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471.
Duu-Jong Lee Chin-Yu Lee Jo-Shu Chang Qiang Liao Ay Su 《International Journal of Green Energy》2015,12(10):998-1004
The microbial fuel cell (MFC) was employed to convert reductive potential in sulfate-laden wastewaters to electricity via reducing sulfate to sulfide by sulfate-reducing bacteria and then oxidizing sulfide to sulfur by exoelectrogens. The excess sulfide presented in the anodic solution inhibited the activities of functional strains in MFC. This study proposed the use of a two-anode system, with a sulfate-reducing bacteria anode and an exoelectrogen (C27) anode in the anodic cell, to efficiently convert reductive potential of sulfate into electricity. The microbial community of sulfate-reducing bacteria anode and the electrochemical characteristics of the studied MFCs were reported. 相似文献
472.
A combined nitritation–anammox reactor was developed to treat the digestion supernatant under various C/N ratios. Due to the difficulties for heterotroph to utilize the refractory organics, the reactor presented relatively stable performance with increasing supernatant addition. Nevertheless, the adverse effects of supernatant would accumulate during the long-term operation and thus weakened the activity and shock resistance of microbes,which further led to the gradual decrease of reactor performance after 92 days' operation.Under this circumstance, supernatant with volatile fatty acids(VFAs) residuals was further introduced into the reactor to investigate the performance of combined nitritation–anammox process with VFA addition. With the appearance of VFAs, the nitrogen removal performance gradually restored and the reactor finally achieved stable and efficient performance with C/N ratio of 0.35. The VFA residuals within 150 mg/L in the supernatant served as the extra electron donors and stimulated the heterotrophic denitrification process, which was vital for the enhancement of reactor. The nitrogen removal rate and total nitrogen removal efficiency reached 0.49 kg N/(m3·day) and 88.8% after 140 days' operation, respectively. The combined nitritation–anammox reactor was proved suitable to treat digestion supernatant. 相似文献
473.
补充碳源提取液对人工湿地脱氮作用的影响 总被引:6,自引:1,他引:5
为了提高人工湿地的脱氮效率,在不同条件下分别对美人蕉、香蒲及稻杆进行稀硫酸水解,以获得相应碳源提取液.正交实验表明,稀硫酸浓度的提高和水解时间的增加都会导致碳源释碳能力的提高,稻杆在5%稀硫酸溶液中水解30 min以上,释碳能力最高.通过观察,前2 d是系统脱氮反应高峰时段.对以NH4+-N和NO3--N为氮源的脱氮过程,随C/N比升高,NO3--N和TN去除率增长明显;而NH4+-N受溶解氧制约,去除有限;随C/N比升高,碳源对系统溶解氧的竞争会进一步抑制硝化反应的彻底进行.而对以NO3--N为氮源的反硝化过程,补充碳源对TN和NO3--N的去除有明显作用;TN去除率由54%提高到95%,NO3--N去除率由48%提高到96%;中间产物NO2--N的积累与NO3--N去除率有关;当NO3--N去除率较高时,NO2--N无积累.此外,基质反硝化强度也随C/N比升高呈上升趋势,湿地填料细沙层的反硝化强度略高于碎石层. 相似文献
474.
黄土丘陵区小流域土壤碳氮比的变化及其影响因素 总被引:8,自引:0,他引:8
研究土壤C:N的变化有助于深入理解土壤有机碳氮的积累过程及其土壤质量的变化趋势。以黄土高原丘陵沟壑区砖窑沟小流域为单元,基于地貌类型和土地利用方式两大因素,采集737个土壤样品,研究流域内土壤C:N的变化差异及其影响因素。梁峁坡上,林地和草地0~20 cm土层的土壤C:N分别是农田土壤C:N的1.13和1.03倍;沟坡上,林地、草地和农田土壤的C:N分别为13.88、12.58、9.02。农田条件下,梁峁坡、沟坡和沟谷的土壤C:N分别为10.34、9.02和10.77;林地条件下,沟坡和梁峁坡的土壤C:N分别为13.88、11.67;草地条件下,沟坡土壤C:N是梁峁坡土壤C:N的1.19倍。同一地貌类型或土地利用方式条件下,土壤C:N均呈现表层大于深层的趋势,0~20 cm和20~40 cm土层的土壤C:N分别是40~100 cm土层土壤C:N的1.05~1.17和1.16~1.42倍。 相似文献
475.
476.
在缺氧滤床+好氧悬浮填料生物膜工艺中实现部分亚硝化,然后进行厌氧氨氧化(ANAMMOX),考察其对高含氮、低C/N污泥脱水液的处理能力.结果表明,亚硝化反应器在15~29℃、DO 6~9mg/L条件下,通过综合调控进水氨氮负荷(ALR)、进水碱度/氨氮、水力停留时间(HRT)等运行参数,可以调节出水(NO2--N)/(NH4+-N)的比率,能够较好地实现部分亚硝化反应以完成厌氧氨氧化.当进水ALR为1.16kg/(m3·d),进水碱度/氨氮为5.1时,出水(NO2--N)/(NH4+-N)在1.2左右,(NO2--N)/(NOx--N)大于90%,进入ANAMMOX反应器的氮物质去除率达到83.8%. 相似文献
477.
478.
Introduction T he dem and for new technologies to rem ove or to detoxify organics, especially those that are toxic to biological treatm ent processes from aqueous effluents, is w idely recognized. T he electrochem ical m ethod for treatm ent of such kinds of w astew ater has attracted a great deal of attention recently, m ainly because of its ease of control, am enability to autom ation, high efficiency and environm ental com patibility(C om ninel- lis and N erini, 1995). A t present, dim ens… 相似文献
479.
Geels C Christensen JH Hansen AW Heinemeier J Kiilsholm S Larsen NW Larsen SE Pedersen T Sørensen LL Brandt J Frohn LM Djurhuus S 《Environmental monitoring and assessment》2006,117(1-3):387-409
As part of the Danish NEAREX project the origin and variability of anthropogenic atmospheric CO2 over the Northeast Atlantic Region (NEAR) has been studied. The project consisted of a combination of experimental and modelling
activities. Local volunteers operated CO2 sampling stations, built at University of Copenhagen, for 14C analysis at four locations (East Denmark, Shetland Isles, Faroe Isles and Iceland). The samples were only collected during
winter periods of south-easterly winds in an attempt to trace air enriched in fossil-fuel derived CO2 due to combustion of fossil fuels within European countries. In order to study the transport and concentration fields over
the region in detail, a three-dimensional Eulerian hemispheric air pollution model has been extended to include the main anthropogenic
sources for atmospheric CO2. During the project period (1998–2001) only a few episodes of transport from Central Europe towards NEAR arose, which makes
the data set for the evaluation of the method sparse. The analysed samples indicate that the signal for fossil CO2, as expected, is largest (up to 3.7±0.4% fossil CO2) at the Danish location closest to the European emissions areas and much weaker (up to ∼1.5±0.6% fossil CO2) at the most remote location. As the anthropogenic signal is weak in the clean atmosphere over NEAR these numbers will, however,
be very sensitive to the assumed background 14CO2 activity and the precision of the measurements. The model simulations include the interplay between the driving processes
from the emission into the boundary layer and the following horizontal/vertical mixing and atmospheric transport and are used
to analyse the meteorological conditions leading to the observed events of high fossil CO2 over NEAR. This information about the history of the air masses is essential if an observed signal is to be utilised for
identifying and quantifying sources for fossil CO2. 相似文献
480.
多环芳烃测定中净化方法的研究 总被引:2,自引:1,他引:1
对多环芳烃测定中的净化方法进行研究,为了选出最佳净化柱,在一定条件下分别采用硅胶LC-Si、弗罗里LC-Florisil和C18固相萃取净化柱对一定浓度的多环芳烃标准溶液进行净化,测定吸附后流出液多环芳烃浓度,计算吸附率;测定洗脱后流出液多环芳烃浓度,计算洗脱率。测定结果为硅胶、弗罗里和C18固相萃取净化柱对多环芳烃的吸附率分别在87.1%~100%,99.5%~100%和96.6%~100%之间,洗脱率分别在0~106%,78.7%.109%和79.0%~115%之间。结果表明,GC/MS内标法测定样品中多环芳烃使用最理想的净化柱为弗罗里净化小柱,其次为C18净化小柱,最后为硅胶净化小柱。 相似文献