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971.
生化-物化-生态组合工艺用于离散型住宅小区污水处理与中水回用 总被引:1,自引:0,他引:1
以武汉市东西湖区园艺花城小区(3期)污水深度处理和中水回用系统建设为例,介绍和推广一套具有较强实用性的生活污水生化—物化—生态组合处理工艺。该项工艺特别适用于氮含量偏高情况下的离散型住宅小区生活污水深度处理与回用,具有占地省,处理效果稳定,易与周边环境协调等诸多优势。采用组合工艺,可使小区污水经处理后实现达标排放,中水处理系统的出水水质满足《城市污水再生利用(城市杂用水和景观环境用水)水质标准》;系统运行能耗低,污水处理和中水制水的总成本仅为0.69元/m~3。 相似文献
972.
自行研制了平板式介质阻挡放电冷电弧装置,探讨了施加电压、气体流量、甲醛初始浓度和不同设备形式对甲醛气体脱除率的影响。结果表明:在电极间距1.6 cm、施加电压20 kV、气体流量667 mL/min、甲醛初始浓度为50.0 mg/m3以及添加涂有TiO2膜的陶瓷拉西环催化剂的条件下,甲醛的脱除率可以达到90%以上。 相似文献
973.
国道318线二郎山西口至康定县城沿线地质灾害发育特征及治理对策 总被引:4,自引:0,他引:4
在川藏公路关键段二郎山西口至康定县城长74km的范围内,共发育滑坡34处、崩塌33处、泥石流43处,其发育密度分别达0.46,0.44和0.58个(条)/km。分析表明,上述地质灾害的分布与该地所赋存的地形地貌、地持构造及岩性条件等密切相关。 相似文献
974.
中国加入WTO与绿色贸易(非关税)壁垒 总被引:6,自引:0,他引:6
林群慧 《城市环境与城市生态》2001,14(1):28-29,32
文章以我国即将加入世贸组织的新阶段为背景,阐述了绿色贸易壁垒的起因特征,其内容包括环境税、市场准入、环境技术标准、环境标专和绿色消费意识。基于此,指出目前急街解决的主要问题是加快ISO 14000和环境标志认证、环境经济政策的研究和制定以及人才培养,大力发展环保产业和高效农业。 相似文献
975.
An individual-oriented model is constructed which simulates the collective foraging behaviour of a colony of honey-bees,
Apis mellifera. Each bee follows the same set of behavioural rules. Each rule consists of a set of conditions followed by the behavioural
act to be performed if the conditions are fulfilled. The set of conditions comprises the state of external information available
to the bee (e.g. the dancing of other bees) and internal information variables (like memorised location of a food source and
homing motivation). The rules are partly observational (i.e. they capture the observable regularities between the present
external information and the individual bee's behaviour), and partly involve hypothesised internal-state variables (e.g. abandoning
tendency and homing motivation), because no observable (physiological) aspect has as yet been detected in the bee which correlates
with changes in the internal motivation. Our aim is to obtain a set of rules that is necessary and sufficient for the generation
of the collective foraging behaviour observed in real bees. We simulated an experiment performed by Seeley et al. in which
a colony of honey-bees chooses between two nectar sources of different profitabilities which are switched at intervals. A
good fit between observed and simulated collective forager patterns was obtained when the model included rules in which the
bees (1) relied on the information acquired from previous flights to a source (e.g. profitability and time of day when the
source was found), (2) used positional information obtained by attending recruitment dances and (3) did not abandon a (temporarily)
deteriorated source too fast or too slowly. The significance of the following issues is discussed: the role of internal and
external information, source profitability, the spatial precision of the dance communication, the ability to search for a
source after the source position has been transmitted, the tendency to abandon a deteriorated source, and the concepts of
scout, recruit, (un)employed forager, and foraging history.
Received: 26 January 1998 / Accepted after revision: 16 May 1998 相似文献
976.
Although the reuse of bottom ash has been favored gradually, reflected on regulations and researches, the associated risk is still an issue of great concern. This study quantified the health risks from multimedia transport and multi-pathway exposure to the concerned chemicals as a result of reusing bottom ash in road paving with consideration of various application scenarios. In particular, the using duration of the pavement was taken into consideration because movement of chemicals in the soils and groundwater would affect the subsequent exposure and risk. By using soil and groundwater transport modeling linked to food chain exposure assessment and incorporating the Monte Carlo method, the study identified Cr as the crucial toxicant and ingestion of drinking water and vegetables as the key exposure pathways. Furthermore, control of the using duration of road pavement is an essential factor of management and regulations to minimize the leaching of the hazardous constituents into the groundwater and subsequent contamination of food chain. 相似文献
977.
Spatial distribution of soil heavy metal pollution estimated by different interpolation methods: accuracy and uncertainty analysis 总被引:15,自引:0,他引:15
Mapping the spatial distribution of contaminants in soils is the basis of pollution evaluation and risk control. Interpolation methods are extensively applied in the mapping processes to estimate the heavy metal concentrations at unsampled sites. The performances of interpolation methods (inverse distance weighting, local polynomial, ordinary kriging and radial basis functions) were assessed and compared using the root mean square error for cross validation. The results indicated that all interpolation methods provided a high prediction accuracy of the mean concentration of soil heavy metals. However, the classic method based on percentages of polluted samples, gave a pollution area 23.54-41.92% larger than that estimated by interpolation methods. The difference in contaminated area estimation among the four methods reached 6.14%. According to the interpolation results, the spatial uncertainty of polluted areas was mainly located in three types of region: (a) the local maxima concentration region surrounded by low concentration (clean) sites, (b) the local minima concentration region surrounded with highly polluted samples; and (c) the boundaries of the contaminated areas. 相似文献
978.
介绍了国内燃煤电厂"烟塔合一"技术的应用现状,结合实际情况阐述了"烟塔合一"环境防护距离设置的必要性,列举工程实例说明现阶段大气环境防护距离估算方法。 相似文献
979.
气相介质阻挡放电氧化降解酸性红88的机理 总被引:1,自引:0,他引:1
为了有效处理难生物降解的染料废水,采用气相介质阻挡放电产生以羟基自由基为主的氧化性物质,对偶氮染料酸性红88(AR88)进行了氧化降解,并对放电过程中各化学效应对AR88降解的作用机理进行了分析。结果表明,当用相对湿度100%的空气为气源时,放电过程中生成的活性物种如OH·、O,和H2O2是引起放电过程中AR88氧化降解反应的主体,其中OH·在AR88的降解过程中起主要作用,O3参与了对AR88的氧化降解,H2O2对AR88的降解没有明显作用。采用GC/MS分析AR88的主要降解中间产物为萘磺酸、1,2-萘醌、1,2-苯并吡喃酮、萘酚和邻苯二甲酸。通过产物测定和前线电子密度理论,推测了降解途径。 相似文献
980.