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951.
An adaptive neuro fuzzy inference system was used for classifying water quality status of river. It applied several physical and
inorganic chemical indicators including dissolved oxygen, chemical oxygen demand, and ammonia-nitrogen. A data set (nine weeks,
total 845 observations) was collected from 100 monitoring stations in all major river basins in China and used for training and validating
the model. Up to 89.59% of the data could be correctly classified using this model. Such performance was more competitive when
compared with artificial neural networks. It is applicable in evaluation and classification of water quality status. 相似文献
952.
Weidong Guo Jing Xu Jiangping Wang YingrouWen Jianfu Zhuo Yuchao Yan 《环境科学学报(英文版)》2010,22(11):1728-1734
Wastewater dissolved organic matter (DOM) from different processing stages of a sewage treatment plant in Xiamen was
characterized using fluorescence and absorption spectroscopy. Parallel factor analysis modeling of excitation-emission matrix spectra
revealed five fluorescent components occurring in sewage DOM: one protein-like (C1), three humic-like (C2, C4 and C5) and one
xenobiotic-like (C3) components. During the aerated grit chamber and primary sedimentation tank stage, there was only a slight
decrease in fluorescence intensity and the absorption coefficient at 350 nm (a350). During the second aeration stage, high concentration
of protein-like and short-wavelength-excited humic-like components were significantly degraded accompanied by significant loss of
DOC (80%) and a350 (30%), indicating that C1 and C2 were the dominant constituents of sewage DOM. As a result, long-wavelengthexcited
C4 and C5 became the dominant humic-like components and the DOM molecular size inferred from the variation of spectral
slope S (300–650 nm) and specific absorption (a280/DOC) increased. Combination use of Fmax of C1 and the ratio of C1/C5, or a350
may provide a quantitative indication for the relative amount of raw or treated sewage in aquatic environment. 相似文献
953.
954.
膜生物反应器中膜组件性能的对比研究 总被引:1,自引:0,他引:1
膜生物反应器中不同膜组件对废水的处理效果不同。论文主要对膜生物反应器中分别产自日本和德国的聚乙烯中空纤维膜膜组件处理生活污水的情况进行了考察,在给定的水力停留时间、污泥浓度、pH值等参数的条件下,对其膜组件性能进行了对比研究。通过对生活污水的降解试验发现,在相同的条件下,两种膜组件在浊度的去除方面均达到100%,并且系统处理出水COD均<50mg/L,去除率可分别达到86%和85%,但对氨氮去除两者均未达到60%,另外两种膜组件的膜通量的衰减相差较大,日本膜组件的衰减较缓慢而德国膜组件的衰减很快。 相似文献
955.
卓德勇 《安全.健康和环境》2008,8(7)
针对氯乙烯球罐防腐作业存在的火灾爆炸、中毒窒息及其它危险因素,从技术、管理等方面提出措施,降低防腐作业风险,保证作业安全。 相似文献
956.
957.
Yishan Lin Yanling He Zhuo Meng Shucheng Yang 《Frontiers of Environmental Science & Engineering in China》2008,2(2):241-246
The direct conversion of methanol into methane is the main process in anaerobic treatment of methanol containing wastewater.
However, acetic acid can also be produced from methanol theoretically, which may probably result in an abrupt pH drop and
deteriorate the anaerobic process. Therefore, it is interesting to know what would really happen in an anaerobic reactor treating
methanol wastewater. In this study, an up-flow anaerobic sludge bed (UASB) reactor treating methanol wastewater was operated.
The chemical oxygen demand (COD), acetic acid and pH of the effluent were monitored at different loadings and influent alkalinity.
The results showed that the anaerobic reactor could be operated steadily at as low as 119 mg/L of influent alkalinity and
high organic loading rate with no obvious pH drops. Volatile fatty acids accumulation was not observed even at strong shock
loadings. The microorganisms in the sludge at the end of the test became homogeneous in morphology, which were mainly spherical
or spheroidal in shape.
__________
Translated from China Water & Wastewater, 2006, 22(13): 42–44,48 [译自: 中国给水排水] 相似文献
958.
Cribb BW Stewart A Huang H Truss R Noller B Rasch R Zalucki MP 《Die Naturwissenschaften》2008,95(1):17-23
A number of arthropod taxa contain metals in their mandibles (jaws), such as zinc, manganese, iron, and calcium. The occurrence of zinc and its co-located halogen chlorine have been studied in relation to the mechanical properties and shown to be linked in a direct fashion with increasing concentration. Hardness along with elastic modulus (stiffness) has also been linked to zinc and halogen concentration in some marine polychaete worms. The metal appears to be incorporated within the biological matrix, possibly bonding with proteins. However, the comparative advantage of metal inclusion has not been tested. It is possible that without metals, alternative mechanisms are used to achieve hardness of equal value in similar 'tools' such as mandibles. This question has direct bearing on the significance of metal hardening. In the present article, we compare across mandibles from six termite species, including samples with major zinc concentration, minor manganese, and no metals. Nanoindentation, electron microscopy, and electron microanalysis are used to assess metal concentration, form, and mechanical properties. The data demonstrate that termite mandibles lacking metals when fully developed have lower values for hardness and elastic modulus. Zinc is linked to a relative 20% increase in hardness when compared with mandibles devoid of metals. The similar transition metal, manganese, found in minor concentrations, is not linked to any significant increase in these mechanical properties. This raises the question of the function of manganese, which is as commonly found in insect mandibles as zinc and often located in the same mandibles. 相似文献
959.
960.
人粪便序批式好氧堆肥热平衡分析 总被引:1,自引:0,他引:1
利用以锯末为载体的Bio—LuxS15型生态卫生设备,进行人粪便连续堆肥试验。在90天的试验周期内,每天定时定量投加1kg粪便,分析了系统的输入热量与输出热量组成和热量平衡。试验结果表明,水蒸发速率随着反应时间而增加,其值在1.1kg/d~5.1kg/d的范围内。反应器温度维持在50℃~60℃时下,输入热量的77.2%-99.5%主要用来进行水分的蒸发,在保证堆肥反应器中含水率维持在50%-60%的前提下,减少多余水分可有效减少热量消耗。整个过程无臭无味,通过外加热源,可以保证高含水率粪便堆肥化顺利的进行。 相似文献