Acidithiobacillus thiooxidans浸出印刷线路板中金属的研究

印刷线路板(PCB)作为电子垃圾的主要成分,传统的处理方法环境污染严重,而且造成资源的严重浪费,因此找到无污染和可回收再利用的处理技术显得尤为重要.实验检测了利用嗜酸浸矿微生物处理印刷线路板回收其中金属的可行性,选用本实验室筛选的A.thiooxidans,对PCB中的金属进行了摇瓶浸出试验.在摇瓶培养中,10%的接种量,添加1.0 g样品时,Cu的浸出率达到了59.76%,而同期对照的H2SO4浸出试验中,其浸出率只有42.94%,对其他金属元素也有较好的效果.结果表明,利用A.thiooxidans比纯酸浸更能取得良好的效果.

嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans)TT03对碱性土壤的作用效果

针对前期研究中选育出的氧化硫硫杆菌TT03,为了解其对单质硫的转化作用而进行了试验。试验的结果表明,TT03与硫粉的加入,使得碱斑土壤与碱性耕作土壤的pH及性状发生改变,土壤向有利于耕作的方向发展;在碱性土壤中,培养到28d时pH下降到7.94,硫酸根含量达到187.4mg/kg,单质硫转化率达56.4%;在培养至63d时,pH下降到7.73,硫酸根含量上升到232.3mg/kg,单质硫转化率达71.4%。

Electrogenerative leaching for sphalerite-MnO_2 in the presence of Acidithiobacillus thiooxidans

A dual cell system was used to study the electrogenerative leaching sphalerite-MnO2 in the presence and absence of Acidithiobacillus thiooxidans (A. thiooxidans). The polarization of anode and cathode, and the relationship between the electric quantity (Q) and some factors, such as the dissolved rate of Zn2+ and Fe2+, and the time in the bio-electro-generating simultaneous leaching (BEGL) and electro-generating simultaneous leaching (EGL) were studied. A three-electrode system was applied to studying anodic and cathodic self-corrosion current, which was inappreciable compared with the galvanic current between sphalerite and MnO2. The results show that the dissolved Zn2+ in the presence of A. thiooxidans is nearly 43% higher than that in the absence of A. thiooxidans; the electrogenerative quantity in the former is about 150% more than that in the latter. The accumulated sulfur on the surface of sulfides produced in the electrogenerative leaching process can be oxidized in the presence of A. thiooxidans, and the ratio of biologic electric quantity reaches 27.9% in 72 h.

氧化硫硫杆菌(Acidithiobacillus thiooxidans)TT03的生长条件研究

针对前期筛选鉴定的氧化硫硫杆菌(Acidithiobacillus thiooxidans)TT03,为进一步了解和掌握其培养方法进行了本项研究。结果表明:TT03适宜在初始pH2.0～6.0与温度25℃～35℃的范围内生长;以硫酸铵为第一氮源,也可利用尿素和硝酸盐生长;为保证稳定的培养,需要加大接种量到2.0%以上;适量的氧气供给对TT03的生长是有利的;在二氧化碳的浓度达6%以上时生长受到抑制,而在6%以下时,对TT03的生长有促进作用。

Bioleaching of low-grade copper sulfide ores by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans

The grown conditions of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were investigated,and then experiments were conducted to research the bioleaching behaviors of crude ore of copper sulfide and hand-picked concentrates of chalcopyrite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans.The experimental results show that the bacteria grow best when the temperature is(30±1) °C and the pH value is 2.0.The bacteria concentration is 2.24×107 mL-1 in this condition.It is found that the copper extraction yield is affected by the inoculum size and the pulp density and the extraction yield increases as the inoculum size grows.The bioleaching rates reach their highest point in sulfide copper and chalcopyrite with a pulp density of 5% and 10%,respectively.Column flotation experiments of low-grade copper sulfide ores show that the bioleaching recovery reaches nearly 45% after 75 days.

Bioleaching and electrochemical properties of chalcopyrite by pure and mixed culture of Leptospirillum ferriphilum and Acidthiobacillus thiooxidans

The bioleaching of chalcopyrite was investigated using a pure and mixed culture consisting of iron-oxidizing Leptospirillum ferriphilum （L. ferriphilum） and sulfur-oxidizing Acidthiobacillus thiooxidans （.4. thiooxidans）. The electrochemical tests were conducted to investigate the bioleaching behavior of chalcopyrite by various bacteria. Bioleaching efficiency of chalcopyrite in mixed culture is higher than that in the pure culture of L.ferriphilum alone. The iron-oxidizing L.ferriphilum plays a dominant role during bioleaching of chalcopyrite in the mixed culture of L. ferriphilum and A. thiooxidans. During bioleaching, certain values of redox potential are beneficial to the decomposition of chalcopyrite. Jarosite and sulfur are observed as products of bioleaching. The addition of A. thiooxidans during leaching by L. ferriphilum can change the electrochemical control steps of leaching. The corrosion current density is substantially promoted in the culture involving bacteria, especially in the mixed culture.

萃取有机物污染黄铜矿的At.thiooxidans菌浸出

铜萃取有机物对浸矿微生物的危害日益受关注,探讨了Acidithiobacillus thiooxidans(At.thiooxidans)菌在被铜萃取有机物污染的低品位黄铜矿表面的吸附行为及其生物浸出特征。结果表明:由于萃取有机物的吸附增强了矿石表面疏水性与电负性,使At.thiooxidans细胞在受污染低品位黄铜矿表面的吸附率提高19%。然而,高细胞吸附率并不意味着高浸出率。在受污染低品位黄铜矿的生物浸出过程中,细胞生长速度降低9%,铜浸出率降低29%。CLSM以及SEM观察发现,在萃取有机物胁迫下,附着细胞的胞外多聚物(Extracellular polymeric substances,EPS)分泌受到抑制,势必影响生物膜的构建。在矿石被污染的情况下,有机膜覆盖、细胞新陈代谢受抑制、EPS分泌减少,是导致浸出率降低的主要原因。

Single and cooperative bioleaching of sphalerite by two kinds of bacteria——Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans

A cooperative bioleaching(Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans)and single bioleaching(Acidithiobacillus ferriooxidans or Acidithiobacillus thiooxidans)of sphalerite were investigated by X-ray diffractometry,energy dispersive spectrography and scanning electron microscopy.The experimental results show that the leaching rate of zinc in the mixed culture is higher than that in pure culture and the sterile control.In these processes,two kinds of bacteria perform different functions and play a cooperative role during leaching of sphalerite.The bioleaching action carried out by Acidithiobacillus ferriooxidans(A.ferriooxidans)is not directly performed through Fe2+ but Fe3+,and its role is to oxidize Fe2+ to Fe 3+ and maintain a high redox potential.Moreover,the addition of an appropriate concentration of ferric iron to the leaching systems is beneficial to zinc dissolution.In the leaching systems without Acidithiobacillus thiooxidans(A.thiooxidans),elemental sulfur layers are formed on mineral surface during the dissolution of zinc and block continuous leaching.Acidithiobacillus thiooxidans,however,eliminate the passivation and cause the bioleaching process to continue in the leaching systems.At the same time,protons from the bacterial oxidization of the elemental sulfur layers also accelerate the leaching of zinc.

Microbial leaching of marmatite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans

The bioleaching of marmatite in shaken flasks was studied. After leaching for 29 days, the leaching ratio of zinc was 91%. Three kinds of bacteria, mixture-based bacteria, 9K-based bacteria and sulfur-based bacteria were used in marmatite leaching, of which the mixture-based bacteria have the best leaching result while the sulfur-based bacteria have the worst. By analyzing the leaching residue using SEM and EDXA, the marmatite leaching mechanism was discussed.

微波强化嗜酸氧化硫硫杆菌浸出废线路板中铜的条件优化

为提高电子废弃物中金属铜的生物浸出率,用微波强化嗜酸氧化硫硫杆菌(Aidithiobacillus thiooxidan)对废线路板中铜的浸出,采用Plackett-Burman法和Box-Behnken法优化强化浸出条件。Plackett-Burman法表明微波功率、辐照时间和浸出时间能够显著影响废线路板中铜的生物浸出率。最陡爬坡实验确定3因素的中心值为微波功率340 W、辐照时间3.60 min和浸出时间6.80 d。采用Box-Behnken法优化浸铜条件。研究发现,微波功率、浸出时间、微波功率和浸出时间及辐照时间和浸出时间的交互作用对浸铜有显著影响,辐照时间有影响但不显著。模型预测最优条件为微波功率336.10 W、辐照时间3.59 min和浸出时间6.82 d,预测最优浸出率为75.69%。调整微波强化废线路板中铜的生物浸出条件为微波功率336 W、辐照时间3.60 min和浸出时间6.80 d,实际铜浸出率为75.41%±0.76%,与模型预测结果相近。表明所得最优条件真实有效,可用于后续研究。

A3钢在氧化硫硫杆菌作用下的腐蚀行为

采用表面分析技术、失重法和电化学测试研究了A3钢在氧化硫硫杆菌(T.t)作用下的腐蚀行为.扫描电子显微镜(SEM)分析结果表明,与无菌体系相比,氧化硫硫杆菌会在A3钢表面形成致密的生物膜和腐蚀产物膜.去除膜层后,无菌体系中的试样出现点蚀,氧化硫硫杆菌体系中试样呈现为均匀腐蚀.浸泡三周后,氧化硫硫杆菌体系中A3钢的腐蚀失重远小于无菌体系.电化学交流阻抗谱(EIS)测试结果显示,在浸泡10d后,氧化硫硫杆菌中的电极表面只存在两个时间常数,这表明氧化硫硫杆菌会在试样表面形成致密且附着力非常强的产物膜层,有效地阻碍了腐蚀介质对基体的侵蚀.极化曲线结果表明,浸泡20d后,氧化硫硫杆菌的存在使得金属具有较小的自腐蚀电流密度.

In vitro microbiologically-induced concrete corrosion behavior of Ag^(+) loaded zeolite-polyurethane coating for concrete sewer applications

Microbiologically-induced concrete corrosion(MICC)refers to chemical reactions between biologically produced sulphuric acid and with hydration products in the hardened concrete paste,resulting in an early reduction of strength,deterioration,and very severe circumstances,structural failure.This paper explores the bactericidal characteristics of cementitious materials with surface coated with modified zeolite-polyurethane.The zeolite-polyurethane coating incorporated with silver was studied in environments inoculated with A.thiooxidans bacteria for 8 consecutive weeks.The antibacterial characteristics were evaluated in terms of pH,optical density(OD),sulphate production and bacteria count to determine the effectiveness of the zeolite-polyurethane coatings in environments inoculated with A.thiooxidans bacteria producing the sulphuric acid.The results revealed that the samples incorporated with silver modified zeolites generally showed antibacterial performance(regardless of the zeolite type)compared with unmodified polyurethane coating.This was evaluated by the lack of bacteria attachment and the deformed microcolonies on the sample surface,lag in pH reduction,increase in OD,and sulphate production.The silver zeolites gained their antibacterial performance from the release of silver ions(Ag^(+))when the sample comes into contact with aqueous solutions.This results in the inhibition of cell functions of the bacteria and subsequently causes cell damage.

Efficacy of chalcopyrite bioleaching using a pure and a mixed bacterium

To determine the efficacy of chalcopyrite bioleaching using pure cultures of Thiobacillus ferrooxidans or Thiobacillus thiooxidans and a mixed culture composed of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, experiments were carried out in shake flasks with [Fe^2＋] 4 g·L^-1 and S 1 g·L^-1 at pH=1.80, 130 r/min and 30℃. The tests showed that the copper extraction in a mixed culture composed of Thiobacillusferrooxidans and Thiobacillus thiooxidans is higher than that in a pure culture. On the other hand, an important potential of Thiobacillus thiooxidans to leaching chalcopyrite was indicated. Thiobacillus thiooxidans can prevent jarosites accumulating on the substrate and allow further copper to dissolute through the action of ferric ion. The selection of the suitable pH in a leaching solution would be significant. Thiobacillus thiooxidans and Thiobacillus ferrooxidans play an important role in the bioleaching process. Finally, the mechanism and the reason for iron precipitation were also discussed in detail.

Effect of technological factors on bacterial leaching of low-grade Ni-Cu sulfide ore

The bioleaching of a low grade Ni Cu sulfide ore from Jinchuan Mine with Thiobacillus ferrooxidans (TF5) and Thiobacillus thiooxidans (TT) was investigated. The effect of pH, the initial cell numbers of bacteria, the pulp density and the ratio of TF5 and TT on leaching was described, and the favorable bioleaching conditions for the ore were experimentally confirmed. The aeration leaching, agitation leaching with air bubbling, and column leaching were respectively tested. The highest recovery was achieved in the aeration leaching. After leaching for 20?d with pulp density of 15%, the extractions of Ni, Cu and Co were respectively 95.4%, 48.6% and 82.6%.

A new strain Acidithiobacillus albertensis BY-05 for bioleaching of metal sulfides ores

An acidophilic,rod-shaped Gram-negative sulfur oxidizing strain BY-05 was isolated from an acid mine drainage of copper ore in Baiyin area,Gansu Province,China.Ultrastructural studies show that the isolate has a tuft of polar flagella and possesses sulfur granules with clear membrane adhering to the cell innermembrane.Physiological study shows that this isolate grows autotrophically and aerobically by oxidizing S0and reduced inorganic sulfur compounds(SO, 2 23-SO, 2 24- S2 -and ZnS)with the optimum growth at pH 3.5-4.0 and at the temperature range of 25-30℃.The 16S rRNA gene sequence(DQ 423683)of strain BY-05 has 100%sequence similarity to that of Acidithiobacillus albertensis(DSM 14366).So it is identified and named as A. albertensis BY-05.Bioleaching experiments with this new strain show that it can play an important role in recovery of metals from chalcopyrite and sphalerite.

Liquid-nitrogen cryopreservation of three kinds of autotrophicbioleaching bacteria

Three kinds of autotrophic bioleaching bacteria strains,including mesophilic and acidophilic ferrous ion-oxidizing bacteria Acidithiobacillus ferrooxidans(A.ferrooxidans),mesophilic and acidophilic sulfur-oxidizing bacteria Acidithiobacillus thiooxidans(A.thiooxidans),and moderately thermophilic sulfur-oxidizing bacteria.4cidianus brierleyi,were cryopreserved in liquid nitrogen and their ferrous ion-or sulfur-oxidizing activities were investigated and compared with the original ones.The results revealed that ferrous ion/sulfur oxidation activities of the strains were almost equal before and after cryopreservation.Glycerin was used as cryoprotective agent.In conclusion,liquid-nitrogen cryopreservation is a simple and effective method for autotrophic bioleaching microorganisms.

氧化硫硫杆菌的研究进展

综述了氧化硫硫杆菌(Thiobacillusthiooxidans,T.t)培养方法和应用方面的研究进展。

三株氧化硫硫杆菌的分离与鉴定(英文)

从煤堆废水中分离得到3株嗜温嗜酸硫氧化细菌。这3株菌株为革兰氏阴性、菌体大小0.4～0.7μm×1～2μm、短杆状运动细菌,其最适生长温度为30℃和最适生长pH2.0～2.5。它们能够利用元素硫,硫代硫酸钠和连四硫酸钾为能源进行自养生长,不能利用有机物质以及硫酸亚铁、黄铁矿和黄铜矿等无机物质作为能源生长。细菌的形态、生理生化特性研究以及基于16SrRNA序列同源性构建的系统发育树结果表明,这3株细菌初步鉴定为氧化硫硫杆菌。氧化硫硫杆菌能够通过产酸有效促进黄铜矿的浸出速率和浸出率。

氧化硫硫杆菌和芽孢杆菌协作下Q235钢腐蚀行为

采用表面分析技术、失重法和电化学测试技术研究了Q235钢在氧化硫硫杆菌(T.t,Thiobacillus thiooxidans)和芽孢杆菌(Bacillus)协同作用下的腐蚀行为.扫描电镜结果表明,与单菌体系相比,混菌体系会形成最为致密的生物膜;混菌体系中浸泡的试样表面会出现不同于单菌体系的圆形蚀坑.腐蚀失重结果表明,混菌中试样的腐蚀速率介于2个单菌体系之间.交流阻抗结果表明,混菌体系浸泡2天后试样表面出现2个时间常数,表面膜层电阻经历了先增大后减小的过程.

储罐罐底水含酸及对喷气燃料性能的影响

对喷气燃料储罐罐底含酸的原因及危害进行了研究 ,指出氧化硫硫杆菌生长繁殖产生的硫酸导致罐底水pH降低 ,硫酸与罐底水中的硫化物反应生成硫化氢导致喷气燃料银片腐蚀不合格。