加入多孔球形颗粒微生物燃料电池的性能研究

设计了一个典型的双室微生物燃料电池,并考察了在阳极室加入多孔球形颗粒条件下对人工合成污水产电性能的影响。实验发现,加入多孔球形颗粒后,最高电压从不加颗粒的253 mV提高到280 mV,持续产电时间从5.5 d提高到8 d,COD去除率从78%提高到82.6%。进一步的实验发现,加入多孔球形颗粒后,系统内阻从286Ω降低到199.4Ω,最大功率密度从78.6 mW/m2提高到114.3 mW/m2。结果表明,微生物易于在多孔球形颗粒上附着和生长,颗粒通过均匀搅拌与阳极表面产生持续碰撞,有利于胞外电子传递到阳极,这一过程大大减小阳极的内阻,增大电池的输出电压进而增大输出功率,从而显著提高电池的产电性能。     

以养殖废水为底料的微生物燃料电池产电性能与水质净化效果

以养殖场沼泥为接种物,构建了乙二胺、三氯化铁改性碳毡阳极的单室无膜微生物燃料电池,探讨了2种阳极改性电池的产电规律,考察了其去除养殖废水中COD、氨氮的效果以及臭味的表观性状变化。结果表明,以葡萄糖为底物时,乙二胺、三氯化铁改性阳极微生物燃料电池在启动20 d和22 d后分别达到稳定,输出电压分别为0.514 V和0.527V(外阻为500Ω),对应输出功率密度分别为332 mW/m2和349 mW/m2。逐渐增大废水投加比例至原水时,2个电池的最大功率密度分别为208 mW/m2和158 mW/m2,COD去除率分别为85%和78%,氨氮去除率分别为52%和45%。此外,养殖废水的臭味去除效果明显。因此,构建的2种改性阳极微生物燃料电池可以利用养殖废水产电,同时使水质得到一定程度的净化。     

微生物燃料电池处理含铜废水的研究

构建了以乙酸钠为阳极基质、Cu~(2+)为阴极电子受体的双室微生物燃料电池(MFC),考察了该MFC处理含铜废水的效果及Cu~(2+)浓度对MFC产电性能的影响。通过改变阴极液中CuSO_4的质量浓度(20~130mg/L),测试了MFC运行过程中的输出电压、输出功率密度、内阻、Cu去除率等指标。结果表明:Cu~(2+)可作为MFC的阴极电子受体;在外电路电阻为1 000Ω的条件下,Cu~(2+)质量浓度为130mg/L的MFC性能最佳,其稳定输出电压为0.33V、最大输出功率密度为114.42mW/m~2,内阻为231.62Ω,最高Cu去除率为84.59%;通过X射线衍射测试发现,阴极还原产物为Cu_2O。     

微生物燃料电池修复石油污染盐碱土壤

生物电化学技术修复石油污染土壤并同步产出电能是一种新兴的污染土壤生态修复技术。对石油污染土壤通过其微生物燃料电池的构造,利用电化学阻抗谱分析了土壤的欧姆内阻,拟合估算了土壤的电导率,并考察了土壤微生物燃料电池的产电性能和修复效果。结果表明:采用丙酮清洗过的阳极并有水封的情况下,土壤微生物燃料电池的欧姆内阻下降了52%,电导率升高了1倍;在启动后的120 h内,最大电压和累计产出电量分别达189 m V和36 C,与对照相比分别增加了20和29倍。输出电压随着阴极与阳极之间距离的增大而减小。经过30 d的生物电化学处理,土壤中的总石油烃去除率是开路对照的3.3倍。该研究是石油污染盐碱土壤生物电化学修复的初步探索,以为污染土壤的生态修复提供新的思路。     

高盐废水MFCs不同阴极电子受体产电及微生物群落分析

为探查不同电子受体产电性能及对阳极微生物群落的影响,研究了3种电子受体(铁氰化钾、曝气阴极、过硫酸钾),构建了双室榨菜废水微生物燃料电池系统(microbial fuel cells,MFCs),实现了污水处理和能量回收的双重目的,探讨了不同电子受体(铁氰化钾、曝气阴极、过硫酸钾)对榨菜废水MFCs产电性能及阳极微生物群落的影响。结果表明:在产电性能方面,当过硫酸钾作为阴极电子受体时,电池输出电压、库仑效率、功率密度均优于另外2种常用阴极电子受体(铁氰化钾和氧气);在500Ω的外接电阻间歇运行的条件下,其输出电压、库仑效率、功率密度分别为802 mV、(33±1.6)%、697 mW·m~(-2)。阳极生物16S rRNA基因测序分析表明,水解发酵菌为榨菜废水微生物燃料电池阳极核心菌群,铁氰化钾、氧气和过硫酸钾MFCs阳极微生物菌群相对丰度分别为64.3%、63.6%和75.51%,包括Lentimicrobium、Synergistaceae、Sphaerochaeta、Anaerolineaceae、Draconibacteriacea菌属。阴极电子受体不同的MFCs的阳极微生物群落核心菌群类似,但是丰度有所不同。势差较大的电子受体(过硫酸钾)微生物群落多样性和丰富度较高,产电和污染物去除效果较好。     

填充竹炭对微生物燃料电池性能的影响

微生物燃料电池(MFC)的阳极对提高MFC产电性能有至关重要的影响。利用竹炭比表面积大、吸附能力强等特性,将其作为"三合一"膜电极MFC的阳极填充材料,通过增大阳极比表面积来提高其产电能力。实验结果表明,加入竹炭至阳极室后,MFC最高输出电压(外接电阻1 000Ω时)由0.280V增大到0.387V,提高了38.2%,并且输出电压更加稳定;而最大功率密度也由原来的0.22W/m3增大到1.42W/m3,同时内阻降低了80.85%(由235Ω降为45Ω);库仑效率由15.0%增大到25.6%。说明MFC阳极室填充竹炭可以显著促进MFC的产电性能。     

生物质活性炭纤维笼电极微生物燃料电池产电性能

首次构建了以生物质活性炭纤维笼电极为空气阴极的微生物燃料电池(biomass activated carbon fiber cageshaped air-cathode microbial fuel cell,BACFC-ACMFC),并以厌氧污泥接种,以葡萄糖作为碳源,研究了该MFC在连续运行条件下的产电性能、电池内阻情况和最优运行条件。结果表明:在一个运行周期内,该MFC最佳运行条件为:体积浸没比为50%、p H=8、污泥投加量为1.8 g·L-1。当外接电阻为1 000Ω时,该MFC最大输出电压为257.89 m V,最大输出功率密度为4 082.99 m W·m-3,电池内阻为419.88Ω,与目前其他阴极材料的微生物燃料电池相比,该新型生物质活性炭纤维笼空气阴极微生物燃料电池功率密度较高,内阻较低。SEM分析可知,阴极具有较大的比表面积和孔隙率,有利于与氧气的充分接触。在浸入溶液中的半面阴极上发现大量微生物附着,这可能和氧气还原有关。     

稳恒磁场作用下微生物燃料电池的产电特性和电化学阻抗谱分析

对混合菌接种的双室微生物燃料电池加载磁场强度为175 mT的稳恒磁场,利用电化学交流阻抗等电化学分析方法,考察了在磁场作用下微生物燃料电池（MFC）产电性能的变化,分析了磁场对MFC各部分内阻的影响。加载磁场使已启动完成的MFC的产电明显增强,开路电压提高了10%。加载磁场后最大功率密度为2.08 W/m2,大于加载前的1.58 W/m2,表观内阻由170Ω降至80Ω。电化学阻抗谱分析确定了阳极、阴极和全电池的等效电路模型,拟合结果发现阳极极化内阻约为5Ω。加载磁场使MFC的阴极极化内阻由74.98Ω降至56.73Ω。     

MnO_2-r-GO阳极对微生物燃料电池产电性能的影响

考察了MnO_2-r-GO阳极对微生物燃料电池(MFC)的产电性能和体系有机质去除率的影响。实验结果表明,MnO_2-r-GO极的电荷转移内阻(Rct)由145.9Ω降低到14.8Ω。运行稳定后,MnO_2-r-GO阳极体系与空白碳布阳极体系相比,输出电压由200 m V增大到550 m V;最大功率密度(Pmax)由192.2 m W·m-2增大到761.4 m W·m-2,表观内阻由424.6Ω降低到141.4Ω;体系的COD去除率由83.6%增大到89.6%,库伦效率(CE)由19.8%增大到39.5%。     

微生物燃料电池在高盐榨菜废水处理中的产电性能

基于双室微生物燃料电池(microbial fuel cells,MFCs),以高盐榨菜废水为燃料,考察了电池的运行状况,同时探讨了盐度变化对电池产电性能影响,并通过投加甜菜碱研究其对MFCs系统抵抗盐度负荷冲击能力的影响。结果表明:MFCs稳定运行时(阳极室容积80 m L),最大功率密度、开路电压和电池内阻分别为3.55 W·m-3、0.698 V和427Ω;底物中添加2 mmol·L~(-1)甜菜碱后电池产电性能得到明显提升;当废水含盐量(增加到5 g·L~(-1)Na Cl)为31.2 g·L~(-1)时电池产电性能达到最佳,但是继续增高盐度后电池产电性能会急剧下降;投加甜菜碱有助于提高系统抵抗盐度负荷变化造成的冲击,维持电池的产电输出。     

Hydrogen fuel and fuel cell technology for cleaner future: a review

Environmental Science and Pollution Research - One of the main problems facing our planetary bodies is unexpected and sudden climate change due to continuously increasing global energy demand,...     

微波预处理污泥上清液为燃料的微生物燃料电池的影响因素研究

以微波预处理的剩余污泥上清液做为燃料,经过30 d成功地启动了单室无膜燃料电池.考察了可能影响输出功率密度的相关因素.结果表明,电池阳极面积越大,输出功率密度反而越小.阴阳极距离从5 cm缩小到0.5 cm时,输出功率密度先增加后降低,在距离为2 cm时,输出功率密度达到最大值282.7 mW/m2,说明阴阳极距离过近...     

Real-world fuel use and gaseous emission rates for flex fuel vehicles operated on E85 versus gasoline

Flex fuel vehicles (FFVs) typically operate on gasoline or E85, an 85%/15% volume blend of ethanol and gasoline. Differences in FFV fuel use and tailpipe emission rates are quantified for E85 versus gasoline based on real-world measurements of five FFVs with a portable emissions measurement system (PEMS), supplemented chassis dynamometer data, and estimates from the Motor Vehicle Emission Simulator (MOVES) model. Because of inter-vehicle variability, an individual FFV may have higher nitrogen oxide (NO_x) or carbon monoxide (CO) emission rates on E85 versus gasoline, even though average rates are lower. Based on PEMS data, the comparison of tailpipe emission rates for E85 versus gasoline is sensitive to vehicle-specific power (VSP). For example, although CO emission rates are lower for all VSP modes, they are proportionally lowest at higher VSP. Driving cycles with high power demand are more advantageous with respect to CO emissions, but less advantageous for NO_x. Chassis dynamometer data are available for 121 FFVs at 50,000 useful life miles. Based on the dynamometer data, the average difference in tailpipe emissions for E85 versus gasoline is ?23% for NO_x, ?30% for CO, and no significant difference for hydrocarbons (HC). To account for both the fuel cycle and tailpipe emissions from the vehicle, a life cycle inventory was conducted. Although tailpipe NO_x emissions are lower for E85 versus gasoline for FFVs and thus benefit areas where the vehicles operate, the life cycle NO_x emissions are higher because the NO_x emissions generated during fuel production are higher. The fuel production emissions take place typically in rural areas. Although there are not significant differences in the total HC emissions, there are differences in HC speciation. The net effect of lower tailpipe NO_x emissions and differences in HC speciation on ozone formation should be further evaluated.

Implications: Reported comparisons of flex fuel vehicle (FFV) tailpipe emission rates for E85 versus gasoline have been inconsistent. To date, this is the most comprehensive evaluation of available and new data. The large range of inter-vehicle variability illustrates why prior studies based on small sample sizes led to apparently contradictory findings. E85 leads to significant reductions in tailpipe nitrogen oxide (NO_x) and carbon monoxide (CO) emission rates compared with gasoline, indicating a potential benefit for ozone air quality management in NO_x-limited areas. The comparison of FFV tailpipe emissions between E85 and gasoline is sensitive to power demand and driving cycles.     

Influence of diesel fuel on seed germination

The use of plant-based systems to remediate contaminated soils has become an area of intense scientific study in recent years and it is apparent that plants which grow well in contaminated soils need to be identified and screened for use in phytoremediation technologies. This study investigated the effect of diesel fuel on germination of selected plant species. Germination response varied greatly with plant species and was species specific, as members of the same plant family showed differential sensitivity to diesel fuel contamination. Differences were also seen within plant subspecies. At relatively low levels of diesel fuel contamination, delayed seed emergence and reduced percentage germination was observed for the majority of plant species investigated. Results suggest the volatile fraction of diesel fuel played an influential role in delaying seed emergence and reducing percentage germination. In addition, the remaining diesel fuel in the soil added to this inhibitory effect on germination by physically impeding water and oxygen transfer between the seed and the surrounding soil environment, thus hindering the germination response.     

Effects of fuel types and fuel sulfur content on the characteristics of particulate emissions in marine low-speed diesel engine

Environmental Science and Pollution Research - The emission of particulate matter from ships does great harm to human health and atmospheric environment. Sulfur emission regulations also affect...     

Radiative forcing from household fuel burning in Asia

Household fuel use in developing countries, particularly as biomass and coal, is a major source of carbonaceous aerosols and other air pollutants affecting health and climate. Using state-of-the-art emission inventories, a global three-dimensional photochemical tracer/transport model of the troposphere, and a global radiative transfer model based on methods presented in the latest IPCC Assessment Report (2007-AR4), we estimate the radiative forcing (RF) attributable to household fuel combustion in Asia in terms of current global annual-mean RF and future global integrated RF for a one-year pulse of emissions (2000) over two time horizons (100 and 20 years). Despite the significant emissions of black carbon (BC) aerosols, these estimates indicate that shorter-lived (non-Kyoto) air pollutants from household fuel use in the region overall seem to exert a small net negative RF because of the strong influence of reflective aerosols. There are, however, major uncertainties in emission estimates for solid fuel burning, and about the sustainability of household fuel wood harvesting in Asia (the carbon neutrality of harvesting). In addition, there is still substantial uncertainty associated with the BC radiative forcing. As a result we find that the sign of the RF from household biomass burning in the region cannot be established. While recognizing the value of integrating climate change and air pollution policies, we are concerned that for a ‘Kyoto style’ post-Kyoto treaty (with global cap-and-trade and the Global Warming Potential as the metric) expanding the basket of components with a selection of short-lived species without also including the wider range of co-emitted species may lead to unintended consequences for global-scale climate. Additional measurement, modelling, and policy research is urgently needed to reduce the uncertainties so that the net impact on climate of emissions and mitigation measures in this sector can be accurately assessed.     

生物脱硫技术用于清洁燃料生产的初步研究

从高硫油田筛选的红球菌Rhodococcus sp.FS-2可以通过专一性断裂C-S键的"4S"途径将二苯并噻吩(DBT)转化成2-羟基联苯,从而降低油品中的硫含量.利用该菌株对DBT和汽油、柴油的脱硫研究结果表明,FS-2菌株对DBT及柴油中的有机硫有良好的选择性脱除作用,而且脱硫前后的烃类组分基本没有改变.说明该菌的脱硫过程不会破坏燃料油的有效成分,可以用于燃料油的深度脱硫.     

双室微生物燃料电池型BOD传感器性能

构建了双室微生物燃料电池(MFC),并应用于污水BOD的检测。优化了MFC型BOD传感器的检测条件,分析了传感器进行污水BOD检测的特征。结果表明,以A2/O污水处理工艺中厌氧段污泥进行接种,双室MFC型BOD传感器2周内完成启动,所产电流达到稳定。传感器的最佳检测条件为外接电阻500Ω,添加缓冲溶液并维持待测水样pH为7.0,添加35 mg/L的L-半胱氨酸作为吸氧剂维持阳极室厌氧环境,阴极室富氧水流量为20 mL/min。利用MFC产生的电流峰值准确检测污水水样BOD浓度,传感器检测范围为10~50 mg/L,检测时间小于3 h;利用MFC产生的电荷量准确检测污水水样BOD浓度,检测范围为10~100 mg/L,检测时间小于10 h。利用MFC电流峰值和电荷量检测污水水样BOD浓度,偏差均小于15%,传感器运行稳定,寿命较长。     

生物脱硫技术用于清洁燃料生产的初步研究

从高硫油田筛选的红球菌Rhodococcus sp．FS-2可以通过专一性断裂C-S键的“4S”途径将二苯并噻吩（DBT）转化成2-羟基联苯，从而降低油品中的硫含量。利用该菌株对DBT和汽油、柴油的脱硫研究结果表明，FS-2菌株对DBT及柴油中的有机硫有良好的选择性脱除作用，而且脱硫前后的烃类组分基本没有改变。说明该菌的脱硫过程不会破坏燃料油的有效成分，可以用于燃料油的深度脱硫。