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841.
842.
福州市城市化进程与大气污染关系研究 总被引:1,自引:0,他引:1
以福州市为研究区域,选取福州市1996—2012年的时间序列数据,将大气污染物浓度作为被解释变量,城市化水平作为解释变量,分别设定二次曲线模型和三次曲线模型,通过比较PM10、SO2、NO2浓度与城市化水平的二次曲线和三次曲线模型的回归拟合效果,得出福州市大气污染与城市化水平之间的演化规律。结果表明,1996—2012年,福州市城市化水平平稳上升,城市的大气污染程度与城市化水平之间的关系并不完全符合"倒U型"的环境库兹涅茨曲线,不同的污染物类型具有不同的演化规律。PM10、SO2与城市化水平呈"倒N型"的曲线关系;NO2与城市化水平之间呈现"倒U型"曲线关系。由于研究的时间序列较短,因而研究结果可能只是真实曲线的一部分,福州市的大气污染与城市化水平之间的关系还有待进一步研究。 相似文献
843.
Assessment of Aquifer Vulnerability in an Agricultural Area in Spain Using the DRASTIC Model 总被引:1,自引:0,他引:1
Georgios Bartzas Dimitra Zaharaki Ma Teresa Hernández-Fernández Jose Luis Moreno Ortego 《Environmental Forensics》2015,16(4):356-373
The assessment of aquifer vulnerability is a very important task, especially in agricultural areas because the quality and availability of groundwater affects both the sustainability of agriculture and the quality of life. In this study, an integrated approach is considered, with the use of the generic and agricultural DRASTIC models as well as a geographic information system (GIS), to assess groundwater vulnerability in the agricultural area of Barrax, in the province of Albacete, in Spain. Seven parameters—depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone media, and hydraulic conductivity of the aquifer (DRASTIC)—have been considered as weighted layers to enable an accurate groundwater risk mapping. The results of the generic DRASTIC model indicated very low vulnerability to contamination for Barrax groundwater due to limited urban and industrial development in the wider area. However, agricultural activities impose pressure to groundwater resources and the results of the agricultural DRASTIC model show that 6.86% of the study area is characterized by very high, 2.29% by high, 47.28% by medium, 38.28% by low, and the remaining 5.29% by no vulnerability to groundwater contamination. The distribution of nitrate concentration in groundwater in the area under study is quite well correlated with the agricultural DRASTIC vulnerability index. Sensitivity analysis was also performed to acknowledge statistical uncertainty in the estimation of each parameter used, to assess its impact, and thus to identify the most critical parameters that require further investigation. Depth to water and impact of vadose zone are the parameters that had the most noticeable impact on the generic DRASTIC vulnerability index followed by the soil media and topography. In contrast, the agricultural DRASTIC method is more sensitive to the removal of the depth to water parameter followed by the topography and the soil media parameters. 相似文献
844.
Two industrial sites were investigated based on years of available hydrogeologic information and monitoring data for soil and groundwater. Collected data were forensically evaluated using age-dating and fingerprinting methods. The previous business uses of the project sites were as a gas station, laundry/dry-cleaning service, and car wash with petroleum underground storage tanks (USTs). As a result, these sites were exposed to a number of toxic contaminants at relatively high concentrations. Source control was necessary for successful remediation and the ultimate removal of the remaining compounds from these industrial sites. Although contaminated soil around the source was excavated during the remedial action and the high concentrations of contaminants were reduced, typical groundwater contaminants such as petroleum hydrocarbons as gasoline (TPH-G), benzene, toluene, ethylbenzene, xylenes (BTEX), and oxygenates including methyl tert-butyl ether (MTBE), diisopropyl ether (DIPE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and tert-butyl alcohol (TBA) were persistently found at the studied sites around the source points. The plume and concentration of contaminants had changed their shapes and strength for all monitoring periods. Thus, additional source control seems to be a requirement for the complete removal of source contamination, which must be ascertained with groundwater and soil monitoring on a regular time base. For the study sites, monitored natural attenuation was relatively feasible for the long-term plan; however, it did not offer a perfect remediation solution for an ultimate goal because of residual toxic compounds that might have affected the surrounding residential areas at higher concentrations than their health limits. Therefore, as a remediation strategy, the combination of clean-up technology and natural attenuation with monitoring activities are more highly recommended than either clean-up or natural attenuation used separately. 相似文献
845.
Vahab Vaezzadeh Aileen Tan Shau-Hwai Zelina Zaiton Ibrahim Shuhaimi Mustafa Mehrzad Keshavarzifard 《Environmental Forensics》2015,16(2):135-142
This article is the most recent report of polycyclic aromatic hydrocarbons (PAHs) in the Muar River and Pulau Merambong, Peninsular Malaysia. A total of 16 priority pollutant PAHs in addition to methylphenanthrene among alkylated PAHs were analyzed in surface sediments during May 2013. Total PAHs ranged from 212 to 440 and 151 to 412 ng g?1 dw in sediments from the Muar River and the Pulau Merambong, respectively. The Muar River showed an increasing trend of PAH concentrations, while no previous data exist for the Pulau Merambong. Generally, mixed petrogenic and pyrogenic sources of PAHs with predominance of the latter were detected in the study area. Effective management of oil pollution has caused a drastic decrease in petrogenic sources of PAHs. 相似文献
846.
城市面源污染是重要水体污染源之一,降雨发生时,雨水径流会携带累积在路面、屋面的含有机物、氮磷、重金属等污染物质进入水体,其中氮磷是造成水体富营养化的重要因素。针对这一情况,采用不同种类沸石,对雨水径流中的氮磷进行了吸附研究,着重考察了沸石对氨氮的吸附动力学,吸附等温线特征,并考察了p H、共存阳离子以及COD对吸附能力的影响。结果表明,Na型改性沸石吸附性能优于其他2种,饱和吸附量达到9.09 mg/g,沸石的吸附过程符合准二级动力学模型。Mg2+、Ca2+对Na型改性沸石的影响较大,Na型改性沸石吸附氨氮的适宜p H为5~8。本研究为探索用物化方法来处理雨水提供了依据,Na型改性沸石可以作为吸附雨水中氨氮的优选吸附剂。 相似文献
847.
选取废水、挥发酚、氰化物、COD、石油类和氨氮为中国工业水污染指标,利用分解分析方法将2004—2010年间的污染变化分解为规模效应、结构效应、污染治理效应、清洁技术效应和广义技术效应。结果显示,这5类效应的平均作用强度分别为2.08%、3.04%、15.61%、17.37%和32.88%,其中规模效应和广义技术效应是影响工业水污染的主导效应。各类效应对不同污染物的作用方向并不完全一致,规模效应促进污染物排放量的增加;结构效应以加重污染为主,污染治理效应和清洁技术效应以减轻污染为主;广义技术效应的平均作用强度和负向作用概率均最大,是现阶段中国工业水污染控制最为有效的手段。 相似文献
848.
简述了炼油装置区恶臭污染源的主要分布、恶臭气体组成和排放规律,介绍了恶臭治理的基本方法。通过治理实例,重点分析了目前常用的吸收法、燃烧法、生物法和吸附法等恶臭治理技术的优势和相对不足,并对恶臭治理应用技术方案的选择提出建议。 相似文献
849.
850.
Mark F. Zaranyika Pamhidzai Dzomba Jameson Kugara 《Journal of environmental science and health. Part. B》2013,48(12):908-918
The aim of the present work was to establish the kinetics for the degradation of doxycycline in the aquatic environment with a view to arriving at a kinetic model that can be used to predict the persistence of antibiotic with confidence. The degradation of doxycycline in both water and sediment phases of aquatic microcosm experiments, as well as in distilled water control experiments, was studied over a period of 90 days. An initial 21% loss due to adsorption by the sediment was observed in the microcosm experiment soon after charging. Biphasic zero-order linear rates of degradation, attributed to microbial degradation of the free and sediment or colloidal particle-adsorbed antibiotic, were observed for both water phase (2.3 × 10?2 and 4.5 × 10?3 μgg?1 day?1) and sediment phase (7.9 × 10?3 and 1.5 × 10?3 μgg?1 day?1) of the microcosm experiment. The covered distilled water control experiment exhibited a monophasic zero-order linear rate (1.9 × 10?3 μgg?1 day?1) attributed to hydrolysis, while the distilled water experiment exposed to natural light exhibited biphasic liner rates attributed to a combination of hydrolysis and photolysis (2.9 × 10?3 μgg?1 day?1) and to microbial degradation (9.8 × 10?3 μgg?1 day?1). A kinetic model that takes into account hydrolysis, photolysis, microbial degradation as well as sorption/desorption by colloidal and sediment particles is presented to account for the observed zero-order kinetics. The implications of the observed kinetics on the persistence of doxycycline in the aquatic environment are discussed. 相似文献