微生物对煤矿固体废弃物的脱硫效应

煤矸石是煤矿特有的一种固体废弃物，应用本实验室筛选出的氧化亚铁硫杆菌Thiobacillus ferrooxidans和嗜酸氧化硫硫杆菌Thiobacillus thiooxidans对宁夏大武口高硫煤矸石进行微生物脱硫技术及应用条件的研究，如不同煤矸石粒径、不同接种浓度和不同煤矸石浓度。2种脱硫细菌对煤矸石的脱硫效果显著，小粒径煤矸石的微生物脱硫效果更好。考虑脱硫成本及脱硫效率，Thiobacillus ferrooxidans菌最佳的接种浓度为25%，在Thiobacillus Thiobacillus thiooxidans菌悬液中，能脱出最大量硫酸根的煤矸石最佳比例是10%。2种菌混合较单菌株脱硫效果更好，以Thiobacillus ferrooxidans∶Thiobacillus thiooxidans=2∶3的比例混合后对煤矸石的脱硫效果最佳，该结果为煤矿废弃物煤矸石的污染防治提供技术依据。     

微生物浸取废弃电路板粉末中的铜

以单质硫为能源物质,城市污水厂污泥为菌株来源及培养基主要成分来培养氧化硫硫杆菌.取100 mL氧化硫硫杆菌菌液用于浸取15 g废弃电路板粉末中的铜,反应到顶设时间后进行固液分离,另取100 mL氧化硫硫杆菌菌液用于继续浸取剩余固体中的铜,考察不同浸取频次对铜累计浸取率的影响.研究结果表明,随着浸取频次的增加,铜累计浸取率逐渐提高.耗时24 d,浸取频次分别为3、4、6、12、24次中.浸取24次的铜累计浸取率最高,为93.69%,其次是浸取12次的,铜累计浸取率为91.18%.虽然浸取24次的铜累计浸取率比浸取12次的高,但是前者在耗时24 d后产生的浸取液(2.4 L)是后者(1.2 L)的2倍,考虑到微生物培养及后续处理成本,所以最佳浸取频次为12次.     

污泥中氧化硫硫杆菌的分离及其应用效果

以硫粉为能源物质,采用Waksman液体培养基培养,然后以Waksman固体培养基平板接种法直接从污泥中分离出1株高度嗜酸的氧化硫硫杆菌(Thiobacillus thiooxidan).该菌株适应环境速度快,易于驯化.序批式试验法研究表明,接种该菌株进行污泥生物淋滤可有效溶出污泥中的重金属.经过14 d的生物淋滤,Zn、Cu、Pb、Cr的最高去除率分别达到97%、96%、43%、44%.     

元素硫颗粒粒径对污泥重金属生物沥滤的影响

以城市污水处理厂剩余污泥作为处理介质,土著嗜酸氧化硫硫杆菌(Acidithiobacillus thiooxidans,A.thiooxi-dans)为主要沥滤微生物,采用序批式生物沥滤装置,就投加150~725μm的不同粒径元素硫对沥滤的酸化效果、硫酸根产率和重金属去除效果的影响进行了研究。结果表明,在元素硫投配量为3 g/L,曝气强度为1.0 L/(min.L)的条件下,元素硫粒径在165~215μm范围减小时能显著改善污泥酸化速度、提高酸化程度和硫酸根产率。底物元素硫的最佳粒径为165μm,此时沥滤体系pH下降速率为0.85个pH单位/d,硫酸根的产率为454.9 mg/(L.d),沥滤6 d后污泥中高浓度重金属Cu、Zn、Cd的去除率达到70.3%、81.2%、87.8%.     

微波预处理和微生物联合煤炭脱硫技术初探

将微波技术应用于微生物法煤炭脱硫,研究了煤粉粒径、煤浆浓度、初始pH值、嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)接种量、微波辐照时间、脱硫周期等因素对微波预处理和微生物联合脱硫效果的影响,同时以单纯Acidithiobacillus ferrooxidans煤炭脱硫作对照.在煤样粒径为200目(＜0.074 mm)、煤浆浓度为10%、初始pH为2.5、菌体接种量为10%、微波辐照时间3 min、脱硫周期4 d、温度30℃、摇床转速为160 r/min条件下,微波预处理和微生物联合作用对煤炭中全硫的脱除率可达51.3%.该结果表明,微波预处理和微生物联合煤炭脱硫技术可以大大缩短微生物脱硫周期.该研究结果可为开发新脱硫工艺提供参考.     

pH、接种量及固形物含量对氧化亚铁硫杆菌LX5煤炭生物脱硫的影响

高硫煤燃烧释放SO2污染环境。采用摇瓶实验,以FeS2驯化的嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)LX5为供试菌株,研究了pH、接种量及煤粉数量对菌株LX5进行生物脱硫的影响。实验结果表明,在15 d的反应周期中反应液的起始pH为2.0、2.5、3.0和4.0时,菌株LX5的脱硫效率分别为43.1%、73.3%、61.9%和37.3%;将菌株LX5的接种量控制为5%、10%及15%时,其脱硫效率分别为44.2%、68.1%及72.2%;将煤粉含量调整为5%、10%及15%时,LX5的脱硫效率分别为73.1%、72.2%及56.3%。摇瓶实验确定的最合适的生物脱硫条件是:培养液起始pH为2.5,LX5接种量为培养液体积的10%,煤粉加入量为培养液质量的10%。在5 L序批式反应器进行煤炭生物脱硫的启动实验,研究表明,反应15 d后煤炭脱硫率达到69.2%,而煤中黄铁矿硫的脱硫率可达78%。     

利用巨大芽孢杆菌制备高硫煤矸石肥料

高硫煤矸石的大量堆积对环境造成了严重污染,为了开发利用高硫煤矸石,对巨大芽孢杆菌处理高硫煤矸石生产煤矸石肥料进行了研究,包括煤矸石的粒径、体系p H、温度、接菌量、培养时间、振荡等因素条件对制备煤矸石肥料的影响,得到制备煤矸石肥料的最佳条件。研究表明,当煤矸石的粒径为60目、体系p H 7.0~8.0、接菌量为2.5×1014~5.0×1014cfu/g、30℃下培养5 d时煤矸石中的碱解氮、有效磷和速效钾的含量分别比原样提高了26.84倍、65.71倍和10.55倍;有效硫、有效钙和有效硅的含量分别比原煤矸石中提高2.70倍、1.27倍和1.07倍。     

微生物絮凝剂的制备及其絮凝活性

从土壤和活性污泥中筛选获得性能稳定、对高岭土悬浮液的絮凝率达75%以上的菌株20株,其中编号为Ⅰ-18的菌株培养液对高岭土悬浮液的絮凝率达85%以上,经鉴定为球形芽孢杆菌Bacillus sphaericus.实验表明,该菌株以质量分数为2%的蔗糖为碳源,以质量分数均为0.15%的蛋白胨与尿素组合为氮源;生长与分泌絮凝剂的合适温度为30℃,适宜的pH为7.0,最佳培养时间为80 h.利用该微生物絮凝剂处理水性油墨废水效果明显,15 min浊度去除率达98.7%.     

一株高效脱硫菌的分离鉴定和脱硫特性研究

从污水净化厂二沉池回流污泥中分离到一株硫杆菌菌株dj-5，该菌株是一种兼性厌氧菌,通过生理生化特性鉴定,并结合16S rDNA序列分析及鉴定,该菌株可以确定为脱氮硫杆菌（Thiobacillus denitrificans）。该菌株的生长曲线表明菌体生长迅速,延滞期约为8 h,然后细菌进入对数生长期,这一阶段持续时间大约20～24 h,稳定期较短,细菌很快进入衰亡期。通过脱硫工艺实验考察了pH值、温度和搅拌速度对脱硫率和菌体生长的影响,结果表明，在进气量180 L/h、pH=6～8、温度为25～35℃和搅拌速度为270 r/min时,该菌株能正常生长,对进气浓度高达2 500 mg/m³的硫化氢脱除率在91%以上。     

嗜酸硫杆菌和黑曲霉对电镀污泥重金属浸出效果

电镀污泥重金属浸出对电镀污泥资源化利用具有重要意义。为了降低处置成本,采用嗜酸硫杆菌与黑曲霉对电镀污泥重金属浸出效果进行了研究。结果表明,采用嗜酸性氧化硫硫杆菌和氧化亚铁硫杆菌混合菌种对含固率为3%的电镀污泥进行为期15 d(培养驯化后)的处理后,污泥中Ni、Cr与Cu的浸出率虽分别高达92.8%、85.0%和96.8%,但耗时久,无法大规模地实际应用。利用黑曲霉对电镀污泥进行为期6 d的处理,Ni、Cr和Cu的浸出率分别达到92.0%、74.4%和55.3%。若采用黑曲霉培养15 d后产生的生物有机酸和同pH的柠檬酸处理电镀污泥4 h后,两者对Ni、Cr和Cu的浸出率分别为:85.0%与94.2%、63.8%与73.7%、57.9%与99.6%。可见,利用黑曲霉发酵菌液浸出电镀污泥中重金属有一定的实际应用价值。     

煤矸石和粉煤灰pH与电导率动态变化规律及其相关性研究

煤矸石和粉煤灰是煤矿区两种常见的固体废弃物，对环境造成极大的污染。pH波动幅度大是废弃物农用治理的主要障碍之一。对两种废弃物连续浸提时的pH和电导率(EC)进行长期动态监测，结果表明，不同层次的煤矸石尽管风化程度不同，但经过长时间浸取后，pH和EC变化趋势相似，且煤矸石、粉煤灰的pH、EC值有很大的相关性。该试验为今后两种废弃物合理利用奠定了基础。     

贝壳粉型煤固硫剂固硫的实验及机理研究

以贝壳粉作为型煤固硫剂,用正交实验的方法研究了影响贝壳粉固硫率的主要影响因素,在高温(1 150℃)时固硫效率达到56.6%,比CaCO3的固硫率提高40%以上,具有较好的高温固硫性。分析得知,贝壳的主要成分为CaCO3,其含钙量在40%左右,贝壳中又含有较高的Na等碱金属元素以及Fe,Al和Si等。用X射线粉末衍射法分析了高温(1 150℃)型煤样生成的灰渣,分析了贝壳粉作为型煤固硫剂在高温下具有较高固硫率的机理。发现CaAlSi2O8为主的复合晶体在高温下包裹在CaSO4的表面,抑制了CaSO4的热分解从而有效地提高了固硫率。     

高效脱硫菌的筛选及其性能研究

从高硫污染的活性污泥中富集培养，分离纯化得到一株可以降解噻吩的菌株s_4，并对该菌株的形态特征进行观察。应用Design—Expert8．0．5b软件进行响应面优化实验，研究了反应时间、噻吩浓度、微生物浓度3个因素的组合对菌株s_4脱硫效果的影响，并拟合得到多元二次回归方程，得出最佳实验条件。拟合结果表明，当反应时间27．46h，噻吩浓度为1．04％，微生物浓度4．04％时，预测噻吩降解率为14．8％，通过验证得最佳条件下的降解率为14．3％，与预测值相符。     

高效脱硫菌的筛选及其性能研究简

从高硫污染的活性污泥中富集培养，分离纯化得到一株可以降解噻吩的菌株S-4，并对该菌株的形态特征进行观察。应用Design-Expert8.0.5b软件进行响应面优化实验，研究了反应时间、噻吩浓度、微生物浓度3个因素的组合对菌株S-4脱硫效果的影响，并拟合得到多元二次回归方程，得出最佳实验条件。拟合结果表明，当反应时间27.46 h，噻吩浓度为1.04%，微生物浓度4.04%时，预测噻吩降解率为14.8%，通过验证得最佳条件下的降解率为14.3%，与预测值相符。     

Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil

The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome very gravelly loam soil subjected to these treatments. The control consisted of Krome soil without any amendment. The loading rate was 205 g pot(-1) for each amendment (equivalent to 50 t ha(-1) of the dry weight), and the amounts of the cover crops incorporated into the soil in the pot were those that had been grown in it. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO3-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments. The leguminous cover crop, sunn hemp, returned into the soil, increased the leachate NO3-N and inorganic P concentration significantly compared with the non-legume, sorghum sudangrass. The results suggest that at heavy loading rates of soil amendments, leaching of NO3- could be a significant concern by application of biosolids. Leaching of inorganic P can be increased significantly by both co-compost and biosolids, but decreased by coal ash and N-viro soil by virtue of improved adsorption. The leguminous cover crop, sunn hemp, when incorporated into the soil, can cause the concentration of NO3-N to increase by about 7 fold, and that of inorganic P by about 23% over the non-legume. Regarding the metals, biosolids, N-viro soil and coal ash significantly increased Ca and Mg concentrations in leachates. Copper concentration in leachate was increased by application of biosolids, while Fe concentration in leachates was increased by biosolids, coal ash and co-compost. The concentrations of Zn, Mo and Co in leachate were increased by application of coal ash. The concentrations of heavy metals in leachates were very low and unlikely to be harmful, although they were increased significantly by coal ash application.     

Remediation of metal-contaminated soils with the addition of materials - part II: leaching tests to evaluate the efficiency of materials in the remediation of contaminated soils

The effect of the addition of materials on the leaching pattern of As and metals (Cu, Zn, Ni, Pb, and Cd) in two contaminated soils was investigated. The examined materials included bentonites, silicates and industrial wastes, such as sugar foam, fly ashes and a material originated from the zeolitization of fly ash. Soil + material mixtures were prepared at 10% doses. Changes in the acid neutralization capacity, crystalline phases and contaminant leaching over a wide range of pHs were examined by using pH_stat leaching tests. Sugar foam, the zeolitic material and MX-80 bentonite produced the greatest decrease in the leaching of pollutants due to an increase in the pH and/or the sorption capacity in the resulting mixture. This finding suggests that soil remediation may be a feasible option for the reuse of non-hazardous wastes.     

燃煤炉窑烟气净化工艺及其装置的研究

在实验测试基础上,对燃煤烟气喷钙水浴复合脱硫工艺及设备进行了研究.实验表明,采用喷钙水浴复合脱硫工艺较单一喷钙或水浴具有更高的脱硫效果,且喷入的碳酸钙可得到充分利用.此外,还对钙硫比、喷钙方向及喷管插入水深等影响脱硫效率的因素进行了测试分析.     

Study of the use of coal fly ash as an additive to minimise fluoride leaching from FGD gypsum for its disposal

The use of coal fly ash as a fluoride retention additive has been studied as a way of treating flue gas desulphurisation (FGD) gypsum for its disposal in landfills. With this end leaching studies following the standard EN-12457-4 [Characterization of waste- Leaching-Compliance test for leaching of granular waste materials and sludges - Part 4: One stage batch test at a liquid to solid ratio of 10l/kg for materials with particle size below 10mm (without or with size reduction)] have been performed on FGD gypsum samples treated with different proportions of fly ash (0.1-100%). It was found that the fluoride leachable content in FGD gypsum was reduced in the range 1-55%, depending on the fly ash proportion added to FGD gypsum. High levels of fluoride leaching reduction (close to 40%) were achieved even at relatively low fly ash additions (5%). So, low fly ash incorporations assure the characterization of this by-product as a waste acceptable at landfills for non-hazardous wastes according to the Council Decision 2003/33/EC [Council Decision 2003/33/EC of 19 December 2002 establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC] on waste disposal. Furthermore, the effectiveness of the proposed FGD gypsum stabilization method was also studied in column leaching systems, proving its good performance in simulated conditions of disposal. In such conditions a fluoride leaching reduction value slightly higher than 25% was displayed for a fly ash added amount of 5%.     

煤矸石堆积下多环芳烃的淋溶污染特征

淋溶是使有害物质析出的主要途径之一。为查明煤矸石堆放淋溶造成的有机污染效应,对不同风化强度煤矸石进行了动态淋溶模拟实验,系统研究了煤矸石中US EPA优先控制的16种多环芳烃（PAH16）的析出规律和迁移方式。获得煤矸石中多环芳烃（PAHs）淋溶特征如下：煤矸石堆积期遭受短期降雨（500~1 600 mm）作用后,煤矸石溶出的PAH16总质量浓度达125.6~451.2 ng/L。PAH16溶出量初期较高,在一定降雨期后又达到峰值,酸雨条件下,煤矸石山淋溶出的PAH16可由线性累加转为指数快速累加的趋势。淋溶液中优势组分为萘、二氢苊、芴和菲,4种组分之和占所测PAHs总量的80%~90%。煤矸石溶出的PAHs环数分布为2环〉3环〉4环〉5环、6环。迁移方式上,2环PAHs多以溶解相迁移,3环PAHs主要以颗粒态迁移,存在少量溶解形式,而4环以上PAHs则以颗粒相形式迁移。     

HISTORY of the Air Pollution Control Association

Bottom ash is a waste material from coal-fired power plants, and it is known to contain elements that are potentially toxic at high concentration levels when disposed in landfills. This study investigates the use of bottom ash as a partial substitute sorbent for wet flue gas desulfurization (FGD) processes by focusing on its leaching kinetics in adipic acid. This was studied basing on the shrinking core model that was applied to the experimental data obtained by the authors presented at the International Conference on Industrial, Manufacturing, Automation and Mechanical Engineering, Johannesburg, South Africa, November 27–28, 2013) on dissolution of bottom ash. The leaching rate constant was obtained from different reaction variables, namely, temperature, pH, acid concentration, and solid-to-liquid ratio, that could affect the leaching process. The solid sample of bottom ash was characterized at different leaching periods using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that solid-to-liquid ratio had a significant effect on the leaching rate constant when compared with other variables. The leaching kinetics showed that diffusion through the product layer was the rate-controlling step during leaching, and the activation energy for the process was found to be 18.92 kJ/mol.

Implications:?The use of coal bottom ash waste as a sorbent substitute in wet flue gas desulfurization (FGD) has both economic and environmental advantages. This is because it is a waste from coal-fired thermal power plant and this study has proven that it can leach out a substantial amount of calcium ions for wet FGD process. This will abate anthropogenic pollution due to landfill disposal of bottom ash wastes and also reduce sulfur dioxide emissions.