Using permeable reactive barriers for the treatment of acid rock drainage

Acid mine drainage (AMD) is the most serious environmental problem facing the Canadian mineral industry today. It results from oxidation of sulphide minerals (e.g. pyrite or pyrrhotite) contained in mine waste or mine tailings and is characterized by acid effluents rich in heavy metals that are released into the environment. A new acid remediation technology is presented, by which metallurgical residues from the aluminium extraction industry are used to construct permeable reactive barriers (PRBs) to treat acid mine effluents. This technology is very promising for treating acid mine effluents in order to decrease their harmful environmental effects.     

用零价铁渗滤墙技术修复我国铀尾矿地下水的探讨

活性渗滤墙技术凭借其各方面的优越性成为人们在治理污染地下水时的首选。零价铁廉价、易得,据国外文献介绍,其在用于包括铀在内的重金属去除时都可以达到很好的效果。在进一步的研究基础上,有望将这一新技术应用于我国铀尾矿库区地下水的修复中。     

酸性矿山废水中表面钝化技术的研究进展北大核心

酸性矿山废水(AMD)是最为严重的环境污染之一,主要由黄铁矿氧化引起。AMD的治理主要有末端处理和源头控制两条途径,末端处理技术不能从根本上解决污染问题,因此从源头控制黄铁矿的氧化是治理AMD的根本途径。源头控制技术主要有覆盖法、杀菌法和表面钝化法等,表面钝化法是目前科研工作者的研究热点。在介绍AMD成因的基础上,综述了各种表面钝化技术。重点概述了有机硅烷、载体-微胶囊化、自修复等技术的研究现状,分析了不同方法的优缺点,并针对其不足之处提出了今后的研究方向。为解决黄铁矿氧化问题、实现AMD污染的有效治理提供参考。     

酸性矿山废水处理技术及其发展前景

叙述了酸性矿山废水的来源、分布及其危害．分析总结了改造选矿流程、中和法、硫化法和置换中和法等经济、实用的酸性矿山废水处理技术现状．并进一步阐述了酸性矿山废水处理技术的发展前景。     

尾矿库酸性矿山废水的源头控制方法

有色金属矿的尾矿库会产生酸性矿山废水,给矿区周围的土壤和地下水带来严重威胁。通过源头控制技术可以降低尾矿内硫化矿物的氧化速率,从而在源头上减少酸性矿山废水的产生。本文系统介绍了干式覆盖法(无机矿物覆盖层和有机覆盖层)、湿式覆盖法、掺碱混合填埋法以及细菌活性抑制法等几种源头控制方法的工作原理、实施方法以及工程应用实例。另外,论文还对各种源头控制方法存在的问题进行了分析和总结,并指出该领域未来需要在以下方面进行重点研究:对于无机矿物覆盖层,要注意研究其长期性能的劣化问题;对于有机覆盖层,需要对其可能存在的负面效应问题进行探讨;分析环境条件对作用效果的影响是湿式覆盖法在未来需要着重研究的问题;克服包裹效应是掺碱混合填埋法需要首先解决的问题;而对于细菌活性抑制法,则应重点考虑新型抑菌剂的研制及投放方式开发问题。     

Development of a new covering strategy in Indonesian coal mines to control acid mine drainage generation: a laboratory-scale result

The waste dump of sulphide-containing rocks is one of the potential acid mine drainage sources, since it contains a huge amount of readily oxidised sulphide mineral, due to its exposure to air and water. The application of the dry cover system is regarded as one of the best practices since it prevents acid mine drainage of the waste rock dump at the surface coal mine. However, the implementation of the dry cover system in field practice has faced several obstacles due to the limited number of cover materials. The nature of geological condition is considered to be a controlled issue, whilst the problem is the mining method and equipment size. This article describes the acid generation mechanism and its control, application of cover system and the problems that are faced in Indonesian coal mines, whilst discussing the preliminary laboratory results of multi-layer cover systems. It finally proposes a new covering strategy in an attempt to overcome the problem.     

煤矿酸性矿井水中有害元素的迁移特性

利用电感耦合等离子质谱（ICP-MS）、离子色谱（IC）和X射线衍射（XRD）等方法研究了马兰煤矿酸性矿井水及其沉淀物的化学成分和物相组成,并通过吸附解吸实验和PHREEQC水化学模拟计算研究了典型酸性矿井水样品中Pb,Th,U,Be,Zn,Ni,Co,Cd,Cu,As,Cr,V,Ba等有害元素的迁移特性.研究表明：① 煤矿酸性矿井水中SO^2-₄,Fe,Mn,Al,Pb,Th,U,Be,Zn,Ni,Co,Cu等离子含量较高,对环境存在潜在危害;② 酸性矿井水中有害元素的迁移主要受pH,Fe-Al-Mn含量和水体颗粒物矿物组成的控制;③ Fe,Al和Mn的含量随pH上升而迅速下降,并控制着Pb,Th,U,Be,Zn,Ni,Co,Cu等潜在有害微量离子的迁移行为; ④ 各离子随pH上升被去除的先后顺序为: Th>Fe>Pb >Cr>Al>Cu>Be>U>Zn>As>Cd>Mn>Co>Ni>Ba;⑤ 酸性矿井水中V不能够随pH的升高而去除,反而会有更多的V溶解在水中.     

煤矸石用于人工湿地处理酸性矿井水的研究

阐述了利用煤矸石作为人工湿地填料处理酸性矿井水的技术研究,对煤矸石的综合利用、酸性矿井水的回用以及矿区生态环境的综合治理都有重要意义。     

基于不同形式MFC的PRB对AMD处理效果影响

基于SRB生物阴极MFC的可渗透反应墙（SRB-PRB）原位处理酸性矿井水,MFC结构与MFC 在SRB-PRB布局设计是影响预调节C/S,pH,M2+浓度效果的主要因素。实验构造了2种MFC结构（圆筒型、平板MFC）及在PRB中3种布局方式（点阵、顺流、横向渗流）,用于相同体积活性填料的可渗透反应墙中,研究不同结构MFC对AMD的预处理效果。AMD水质为pH=3,ρ（SO2-4）=3 000 mg/L,Fe2+,Cu2+,Zn2+质量浓度均为30 mg/L,调节HRT为3,2.5,1.5 d。结果表明,MFC对AMD预处理调节效果与污泥碳源可利用性、MFC结构及在PRB中的布置方式有关,影响程度:碳源＞MFC结构＞布置方式。圆筒型MFC结构优于平板型,功率密度是平板型的2倍。3种布局方式圆筒点阵式结构PRB出水pH值在7左右,Fe2+,Cu2+,Zn2+去除率分别为96.2%～100%,99.6%～100%,95.3%～99.3%,且均高于高于平板型;SO2-4去除速率平均高于平板式7 g/（m3·h）左右。圆筒型MFC点阵布局方式表现出性能稳定、设计灵活的特点。     

方解石处理酸性矿排水次生矿物学和渗透性的研究

采用批实验和柱长期运行实验研究方解石处理酸性矿排水中次生矿物学和渗透性问题,扫描电镜（SEM）和傅里叶红光谱（FTIR）结果揭示方解石包覆层包括两层,内层为结晶石膏层,外层为纤铁矿层,后变为针铁矿;通过费克第一定律建立包覆下的溶解模型, ρ (Ca 2+ )= At 1/2 +B,其A 值与包覆层石膏比例（ f gyp ）平方成反比;柱实验结果揭示渗透系数变化是一个突变过程,长期处理中外层的Fe系包覆层是引起堵塞的关键。     

AMD蚀化砂岩细观力学效应

通过pH值为1.25,3.38的AMD溶液蚀化下砂岩细观结构及力学试验,分析砂岩细观结构及力学性质变化规律;运用分形理论描述砂岩细观结构分布特征,得到AMD蚀化下砂岩表面SEM图像的分形维数（D）;基于砂岩弹性模量的变化,引入AMD蚀化下砂岩化学损伤变量（w）,建立w与 D 之间的关系。结果表明：AMD蚀化下砂岩细观结构分布具有分形特征, w 与 D 存在较好的线性关系。pH=1.25时, w=0.78D－1.62;pH=3.38时, w=0.97D－2.04,相关系数均在0.98以上。研究结果从细观层次揭示了AMD蚀化砂岩力学效应。     

金属矿山酸性废水处理技术研究进展

概述了矿山酸性废水的形成及危害,重点介绍了几种常见的处理矿山酸性废水的处理技术如中和法、硫化物沉淀法、吸附法、离子交换法和人工湿地法,同时介绍了它们的原理、特点和存在的问题,在此基础上,对矿山酸性废水处理技术的研究进行了展望。     

矿山酸性废水处理高密度泥浆法及辅助沉降协同试验研究

针对某矿山含铜含氰酸性废水,采用高密度泥浆法底泥回流及金选厂炭浸尾矿渣浆辅助沉降综合协同试验,进行了絮凝剂选型及用量、底泥回流、添加金选厂炭浸尾矿增加固含量来提高浓密沉降效果等一系列试验研究。试验结果表明:在应用高密度泥浆法同时,协同添加炭浸尾浆辅助沉降时体系固含保持在1%～2%较为适宜,当体系固含从1%增加到2%时(底流全部回流),絮凝沉降半小时后,上清液总铜浓度从0.227mg/L降低到0.162mg/L;当体系固含2%(底流按固含1.5%回流,剩余固含0.5%由新炭浸浆补充)时,絮凝沉降半小时后,上清液总铜浓度为0.150mg/L。当体系固含量2%,絮凝剂DRYFLOC23E用量为2mg/L时,底流部分回流在底流按固含1.5%回流加0.5%由新炭浸浆补充的时候,出水水质的总铜浓度、达标稳定性、沉降效果总体指标最佳。     

基于《水处理工程》的酸性高铁矿井水综合实验设计

菱镁矿尾矿煅烧后产生的轻烧镁粉对于酸性矿井水的处理具有效果好、操作条件良好、沉渣少等优点。通过对轻烧镁粉的成分分析可知,主要成分氧化镁占比高于90%。以山西某煤矿酸性矿井水为研究对象,对其进行常规水质分析可知,总铁浓度为230.01mg/L、亚铁离子浓度为66.98mg/L、pH值为3.24。采用轻烧镁粉进行酸性矿井水处理,设计正交实验,分析初始pH值、药剂投加量、曝气量、曝气时间等对处理效果的影响。实验结果表明,在投加轻烧镁粉量为0.50～1.00g/L时,酸性矿井水初始pH值可由3.15～3.31提高到6～9左右,缓冲性能较好,较容易控制投加量使pH值控制在6～9;轻烧镁粉处理酸性矿井水时三个主要因素的影响程度大小为:投加量搅拌时间搅拌速度,当轻烧镁粉投加量为0.85g/L、搅拌速度为400r/min、搅拌时间为12min时,实验效果较好;利用轻烧镁粉提高酸性矿井水的pH值到7.48时,曝气5min,曝气量为0.5m3/h,聚合氯化铝(PAC)投加量为10mg/L时,经处理矿井水中亚铁离子和总铁浓度可分别降至0.07mg/L和0.17mg/L,满足排放或回用水对总铁的要求,且改善了沉渣的沉降性能,大大缩短了沉降时间。     

SRB菌的分离鉴定及其对矸石山酸性废水的处理

为了得到煤矸石山酸性废水处理的专属功能微生物,从湖南湘潭某煤矸石山周边土壤中分离筛选硫酸盐还原菌,分析菌株的16S rRNA基因序列,形态和生理生化特性,并利用得到的菌株处理矸石山酸性废水。16S rRNA基因序列分析表明,所分离得到的硫酸盐还原菌株S-7与Desulfuromonas alkenivorans同源性达到99.0%。该菌株为杆状稍有弯曲,能运动,大小(0.5~0.8)μm×(3.0~4.0)μm,革兰氏染色显阴性,最适生长温度为30℃,最适p H值范围6~8,酵母粉为最好的碳源和氮源,硫酸钠为最适合硫源,菌株经培养96 h后细胞浓度高达1.76×109个/m L。培养初始p H为7时,6 d可去除体系中90%硫酸根离子,而不同硫酸根离子浓度对菌株生长和硫酸盐去除效率影响不明显。S-7菌株对矸石山酸性废水中Fe,Mn,Pb和Zn四种重金属离子均存在处理效果,整体上去除效率为PbFeZnMn,其中Pb离子经7 d处理后去除率达到100%。     

Organic wastes as carbon sources to promote sulfate reducing bacterial activity for biological remediation of acid mine drainage

Chicken manure, dairy manure and sawdust were evaluated as carbon sources in promoting sulfate reduction, and the mechanism of heavy metals removal in sulfidogenic bioreactor was revealed. The sulfate reduction reached 79.04% for chicken manure, 64.78% for dairy manure, and 50.27% for sawdust on 35th day, which showed that chicken manure could promote sulfate reducing bacteria (SRB) activity, followed by dairy manure and sawdust. In batch experiment, although chicken and dairy manure bioreactors showed sulfidogenic activity, it demonstrated less than 5% contribution from sulfide precipitation and over 95% from other removal mechanisms (sorption to manure particles and hydroxides precipitation, etc.). Column bioreactor showed satisfactory performance in biological remediation of acid mine drainage, evidenced by effluent Eh and pH, high removal efficiencies of sulfate and metals, and a considerable SRB counts. SEM–EDS analysis of the formed precipitate showed metal sulfides were formed. The results indicated that organic waste played an important role in sulfidogenic activity, which could not only provide reducing condition and carbon source for sulfate reduction process, but also reduce the adverse effect of heavy metal and strong acidity on SRB activity owning to metals sorption and acidity buffer of organic waste.     

Fate of sulphate removed during the treatment of circumneutral mine water and acid mine drainage with coal fly ash: Modelling and experimental approach

The treatment of acid mine drainage (AMD) and circumneutral mine water (CMW) with South African coal fly ash (FA) provides a low cost and alternative technique for treating mine wastes waters. The sulphate concentration in AMD can be reduced significantly when AMD was treated with the FA to pH 9. On the other hand an insignificant amount of sulphate was removed when CMW (containing a very low concentration of Fe and Al) was treated using FA to pH 9. The levels of Fe and Al, and the final solution pH in the AMD–fly ash mixture played a significant role on the level of sulphate removal in contrast to CMW–fly ash mixtures. In this study, a modelling approach using PHREEQC geochemical modelling software was combined with AMD–fly ash and/or CMW–fly ash neutralization experiments in order to predict the mineral phases involved in sulphate removal. The effects of solution pH and Fe and Al concentration in mine water on sulphate were also investigated. The results obtained showed that sulphate, Fe, Al, Mg and Mn removal from AMD and/or CMW with fly ash is a function of solution pH. The presence of Fe and Al in AMD exhibited buffering characteristic leading to more lime leaching from FA into mine water, hence increasing the concentration of Ca²⁺. This resulted in increased removal of sulphate as CaSO₄·2H₂O. In addition the sulphate removal was enhanced through the precipitation as Fe and Al oxyhydroxysulphates (as shown by geochemical modelling) in AMD–fly ash system. The low concentration of Fe and Al in CMW resulted in sulphate removal depending mainly on CaSO₄·2H₂O. The results of this study would have implications on the design of treatment methods relevant for different mine waters.     

Remediation of acid mine drainage using metallurgical slags

In this study basic oxygen and stainless steel slag were both assessed for potential use in treating acid mine drainage. The stainless steel slag was able to effect some pH change but was found to not be suitable. Basic oxygen slag was found to have a significant potential as a remediating agent. For a model acid mine water with a pH of 2.5, sulfate concentration of 5000 mg/L and iron concentration of 1000 mg/L, the slag was able to increase pH to 12.1, reduce the soluble iron by 99.7% and reduce sulfate by 75% in batch experiments. In these batch reactors most reaction was completed within 30 min indicating that this is a rapid process. Additional experiments were conducted with continuous flow reactors to assess the maximum treatment capacity of the slag. These experiments indicated that slag replacement strategies are wholly dependent on the strength of the acid mine drainage, the required residence time and the specified residual concentrations of iron or sulfate and the pH. The data indicate that in particular, basic oxygen furnace slag has significant potential as a replacement reagent for lime in treating acid mine drainage.     

矿用立泵在济三煤矿工作面排水中的应用

一般的潜水泵在输送含沙水、泥浆水或污水时技术性能急剧恶化,主要原因是固体之间是撞击磨损.矿用立泵的流道设计符合固体流场的变化规律,叶轮发生的主要是摩擦磨损,极大地延长了潜水泵的使用寿命.采用KL120-50型矿用立泵进行井下工作面低洼点处排水,轻便安全、高效节能,能够适应矿井复杂多变的环境.     

酸性矿井水中氧化亚铁硫杆菌的抑制研究

在氧化亚铁硫杆菌(T.f)的生物氧化作用下,煤中的硫铁矿被氧化成硫酸和铁离子,是形成酸性矿井水的主要原因。本研究以亚铁离子的被氧化程度和速率为指标,以温度、pH和抑制剂硫酸月桂酯钠(SLS)浓度作三因素三水平正交试验,探讨抑制T.f氧化作用的因素,达到从源头控制酸性矿井水产生的目的。结果表明SLS浓度对抑制T.f的影响明显。当温度为25℃,pH为3,SLS浓度为7.5mg/L时,抑制作用最强。