三种硫化铁单矿物的细菌氧化过程研究

载金的硫化铁矿物成分主要是黄铁矿,其次是磁黄铁矿和镍黄铁矿.三种单矿物分布在金矿石中的含量不同,细菌氧化周期也随之改变.试验表明,三种矿物氧化过程均产酸,黄铁矿被细菌直接氧化,溶液中细菌浓度较小;磁黄铁矿和镍黄铁矿除受细菌直接氧化,被Fe3+间接氧化也很显著.黄铁矿氧化时间大致是其他两种矿物的3倍,因而工业配矿可酌量降低富含黄铁矿之金精矿用量.本试验通过研究三种单矿物各自的细菌氧化过程,为成分复杂金精矿的细菌浸出工业实践提供了重要理论依据.     

氟苯酚好氧生物降解性能的研究

利用OxiTopBOD测试仪测定微生物耗氧量的方法,对邻氟苯酚、间氟苯酚和对氟苯酚三种污染物好氧生物降解性能进行了研究.结果表明:邻氟苯酚、间氟苯酚和对氟苯酚的生物氧化率分别是25.30%,35.28%和36.60%,其好氧生物降解速率常数分别是0.0093,0.0133和0.0145L·(g·h)-1,好氧生物降解性能的顺序为对氟苯酚>间氟苯酚>邻氟苯酚.     

氧化亚铁硫杆菌氧化黄铜矿的实验研究

黄铜矿是自然界中最为常见的含铜硫化物,矿石或尾矿中黄铜矿的风化往往会导致严重的矿区重金属污染,细菌的参与可以改变黄铜矿的氧化分解行为.本文通过对比实验系统研究了氧化亚铁硫杆菌（Acidothiobacillus ferrooxidans）对黄铜矿氧化分解的影响.利用等离子光谱仪（ICP-AES）、pH计、X射线衍射仪（XRD）和激光拉曼光谱分别测定了实验溶液的成分变化以及黄铜矿表面沉淀的物质组成.结果表明,细菌对实验溶液的pH值、Eh值和黄铜矿的氧化进程起着重要的控制作用.随着反应的进行及细菌的生长,溶液的pH值呈下降趋势,Eh值呈上升趋势,H＋和Cu2＋离子浓度升高.实验表明,细菌是整个氧化过程的主导因素,反应初期,Acidothiobacillus ferrooxidans氧化溶液和黄铜矿中的Fe2＋成Fe3＋ 随着反应的进行和Fe3＋的增多,在Acidothiobacillus ferrooxidans和Fe3＋的共同作用下,黄铜矿被氧化,并可生成自然硫,自然硫进而被Acidothiobacillus ferrooxidans氧化为SO42- Fe3＋对黄铜矿的化学氧化作用和细菌的生物氧化作用持续进行,构成了黄铜矿的氧化过程.反应后期,Fe3＋以次生沉淀形式覆盖在矿物表面,沉淀物对黄铜矿的溶出有抑制作用.     

难处理金矿吸附浸矿细菌多糖含量变化的研究

采用苯酚-硫酸方法测定HQ0211菌裂解液中多糖含量,得出最佳的裂解时间为25 min,最佳吸收波长为430 nm,最佳冷却时间为10 min.在利用HQ0211菌对含砷金矿进行吸附氧化试验研究时,微生物细胞多糖含量随着溶液体系电位的变化而变化.在480~572 mV阶段,游离在溶液中的细菌的多糖质量浓度为0.033~0.123 mg/mL,吸附在含砷金矿石矿物上的细菌细胞多糖为5.3~8.9 mg/g;当电位达到638 mV时,溶液中游离的细菌细胞多糖质量浓度达1.155 mg/mL,吸附在矿物上的细菌细胞多糖可高达57.5 mg/g.     

Bio-oxidation of pyrite, chalcopyrite and pyrrhotite by Acidithiobacillus ferrooxidans

This paper deals with the bio-oxidation processes by Acidithiobacillus ferrooxidans of pyrite, chalcopyrite and pyrrhotite. Our experimental results show distinctive bio-oxidation characteristics for the three sulfide minerals. In the presence of A. ferrooxidans, the sulfide oxidation rates generally decrease in the order of pyrrhotite, chalcopyrite and pyrite. The pH during bio-oxidation of pyrite tends to decrease as a whole, whereas a rise-fall pattern was recorded for both chalcopyrite and pyrrhotite in their pH variations. No deposition was observed during the bio-oxidation of pyrite, suggesting a possible link to lower pH value in the process. However, large amounts of jarosite and element sulfur were determined in the bio-oxidation processes of chalcopyrite and pyrrhotite. A. ferrooxidans individuals were found directly as attachments to erosion pits on the smooth surface of pyrite. The erosion pits are similar to the bacterium in shape and length, and thus are probably products of dissolution of organic acid secreted by the cells on the mineral surface. More complicatedly, biofilm exists on the surfaces of chalcopyrite and pyrrhotite. This type of structured community of A. ferrooxidans is enclosed in the extracellular polymeric substances (EPS), and covered with the deposition generated in the bio-oxidation processes of chalcopyrite and pyrrhotite. Different bio-oxidation processes of pyrite, chalcopyrite and pyrrhotite may be linked mainly to characteristics of individual minerals and the pH in the reaction solution of the bio-oxidation system.     

难处理金矿细菌氧化工艺中和水的成分分析

通过对中和水及结晶物进行的化学分析和X射线粉晶分析,查明中和水中含有大量的Mg,K,Na,Ca物质;其结晶物主要是硫酸盐:MgSO4·3H2O,MgSO4·4H2O,MgSO4·1 25H2O及CaSO4·2H2O·这些大量的镁和钙来源有:①细菌氧化工艺中使用的金矿中矿物成分复杂,其中含镁、含钙的碳酸盐、硅酸盐矿物较多,工艺过程中部分进入溶液,并积累起来·②用石灰进行中和时,中和后剩余的钙,停留在溶液中·中和水在复用返回细菌氧化流程时,由于镁、钙的浓度过高,会以硫酸盐形式结晶析出,造成水路堵塞,同时高浓度的镁会抑制浸矿细菌的生长,对工艺带来不利的影响·     

低品位原生金矿的生物柱浸

采用粘结剂S-11将某低品位原生金矿的精矿粘结包裹在其原矿矿石上进行生物柱浸与原矿生物柱浸的对比研究.主要研究了生物柱浸过程中Fe2+浓度,pH,Eh,矿石表面吸附的细菌及菌液中游离细菌数量的变化、矿石的脱砷率、脱硫率,生物柱浸后矿石金的氰化浸出率.结果表明:金精矿包裹后的矿石表面因含硫化矿物较多,更适合细菌的吸附与繁殖;包裹生物柱浸120 d后矿石的脱砷率为70.14%,脱硫率为41.26%,金的氰化浸出率为81.21%,比传统生物柱浸矿石的脱砷率、脱硫率和浸金率分别高24.01%,19.11%和21.48%.包裹生物柱浸对矿石的氧化效果明显.     

The Aerobic Biodegradability of Mono-fluorophenols by the Activated Sludge

By measuring the respiratory oxygen consumption, a study on the aerobic biodegradability of 2-fluorophenol, 3- fluorophenol and 4-fluorophenol was conducted using activated sludge acclimated by themselves respectively. The experimental results showed that bio-oxidation ratios of 2- fluorophenol, 3- fluorophenol and 4- fluorophenol were 25.30%, 35.28% and 36.60% respectively, and the constmdng rate constants were 0.009 3, 0.013 3 and 0.014 5 L/ gSS. h respect/vdy. The aerobic biodegradability of the mono-fluorophenols decreased in the order of 4- fluorop- henol〉3 - fluorophenol 〉2 - fluorophenol, resulting mainly from the different octanol/water partition coefficient and the different steric parameter of the fluorophenols which can affect the penetration of fluorophenol into cell membrane.     

闪锌矿-MnO2同时发电浸出过程的动力学

将发电浸出技术用于闪锌矿-MnO2的同时浸出,建立了生物发电浸出的原电池体系,分别研究不同粒度、不同温度时,有菌和无菌条件对闪锌矿发电浸出的影响。采用未反应核模型来研究有菌和无菌发电浸出过程中化学反应和扩散现象、采用SEM研究同时发电浸出中A.f菌对闪锌矿表面的作用,结果表明:有菌时,闪锌矿粒度为16.6μm时,12 h Zn2 浸出率达到32.01%,而达到同样的浸出率采用常规生物浸出时需要10 d;发电浸出过程的控制步骤是扩散;在阳极液中有菌时,发电浸出体系的活化能为11.97 kJ/mol,而无菌时的活化能为14.39 kJ/mol,这表明A.f菌能降低发电浸出反应的活化能。发电浸出进行24 h后,A.f菌能氧化发电浸出产生的硫。     

加压生化-混凝法处理喷漆废水试验研究

采用加压生化-混凝法处理汽车喷漆废水,具有COD去除率高、除磷效果明显,工艺流程简单等特点,处理出水可达到国家一级排放标准.