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81.
改进型波形潜流人工湿地处理猪场废水 总被引:1,自引:0,他引:1
提出了一种改进型波形潜流人工湿地(improved wavy subsurface flow constructed wetland,IW-SFCW)并研究了该湿地系统在5个水力停留时间(hydraulic retention time,HRT)(2、3、4、6和8 d)下对猪场废水的处理效果。结果表明,该湿地系统对猪场废水中各污染物有较好的去除效果。在水力停留时间为4 d,进水COD、TN、NH4+-N和TP浓度分别为511、120、110和10 mg/L左右时,该湿地系统对COD、TN、NH4+-N和TP的去除率分别为86.0%、54.4%、70.1%和91.6%。此外,该湿地系统对废水中COD、TP的去除效率随水力停留时间的延长逐渐提高,在HRT=8 d时去除效果最好,去除率分别达到92.7%和96.8%;但对TN、NH4+-N的去除率却随水力停留时间的延长出现先上升后下降的趋势,在HRT=4 d时去除率最高,分别为54.4%和70.1%。 相似文献
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83.
利用衡水市环境监测站2005—2007年度大气例行检测的数据,对衡水市大气中主要污染物SO^2、NO^2、PM10体积质量值的逐日数据进行统计分析,得出了衡水市空气污染的现状和时间变化规律:(1)污染物体积质量值的月变化曲线呈槽型分布,非取暖期的空气状况明显好于取暖期,取暖期SO^2平均体积质量是非取暖期的2.45倍;(2)污染物体积质量值的日变化曲线基本为两高两低型,其中取暖期污染指数早晨出现极高值的时间比非取暖期明显偏晚;(3)污染物体积质量值的年变化表明了SO^2的体积质量在降低,而NO^2的体积质量却有了小幅增长。 相似文献
84.
Moe MK Huber S Svenson J Hagenaars A Pabon M Trümper M Berger U Knapen D Herzke D 《Chemosphere》2012,89(7):869-875
For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by 1H, 13C and 19F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility. 相似文献
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86.
基于适应性管理的水污染控制体系构建——以太湖流域为例 总被引:1,自引:0,他引:1
从规划内容与目标、规划方法及方案实施和评估3方面对太湖近20年水污染物控制历程进行综合分析,认为太湖水污染物控制正处面源污染、生活污染及新型污染问题凸显且更难处理,更为广泛的利益相关者和科研队伍积极参与的转型期.这种变化将导致污染治理面临更难应付的动态性和复杂性,使得当前以环境容量为总量为指导通过自上而下分配排污量和削减量的控制方案面临极大挑战.结合太湖水污染现状,通过与现行治理方法在管理假设、适合对象、协调管理手段、管理目标、规划方法、公众参与程度以及规划的优劣势等方面的比较发现,适应性管理可以积极有效应对由于环境趋势和管理协调对象变化所带来的系统不确定性和复杂性,将是一个积极有效的补充方法.同时,本文基于适应性管理提出了太湖水环境污染物排放控制体系的构建框架,突出适应性管理平台、科学研究及公众与基层单位参与在污染物控制中的重要作用. 相似文献
87.
A two-dimensional numerical model for evaluating the wind flow and pollutant dispersion within a street canyon was first developed using the FLUENT code, which was then validated against a wind tunnel experiment. Then, the effects of the upstream building width and upwind building arrangement on the airflow and pollutant dispersion inside an isolated street canyon were investigated numerically. The numerical results revealed that: (1) the in-canyon vortex center shifts downwards as the upstream building width increases; (2) the recirculation zone covers the entire upstream building roof for the cases when W/H = 0.5, 1.0, 1.5, and 2.0 (W is the upstream building width and H is the building height), whereas the flow reattaches the upstream building roof for the cases when W/H = 2.5 and 3.0; (3) when the upstream building width is shorter than the critical width WC (= 2H), an increase in the upstream building width leads to an increase in the pollution level on the leeward wall of the canyon and a decrease in the roof-level concentrations at the upstream building; (4) when the upstream building width is longer than the critical width, the roof-level concentrations at the upstream building are negligibly small and the pollution level on the leeward wall of the canyon is almost unaffected by a further increase in the upstream building width; (5) when the buildings are placed upwind of the canyon, the flow attaches the upstream building roof and, therefore, almost none of the pollutants are distributed on the upstream building roof; and (6) the pollution levels inside the canyon and on the downstream building roof increase significantly with the number of upwind buildings. 相似文献
88.
Occurrence and source analysis of typical veterinary antibiotics in manure, soil, vegetables and groundwater from organic vegetable bases, northern China 总被引:19,自引:0,他引:19
The residue of antibiotics is becoming an intractable environmental problem in many organic vegetable bases. However, their residual levels and distribution are still obscure. This work systematically analyzed the occurrence and migration of typical veterinary antibiotics in organic vegetable bases, northern China. The results showed that there was no obvious geographical difference in antibiotic distribution between soil and manure. A simple migration model can be easy and quick to predict the accumulation of antibiotics in soil. Antibiotics were mainly taken up through water transport and passive absorption in vegetables. The distribution of antibiotics in a plant was in the sequence leaf > stem > root, and performed biological accumulation. The residues of antibiotics in all samples in winter were significantly higher than those in summer. Overall, this work can lay the foundation for understanding ecological risk of antibiotics and their potential adverse effects on human health by food chain. 相似文献
89.
90.
在深刻论述新疆地区近年来开展节能减排和总量控制工作情况的基础上,针对我区污染物总量控制工作所面临的形势和问题进行了认真总结,并结合我区今后经济发展要求,为确保完成“十一五”总量控制目标,认真做好“十二五”总量控制工作,提出了加强污染源监督管理、完善考核制度、推进大集团战略及提高环境准入条件等8个方面的对策和建议。 相似文献