湿式氧化铜基催化剂稳定性及溶出机理的探究

主要介绍了催化湿式氧化中铜系列催化剂稳定性的影响因素，考察了不同制备方法及工艺参数对催化剂稳定性的影响，研究了湿式处理的反应温度、氧气分压对铜溶出的影响，探讨了催化剂的溶出机理，为湿式氧化的广泛应用提供技术支持。     

用TiO2-Ag-改性膨润土复合催化剂光催化氧化处理染料废水

制备了一种Ti02-Ag-改性膨润土复合催化剂，用该催化剂对直接黑L-N和直接铜蓝BR染料废水进行了光催化氧化处理，取得了较好的实验效果。     

载铜活性炭催化氧化干法腈纶废水的研究

通过浸渍法制备了载铜活性炭(Cu/AC)催化剂,用于催化过氧化物氧化干法腈纶废水,结果表明:Cu/AC催化活性高于均相催化剂Cu(NO3)2,Cu溶出量则小于均相催化剂.非均相催化氧化对干法腈纶废水有很好的处理效果.催化剂的活性和稳定性与制备条件关系很大,通过单因子影响实验,确定催化剂的最佳制备条件为焙烧温度700℃,焙烧时间4小时,浸渍溶液初始浓度10.6gCu/L,浸渍时间20小时.     

汽车尾气催化剂的发展

文章介绍了汽车尾气催化净化的发展简史，概述了三效催化剂的组成及相关性能和制备方法，分析了汽车尾气三效催化剂技术发展热点和趋势。     

新型可见光响应光催化剂的研究进展

研究开发高活性的可见光响应催化剂对于解决环境污染和能源短缺问题具有重要意义。在阐述反应机理的基础上,介绍了改性Ti O2、多元金属复合氧化物、卤氧化物、铋系化合物等新型可见光响应光催化剂的研究现状,并对未来可见光响应催化剂的机理探讨、催化活性提高、制备新技术等方面的研究进行了展望。     

低温等离子体协同锰基催化剂降解甲苯、邻二甲苯的实验研究

VOCs的化学成分复杂,对于人体健康和生态环境产生潜在威胁。文章选取了甲苯和邻二甲苯两 种典型的苯系物VOCs,制备5种Cu-Mn/γ-Al2O3系列催化剂并进行XRD、BET和XPS表征。将催化剂置于DBD反应器的放电区域来降解苯系物,探寻其降解效果和副产物生成情况。实验结果表明,Cu掺杂的MnO2催化 剂的引入显著提高了VOCs去除率和CO2选择性。其中,等离子体催化系统中催化剂Cu0.15Mn的性能最佳,甲苯和邻二甲苯的去除率可达100％,CO2的选择性为92.73％,同时能抑制副产物O3和NO2的产生。催化剂的表征 结果表明,Cu-Mn固溶体中Cu和Mn的协同作用可以提高表面活性氧的量和还原性,从而提高催化性能。     

火电厂烟气脱硝关键技术的优化创新

燃煤烟气中的氮氧化物（NOX）脱除，国际上主要采用SCR法，但SCE催化剂制备工艺技术是制约我国脱硝技术产业化的瓶颈。对催化剂配方和成型工艺进行优化和创新研制的TZ型板式催化剂填补了国内空白。     

蜂窝状活性炭研究

蜂窝状活性炭是一种新型的活性炭。简要介绍了蜂窝状活性炭的结构特性和吸附性能，重点总结了蜂窝状活性炭基催化剂的制备方法及其在催化方面的应用。     

磺化石油焦酸催化剂的制备

以石油焦为原料、浓硫酸为磺化剂，通过磺化反应制得磺化石油焦酸催化剂。分析了制备条件的影响，获得了制备磺化石油焦的优化条件：反应温度120℃、反应时间30h、酸（摩尔）焦（g）比0．8mol／g。在优化条件下，磺化石油焦的交换容量可达2．6mmol／g。与强酸性阳离子交换树脂K2641相比，在相同的反应条件下，磺化石油焦作为酸催化剂催化合成乙酸乙酯表现出较高的催化活性，且重复使用5次后催化剂活性基本保持不变。     

HPA／ZnFe2O4-TiO2光催化剂的制备及对马拉硫磷的可见光降解

以纳米TiO2载体，利用浸渍法制备了HPA／ZnFe2O4-TiO2光催化剂。对制备的催化剂进行了XRD、BET、TEM和UV-vis DRS表征。结果表明，催化剂样品均为锐钛矿相且ZnFe2O4很好地分散在载体表面，HPA／ZnFe2O4-TiO2光催化荆的平均粒径为10nm且在380-670nm均有强的光响应；反应最佳的HPA浓度为O.08molfL，最佳的ZnFe2O4负载量为1％。考察了HPA溶液初始浓度、ZnFe2O4负载量、溶液初始pH值、H2O2用量、催化剂用量对催化剂活性的影响。在溶液初始pH=13，H2O2=6mmol／L，催化剂用量为2g/L的最优条件下，光照反应进行100min后，马拉硫磷的降解率可达87％；重复4次后马拉硫磷的降解率仍可以达到67％。     

Leaching characteristics of copper flotation waste before and after vitrification

Copper flotation waste from copper production using a pyrometallurgical process contains toxic metals such as Cu, Zn, Co and Pb. Because of the presence of trace amounts of these highly toxic metals, copper flotation waste contributes to environmental pollution. In this study, the leaching characteristics of copper flotation waste from the Black Sea Copper Works in Samsun, Turkey have been investigated before and after vitrification. Samples obtained from the factory were subjected to toxicity tests such as the extraction procedure toxicity test (EP Tox), the toxicity characteristic leaching procedure (TCLP) and the "method A" extraction procedure of the American Society of Testing and Materials. The leaching tests showed that the content of some elements in the waste before vitrification exceed the regulatory limits and cannot be disposed of in the present form. Therefore, a stabilization or inertization treatment is necessary prior to disposal. Vitrification was found to stabilize heavy metals in the copper flotation waste successfully and leaching of these metals was largely reduced. Therefore, vitrification can be an acceptable method for disposal of copper flotation waste.     

Long-term leaching of uranium from different waste matrices

A semi-dynamic leaching test was carried out for metallurgical wastes and ore samples from the uranium and copper mining industry over a 142 day period using distilled water and 0.1N NaNO(3) as solvents. Laser fluorimetry was used as the analytical technique to determine the total uranium content in the leachates. The cumulative leach fraction (CLF) of uranium release from the samples was calculated to be 0.22, 0.22, 0.07 and 0.39% for rock, uranium tailings, copper kinker ash samples and copper tailings respectively using distilled water as solvent and 0.31, 0.27, 0.05 and 0.59% for the same matrices using 0.1N NaNO(3). The release of mobile uranium fraction was very slow, being faster in the initial stage and then attained a near steady state condition. The diffusion coefficient and bulk release of uranium from the samples have been calculated. The processes governing the release of uranium from these matrices have been identified to be surface wash-off and diffusion. Hence the use of weak solvents (leach out the mobile/exchangeable fraction of uranium) under semi-dynamic conditions aids the determination of leaching parameters and identification of the leaching mechanism for mobile uranium fraction from different matrices by slow leaching processes.     

Preservative leaching from weathered CCA-treated wood

Disposal of discarded chromated copper arsenate (CCA)-treated wood in landfills raises concerns with respect to leaching of preservative compounds. When unweathered CCA-treated wood is leached using the toxicity characteristic leaching procedure (TCLP), arsenic concentrations exceed the toxicity characteristic (TC) limit of 5mg/L in most cases. The majority of discarded CCA-treated wood, however, results from demolition activities, where the wood has typically been subjected to weathering. Since preservatives do migrate from the wood during its normal use, leaching characteristics of weathered and aged CCA-treated wood may differ from unweathered wood. To evaluate this, CCA-treated wood removed from service after various degrees of weathering was collected from multiple sources and leached with the TCLP, the synthetic precipitation leaching procedure (SPLP) and California's waste extraction test (WET). Five to seven individual pieces of wood were analyzed from each source. The average TCLP arsenic concentration for the 14 sources ranged from 3.2 to 13 mg/L. The average TCLP concentrations of the 100 wood pieces tested were 6.4, 5.9 and 3.2 mg/L for arsenic, copper and chromium, respectively. Overall, in 60 out of 100 samples tested by the TCLP, arsenic concentrations exceeded 5 mg/L (the TC regulatory value). SPLP leachate concentrations were similar to TCLP concentrations, although copper leached somewhat more with the TCLP. WET leachate concentrations were approximately a factor of 10 higher than TCLP concentrations. Discarded CCA-treated wood, even after exposure to years of weathering, often exceeds the TC limit for arsenic and without the current regulatory exemption would possibly require management as a TC hazardous waste in the US.     

WATER USE AND WATER CONSERVATION BY THE COPPER MINING INDUSTRY1

ABSTRACT: This paper examines the use of water by copper mines for treating low grade ores. The froth flotation process for treating sulphide ore and the heap leaching process for treating oxide ore are described, and ways of reducing the amount of water used in these processes are discussed. Estimates of the costs reducing water consumption are given. Finally, the circumstances in which it would be desirable for a copper mine to reduce its level of water consumption are considered.     

Antifouling paints: Use on boats in San Diego Bay and a way to minimize adverse impacts

High concentrations of copper and tributyltin, two biocides used in antifouling paints, are found in harbors. Efforts are necessary to reduce the adverse impact of biocides from antifouling paints, but little is known about the actual use of such material. I surveyed the operators of 435 boats berthed in San Diego Bay, to determine what paints and maintenance procedures were being used.More than 90% of the respondents used conventional leaching paints. These paints contain 40% to 65% copper compounds and 3% to 7% tributyltin compounds. Few respondents used copolymer paints. Those who did use copolymer paints seemed to repaint less frequently than those using conventional leaching paints.Professional maintenance companies do not initiate repainting as frequently as individuals doing their own maintenance.It appears that the input of antifouling biocides to harbor waters could be reduced by at least one-third simply by educating boat-owners about the chemical mechanisms involved in antifouling paints, by explaining the environmental and economic advantages of using slow-release paints, and by encouraging them not to repaint until their paint's useful life has expired.     

Biodiesel production from a free fatty acid containing Karanja oil by a single-step heterogeneously catalyzed process

Karanja oil, containing 6.2% free fatty acids (FFAs), was considered for biodiesel production using a single-step solid-phase acid catalyzed process. Different types of zeolites and Amberlyst15 catalysts were tested and biodiesel was produced. Under similar conditions, the highest biodiesel yield was achieved using an Amberlyst15 catalyst, which contained 3–5% of moisture. The effects of operating parameters of the reaction such as reaction temperature, catalyst amount, and methanol-to-oil ratio were studied. An increase of methanol:oil ratio revealed a non-monotonic increase in biodiesel yields. Similar non-monotonic behavior was observed when Jatropha oil was used. Leaching and catalyst reusability were also considered. No significant effects of leaching were observed and catalyst reusability appeared to be affected by methanol interactions. The presence of a co-solvent, Tetrahydrofuran (THF), increased the biodiesel yield. Furthermore, an optimum amount of THF (THF:methanol volume ratio of 1:2) gave rise to the highest biodiesel yield. A biodiesel yield of 93% was achieved at 120 °C using a single-step process with Amberlyst15 as a catalyst, THF as a co-solvent, and a methanol:oil ratio of 30:1.     

The composition and environmental hazard of copper slags in the context of the Basel Convention

A recent comprehensive review of the characteristics and utilization of copper slags encourages (properly) several applications for this important pyrometallurgical byproduct. However, the review does not include possible environmental effects from these slags. The United Nations Basel Convention on the Transboundary Movement of Hazardous Wastes and Their Disposal characterizes copper compounds that exhibit specified hazard characteristics as hazardous wastes. In 1996, the Convention considered further characterization of these and other compounds and substances. The final characterization of copper slags is as non-hazardous, i.e., exempt from control. This decision was based in part (if not largely) on the data that are presented here. Literature reports were used to accumulate data describing the chemical composition and acid leaching of commercial copper slags from three countries. From these data, average values of chemical composition and their statistical confidence limits (95%) were calculated. The variability of the chemical analyses of three commercial slags produced over 19 or 20 months were statistically analyzed and shown to be small. The concentrations of toxic heavy metals in the slags are low and the frequency distributions of the values are narrow. Most of the data are normally distributed, validating the use of the statistics used and permitting predictions of likely values. The amounts of heavy metals extracted by an aggressive standard acid leach procedure are low and well below the United States. regulatory levels derived from drinking water standards. The results for total composition and leaching illustrate why the U.S. Environmental Protection Agency made a regulatory determination that such slags are not hazardous wastes. Later, in 1996, the Basel Convention Technical Working Group concurred and the Parties to the Convention adopted their recommendation.     

Copper and calcium transport through an unsaturated soil column

To determine the relative importance of the physical and chemical factors that influence the movement of heavy metals through soils, leaching experiments were carried out under conditions of constant molarity during unsaturated steady-state water flow through a Manawatu fine sandy loam (a Dystric Fluventic Eutochrept). The movement and exchange of copper was studied in a binary Cu-Ca system. The movement of the associated anions, namely chloride and sulfate, was also monitored. The measurements were compared with predictions from the convection-dispersion equation (CDE), linked with cation exchange theory. The agreement between the measured and predicted breakthrough of sulfate and copper was good. This indicates that copper retardation in the Manawatu soil is closely related to the cation exchange capacity, and that exchange between Ca and Cu is the main process of Cu retardation in the Manawatu soil. However, copper appeared slightly later in the effluent than predicted, indicating that non-exchange processes are also involved in copper transport. Measurements of suction cups could also be used to obtain the parameters for the CDE to describe sulfate movement through the soil. Time domain reflectometry (TDR) measurements of the bulk-soil electrical conductivity could be used to monitor the movement of both sulfate and copper. This indicates that TDR can also be used to monitor cation transport and exchange through the soil, provided the percolating solution causes a sufficient change in the electrical conductivity.     

Leachability of printed wire boards containing leaded and lead-free solder

Due to environmental concerns and regulatory initiatives, electronics manufacturers are replacing the tin/lead solder commonly used on printed wire boards (PWBs) with alternative solders. To determine the potential waste management impacts of the alternative solders versus the tin/lead solder, two leaching tests on PWBs manufactured with five alternative types of solder were performed: the toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP). These tests are commonly used in the US regulatory community to assess pollutant leachability in different disposal scenarios. The article discusses the application and limitations of these tests. The five types of solders investigated were 63Sn/37Pb, 99.3Sn/0.7Cu, 95.5Sn/4Ag/0.5 Cu, 96Sn/2.5Ag/1Bi/0.5Cu, and 42Sn/1Ag/57Bi. The leaching tests were conducted on four PWB sections, each with a unique configuration and solder density. The largest lead concentrations were observed from the PWBs containing Sn/Pb solder, with concentrations exceeding the hazardous waste toxicity characteristic (TC) in TCLP leachates. Silver, the other regulated element used in the solders, was rarely detected, with none of the samples exceeding the TC limit for silver. High copper concentrations were observed and were determined to result from the PWB itself, not from the copper-containing solders.     

不同造孔剂负载金属活性炭的制备及其脱硫性能初步研究

以糠醛渣、酚醛树脂和一定的造孔剂为原料制备球形活性炭，考察其碘吸附值和负载金属的性能，结果表明，较好的造孔剂为CMC。同时，通过浸泡方式在活性炭上负载铜、钒以及铜钒复合物，在不同温度下考察各活性炭的脱硫性能，结果表明，负载钒的活性炭在437K下对SO2的转化有明显的催化作用，而铜、钒负载量的适当增加有利于活性炭吸附性能的提高。