污染,以粉煤灰活性炭为吸附剂、还原剂对含Cr(Ⅵ)的电镀废水进行了处理.考察了活性炭吸附废水中的Cr(Ⅵ)时,溶液的pH值、吸附时间、Cr(Ⅵ)浓度等因素对Cr(Ⅵ)的吸附量及废水中残余Cr(Ⅵ)浓度的影响;同时,还对活性炭的再生条件进行了研究.试验表明:溶液中Cr(Ⅵ)质量浓度为50 mg/L,pH=3,吸附时间1.5 h时,活性炭的吸附性能稳定,Cr(Ⅵ)离子的去除效果最好,经处理的废水Cr(Ⅵ)含量达到国家排放标准.     

硝酸氧化改性活性炭处理含铬废水的研究

含Cr的电镀废水严重污染环境,利用改性的活性炭对它进行处理,效果明显.活性炭用HNO3(1∶ 1)氧化并经300 ℃左右温度煅烧改性后,具有较高的阳离子交换容量,其阳离子交换容量达到1.88 mmol/g.常温条件下以该改性活性炭作吸附材料处理镀铬厂含铬废水,在酸性条件下具有较高的还原性和吸附性,可将废水中以CrO2-4和Cr2O2-7两种形式存在的Cr(Ⅵ)离子完全还原成Cr3 ,获得了较高的Cr(Ⅵ)离子去除率,并对溶液的pH值和吸附时间对废水中Cr(Ⅵ)离子去除率的影响进行了探讨.结果表明,当溶液的pH值为2.5～3.0,吸附时间为3～4 h时,废水中Cr(Ⅵ)离子的去除率可达到97.5%左右.     

聚丙烯腈纤维改性条件优化及其对模拟电镀废水的净化作用

为了寻求低价、环保的电镀废水处理方案,将廉价的聚丙烯腈(PAN)纤维与羟胺试剂反应对PAN纤维进行改性,使其上氰基螯合获得偕胺肟基纤维。通过改变各种改性条件,探讨了改性条件对PAN改性纤维在重金属单离子溶液和多离子混合溶液中吸附性能的影响。结果表明:最佳改性条件为21.2 g/L PAN纤维,27.0 g/L盐酸羟胺,pH值为7.0,70℃下反应2 h;改性PAN纤维对模拟电镀废水中的Cu2+,Zn2+,Ni2+,Pb2+,Cd2+等重金属离子均有较好吸附性能,其中对Cd2+吸附效果最好,吸附量为55 mg/g;在多离子混合溶液中优先选择吸附Cd2+;改性PAN纤维再生效果优良,可重复利用。     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.