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731.
生活垃圾安全无害化处理是目前迫切需要解决的问题,直接气化熔融焚烧垃圾技术以降低二恶英排放方面巨大优势得到广泛关注,在此基础上提出纯氧熔融焚烧垃圾技术,几乎可以实现所有二次污染物近零排放。以350 t/d回转窑垃圾焚烧炉为例,对纯氧代替空气应用在回转窑上熔融焚烧垃圾系统进行了详细热力计算及分析。结果表明,纯氧熔融焚烧垃圾系统的锅炉效率可达90.56%,回转窑熔融焚烧系统还可以在垃圾焚烧后灰渣达到熔融温度的条件下,保持该系统热量平衡,稳定燃烧。并参考回转窑设计标准对该纯氧熔融焚烧城市生活垃圾的回转窑参数进行确定。 相似文献
732.
Photocatalytic mineralization of glyphosate in a small-scale plug flow simulation reactor by UV/TiO2
Jian Q. Chen Zhi J. Hu Nan X. Wang 《Journal of environmental science and health. Part. B》2013,48(6):579-588
The present work involves the photocatalytic mineralization of glyphosate on a plug flow reactor by UV/TiO2. The effect of catalyst loading shows an optimal value (0.4 g L?1) which is necessary to mineralize glyphosate. The kinetic rate of glyphosate mineralization decreases with the increasing initial concentration of glyphosate, and the data can be described using the first-order model. An alkaline environment is conducive to glyphosate mineralization. The mineralization efficiency increases with elevated flow rate to 114 mL min?1, which is followed by a decrease with a further increase in flow rate due to the reduction of the residence time. The presence of external oxidants (K2S2O8, H2O2 and KBrO3) and photosencitizer (humic acid) can significantly enhance glyphosate mineralization. Photocatalysis oxidation ability of the three studied oxidants decrease in the order of: S2O8 2? > BrO3 ? > H2O2. Finally, the Langmuir–Hinshelwood (L-H) model was used to rationalize the mechanisms of reactions occurring on TiO2 surfaces and L-H model constants were also determined. 相似文献
733.
Ashwani Kumar Sonkar Ramita Varshney Shah Izhar Ahmed Ashish Kumar Vishwakarma Aarif Jamal 《环境质量管理》2023,33(1):311-325
The coal mining industries influence hydro-geological parameters, which affect the aquifer recharge in the coal mining areas. This research aimed to evaluate the impact of various hydro-geological parameters on fluctuation of groundwater level in the study area. The various hydro-geological parameters such as soil, geology, drainage pattern, elevation and slope have been considered to accomplish the objective. A comparative analysis was performed by comparing the groundwater level fluctuation (WLF) map with the GIS-based various hydro-geological parameter maps to assess the combined influence of different hydro-geological parameters on groundwater level fluctuation. A total of eighty-six (86) dug-wells were chosen to monitor the level of the groundwater for around ten blocks of Singrauli coalfield, and these wells were examined during the months of dry and wet seasons for 2016. Based on the comparative analysis between the WLF map and thematic maps of various hydro-geological parameters, it has been found that WLF in the south-western and some portions of the north-eastern showed moderate to a higher value. This may be because most of the non-hilly areas come under gentle to moderate slope category, with lower elevation in the area forming the suitable hydro-geological condition for recharging groundwater. It was observed that the northwest, south-east and central part of the study area showed lower WLF, which may be due to the presence of overburden dump, presence of higher elevation and steep slope. Thus, the combined effect of slope, elevation, geology, drainage and mining activities on the WLF in the study region is moderate. 相似文献
734.
The utilization of water quality analysis to inform optimal decision-making is imperative to achieve sustainable management of river water quality. A multitude of research works in the past has focused on river water quality modeling. Despite being a precise statistical regression technique that allows for fitting separate models for all potential combinations of predictors and selecting the optimal subset model, the application of best subset method in river water quality modeling is not widely adopted. The current research aims to validate the use of best subset method in evaluating the water quality parameters of the Godavari River, one of the largest rivers in India, by developing regression equations for different combinations of its physicochemical parameters. The study involves in formulating best subset regression equations to estimate the concentrations of river water quality parameters while also identifying and quantifying their variations. A total of 17 water quality parameters are analyzed at 13 monitoring sites using 13 years (1993–2005) of observed data for the monsoon (June–October) period and post-monsoon (November–February) period. The final subset model is selected among model combinations that are developed for each year's dataset through widely used statistical criteria such as R2, F value, adjusted R2a, AICc, and RSS. The final best subset model across all parameters exhibits R2 values surpassing 0.8, indicating that the models possess the ability to account for over 80% of the variations in the concentrations of dependent parameters. Therefore, the findings demonstrated the appropriateness of this method in evaluating the water quality parameters in extensive rivers. This work is very useful for decision-making and in the management of river water quality for its sustainable use in the study area. 相似文献
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736.
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738.
土动力参数变异性对深软场地地表地震动参数的影响 总被引:5,自引:0,他引:5
采用等效线性化技术考虑土的动力非线性特性,利用一维波传法及SHAKE91软件计算水平成层场地的地震反应,研究了土的动剪模量比和阻尼比与剪应变幅值的关系曲线、土层剪切波速的变异性对深软场地地表峰值加速度及其反应谱的影响。结果表明:土的动剪模量比均值加1倍标准差与阻尼比均值减1倍标准差、动剪模量比均值减1倍标准差与阻尼比均值加1倍标准差的组合对地表峰值加速度的影响最为显著,但对地表加速度反应谱形状的影响不大;土层剪切波速15%的变异性对地表加速度反应谱形状有较大影响;土层剪切波速的变异性对地表加速度和反应谱的影响比动剪模量比和阻尼比变异性的影响更为显著。 相似文献
739.
740.
ABSTRACTWhen the proton exchange membrane fuel cell (PEMFC) works in the mode of dead-ended anode (DA), the water and the nitrogen in the cathode flow channel will diffuse, and accumulate, to the anode flow channel resulting in fuel starvation on the anode side as well as the performance degradation of PEMFC, which has an important impact on the durability and working state of PEMFC. Because the PEMFC performance is closely related to the cathode working parameters, in order to study the influence of the cathode working parameters on the performance of the PEMFC with DA, a two-dimensional analytical model of PEMFC with DA is established in this article, and the parameters in the model are corrected by experiments. The effects of humidity, stoichiometric ratio and working pressure of cathode gas on the performance of PEMFC with DA are studied by model and experiment, as well as the effects of these working parameters on the accumulation process and distribution of water vapor and nitrogen on the anode side, and the relative performance of PEMFC with DA under different cathode working parameters is obtained. This model is of great significance to guide the practical work of the PEMFC with DA. 相似文献