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991.
高、中频混响声场噪声治理技术的研究及应用   总被引:1,自引:0,他引:1  
沈仁 《环境工程》2004,22(3):53-55
我国目前纺织厂织造车间的噪声级均较高。应用吸声降噪原理 ,通过模拟、中试和二项试点三步的实践证明 ,采用在厂房建筑上架设大面积“强吸声吊顶”技术的方法 ,能使织造车间的噪声降低 4~ 6dB(A) ,收到较好的降噪效果。  相似文献   
992.
采用上流式厌氧污泥床 (UASB)处理城市垃圾渗沥液 ,结果表明 :在水力停留时间为 1~ 6d和容积负荷为 1 5~ 7 8kgCOD/m3 ·d的条件下 ,COD的去除率为 6 0 %~ 85 5 % ,且去除率随水力停留时间的延长和负荷的增加而增加 ;甲烷产量随容积负荷的增加而呈线性增加 ;沼气中甲烷的含量基本在 90 %之上 ;污泥的VSS/SS先由 0 6 2逐渐减小到 0 5 6 ,随后稳定在 0 5 4~ 0 5 8之间 ;污泥的比产甲烷速率一直维持在 0 0 0 35~ 0 0 0 5 3gCODCH4 /gVSS·gCOD·d之间 ;厌氧处理渗沥液的基本动力学常数Ks、μm、Y和kd 分别为 380 7mgCOD/L、0 0 337d-1、0 0 6 6 1gVSS/gCOD和 0 0 0 14d-1。  相似文献   
993.
Environmental Science and Pollution Research - This study evaluated the reutilization of waste materials (scrap tires, sewage sludge, and wood chips) to remove volatile organic compounds (VOCs)...  相似文献   
994.
This study analyzed the wintertime surface heat exchange for the Inner Mongolia reach of the Yellow River, China, based on the data from the nearby weather station at Wulateqianqi. In this analysis, the solar radiation is based on the observed data. Other components of the surface heat flux, that is, long‐wave radiation, and evaporative and conductive heat fluxes, are calculated. The relative importance of the contributions of long‐wave radiation, conductive, and evaporative heat fluxes are in descending order. The air temperature is the most important meteorological factor to the total heat flux. Although the wind speed influences evaporative and conductive heat fluxes, it has the least correlation with the total heat budget. The heat exchange coefficient for the linearized surface heat exchange equation is 21.87 W/(m2 °C), which is comparable with published values in the regions of United States and Canada with similar latitudes.  相似文献   
995.
To investigate the spatial distribution and diurnal variation of the chemical composition of PM2.5 pollution in an industrial city of southern Taiwan, 12-h PM2.5 was diurnally continuously collected simultaneously at the Kaoping Air Quality Zone (KAQZ) during one highly PM2.5-polluted episode. Water-soluble ions, metallic elements, carbonaceous contents, dicarboxylic acids, and anhydrosugars were analyzed to characterize the chemical fingerprint of PM2.5. Backward trajectory simulation and chemical mass balance (CMB) receptor modeling were applied to identify the potential sources of PM2.5 and their contributions. It showed that Chaozhou (rural area) accompanying the highest SORs and NORs suffered from the most severe PM2.5 pollution during the episode. Sulfate (SO42−) was probably formed by the atmospheric chemical reaction in the daytime, while NO3− processed at nighttime at the KAQZ. A homogeneous formation of NO3− occurred at Chaozhou. The concentrations of Zn, Pb, Fe, Cu, V, and Al, mainly emitted from anthropogenic sources, increased significantly at the KAQZ. The highest OC, SOC/OC, and DA/OCs at Daliao (industrial area) were attributed to the transformation of primary VOCs to secondary OC via photo-oxidation during the episode. Oxalic acid was mainly produced through photochemical reactions since a high correlation between oxalic acid and Ca2+ was observed at Nanzi (urban area) and Daliao during the episode. During the episode, PM2.5 mostly originated from local primary or secondary aerosol than long-range overseas transport. The dominant source was anthropogenic emissions, accounting for 67.1% and 70.4% of PM2.5 at Nanzi and Daliao, respectively. At Chaozhou, the contribution of anthropogenic emissions was the lowest (42.4%), but secondary aerosols had the highest contribution of 38.3% of PM2.5 among the three areas during the episode.  相似文献   
996.
农村污水治理是农村人居环境整治的重点任务之一,也是其难点所在。基于乡村振兴及改善农村人居环境的战略需求,本文以成都市温江区为研究对象,分析农村污水治理的现状和存在的关键问题,探讨农村污水治理技术与模式,从农村生活污水的处理模式,农村黑臭水体处理模式以及农村污水管理模式三个方面,探索符合温江农村特点、可复制可推广的农村污水治理模式,以期为川西地区农村污水治理提供理论参考。  相似文献   
997.
青霉素G钾在蔬菜地土壤中的降解动力学研究   总被引:1,自引:0,他引:1  
为确定青霉素G钾(penicillin G potassium,PG)在土壤中的半衰期和降解动力学,选择灭菌与未灭菌、施肥与未施肥蔬菜地土壤作为基质,研究了PG在不同基质中的降解曲线,并拟合了降解动力学方程。结果表明,PG在蔬菜地土壤中的半衰期为1.61~1.67 d,最终降解率均达到99.7%以上,但PG不会完全降解,仍会以较低的水平(21~73μg·kg-1)在土壤中长期存在。降解动力学方程拟合结果表明,PG的初始浓度会对降解速率产生影响,初始浓度越高,降解速率越快。在灭菌与未灭菌土壤中降解曲线显示其降解过程受生物和非生物作用共同影响,但添加有机肥的降解过程和未添加组没有显著差异。由于PG在土壤中不能被完全降解,从而增加了诱导抗性基因产生及转移的风险。  相似文献   
998.
Environmental Science and Pollution Research - In order to understand the influence of feedstock type on biochar adsorption of heavy metals, the adsorption characteristics of nickel (Ni2+), copper...  相似文献   
999.
Aeolian dust episodes (ADEs) have been an emergency disaster in the Kaoping River Valley during the rainy season (May-September), which can severely deteriorate ambient particulate air quality in the region surrounding the Kaoping River. Thus, this study aims to characterize the metallic fingerprint of Aeolian dust (AD) and investigate the effects of ADEs on ambient particulate air quality along the Kaoping River Valley. Four manual sampling sites adjacent to the riverside were selected to collect fine (PM2.5) and coarse (PM2.5–10) aerosol samples during and after the ADEs in the periods of six events. A total of 13 metallic elements were analyzed using an inductively coupled plasma-atomic emission spectrometer. With metallic elements analysis and nonparametric statistical methods of Wilcoxon rank-sum test and Kruskal-Wallis test, this study successfully derived the metallic indicators of ADEs. The mass ratios of crustal elements (Fe, Ca, or Al) to reference element (Cd) obtained during the ADEs were much higher than those obtained after the ADEs. High mass ratios of Fe/Cd, Ca/Cd, and Al/Cd in PM2.5-10 were observed on the influenced areas of ADEs. Among them, (Fe/Cd)2.5-10 was proven as the best indicator which can be applied to effectively validate the existence of ADEs and evaluate their influences on ambient air quality. Moreover, PM2.5 concentrations during the ADEs were 3-3.6 fold higher than those after the ADEs. PM2.5 should be a contributor to AD, even though the mass ratios of PM2.5/PM10 ranged from 0.05 to 0.20 during the ADEs. Our findings provide valuable information regarding the characteristics of the AD during the ADEs in the Kaoping River.

Implications: Indicators of (Fe/Cd)2.5-10 are approximately applied to observe the effects of ADEs. Local governments could realize the mechanisms of S- and NW-type aeolian dust episodes (ADEs). They can cause deterioration in different ways for the regional air quality surrounding Kaoping River Valley. Residents who have been living in the influenced areas can take precautions to prevent damage from aeolian dust. Strategies for curbing ADEs must reduce the area of bare lands by artificial measures in the long period of the sunny days during the rainy season. Future research should examine physical conditions of topsoils and other chemical composition in aeolian dust.  相似文献   

1000.

This study is the first report describing the occurrence of 15 phthalate acid esters (PAEs) in the three typical water sources of YiXing City, Taihu Upper-River Basin, East China. The fate of target PAEs in the Jiubin drinking water treatment plant (JTP) was also analyzed. The amounts of Σ15PAE in the Hengshan (HS), Youche (YC), and Xijiu (XJ) water sources were relatively moderate, with mean values of 360, 357, and 697 ng L−1, respectively. Bis(2-ethylhexyl) phthalate (DEHP) dominated the PAE concentration, making up 80% of the 15 total PAEs. The highest levels of Σ15PAE were found in HS, YC, and XJ in March 2015, January 2015, and July 2014, respectively. The occurrence and concentrations of these compounds were spatially dependent, and the mean concentrations of Σ15PAE in HS, YC, and XJ samples increased from the surface layer to the bottom layer with varied percentage increases. The removal efficiency of the PAEs in the finished water varied markedly, and the removal of PAEs by the JTP ranged from 12.8 to 64.5%. The potential ecosystem risk assessment indicated that the risk of PAEs was relatively low in these three water sources. However, risks posed by PAEs due to drinking water still exist; therefore, special attention should be paid to source control in the JTP, and advanced treatment processes for drinking water supplies should be implemented.

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