某硫酸盐还原菌株的分离及其在煤矸石山酸化污染修复中的应用

煤矸石堆场氧化导致的高盐酸性废水是严重危害煤矿区环境质量的污染源之一。利用硫酸盐还原菌进行生物固硫,能够有效控制煤矸石氧化产酸及其造成的污染。针对已知的硫酸盐还原菌多为严格厌氧菌、依赖外加碳源、难以应用于露天煤矸石山的问题,从酸性煤矸石堆场周边土壤中分离、筛选出一株兼性厌氧硫酸盐还原菌,分析菌株的16S r RNA基因序列、形态和生理生化特性,并利用柱状淋溶实验测定该菌株对煤矸石酸化污染的修复效果。结果表明:该菌株与Bacillus subtilis具有99.93%同源性,外形为杆状,大小(0.4～0.6)μm×0.2μm,最适生长温度范围为25～35℃,在p H为4～8的环境中均生长良好。该菌株对外加碳源的依赖性低,在无任何外加碳源的好氧条件下,接种该菌株18 d后,可将已酸化煤矸石的p H由3.09提升至4.62,同时去除48.25%的硫酸盐离子和88.40%以上的重金属离子,有效控制煤矸石堆场高盐酸性废水的产生。     

基于化学-微生物法的煤矸石山酸化污染原位控制技术研究进展

含硫煤矸石在露天堆储过程中会产生酸化污染，释放出大量有毒有害气体和高盐酸性废水。常用的物理阻隔措施难以满足煤矸石短期堆储时工程量小、取用矸石方便的需求。因此，找到一种基于化学法和微生物法的煤矸石酸化临时抑制措施是矿区生态修复领域的热点问题。针对煤矸石氧化过程受微生物调控的特点，归纳总结了化学法和微生物法在煤矸石山污染原位控制中的应用现状和存在问题。化学法通过应用有机杀菌剂抑制氧化菌活性，降低了煤矸石氧化速率，但大量施加杀菌剂可能带来环境风险；微生物法通过筛选、驯化还原菌，调节淋溶液pH值的同时去除盐和重金属离子，但需要依赖外加碳源。在此基础上，提出了化学-微生物法协同的煤矸石山酸化污染原位控制技术，利用有机杀菌剂为还原菌提供碳源，还原菌降解杀菌剂能够减少环境风险。此外，改良菌种、研发新型杀菌剂及其缓蚀剂将是未来研究的重点方向。     

硫酸盐还原菌治理地浸采铀地下水的柱实验研究

以新疆某地浸采铀矿山为实例,通过柱实验研究了硫酸盐还原菌去除地浸采铀污染地下水中铀和硫酸盐等污染物的潜力.实验结果表明,硫酸盐还原菌可有效去除地浸采铀矿山地下水中的污染物U(Ⅵ)和SO2-4,U(Ⅵ)的去除率可达94.5%,硫酸根去除率为75.3%,地下水的pH值可达到近中性.U(Ⅵ)和硫酸根都是作为硫酸盐还原菌的电子受体而通过生物还原去除的.研究结果为地漫废水的原住修复提供了新的生物技术思路.     

温度对煤矸石动态淋溶特性的影响

煤矸石长期堆存将对周边环境造成酸性污染和重金属含量超标。为研究煤矸石山发生氧化自热对酸性污染物降雨淋溶释放特性的影响机理,以山西省阳煤集团煤矸石为研究对象,建立了自动温控喷淋系统,通过对不同温度煤矸石进行动态淋溶实验,研究了淋溶液中pH值、电导率(EC)值、氧化还原电位(ORP)和硫酸盐(SO_4~(2-))含量的淋溶规律,并对淋溶前后煤矸石矿物组成进行半定量分析。结果表明:风化煤矸石中含有大量硫酸盐等可溶性组分,且酸性组分含量大于碱性组分和黏土矿物组分中和量总和,初期润湿液SO_4~(2-)含量超过地下Ⅲ类水指标,可看作高度矿化水,呈弱酸性和氧化状态,但氧化性未超过一般界定氧化性土壤的值(400 mV);随着累计淋溶时间延长,淋溶液pH值先增大后减小并最终趋于稳定,在t=3 h达到最大值为7. 34～8. 03,SO_4~(2-)含量和EC值先急剧减小后趋于稳定,稳态值分别约为2 500 mg/L和2 mS/cm,ORP在325. 9～435. 2 mV波动;随着温度升高(50～200℃),淋溶液稳态pH值(pH_s)和煤矸石剩余黄铁矿含量先减小后增大,150～200的pH_s值小于5.79,SO_4~(2-)含量和石膏相对质量分数先增大后减小,ORP波动性增强,相对标准偏差RSD由9. 54%增大到10.06%,EC值受温度影响不显著;淋溶液各项指标均在150℃条件下取得极值,pH_(s,min)为4. 98,呈较强酸性;ORP_(max)为435. 2 mV,呈强氧化态。由此可得:煤矸石中产酸物质氧化作用可分为风化氧化和自热氧化,主要受环境温度、含水量和与空气接触程度的综合影响;煤矸石自热氧化造成的酸性污染演变过程是由碱性组分、含氮物质和氧化产生的酸性组分共同决定的,且3种组分淋溶释放速率经长期堆存后逐渐趋于稳定。本研究解释了煤矸石中黄铁矿氧化产酸受环境温度的影响机制,为自热煤矸石山降雨淋溶造成酸性污染动力学演变预测提供依据。     

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%。     

混合硫酸盐还原菌的筛选及其生理特性研究

从某尾矿坝下500m污泥处筛选得到混合硫酸盐还原菌(SRB),研究了接种量、温度、初始pH、ρ(Fe~(2+))、ρ(SO2-4)以及碳源种类对混合SRB生长的影响。结果表明,该混合SRB在接种量为10%、温度25℃、初始pH=6.5、Fe~(2+)质量浓度为200mg/L、并以乳酸钠为碳源时生长最好。     

硫酸盐还原菌复合碳源的筛选

利用硫酸盐还原菌(Sulfate-Reducing Bacteria, SRB)的生物法可以有效去除酸法地浸采铀地下水中的硫酸根和重金属离子,是一种有发展潜力的酸法地浸采铀地下水修复技术。酸法地浸采铀地下水中的有机物含量较低,无法满足硫酸盐还原菌的生长代谢,需要向其提供充足的碳源。通过复合碳源筛选试验,发现混合比为10∶1的玉米芯和牛粪混合发酵液能够满足SRB生长代谢的需要,且该复合碳源能被SRB充分利用而不增加处理后酸法地浸采铀地下水的COD,可以作为生物法修复酸法地浸采铀地下水的SRB碳源。     

硫酸盐还原菌处理酸性矿山废水研究进展

酸性矿山废水的处理对环境可持续性至关重要。目前,利用硫酸盐还原菌修复酸性矿山废水因高效经济、环境友好、绿色安全等优势,备受国内外研究学者的关注。因此,本文通过对有关硫酸盐还原菌处理酸性矿山废水文献进行梳理,综述了酸性矿山废水的来源及危害,总结了硫酸盐还原菌去除酸性矿山废水中高硫酸盐和金属的机理,详细介绍了影响硫酸盐还原菌处理酸性矿山废水的主要因素,阐述了基于硫酸盐还原的生物反应器系统。最后,对硫酸盐还原菌处理酸性矿山废水的研究进行展望并提出建议。     

粒径对煤矸石污染物溶解释放规律影响研究

为研究粒径对不同地区煤矸石污染组分溶解释放规律的影响,以山西省和辽宁省3个煤矿区的4种煤矸石为试验材料,通过静态浸泡试验,分析了不同粒径、不同浸出时间条件下4种煤矸石浸出液的pH,氧化还原电位(ORP),电导率,总硬度,Fe2+、Mn2+、SO24-浓度等指标变化。结合X-射线衍射和扫描电子显微镜检测,阐明不同地区煤矸石污染组分溶解释放的机制。结果表明:在粒径为0.18～0.25 mm时,4种煤矸石释放的污染物量均达到较大值。阜新海州地区自燃煤矸石和海州地区原煤矸石的浸出液p H呈碱性,阜新高德地区自燃煤矸石和山西某矿原煤矸石的浸出液p H呈酸性。阜新高德地区自燃煤矸石浸出液的总硬度和SO24-质量浓度分别为589、529 mg/L,山西某矿原煤矸石浸出液的Fe2+质量浓度为10.79 mg/L,阜新海州地区自燃煤矸石浸出液的Mn2+质量浓度为1.97 mg/L。煤矸石的表面存在孔隙、附着细小颗粒,且包含的沸石、黄铁矿、绿泥石、高岭石和磁铁矿等矿物容易溶解,向水中释放污染物。煤矸石粒径越小污染物越容易溶解释放;浸出0～3 d内污染物容易溶解释放,后期释放量趋于平稳。建议矿区施工时保持煤矸石的粒径大于0.18～0.25 mm,以减少煤矸石在堆积和填充复垦过程中向土壤和地下水释放污染离子。     

硫酸盐还原菌修复四川某典型铜矿选冶渣复合重金属污染研究

为实现铜矿选冶渣复合重金属污染的修复治理,以四川某铜矿选冶渣为研究对象,采用硫酸盐还原菌为固化/稳定化微生物,探讨了其生长特性、溶液中重金属离子变化规律及修复效果。结果表明,硫酸盐还原菌在修复铜矿选冶渣时生长迅速,适合作为修复复合重金属污染的微生物;由于铁、锌、铜、铅等重金属活性差异较大,因此其固化效果亦有显著差异;修复30 d时,重金属Cu、Pb、Zn、Fe的最佳接种量分别为5%、10%、15%和15%,生物有效性降低率分别为72.36%、98.37%、43.01%和79.31%;随着固化时间的增加,溶液中重金属离子的浓度先增后减,但并不影响其修复效果。因此,硫酸盐还原菌可同时修复多种重金属离子,有效解决某铜矿选冶渣中铁锌铜铅的复合重金属污染。     

硫酸盐还原菌利用不同生物质碳源对酸性矿山废水的处理

针对多组分酸性矿山废水(Acid Mine Drainage,AMD)污染严重,治理费用高的特点,基于硫酸盐还原菌(Sulfate-Reducing Bacteria,SRB)处理AMD具有成本低、适用性强、环境友好等诸多优点,从长期受煤矸石淋溶水污染的土壤中纯化培养一株SRB,并采用廉价易得的玉米芯、甘蔗渣和花生壳作为SRB生长碳源分别构造1号,2号,3号组动态柱,进行处理AMD的模拟实验,以探讨SRB利用生物质碳源处理AMD的有效性和规律性。各动态柱分别按照正交试验最优配比进行装填,其中,1号柱中SRB生物量和60目玉米芯按固液比分别为106. 8∶100(mg∶m L)和3. 5∶100(g∶m L)装填,2号柱中SRB生物量和100目甘蔗渣按固液比分别为71. 2∶100(mg∶m L)和4. 5∶100(g∶m L)装填,3号柱中SRB生物量和100目花生壳按固液比分别为106. 8∶100(mg∶m L)和4. 5∶100(g∶m L)装填。实验结果显示,以100目甘蔗渣为碳源的2号柱处理AMD的效果较好,对SO_4~(2-),Fe~(3+),Mn~(2+),Cr~(6+),Cr~(3+)平均去除率分别为61. 63%,99. 81%,72. 35%,96. 8%,100%,而体系出水的p H值和ORP值分别为6. 38～7. 30,-246 m V,表明SRB以甘蔗渣为碳源时的生长代谢活性优于玉米芯和花生壳,甘蔗渣可实现较持久的碳源供应。通过反应前后生物质材料的SEM和XRD分析表明,大量的Fe元素主要通过生物质材料的化学吸附方式被去除,而Mn和Cr元素主要通过与硫酸盐还原菌的代谢产物反应生成金属硫化物沉淀除去,少部分金属元素通过生物质材料的物理吸附被去除。同时,反应前生物质材料表面结构完整,反应后的生物质材料结构被破坏并附着纳米级金属硫化物沉淀。     

Simultaneous Removal of Copper, Zinc, and Sulfate from Coal Mine Waste in a Laboratory SRB Bioreactor Using Lactate or Ethanol as Carbon Sources

The feasibility of inoculating coal mine waste piles with sulfate-reducing bacteria (SRB) to prevent the production of acidic leachates containing sulfate and metal contaminants was evaluated in batch and column bioreactors. The results showed that SRB growth and activity could be attained in the presence of acidic (pH 4.5) coal mine waste using lactate or ethanol as a carbon source, while no obvious growth was found at pH <3.5. Inoculation of coal mine waste in batch reactors with lactate or ethanol as a carbon source resulted in efficient neutralization and high removal of sulfate and metals. Similar results were attained in dynamic-flow columns inoculated with SRB. SEM-EDS analysis of the precipitates showed iron sulfide to be the main component. This study indicates that SRB could possibly be used to prevent or limit acidic drainage from coal mine waste piles.     

Upper and Lower Concentration Thresholds for Bulk Organic Substrates in Bioremediation of Acid Mine Drainage

Acidic pit lakes can form in open cut mine voids that extend below the groundwater table. The aim of this research was to determine what bulk organic material concentrations best stimulated sulphate-reducing bacteria (SRB) for acid mine drainage (AMD) treatment within a pit lake. An experiment was carried out to assess the effect of different substrate concentrations of sewage sludge on AMD bioremediation efficiency. Experimental microcosms were made of 300 mm long and 100 mm wide acrylic cores, with a total volume of 1.8 L. Four different concentrations of sewage sludge (ranging from 30 to 120 g/L) were tested. As the sewage sludge concentration increased, the bioremediation efficiency also increased, reflecting the higher organic carbon concentrations. Sewage sludge contributed alkaline materials that directly neutralised the AMD in proportion to the quantity added and therefore played a primary role in stimulating SRB bioremediation. The lowest concentration of sewage sludge (30 g/L) tested proved to be inadequate for effective SRB bioremediation. However, there were no measurable beneficial effects on SRB bioremediation efficiency when sewage sludge was added at concentrations >60 g/L. We compared our results with existing literature data to develop a conceptual model for remediation of AMD in pit lakes through organic material amendments. The model indicated that labile organic carbon availability was more important to the bioremediation rate than AMD strength, so long as iron and sulphate concentrations were not limiting. The conceptual model also indicates that bioremediation may still occur when only low concentrations of organic carbon are present in the pit lakes, albeit at a very slow rate. The model also demonstrates the presence of an organic material amendment threshold where excess organic carbon does not measurably influence the final outcome. The conceptual model defined is well supported by the results of the microcosm experiment.     

Sequential precipitation of Cu and Fe using a three-stage sulfidogenic fluidized-bed reactor system

The exposure of sulfides, such as pyrite (FeS₂) to water and air leads to the formation of acidic metal and sulfate containing waters, generally referred to as acid mine drainage (AMD). Under anaerobic conditions and in the presence of a suitable electron and carbon source, sulfate-reducing bacteria (SRB) can reduce sulfate to hydrogen sulfide which can precipitate metals as low-solubility sulfides. In the present study, a three-stage fluidized-bed reactor (FBR) system was operated at 35 °C with ethanol as an electron and carbon source for SRB to sequentially precipitate Cu and Fe from synthetic AMD. The system consisted of two pre-settling tanks before a sulfidogenic FBR for the sequential precipitation of Cu and Fe with biogenic H₂S gas and HS⁻ containing effluent, respectively. Cu and Fe precipitation efficiencies were over 99% and sulfate and COD removals 60-90%. Biologically produced alkalinity increased the initial pH of the AMD from 3.0 to neutral values.     

生铁屑固定硫酸盐还原菌颗粒特性实验分析

针对硫酸盐还原菌(SRB)处理煤矿酸性废水(AMD)需要充足碳源,易受外界因素干扰,单独作用效果差等问题,利用微生物固定化技术,以生铁屑作为主要基质材料,并联合SRB污泥、麦饭石及玉米芯颗粒,制备高活性生铁屑固定化颗粒,以完全活化的固定化颗粒为研究对象,探究生铁屑固定化颗粒的理化性状及对Mn~(2+)的吸附规律。结果表明:颗粒能够抵抗p H值为4的酸溶液(如AMD),并在碱、盐溶液中保持较好的稳定性,对Mn~(2+)的吸附容量符合Freundlich等温吸附方程(R2=0.98868,1/n=0.4896),吸附动力学符合Elovich动力学模型(R2=0.9964),可见,所制备的固定化颗粒对Mn~(2+)具有表面快速吸附的能力,且对处理AMD具有一定的适应性。     

Year-Round Performance of a Passive Sulfate-Reducing Bioreactor that Uses Rice Bran as an Organic Carbon Source to Treat Acid Mine Drainage

The development of compact and cost-effective passive treatment systems is of critical importance for acid mine drainage (AMD) remediation in Japan. The purpose of this study was to construct an AMD treatment system comprising a sulfate-reducing bioreactor using rice bran as a carbon source for sulfate-reducing bacteria (SRB) and to demonstrate its stable operation for at least a year in terms of continuous sulfate reduction and metal removal. Our 35 L bioreactor comprised a packed inoculum layer of a mixture of rice husks, limestone, and field soil, which was covered with rice bran. During operation, the AMD input flow rate was adjusted to 11.7 mL/min (hydraulic retention time, HRT; 50 h). Throughout the year, physicochemical analyses of system input and output AMD samples revealed that both pH and oxidation–reduction potential values were consistent with the process of sulfate reduction by SRB, although this reduction was observed to be stronger in summer than in winter. Efficient metal removal was observed, with concentrations at the outlet port of <0.33 mg/L Zn, <0.08 mg/L Cu, and <0.005 mg/L Cd, more than meeting Japan’s national effluent standards. Illumina sequencing of 16S rRNA genes revealed that Desulfatirhabdium butyrativorans-related species, which belong to a lineage within Deltaproteobacteria, were dominant (39–48% of the total SRB population) within the bioreactor.     

Start-up,adjustment and long-term performance of a two-stage bioremediation process,treating real acid mine drainage,coupled with biosynthesis of ZnS nanoparticles and ZnS/TiO2 nanocomposites

Acid mine drainage (AMD) generation is a widespread environmental problem in Europe, including Portugal. Previous experience has shown that a combined process consisting of an anaerobic sulphate-reducing bioreactor, following neutralization with calcite tailing, produces water complying with legal irrigation requirements from synthetic AMD. Aiming the treatment of real AMD a new bioreactor was inoculated with a SRB enrichment obtained from sludge from a local WWTP anaerobic lagoon. In the initial batch phase, sulphate supplementation was needed to achieve high sulphate-reducing bacteria counts before continuous feeding of AMD was started. The system quickly achieved good performance, proving it is easy to start-up. However, this time the neutralization step failed to keep bioreactor affluent pH higher than 5 for longer than three weeks. This was due to armouring of calcite by precipitates of various metals present in AMD. A new configuration, replacing a packed-bed column by a shallow contact basin, proved to be more robust, avoiding clogging, short-circuiting and providing long-term neutralization. The treated effluent, with excess of biologically generated sulphide, was successfully used to synthesize zinc sulphide nanoparticles, both in pure form and as a ZnS/TiO₂ nanocomposite, thus proving the feasibility of coupling an AMD bioremediation system with the synthesis of metal sulphide nanoparticles and nanocomposites.     

煤系地下水的硫酸盐还原菌与水文地球化学效应

为探索煤系地下水的硫酸盐异常偏低的机理,从井下705 m深钻孔地下水中分离得到1株硫酸盐还原菌GY-2,经16S rRNA测序及序列对比,鉴定为滴状脱硫肠状菌（Desulfotomaculum guttoideum）。实验结果显示,该菌株只在厌氧条件生长,适宜环境为中温、中性-弱碱性、中低矿化度的封闭含水地层,Fe 2+ 对菌株生长有显著促进作用。菌株的发现证实了煤系深部地下水的还原作用和硫酸盐还原菌的存在,对部分煤矿区地下水（HCO - 3 +CO 2- 3 ）/SO 2- 4 之比随着地层的埋深逐渐加大,而由大到小再到大的规律用硫酸盐还原作用和地下水氧化还原电位与水质类型对应关系作出了解释。     

铁屑协同SRB污泥固定化颗粒处理AMD动态试验研究

针对煤矿酸性废水(AMD)具有污染组分多、环境污染严重、传统处理方法容易造成二次污染及占地面积大等问题,采用微生物固定化技术制备高活性SRB污泥固定化颗粒,构建以1#(不含铁屑)、2#(含铸铁屑)和3#(含生铁屑)SRB污泥固定化颗粒为填料的动态柱实验模型,研究各基质材料处理AMD的效果和机理。结果表明:动态柱对AMD处理效果3#2#1#,3#动态柱的出水pH值为8.06,TFe、Mn2+、SO42-平均去除率分别达到99.93%、48.38%、45.85%,COD释放量为60 mg/L。因此,生铁屑作为固定化颗粒主要基质材料,与SRB协同体系能够强化固定化颗粒处理AMD的过程,具有较强的抗冲击负荷能力。     

Preparation of immobilized sulfate reducing bacteria (SRB) granules for effective bioremediation of acid mine drainage and bacterial community analysis

Heavy metal-resistant immobilized sulfate-reducing bacteria (SRB) granules were prepared to treat acid mine drainage (AMD) containing high concentrations of multiple heavy metal ions using an up-flow anaerobic packed-bed bioreactor. The bioreactor demonstrated satisfactory performance at influent pH 2.8 and high concentrations of metals (Fe 463 mg/L, Mn 79 mg/L, Cu 76 mg/L, Cd 58 mg/L and Zn 118 mg/L). The effluent pH ranged from 7.8 to 8.3 and the removal efficiencies of Fe, Cu, Zn and Cd were over 99.9% except for Mn (42.1–99.3%). The bacterial community in the bioreactor was diverse and included fermentative bacteria and SRB (Desulfovibrio desulfiricans) involved in sulfate reduction. The co-existing anaerobic fermentative bacteria (Clostridia bacterium, etc.) with the ability to use lactate as electron donor could explain the differences between actual lactate consumption and what would be expected based solely on sulfate reduction.