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801.
To better understand the atmospheric behaviour of pesticides, heterogeneous ozonolysis of three herbicides (alachlor, terbuthylazine and trifluralin) adsorbed on silica particles were performed in a flow reactor. The experimental setup used in this study and previously validated (Pflieger et al., 2009) has been specially developed to investigate extremely slow reactivity. The pesticides were adsorbed on particles using a gas/solid adsorption equilibrium, in order to simulate atmospheric conditions. After exposure to ozone concentrations ranging from 5 to 41 ppm during 90 min to 6 h, the kinetics were calculated by comparing the initial and the remaining amounts of pesticides adsorbed on silica particles. This work offers the first results of heterogeneous ozonolysis of alachlor and trifluralin adsorbed on mineral particles. Although alachlor and terbuthylazine were expected to react with ozone, no degradation was observed which leads to a lifetime higher than 8 months towards ozonolysis (for 40 ppb of O3). A significant degradation of trifluralin adsorbed on silica particles by heterogeneous ozonolysis was observed. The experimental data could be fit by both the Langmuir–Rideal and the Langmuir–Hinshelwood models resulting in atmospheric lifetimes (towards heterogeneous ozonolysis) of 40 and 32 days respectively (for 40 ppb of O3). These results are discussed and compared to other studies.  相似文献   
802.
不同基质共代谢降解2,4,6-三硝基苯酚的研究   总被引:4,自引:1,他引:3  
以葡萄糖、可溶性淀粉、乙酸钠和苯酚作为共基质,通过35℃恒温生化培养箱缺氧驯化污泥,间歇恒温振荡试验研究了在不同共代谢基质条件下,2,4,6-三硝基苯酚(TNP)的缺氧降解性能。结果表明,经过驯化的微生物加入葡萄糖和苯酚作为碳源,在TNP∶苯酚∶葡萄糖为10∶3∶100的比例下,TNP生物降解率可以从不加碳源时的31.2%提高到86.6%;不同共基质条件下TNP的降解均符合一级反应动力学方程,反应速率常数大小依次是K苯酚K葡萄糖K葡萄糖+苯酚,其中葡萄糖和苯酚同时作为共基质时TNP降解速率常数最大为0.019 h-1。  相似文献   
803.
测定了酚类化合物对硝化颗粒污泥活性抑制的logIC50值,以量子化学参数为自变量,应用偏最小二乘法(PLS),建立了酚类化合物对硝化颗粒污泥活性抑制的定量结构-活性相关(QSAR)模型。模型所提取的PLS主成分所能解释的因变量总方差的比例Qc2um为0.820,表明模型具有较好的稳定性和预测能力。模型的结果表明,影响酚类化合物对硝化颗粒污泥活性抑制的主要因素是logkow、CCR和Ehomo,酚类化合物对硝化颗粒污泥活性抑制的logIC50随着分子logkow的增大而减小,随着Ehomo和CCR的增大而增大。  相似文献   
804.
This study assessed volatile organic compound (VOC) emission characteristics from wastewater treatment plants (WWTPs) in five Taiwanese industrial districts engaged in numerous manufacturing processes, including petrochemical, science-based industry (primarily semiconductors, photo-electronics, electronic products and biological technology), as well as multiple manufacturing processes (primarily pharmaceuticals and paint manufacturing). The most aqueous hydrocarbons dissolved in the wastewater of Taiwanese WWTPs were acetone, acrylonitrile, methylene chloride, and chloroform for the petrochemical districts; acetone, chloroform, and toluene for the science-based districts; and chlorinated and aromatic hydrocarbons for the multiple industrial districts. The aqueous pollutants in the united WWTPs were closely related to the characteristics of the manufacturing plants in the districts. To effectively prevent VOC emissions from the primary treatment section of petrochemical WWTPs, the updated regulations governing VOC emissions were issued by the Taiwanese Environmental Protection Administration in September 2005, legally mandating a seal cover system incorporating venting and air purification equipment. Cost analysis indicates that incinerators with regenerative heat recovery are optimal for treating high VOC concentrations, exceeding 10,000ppm as CH(4), from the oil separation basins. However, the emission concentrations, ranging from 100 to 1000ppm as CH(4) from the other primary treatment facilities and bio-treatment stages, should be collected and then injected into the biological oxidation basins via existing or new blowers. The additional capital and operating costs required to treat the VOC emissions of 1000ppm as CH(4) from primary treatment facilities are less than US$0.1 for perm(3) wastewater treatment capacity.  相似文献   
805.
Cd、Zn、Pb单因素及复合污染对土壤酶活性的影响   总被引:6,自引:0,他引:6  
通过Cd、Zn、Pb单因素处理和复合因素处理的对比性研究发现,无论是单因素或复因素对土壤酶活性的抑制效应顺序均为 Cd> Zn> Pb;在所研究的 4种土壤酶中,脲酶受重金属的抑制作用最为敏感; Cd、 Zn、 Pb复合污染与各单因素的影响有较大差异,同时,Cd、Zn、Pb复合污染对4种土壤酶活性的影响效应亦不同。其复合污染对脲酶表现出协同抑制负效应的特征;对过氧化氢表现出一定的屏蔽作用或拮抗作用;转化酶和碱性磷酸酶主要因Cd浓度的变化而变化。  相似文献   
806.
Background, Aim and Scope Agricultural industrial wastes can frequently be used as raw materials in the production of bio-fuels. Olive-oil milling wastewater is considered as one of the most polluting agro-industrial residues, but fortunately due to its high content of organic matter, it has the potential to be a valuable starting material to obtain bio-ethanol via fermentation with Saccharomyces cerevisiae. The fermentation of olive-oil milling wastewater has been demonstrated with good yield of ethanol (8-12%v/v) once the level of reducing sugars is appropriate and the phenolic fraction, which inhibits the yeast, is removed. Materials and Methods: - Results: - Discussion: - Conclusions: - Recommendations and Perspectives: -  相似文献   
807.
高效液相色谱法检测与化感现象相关的5种酚酸   总被引:17,自引:2,他引:15  
建立了香草酸、对羟基苯甲酸、丁香酸、香豆酸和阿魏酸等5种酚酸的高效液相色谱测定方法,利用本方法在土壤溶液和残茬腐解产物中进行5种酚酸的检测,结果表明,大豆生长一段时间后,在灭菌土壤中、未灭菌土壤中和不同茬口的土壤中,均检测到丁香酸,在残茬腐解产物中检测到香草酸、丁香酸、香豆酸和阿魏酸。  相似文献   
808.
夏小童 《四川环境》2022,(1):175-179
从单一的工程措施到复合生态治理是沙漠治理的必然趋势。为探寻沙漠复合生态治理的可行性方案,探究复合生态治理的实践过程和综合效益。通过对库布其沙漠“林光互补”的实践,进行案例研究。发现“林光互补”复合生态治理,以在沙漠地区建设光伏板的方式,将太阳能转换为电能,利用光伏板下降温增湿的优点,发展板下种植,实现经济效益的同时,减少了风沙对发电设备的影响,促进了当地生态的修复。“林光互补”的复合生态治理将经济发展与生态修复互构,促进沙漠地区的良性运行。同时还应考虑生态与人类生活的关系问题,实现沙漠治理的可持续发展。  相似文献   
809.
分析地表水环境质量标准68项有机指标分析方法的不足,概述其分析方法整合优化的研究现状,并归纳总结目前地表水中68项有机指标的最新分析方法,结合经典分析方法,将68项有机指标的分析方法由40余种整合为20种。  相似文献   
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