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1.
简述了环境影响评价中,公众参与的概念,分析了公众参与的必然性及其发展历程,同时也指出了目前环境影响评价中,公众参与存在的问题,通过分析,提出了若干建议。  相似文献   

2.
徐州市电磁辐射环境的污染现状调查及评价   总被引:3,自引:0,他引:3  
调查了徐州市电磁辐射污染源的状况,分析了其电磁辐射环境质量的现状,并对全市电磁辐射环境质量进行了评价,指出了分析工作中存在的问题,提出了防治对策。  相似文献   

3.
研究了臭氧对乐果的降解效果,并探讨了降解机理。考查了不同浓度的臭氧及不同的接触时间对乐果的降解情况。试验发现,当初始臭氧浓度为10mg/L时,乐果的降解在5min内就达到80%左右,延长反应时间,降解率无明显增加。通过添加重碳酸盐和叔丁醇,初步探讨了降解机理,实验表明,臭氧降解乐果是个分子臭氧反应。对处理后的水样进行GC-MS检测,发现了氧化乐果的存在,证实了臭氧处理不足的情况下会产生毒副产物。  相似文献   

4.
生态市的建设,在中国方兴未艾,是当前中国城市发展的最高目标,因此,从逻辑、时间、空间的三维角度,探讨了生态市建设指标体系的构建框架,发展了指标体系构建的理论;在三维框架指导下,构建了一般生态市建设的指标体系,突出了经济循环能力及其生态文化的相关指标,为各地生态市建设提供参考。  相似文献   

5.
冯玥  王璐  陈泉源 《环境工程学报》2013,7(12):4653-4658
采用臭氧氧化法对某厂染料废水生化出水进行深度处理,考察了废水初始pH值和臭氧气泡大小对废水处理效果的影响,研究了臭氧微气泡对气液传质的影响。结果表明,在pH 2.5~11范围内,废水初始pH值越大,处理效果越好;加载微孔膜片后,臭氧气泡粒径变小,增大了臭氧的传质比表面积,延长了臭氧气泡在反应柱内的停留时间,强化了传质效果,处理废水的臭氧利用率可增大10%~30%,强化了臭氧氧化作用。加载5 μm孔径的膜片相比无膜片的情况,COD去除率提高了近30%,TOC去除率提高了16%。  相似文献   

6.
在实验室条件下,以平衡振荡法研究了土壤吸附1,4-二氯苯的影响因素,用Freudlich和Langmuir经验公式,对实验数据进行了拟合,研究了土壤对1,4-二氯苯的吸附模型,并对其吸附动力学进行了初步探讨,并测定了吸附速率常数。  相似文献   

7.
对硫化物标准溶液保存的时间进行了探讨,试验结果表明,在低温冷藏和密封贮存的条件下,配置的硫化物标准溶液性质比较稳定,可以保存12个月,因此大大降低了试剂的消耗,提高了工作效率,并结合多年的分析体会,提出了分析过程中应注意的事项,在实际工作中有一定的推广价值。  相似文献   

8.
环境中铅和镉的来源及其对人和动物的危害   总被引:6,自引:0,他引:6  
几十年来,由于科学技术的发展,环境中有毒或潜在有毒化学物,特别是重金属,种类和数量增加,对人和动物构成了严重威胁。在这些重金属中,铅和镉尤为突出,毒性最大。本文阐述了它们的主要来源,慢性毒性,长期容许量或安全标准,略述了这二种金属与其他元素或养分的相互作用,因为这些作用显著影响了它们的毒性,特别讨论了这些作用对二种金属的容许量或最小长期安全摄入量的影响及其复杂性,最后建议继续研究以找出显示铅和镉对人体亚临床反应的早期敏感性指标。  相似文献   

9.
发展循环经济 推进生态省建设   总被引:2,自引:0,他引:2  
从经济全球化、一体化现状出发,分析了当今世界经济发展的两大趋势,界定了循环经济的内涵,阐明了发展循环经济是建设生态省的核心,提出了加快循环经济发展的措施。  相似文献   

10.
新型悬浮填料澄清池中填料对澄清作用的影响初探   总被引:2,自引:0,他引:2  
为考察可取代传统二沉池的新型悬浮填料澄清池技术的原理及关键参数,小试试验研究了填料对新型悬浮填料澄清池固液分离过程中附着污泥形成及其絮凝性能的影响,并对填料在澄清中的作用机理进行了探讨。结果表明,当泥水界面上升至填料区后,可以形成较悬浮污泥更加致密稳定的附着污泥区,并形成孔道流,强化了对混合液中污泥颗粒的絮凝效果;填料区可以捕捉去除从悬浮污泥区中“逃逸”的微小污泥絮体,并降低出水浊度,有效地保证了出水水质的稳定性。填料的存在发挥了强大的整流作用,降低了雷诺数Re,提高了弗汝德数Fr,从而改善了污泥絮凝的水力条件,提高了澄清能力。  相似文献   

11.
Although Internet cafes have been designated as nonsmoking areas in Korea, smoke-free legislation has allowed the installation of indoor smoking rooms. The purposes of this study were to determine secondhand smoke (SHS) leakage from an Internet café smoking room and to identify factors associated with SHS leakage. PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) mass concentrations were measured simultaneously both inside and outside the door to the smoking room. During each measurement, a field technician observed how long the smoking room door was opened and closed, the direction of door opening, and the number of smokers. A multivariate linear regression model was used to identify the causality of SHS leakage from the smoking room. A time series of PM2.5 concentrations both inside and outside the door to the smoking room showed a similar trend. SHS leakage was significantly increased because of factors associated with the direction of the smoking room door being opened, the duration of how long the smoking room door was opened until it was closed, and the average PM2.5 concentration inside the smoking room when the door was opened. SHS leakage from inside the smoking room to outside the smoking room was evident especially when the smoking room door was opened. Since the smoking room is not effective in preventing SHS exposure, the smoking room should be removed from the facilities to protect citizens from SHS exposure through revision of the current legislation, which permits installation of a smoking room.

Implications: This paper concerns secondhand smoke (SHS) leakage from indoor smoking room. Unlike previous studies, the authors statistically analyzed the causality of PM2.5 concentration leakage from a smoking room using time-series analysis. Since the authors selected the most common smoking room, the outcomes could be generalized. The study demonstrated that SHS leakage from smoking room and SHS leakage were clearly associated with door opening. The finding demonstrated ineffectiveness of smoking room to protect citizens and supports removal of indoor smoking room.  相似文献   


12.
Abstract

Tuberculosis (TB) is a public health problem that may pose substantial risks to health care workers and others. TB infection occurs by inhalation of airborne bacteria emitted by persons with active disease. We experimentally evaluated the effectiveness of in-room air filtration systems, specifically portable air filters (PAFs) and ceiling-mounted air filters (CMAFs), in conjunction with dilution ventilation, for controlling TB exposure in high-risk settings. For each experiment, a test aerosol was continuously generated and released into a full-sized room. With the in-room air filter and room ventilation system operating, time-averaged airborne particle concentrations were measured at several points. The effectiveness of in-room air filtration plus ventilation was determined by comparing particle concentrations with and without device operation. The four PAFs and three CMAFs we evaluated reduced room-average particle concentrations, typically by 30% to 90%, relative to a baseline scenario with two air-changes per hour of ventilation (outside air) only. Increasing the rate of air flow recirculating through the filter and/or air flow from the ventilation did not always increase effectiveness. Concentrations were generally higher near the emission source than elsewhere in the room. Both the air flow configuration of the filter and its placement within the room were important, influencing room air flow patterns and the spatial distribution of concentrations. Air filters containing efficient, but non-high efficiency particulate air (HEPA) filter media were as effective as air filters containing HEPA filter media.  相似文献   

13.
We report on computational fluid dynamics (CFD) predictions of mixing time of a pollutant in an unventilated, mechanically mixed, isothermal room. The study aims to determine: (1) the adequacy of the standard Reynolds Averaged Navier Stokes two-equation (k−) turbulence model for predicting the mixing time under these conditions and (2) the extent to which the mixing time depends on the room airflow, rather than the source location within the room. The CFD simulations modeled the 12 mixing time experiments performed by Drescher et al. (Indoor Air 5 (1995) 204) using a point pulse release in an isothermal, sealed room mechanically mixed with variable power blowers. Predictions of mixing time were found in good agreement with experimental measurements, over an order of magnitude variation in blower power. Additional CFD simulations were performed to investigate the relation between pollutant mixing time and source location. Seventeen source locations and five blower configurations were investigated. Results clearly show large dependence of the mixing time on the room airflow, with some dependence on source location. We further explore dependence of mixing time on the velocity and turbulence intensity at the source location. Implications for positioning air-toxic sensors in rooms are briefly discussed.  相似文献   

14.
This technical note describes a United States Environmental Protection Agency (U.S. EPA) measurement project to determine elemental mercury (Hg0) emissions from a mercury cell chlor-alkali (MCCA) facility in the southeastern U.S. during a 53-day monitoring campaign in the fall of 2006. The optical remote sensing (ORS) area source measurement method EPA OTM 10 was used to provide Hg0 flux data for the site. These results are reported and compared with cell room roof-vent monitoring data acquired by the facility for similar time periods. The 24-h extrapolated mercury emission rate estimates determined by the two monitoring approaches are shown to be similar with overall averages in the 400 g day?1 range with maximum values around 1200 g day?1. Results from the OTM 10 measurements, which include both cell room emissions and potential fugitive sources outside the cell room, are shown to be approximately 10% higher than cell room monitoring results indicating that fugitive emissions from outside the cell room produce a small but measurable effect for this site.  相似文献   

15.
Air-exchange efficiency is widely used to indicate the ventilation effect and indoor air quality in ventilated rooms. However, it does not take occupant distribution in the room into account and is thus limited. In this paper, a revised air-exchange efficiency (occupant air-exchange efficiency) that differentiates between different zones by considering different occupancy in each zone is developed. Results from studies of a large-space ventilation case, a personalized ventilation case, and a displacement ventilation case show that occupant air-exchange efficiency can better be used to evaluate the ventilation effect of a room.  相似文献   

16.
The magnitude and distribution of cypermethrin from total release, over-the-counter foggers was studied in a test room and in residences to facilitate evaluation of regulatory exposure algorithms and new human exposure assessments based upon urine biomonitoring. Surface residue (SR) was evenly distributed in a small test room (3.6 μ g cypermethrin/cm2) where thorough mixing of the aerosol occurred. In a residence SR was significantly affected by room size and distance from the fogger. Air levels in the residence were as high as 30 μ g cypermethrin/cm3 after 4.5 h. The availability of surface residues was measured with an automated surface cotton cloth wipe and ethyl acetate extraction. Only 5% of the SR was available from nylon carpet. Tile, wood and linoleum resulted in 30, 10, and 10% of SR being available, respectively. These data are used to estimate cypermethrin exposure of children and adults for comparison with existing regulatory reference dosages and exposure assessments based upon biomonitoring.  相似文献   

17.
基于CFD的污泥脱水机房恶臭扩散分布规律研究   总被引:1,自引:0,他引:1  
污泥脱水机房是污水处理厂恶臭污染最严重的处理单元之一,其恶臭污染危害工作人员和周边居民身体健康。为研究脱水机房恶臭扩散分布规律,运用计算流体动力学(computational fluid dynamics, CFD)理论并采用其商用软件FLUENT对脱水机房主要恶臭污染物之一的硫化氢扩散分布进行数值模拟。案例研究了3种典型情景下的硫化氢扩散分布。结果表明,不同通风条件对脱水机房硫化氢扩散分布影响较大。在进行脱水机房设计时,应将脱水机布置于夏季最多风向的下方向,并靠近排风口,使恶臭污染物在最短的路径上排除出去,还应考虑机房其他布置,使工作人员经常接触和经过的地方位于低浓度区。  相似文献   

18.
Residential interior door positions influence the pollutant concentrations that result from short-term indoor sources, such as cigarettes, candles, and incense. To elucidate this influence, we reviewed past studies and conducted new experiments in three residences: a single-story 714 m3 ranch-style house, a 510 m3 two-story split-level house, and a 200 m3 two-story house. During the experiments, we released sulfur hexafluoride or carbon monoxide tracer gas over short periods (≤30 min) and measured concentrations in the source room and at least one other (receptor) room for various interior door opening positions. We found that closing a door between rooms effectively prevented transport of air pollutants, reducing the average concentration in the receptor room relative to the source room by 57–100% over exposure periods of 1–8 h. When intervening doors were partially or fully open, the reduction in average concentrations ranged from 3% to 99%, varying as a function of door opening width and the distance between source and receptor rooms.  相似文献   

19.
Wastewater treatment services are bound to rather strict environmental regulations. However, as the broad range of wastewater expenditure of communities shows, there is room for discretionary policies of communities. The current paper explores wastewater treatment expenditure of Austrian communities by employing a cross-section econometric model. To a significant extent, demographic, geographic and technological variables determine wastewater expenditure with only little possibilities to influence these expenditure. Yet there is also some limited room for short-term discretionary policies with respect to the organisational setting. If communities can organise their wastewater treatment in a collective way, they can influence their expenditure significantly.  相似文献   

20.
Abstract

Air-exchange efficiency is widely used to indicate the ventilation effect and indoor air quality in ventilated rooms. However, it does not take occupant distribution in the room into account and is thus limited. In this paper, a revised air-exchange efficiency (occupant air-exchange efficiency) that differentiates between different zones by considering different occupancy in each zone is developed. Results from studies of a large-space ventilation case, a personalized ventilation case, and a displacement ventilation case show that occupant air-exchange efficiency can better be used to evaluate the ventilation effect of a room.  相似文献   

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