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601.
采集了广州具有代表性的市政污泥,利用热重法对单一污泥、煤及其混合样品在CO_2/O_2及N_2/O_2气氛条件下进行了TG(热重)实验,同时计算了污泥和煤的4个燃烧特性指数,获得了燃烧的动力学参数.实验结果表明,污泥燃烧有4个燃烧阶段,包括水分析出、挥发分析出与燃烧、固定碳的燃烧和无机盐类挥发分解,其中,挥发分析出与燃烧是污泥燃烧的主要阶段;煤掺烧污泥可以提高煤的着火性能.在CO_2/O_2及N_2/O_2燃烧气氛下,增加O_2浓度,污泥与煤混合样的热重曲线整体向低温区移动,微商热重曲线峰值增大,峰宽变小,燃烧性能增强.在CO_2/O_2气氛下,O_2浓度从30%增加到60%时,污泥的挥发分释放特性指数D、可燃性指数C、燃尽指数Cb、综合燃烧特性指数S分别增加了45%、12%、18%、6%.相同O_2浓度条件下,污泥与煤在CO_2/O_2气氛下的着火性能较N_2/O_2气氛滞后,最大峰值变小,高浓度的CO_2抑制其混合样的燃烧.采用Coats-Redfern方程计算得到3个燃烧阶段反应的动力学参数,其中,增加O_2浓度,污泥与煤混合样品的质量平均表观反应活化能Em减小,并且O_2浓度越高越有利于燃烧反应的进行.污泥与煤混合燃烧取n=2可以对挥发分燃烧与固定碳燃尽峰峰前与峰后的反应模型进行描述. 相似文献
602.
LUO Hong-bing LUO Lin HUANG Gu LIU Ping LI Jing-xian HU Sheng WANG Fu-xiang XU Rui HUANG Xiao-xue 《环境科学学报(英文版)》2009,21(9)
e values of MFFn (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to enable more effective and economical design of structural BMPs (best management practices) facilities. 相似文献
603.
采用UASB反应器,接种由好氧颗粒污泥、厌氧颗粒污泥、氧化沟活性污泥及短程硝化活性污泥组成的混合污泥,以污泥脱水液经短程硝化处理后水质为进水,在温度(30±0.2)℃, pH值7.3~7.9,初期进水氨氮、亚硝氮容积负荷分别为0.07, 0.10kg/(m3×d)条件下,经过24d运行,氨氮和亚硝氮得到稳定同步去除,186d时TN去除负荷达0.99 kg/(m3×d).启动初期,氨氮、亚硝氮进水浓度分别为20,30mg/L,二者浓度随去除量增加而逐级增加,最高分别达到157,216mg/L;启动过程中,系统受到O2抑制以及O2和亚硝氮基质的连续抑制,分别经过了约10d和30d才得以恢复. 厌氧氨氧化(ANAMMOX)反应与反硝化反应可以共存于系统中,产气量与总氮去除呈正比关系,可及时地指示系统运行状态,对气体成分检测,氮气含量在99.8%.在稳定期ANAMMOX反应呈pH值升高而碱度略有降低.接种混合污泥、低基质负荷启动ANAMMOX,可30d内实现稳定的氨氮和亚硝氮同步去除,180d左右启动成功. 相似文献
604.
Total mercury in wild fish in Guizhou reservoirs, China 总被引:2,自引:0,他引:2
Haiyu Yan Atle Rustadbakken Heng Yao Thorjorn Larssen Xinbin Feng Ting Liu Lihai Shang Thrond O. Haugen 《环境科学学报(英文版)》2010,22(8):1129-1136
The health hazard of mercury (Hg) compounds is internationally recognized, and the main pathways for methylmercury (MeHg) intake in humans are through consumption of food, especially fish. Given the large releases of Hg to the environment in China, combined with the fast development of hydropower, this issue deserves attention. Provided similar mobilization pathways of Hg in China as seen in reservoirs in North America and Europe one should expect increased Hg contamination in relation to future hydropower reservoir construction in this country. This study presents total Hg (THg) concentrations in wild fish from six Guizhou reservoirs, China. The THg concentrations in fish were generally low despite high background levels in the bedrock and depositions from local point sources. The over all mean ± SD concentration of THg was (0.066 ± 0.078) μg/g (n = 235). After adjusting for among-reservoir variation in THg, there were significant differences in THg among functional groups of the fish, assumed to re?ect trophic levels. Predicted THg- concentration ratios, retrieved from a mixed linear model, between the functional groups were 9:4:4:1 for carnivorous, omnivorous, planktivorous and herbivorous fish. This result indicated that MeHg accumulation may prevail even under circumstances with short food chains as in this Chinese water system. No fish exceeded recommended maximum THg limit for human consumption set by World Health Organization and the Standardization Administration of China (0.5 μg/g fish wet weight (ww)). Only six fish (2.5%) exceeded the maximum THg limit set by US Environmental Protection Agency (0.3 μg/g fish ww). 相似文献
605.
606.
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608.
Krzysztof Lutoslawski Agnieszka Ryznar-Luty Edmund Cibis Malgorzata Krzywonos Tadeusz Mikiewicz 《环境科学学报(英文版)》2011,23(11):1823-1830
Upon aeration, the mixed microbial SCD ProBio OriginalTM culture may be used as the first stage in a two- or multi-stage system for the biodegradation of beet molasses vinasse. 相似文献
609.
复合菌株YH01+YH02强化SBR好氧反硝化脱氮及菌群结构分析 总被引:4,自引:1,他引:3
为探讨复合菌株强化好氧反硝化的脱氮特性以及揭示菌群结构动态演替与生物反应器运行效率之间的联系,以硝态氮为底物,研究了异养硝化-好氧反硝化复合菌株Delftia sp.YH01+Acidovorax sp.YH02强化好氧SBR的脱氮特性,并借助高通量测序技术对强化过程中的菌群结构进行了分析.结果表明,经复合菌株强化后,反应器对NO3--N、TN和COD去除率分别提高了12.1%、9.2%和9.4%;复合菌株YH01+YH02的加入对菌群结构产生了较大的影响,菌群结构在属水平上丰度呈上升趋势,多样性呈下降趋势;PCA主成分析和UPGMA聚类分析大致把反应器运行过程分成4个阶段;Delftia和Acidovorax菌的丰度随着反应器呈上升趋势,复合菌株YH01+YH02在SBR反应器内具有良好的适应能力,对好氧反硝化起着非常重要的作用. 相似文献
610.
Effects of initial resources on the development of strains during a stressful training situation: Some counterintuitive results
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Resource theories of occupational stress argue that employees' personal and environmental resources protect them from too much distress or strain during stressful work experiences. We examined four resources (emotional stability, previous experience, low drain on pre‐existing resources, and workgroup quality) available to soldiers at the beginning of a stressful 3‐month training experience as predictors of the trajectories of their strains over that period of time. Based on conservation of resources theory and the job demands–resources model, we predicted that the trends of strains would be more favorable (would increase more slowly or decline more quickly) if participants started the training with greater resources. The resources, primarily emotional stability and lack of pre‐existing resource drain, tended to be negatively related to strains, consistent with the idea that they can reduce strains. Significant interactions predicting trends were found predicting two of the three strains (post‐traumatic stress symptoms and depression, but not reports of physical health). Contrary to expectations, however, the three resources that significantly predicted trends over time (emotional stability, previous experience, and low pre‐existing resource drain) were associated with worsening rather than improving strains. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献