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151.
臭氧-BAF组合工艺对石化行业废水深度处理的中试研究   总被引:1,自引:0,他引:1  
采用臭氧-曝气生物滤池(BAF)组合工艺对中石化九江分公司二级生化出水进行深度处理中试实验。探讨了臭氧投加量、进水水质冲击负荷等因素对该组合工艺出水COD、NH4+-N的影响。中试结果表明,在该水质条件下,臭氧最佳投加量为20~25 mg/L;组合工艺处理后出水COD低于40 mg/L,NH4+-N低于5 mg/L,达到中水回用设计标准;该组合工艺能够经受一定冲击负荷。  相似文献   
152.
为了更好地发挥产氢产酸/同型产乙酸耦合系统在废水厌氧发酵生产乙酸方面的优势,有必要寻找一种简单有效的方法以获得该系统产酸的优化条件.利用经过加热处理并活化的厌氧污泥作种泥,以模拟废水中的葡萄糖为底物,针对发酵时间、底物浓度、种泥浓度、初始pH进行4因素10水平均匀设计实验,得到了乙酸生产指标与产酸条件之间关系的回归方程;也得到了以高乙酸产量为主要目标导向同时兼顾高乙酸产率和高乙酸生产强度目标的优化条件;优化条件实验乙酸浓度比均匀设计中最高乙酸浓度提高20%左右.研究表明,将均匀设计应用于废水产氢产酸/同型产乙酸耦合产酸条件优化,可以避免盲目性,迅速获得满意结果.  相似文献   
153.
结合660 WM机组电除尘器的设计要求,对电除尘器内气流流动进行了数值模拟与试验研究.计算中选择SIMPLE方法求解三维雷诺平均方程和κ-ε两方程湍流模型.研究结果表明,无论电除尘器两室流量分配还是第一电场进口断面气流分布,计算结果与试验吻合较好,数值计算结果可以指导电除尘器设计与模型试验研究.  相似文献   
154.
水生植物对面源污水净化效率研究   总被引:82,自引:0,他引:82       下载免费PDF全文
于自然条件下研究了慈茹、菱白等7种水生植物对面源污水的净化率。结果表明,7种试验植物对水体中N、P均有很高的净化率,其中以慈茹和菱白的综合净化率为最高。由于不同植物对N、P的净化率不同,所以多种植物配置可提高植物对面源污水的综合净化率。  相似文献   
155.
A three-year study over the Bai, Jingpo and Huayaodai communities in Yunnan Province reveals that the community development is significantly influenced in various ways by such cultural factors as the concepts of development; concepts and traditions of inter-community relationships, consumption, mar- riage and gender; patterns of decision-making and production, resource and income allocation; as well as the role of information dissemination systems, religion and ritual. Based on the analysis over the interactive relevance between each factor and community development, some strategies and methods for dealing with such a cultural relevance in development projects are recommended.  相似文献   
156.
With the further development of socialist market economy, the mobility of factor markets in China, especially the labor market, is strengthened. Externalities interacts with the agglomeration of productive factors. Under the framework of new economic geography, this article presents a theoretical model involving the endogenous population density affected by urban externalities. Results show that the population density is more concentrated around the center because the degree and extent of interaction between individuals intensifies when the distance from the center decreases. When there are several externalities resources, the aggregation of externalities changes the configuration of spatial factor allocation. These results fit well with the empirical facts about the decreasing density of floating population along the cities of Guangzhou, Dongguan and Shenzhen in Guangdong Province which is situated in the eastern coast of the Pearl River Delta. We fred that under the impacts of externalities released from Hong Kong into the coast, floating population was more concentrated around Shenzhen and Dongguan, which are more adjacent to Hong Kong compared with Guangzhou City.  相似文献   
157.
环境与生态系统资本价值评估的若干问题   总被引:17,自引:0,他引:17  
李双成  郑度  杨勤业 《环境科学》2001,22(6):103-107
近年来,环境与生态系统资本价值评估中的概念界定、系统价值认定及评价模式选择等之类的问题成为相关研究中有争议的议题.鉴于此,对环境与生态系统资本价值评估中的一些问题进行了探讨.①在肯定环境与生态系统资本价值评估意义的基础上,指出对于环境与生态系统的整体价值要予以充分估价;②针对目前评价模式单一的现状,提出了整合类型与区域评估的新模式;③在分析了环境与生态系统的资本价值在空间上流动之后,认为应对价值的积累和流动过程给予充分关注;最后,提出了几条具体的建议.  相似文献   
158.
Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government authorities. However, the results of these studies failed to be comparable directly with each other due to imprecise data sets, unmodified accounting methods of pasture and fossil energy, ignored secondary products, undefined process Of calculating yield factors and improper biocapacity for biodiversity. In this paper, we elaborated on EF estimating methods from six categories of consumption in order to overcome the limitations above. We adopted precise data and revised methods, calculated EF of some secondary products, introduced weighted factor to calculate yield factors and adjusted biocapacity by an appropriate amount. Meanwhile, we investigated the resource consumption of Liaoning Province in 2006 to assess EF. Its results showed that Liaoning Province overused its natural capital and was in an unsustainable state. We concluded that two specific problems that had arisen in EF assessment and gave some suggestions for Liaoning Province to improve its unsustainable state.  相似文献   
159.
Understanding ozone (O3) formation regime is a prerequisite in formulating an effective O3 pollution control strategy. Photochemical indicator is a simple and direct method in identifying O3 formation regimes. Most used indicators are derived from observations, whereas the role of atmospheric oxidation is not in consideration, which is the core driver of O3 formation. Thus, it may impact accuracy in signaling O3 formation regimes. In this study, an advanced three-dimensional numerical modeling system was used to investigate the relationship between atmospheric oxidation and O3 formation regimes during a long-lasting O3 exceedance event in September 2017 over the Pearl River Delta (PRD) of China. We discovered a clear relationship between atmospheric oxidative capacity and O3 formation regime. Over eastern PRD, O3 formation was mainly in a NOx-limited regime when HO2/OH ratio was higher than 11, while in a VOC-limited regime when the ratio was lower than 9.5. Over central and western PRD, an HO2/OH ratio higher than 5 and lower than 2 was indicative of NOx-limited and VOC-limited regime, respectively. Physical contribution, including horizontal transport and vertical transport, may pose uncertainties on the indication of O3 formation regime by HO2/OH ratio. In comparison with other commonly used photochemical indicators, HO2/OH ratio had the best performance in differentiating O3 formation regimes. This study highlighted the necessities in using an atmospheric oxidative capacity-based indicator to infer O3 formation regime, and underscored the importance of characterizing behaviors of radicals to gain insight in atmospheric processes leading to O3 pollution over a photochemically active region.  相似文献   
160.
摆脱传统思维方式的束缚,采用科学的、系统的、程序化的方法制定我国县级经济和社会发展战略,是我国现代化建设提出的一项艰巨任务。本文旨在通过介绍“绵竹县经济社会发展总体规划(系统工程应用)研究”的核心部分——绵竹县社会经济系统动态仿真模型设计与发展战略的仿真实验择优,阐述系统工程的原理和运用数学模型方法对县级社会经济系统进行总体设计、预演和优化的一点体会。  相似文献   
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