废弃FR4环氧树脂覆铜板热解特性及固体残余物组成

采用TG(热重分析仪)和自制小尺度管式炉热解试验台架装置分别探讨了电子废弃物FR4环氧树脂玻璃纤维覆铜板在纯N2气氛中,以10 K/min升温速率加热到800℃的热解特性及在不同热解终温、停留时间下的固体残余物质量分布规律;采用SEM(扫描电子显微镜)分别对2种热解终温(450℃、550℃)下热解后玻璃纤维布进行微观形貌表征。TG热解结果表明,试样在N2气氛下热分解反应主要集中在第1阶段(300~400℃),失重量占总失重量65.55%,500℃后热解残余率趋于不变;管式炉热解结果及残余物表观微观形貌表明,热解温度和停留时间对玻璃纤维析出产率影响较大,而对铜析出产率几乎没有影响。当热解温度为550℃且停留时间保持10min时,废弃FR4环氧树脂玻璃纤维覆铜板可充分热解,玻璃纤维层间的环氧树脂系胶结剂已分解完毕,热解残余率达到最低值且玻璃纤维布自身未见明显变化。研究表明,通过热解焚烧技术电子废弃物资源具有规模化再利用的可能性。     

废旧印刷线路板中溴代阻燃剂对微生物浸提金属铜效率的影响

研究废旧印刷线路板中溴代阻燃剂的多寡对氧化亚铁硫杆菌(Thiobacillus ferrooxidans)浸提废旧印刷线路板金属铜的浸出效率的影响。将废旧印刷线路板剪切破碎后过筛,得到不同粒度段的颗粒样品,分别测定不同颗粒样品中溴代阻燃剂的含量,以含溴量最高的40~100目的颗粒作为试验材料,探讨不同样品浓度(5g/L、15g/L和25g/L),萃取部分溴代阻燃剂与未萃取两种条件下T.ferrooxidans浸提金属铜的效率。在500mL三角瓶中接入活化后的T.ferrooxidans,待菌株培养到对数生长期后加入相应样品,摇床培养120h,每隔一定时间取上清液,分别测定上清液中Cu2+、氧化还原电位(ORP)和pH值。结果为,浸提120h后,未萃取溴代阻燃剂的5g/L、15g/L和25g/L浓度时T.ferrooxidans对铜浸出分别是79.59%、90.53%和66.37%;萃取溴代阻燃剂的5g/L、15g/L和25g/L浓度时T.ferrooxidans对铜的浸出浓度分别是90.98%、97.88%和69.05%。表明溴代阻燃剂是影响微生物浸铜效率的重要因素之一,利用CCl4作为萃取剂萃取废旧印刷线路板中溴代阻燃剂后,T.ferrooxidans对废旧印刷线路板金属铜的浸提率提高,废旧印刷线路板加入量为15g/L时浸提金属铜的效率最高。     

Rhizobium sp.W33对不同植物吸收铜和根际分泌物的影响

通过盆栽试验,采用1株植物促生细菌Rhizobium sp.W33接种黑麦草、狼尾草、高羊茅、紫花苜蓿、猪屎豆、油菜和印度芥菜等7种不同植物,考察了Cu胁迫下菌株对植物生物量、Cu含量和根际土壤中分泌物的影响,并筛选根瘤菌-植物联合修复重金属污染土壤的组合体系,以期初步探明细菌-植物联合修复重金属污染土壤的机制.结果表明,接种Rhizobium sp.W33后,有5种植物的干重增加了11%~56%,增加幅度为印度芥菜黑麦草高羊茅狼尾草油菜,紫花苜蓿和猪屎豆的干重下降.黑麦草、狼尾草、高羊茅和猪屎豆根内Cu含量接近或超过1000mg·kg-1,Cu大量积累在植物根部.Rhizobium sp.W33能够显著促进黑麦草吸收Cu(p0.05),并提高其对Cu的富集系数和转移系数,增加根部和地上部的Cu总量.苹果酸是供试植物-细菌联合修复Cu污染土壤的主要有机酸种类,接种根瘤菌W33后黑麦草、狼尾草根际的苹果酸和水溶性糖含量降低,过氧化氢酶活性增加,其中,苹果酸、水溶性糖含量与黑麦草中Cu含量呈显著相关性(p0.05).因此,根瘤菌W33-黑麦草联合体系修复重金属Cu污染土壤的效果最好,具有应用于重金属Cu污染土壤稳定修复的潜力.     

轮叶黑藻和穗花狐尾藻对铜的吸收机制研究

应用室内模拟试验,通过对铜(Cu)的短期吸收动力学、各亚细胞组分吸收动力学以及Cu的释放研究,探讨了两种沉水植物轮叶黑藻[Hydrilla verticillata(L.f.)Royle]和穗花狐尾藻(Myriophyllum spicatum L.)对Cu的吸收机制.结果表明:①轮叶黑藻和穗花狐尾藻均对Cu具有较高的吸收速率,且两种植物最高吸收速率差异不显著[Vmax(DW)为2μmol·(g·min)-1,P>0.05];②在2μmol·L-1Cu溶液中暴露不同时间(0~96 h),两种沉水植物叶片和茎中各亚细胞组分的Cu含量均迅速增加并约在12 h后达到平衡.各时间处理下,两种植物叶片富集的Cu含量均显著高于茎(P<0.05),并且叶片中的Cu均主要分布在细胞壁(>60%),其次是可溶部分和细胞器;③两种植物相比,黑藻叶片细胞壁中富集的Cu含量显著高于狐尾藻,而细胞内富集的Cu含量差异不显著.轮叶黑藻对Cu的富集和释放能力均高于穗花狐尾藻.     

安徽安庆铜矿床硫的来源及转换机制

安庆铜矿床的硫同位素组成复杂．不能用单一硫源或物理化学条件的变化来解释。本文依据区域成矿地质背景及矿床地质特征，研究了硫从硫源地质体转移到成矿热液中的六种可能机理（模型），并确定了矿床的硫源。     

Problems and issues in laser beam welding of aluminum–lithium alloys

Aluminum–lithium (Al–Li) alloys are very attractive for potential aerospace applications due to their lower density, higher specific strength and rigidity, better corrosion and fatigue crack growth resistance properties, compared to conventional aluminum alloys. Laser beam welding (LBW), being an advanced joining method, has already been approved for applications involving aluminum alloys. However, there are still a number of problems and issues to be answered and solved in LBW of Al–Li alloys. In this review, the properties of Al–Li alloys and the characteristics of LBW are introduced, the formation and prevention of the main weld defects such as porosity and hot cracking are discussed, and then the weld microstructure and the joint mechanical properties are described in highlight. At the end, an outlook on future trends is presented.     

反相流动注射法连续测定工业废水中的铜和镍

采用反相流动注射光度分析技术,以能形成颜色相近产物的化学反应为基础,建立了工业废水中Ｎｉ和Ｃｕ的连续测定方法和装置。测定频率６０样／ｈ,Ｎｉ和Ｃｕ的最低检出浓度分别为０．０３μｇ／ｍｌ和０．０４μｇ／ｍｌ。     

双硫腙－醋酸丁酯萃取石墨炉原子吸收法测定海水中痕量铜、铅和镉

用双硫腙－醋酸丁酯萃取石墨炉原子吸收法测定海水中痕量Ｃｕ,Ｐｂ,Ｃｄ。试验选定了测定条件,结果表明,在弱碱性介质中,能同时定量萃取Ｃｕ,Ｐｂ,Ｃｄ。方法的相对标准偏差〈３％。加标回收率９２％－１０２％,检出限分别为Ｃｕ０．０６,Ｐｂ０．１４,Ｃｄ０．００２。本法操作简便,快速,已应用于海水中Ｃｕ,Ｐｂ,Ｃｄ的分析,取得令人满意的结果。     

Influence of the chemical and mineralogical composition on the acidity of an abandoned copper mine in the Bor river valley (eastern Serbia)

Since the end of operations in 1987, the flotation tailing pond in the area of the former Bor River valley has been left without any type of remediation, leading to a great environmental impact on the wider surrounding area. Because the relative abundance of minerals is critical in determining the quality of the water draining from such materials, research to define the influence of the chemical and mineralogical characteristics on the acidity of the Bor flotation tailing was performed. With this aim in mind, core sampling from eight, 20-m deep drilling holes was undertaken, followed by mineralogical analysis of the composites from each drilling hole and chemical analysis of the composites of the holes and samples taken every 5 m. In addition, the tailing acidity was measured on samples from all drilling holes taken every 1 m from the surface to the base of the tailing using distilled water and 1 M KCl. The average tailing acidity was very high, with a pH value between 2.2 and 4.0 along the depth of the holes, indicating that pyrite, as the dominant sulphide mineral, was oxidised even in the deepest layers of flotation tailing.     

Experimental investigations of five different mosses on accumulation capacities of Cu,Pb and Zn

Uptake of Pb, Cu and Zn by different epiphytic moss species Floribundaria floribunda (Doz. &; Molk.) Fleisch., Taxiphyllum giraldii (C. Muell.) Fleisch. and Thuidium sparsifolium (Mitt.) Jaeg., an epilithic moss Thuidium delicatulum (L.) Mitt. and a leafy liverwort Ptychanthus striatus (Lehm. &; Linderb.) Nees. was studied experimentally. The plant bodies were treated with single metal and mixed metal solutions of Pb(NO₃)₂, CuCl₂ and ZnCl₂ at different concentrations ranging from 10^?10 to 10^?2 mol L^?1. Higher uptake of Pb, Cu and Zn by T. giraldii, T. sparsifolium and P. striatus than by F. floribunda and T. delicatulum was shown in both treatments. Compared with the single metal treatment, the uptake of Zn was very low at higher concentrations in the mixed metal treatment. A slight depletion of Zn was noticed in the long-term exposure. Leaching of naturally accumulated Zn from the mosses and leafy liverwort was also observed when treated with higher concentrated (10^?4, 10^?2 mol L^?1) Pb(NO₃)₂ and CuCl₂ solutions. Similarly, the leaching of naturally accumulated Cu was observed in leafy liverwort P. striatus with 10^?2 mol L^?1 Pb(NO₃)₂ and ZnCl₂ treatments. However, insignificant changes were observed on naturally accumulated Pb and Cu in mosses. From these experiments, the epiphytic mosses T. giraldii and T. sparsifolium, which have high Cation exchange capacity and large leaf surface area, have been found to be suitable for assessing heavy metal concentration in a moderately or slightly contaminated environment.