连续流动分析仪与分光光度法测定海水氰化物

按国际标准方法 ISO 14403:2002与《海洋监测规范》GB 17378.4-2007的原理,对海水氰化物的实际样品与加标样品分别使用连续流动分析法和分光光度法同时进行测定。结果显示,两种方法对海水氰化物的测定没有显著差异,但采用连续流动分析法的加标回收率在92.9%~95.6%之间,优于分光光度法(85.9%~91.9%),由此说明连续流动分析法对海水氰化物测定的准确度和精密度优于分光光度法,可以代替常规方法用于海水氰化物的测定。     

水中总氰化物测定方法的改进与应用

针对现行的水质总氰化物测定方法需要用剧毒物质氰化钾绘制标准曲线而存在的管理严格、人员安全防护风险大、对渣液处理要求高等不利因素,建立了采用络合氰化物标样取代剧毒氰化钾绘制工作曲线的新途径,该方法测定结果的准确度满足质控要求,加标回收率90%~110%,测定结果与哈希试剂法测定结果无显著差异。该方法已在实际监测分析过程中得到了充分验证和成功应用。     

膜技术处理氰化废水的应用

采用膜技术分离、浓缩氰化废水中的氰化物，既可以回收废水中的氰化物和贵重金属，提高企业经济效益和竞争力，又可以减少污染，确保环境安全。本文以某工程实例介绍了膜技术处理氰化废水的应用情况。     

黄金矿山氰化物的管理与使用

前言氰化法作为一种主要的提金技术被广泛应用于国内外黄金矿山。它的化学作用原理是:在氧及保护碱的作用下,氰化物与矿石中的金形成络合离子进入溶液,从而使金与矿物中的脉石分离开来。这种方法的工艺设计是在磨浮工艺后面设置氰化装置,通过人工或仪器加入氰化物,精矿在氰化物的作用下生成贵液,然后经过浸出、洗涤、压滤处理,生产出金泥。这是目前黄金矿山一种较为典型的生产工艺流程。氰化法提取黄金需要耗用大量的氰化物,这些氰化物主要有氰化钠、氰化钾、氰化钙、氰化铵等,大部分矿山使用氰化钠,少数企业使用氰化钾、氰化钙。氰化物属于高危险化学品,极少量的氰化物(1毫克每公斤体重数)就会使人在短时间内中毒死     

印刷线路板含氰废水处理工艺实例

氰化物属于剧毒物,含氰废水若不经处理直接排放会严重污染环境.印刷线路板镀金工序会产生含氰废水,对于含氰废水可以根据总氰化物浓度分质处理,也可以采用组合工艺处理.江苏省某印刷线路板生产企业采用"电解+离子交换+纤维吸附"工艺处理含氰废水,处理后,企业委托监测公司对废水水质进行了监测,根据监测结果,废水中总氰化物浓度能够达...     

连续流动分析仪测定氰化物和挥发酚使用混合标准曲线对标准样品测定结果的影响及探讨

氰化物和挥发酚是地表水与地下水监测的重要指标,用连续流动分析仪测定样品时,两个项目放样位置太临近,如分析人员对分析通道不熟练,会存在样品放反的情况,导致无法出峰,影响样品的分析。为了减少分析人员错误率,提高工作效率,通过改变挥发酚保存剂,将氰化物与挥发酚的质控样配制成混标,使用连续流动分析仪测定氰化物和挥发酚时,分别进行单标和混标线性、检出限、精密度和准确度的测定,混标曲线与单标曲线相比,都具有方法线性好,相关系数r≥0.999 5,灵敏度高,检出限低,准确度好,标准物质的测定均在允许的误差范围内,结果说明采用氢氧化钠共同保存氰化物和挥发酚的标准样品方法可行,结果令人满意,可为现场采样工作提供参考。     

我国海水腐蚀试验站海水环境因素的获取和监测进展

简述了影响金属腐蚀的海水环境因素,论述了我国海水腐蚀试验站海水环境因素的获取和监测进展情况,指出了海水环境因素获取和监测中存在的问题和注意事项。     

秦皇岛市海水入侵特征

本文在海水入侵勘查、监测成果的基础上，阐述了该区海水入侵现状、分布特征、演化过程和入侵方式，探讨了海水入侵的机理，指出人类活动是海水入侵的诱发因素，超采地下水是海水入侵的根本原因。应用基于GIS的层次分析法进行了危险性评价，从地学角度，提出了海水入侵灾害生态综合防治对策。     

离子选择电极法测定水和废水中总氰化物

本文在查阅国内外文献的基础上，对氰化物测定中的前处理方法和干扰消除进行了简要综述。同时对氰离子选择电极法测定氰化物进行了研究，测定的ｐＨ应控制为１２－１３，检测下限为０．０３ｍｇ／ｌ。并用离子交换的方法分离阳离子，以ＰｂＣＯ３为沉淀剂分离Ｓ＾２－后，对废水样进行分析，效果良好。     

电镀含氰废水处理中试试验研究

采用"反渗透+离子交换"为核心的组合工艺对电镀含氰废水进行处理,系统净化后的纯净水回到漂洗槽回用于漂洗,氰化物由于受到膜组件的截留而得到浓缩,浓缩液收集后可回收氰化物。     

ICP-OES法直接测定海水中痕量铜

研究运用ICP-OES法直接测定海水中铜的含量。选择特征谱线,调节最佳仪器参数进行测定。研究表明:在0～50μg/L线性范围内,曲线相关系数可以达到0.999 8,方法检出限为0.5μg/L,加标回收率在102%～105%之间,RSD≤4.7。直接进样-电感耦合等离子体发射光谱法(ICP-OES法)测定海水中痕量铜,前处理简单,灵敏度高,检出限低,干扰少,线性范围宽,操作简单、快捷。     

样品保存方法对阳极溶出伏安法测定时的影响

对海水中Cu、Pb、Zn、Cd的日常监测分析方法进行了调查,结果表明在调查范围内阳极溶出伏安法使用数量最高。通过实验研究了不添加保存剂、加浓HNO3、加浓HClO4对阳极溶出伏安法测定海水Cu、Pb、Zn、Cd的影响。发现不添加保存剂时4种金属峰电位变化范围大、出现频次分散,分析方法灵敏度下降。不同类型酸对阳极溶出伏安法测定Pb、Zn、Cd时的峰电位变化影响不大,加浓HNO3时Cu的峰电位变化小于加浓HClO4。根据实验结果,推荐使用保存剂为浓HNO3。     

Heavy metal removal and cyanide destruction in the metal plating industry: an integrated approach from egypt

Wastewater produced from a metal plating is a major environmental problem. Industrial auditing revealed that the main source of pollution mainly originated from rinsing water. The characterization of final effluent showed that it is highly contaminated with hazardous heavy metals and cyanide. The concentration of copper, hexavalent chromium, nickel, and cyanide in the rinsing water of metal plating department was 14.8, 40.9, 13.3, and 19 mg/l, respectively. The concentration of cyanide and zinc from the galvanizing department reached 60 and 80 mg/l. The remediation scheme included the application of in-plant control measures via changing the rinsing process followed by the destruction of cyanide and reduction of hexavalent chromium bearing wastes. The pretreated wastes were then mixed with other industrial wastes prior to a combined chemical coagulation-sedimentation using lime and/or lime in combination with ferric chloride. The results indicated that, after applying the waste minimization measures alone at the source, prior to final treatment of industrial waste, removal rates of cyanide, copper, nickel, and chromium concentrations were 23.2%, 14.9%, 32.3%, and 55.3%, respectively in the rinse water from metal plating department. Furthermore, the removal rates of cyanide and zinc in the galvanizing department reached 59.7% and 24.3. The integrated control measures and treatment scheme led to more than 99% removal of copper, nickel, chromium, and zinc, while the complete removal of cyanide was achieved in the final effluent.     

Seawater neutralization of alkaline bauxite residue and implications for revegetation

Reaction of bauxite residue with seawater results in neutralization of alkalinity through precipitation of Mg-, Ca-, and Al-hydroxide and carbonate minerals. In batch studies, the initial pH neutralization reaction was rapid (<5 min), with further reaction continuing to reduce pH for several weeks. Reaction with seawater produced a residue pH of 8 to 8.5. Laboratory leaching column studies were undertaken to provide information on seawater neutralization of the coarse-textured fraction of the waste, residue sand (RS), under conditions comparable with those that might be applied in the field. An 0.80-m-deep column of RS was neutralized by the application of the equivalent of 2-m depth of seawater. In addition to lowering the pH and Na content of the residue, seawater neutralization resulted in the addition of substantial amounts of the plant nutrients Ca, Mg, and K to the profile. Similar results were also obtained from a field-scale assessment of neutralization. However, the accumulation of precipitate, consisting of hydrotalcite, aragonite, and pyroaurite, in the drainage system may preclude the use of in situ seawater neutralization as a routine rehabilitation practice. Following seawater neutralization, RS remains too saline to support plant growth and would require fresh water leaching before revegetation.     

河北省应对水危机加快发展海水淡化的探讨

21世纪水危机严重威胁河北省经济社会发展。海水淡化是解决水危机问题的重要措施,具有良好的综合效益和发展前景。河北省海水淡化条件较好,基础比较雄厚,为此建议尽快编制河北省海水淡化规划,加快建设海水淡化工程,积极发展海水淡化装备制造业,并开展沿海热电厂非采暖季节利用气热淡化海水的实验研究。     

闽江口海域化学需氧量与溶解氧周年变化特征分析

根据2008年1—12月的调查数据,对闽江口海域海水中的COD和DO分布状况与特征进行周年的研究表明,闽江口海域全年的COD含量为0．63～1．70mg／L,符合第一类海水水质标准,季节性变化的规律不明显,受闽江冲淡水的影响,海水中的COD平面分布呈现近岸高,向外逐渐降低的趋势。海水中的DO含量为5．46—8．03mg／L,海水中DO较充沛。尽管受闽江每年向闽江口海域输送大量COD的影响,但是海水中的COD含量仍然较低,该海域具有较大的COD环境容量。     

Legal measures to reduce marine environmental risks of seawater desalination in China

Seawater desalination has become the focus of many countries to solve the problem of lacking freshwater resources. Seawater desalination in China launched in the 1960s and has developed rapidly since entering into the 21st Century. However, the technology of seawater desalination causes marine environmental pollution. After exploring the regulatory framework and legal system of reducing environmental risks of seawater desalination in China, it can be found that the existing regulatory framework and legal system have played a positive role in the treatment of seawater desalination, but it is undeniable that there are still many problems. How to effectively prevent or reduce the marine environment risks caused by seawater desalination and improve the existing regulatory framework and legal system in China are discussed. Specifically, in addition to further improve the Marine Environmental Protection Law, China shall integrate seawater desalination into unified regulation of marine resources, clarify statutory functions of various regulatory departments, improve the coordination mechanism, and promote marine environment and ecology protection by institutional construction.     

Utilisation of steel slags as neutralising agents in biooxidation of a refractory gold concentrate and their influence on the subsequent cyanidation

A study on the possibilities to utilise steel slag as neutralising agent in biooxidation of a refractory gold concentrate has been done with reference to commercial grade slaked lime. The idea has been to reduce the operating costs for neutralisation in the biooxidation plant, which is known to be the second largest operating cost. Other benefits would be savings in cost for landfilling of slag, possibilities to recycle elements present in the slag and savings of virgin limestone deposits. The slags used were an EAF slag and a slag from ladle refining; both originating from Swedish scrap based steel-making. Continuous biooxidation of the refractory gold concentrate was conducted in a single-stage 5 L reactor at a retention time of 56 h. The neutralisation capacity was determined by comparing the amount needed, per ton of feed concentrate added, to maintain the desired pH of 1.5 during steady state operation. Slaked lime had the highest neutralisation capacity with 110 kg/ton feed followed by ladle slag and EAF slag with values of 152 and 267 kg/ton feed, respectively. Sulphide mineral oxidation was similar and high in all cases although the ladle slag results were slightly better. Gold recoveries after cyanide leaching on the residues obtained were also similar and were in the range of 86-89%. However, the cyanide consumption expressed as kilogram cyanide per ton of concentrate fed to biooxidation, was double in the case of ladle slag and three times as much for the EAF slag compared to the slaked lime experiment. The increased cyanide consumption could not be explained only by the increased amount of elemental sulphur obtained in the slag experiments. The elemental sulphur formed had different reactivities as seen from the thiocyanate formation and cyanide losses due to thiocyanate formation were 16%, 32% and 40% for EAF slag, slaked lime and ladle slag, respectively. It is concluded that the ladle slag could be a possible replacement for limestone if they are mixed in proper proportions so that the microbial carbon dioxide demand is met whereas the EAF slag is less suitable due to the very fine reaction products obtained which gave operational problems with filtration and washing. To come further, experiments with the normal multi-stage biooxidation set-up with total retention time of 120 h should be performed which would increase the sulphur oxidation and eventually also reduce the cyanide consumption.     

低成本海水淡化集成技术探讨

海水淡化集成技术以低温多效蒸馏海水淡化为核心,联合热电与盐碱化工,形成"热-电-水-盐"四联产模式,实现淡水资源、海水资源以及能源的综合利用,大幅降低生产成本,并取得环保效益、社会效益。为未来向城市供水提供了一条现实可行的方案。