Heterogeneous reaction of NO2 on the surface of montmorillonite particles

The studies on heterogeneous reactions over montmorillonite, which is a typical 2:1 layered aluminosilicate, will benefit to the understanding of heterogeneous reactions on clay minerals. Montmorillonite can be classified as sodium montmorillonite or calcium montmorillonite depending on the cation presented between the different layers. Using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), the heterogeneous reaction mechanism of NO₂ on the surface of montmorillonite was firstly investigated. Results showed that the reaction of NO₂ on the surface of sodium and calcium montmorillonite fit a first-order kinetics, and the reaction duration of calcium montmorillonite was longer than that of sodium montmorillonite under the dry condition. For either sodium or calcium montmorillonite, the uptake coefficient decreased as humidity increased.     

如何建立公路声屏障产品质量控制体系

笔者通过对国内公路声屏障产品质量的关注,深入剖析产生产品质量问题的内在原因及外部环境。提出建立公路声屏障产品质量控制体系的思路与实施方法,供大家一起探讨和完善。     

太钢“十一五”污染减排工作

近几年,我国钢铁工业发展很快,但是,钢铁产业长期粗放发展积累的矛盾日益突出。除了产能过剩、产业集中度低、创新能力不强、资源控制力弱等问题外,更为突出的矛盾是钢厂的发展越来越受到环境容量、能源资源等因素的严重制约。如何颠覆传统的"高耗能、高污染"发展方式,走出一条钢厂和谐发展的绿色之路,是实现可持续发展所面临的重大难题。     

改性膨润土对对硝基苯胺的吸附研究

采用十六烷基三甲基溴化铵(CTMAB)制备改性膨润土,重点研究了改性剂的用量、改性时间、改性温度对改性膨润土吸附对硝基苯胺的的影响。同时对膨润土改性前后的吸附性能进行了比较,结果表明,改性膨润土对对硝基苯胺的吸附量明显增加,且吸附等温线符合Langmuir方程。     

排水管道噪声简易评价方法设计的研究

建筑排水管道产生的噪声是家庭噪声的主要来源之一,而目前的测定方法系统较复杂、测试时间又长,本文根据管道声学测量理论对排水管道噪声测定方法进行设计,旨在探寻一种排水管道噪声简易的评测方法,以提高实验测试效率,同时又可为排水管材降噪性能研究提供一种简便方法。     

浅议石墨炉原子吸收法测定水中的四乙基铅

用三氯甲烷萃取水中的四乙基铅,直接在石墨炉原子吸收仪上进行测定。结果表明：本方法的相对标准偏差为5．9％,平均回收率在90．4％～108％之间,检出限为1．3×10^-5mg／L,准确度高,精密度好。     

Seasonal variation of potential denitrification rates of surface sediment from Meiliang Bay, Taihu Lake, China

The regulatory effects of environmental factors on denitrification were studied in the sediments of Meiliang Bay, Taihu Lake, in a monthly sampling campaign over a one-year period. Denitrification rates were measured in slurries of field samples and enrichment experiments using the acetylene inhibition technique. Sediment denitrification rates in inner bay and outer bay ranged from 2.8 to 51.5 nmol N2/(g dw (dry weight)·hr) and from 1.5 to 81.1 nmol N2/(g dw·hr), respectively. Sediment denitrification rates were greatest in the spring and lowest in the summer and early autumn, due primarily to seasonal differences in nitrate concentration and water temperature. For each site, positive and linear relationships were regularly observed between denitrification rate and water columnn itrate concentration. Of various environmental factors on denitrification that we assessed, nitrate was determined to be the key factor limiting denitrification rates in the sediments of Meiliang Bay. In addition, at the two sites denitrification rates were also regulated by temperature. The addition of organic substrates had no significant effect on denitrification rate, indicating that sediment denitrification was not limited by organic carbon availability in the sediments. Nitrate in the water column was depleted during summer and early autumn, and this suppressed effective removal of nitrogen from Taihu Lake by denitrification.     

Photodegradation of new herbicide HW-02 in organic solvents

HW-02 is a new organophosphates herbicide which is discovered and developed in China. The kinetics and mechanism of HW- 02 photodegradation in the organic solvents were studied at 25°C under the irradiation of ultraviolet light. The results showed that photochemical reaction of HW-02 in organic solvents such as n-hexane, methanol, dimethyl benzene and acetone under UV light could be well described by the first kinetic equation, and the photodegradation efficiency decreased with a order of n-hexane methanol xylene acetone. The photodegradation efficiency constant of HW-02 in n-hexane, methanol, xylene and acetone were 4.951 × 10 2 , 3.253 × 10 2 , 2.377 × 10 2 and 1.628 × 10 2 min 1 , and the corresponding half-lives were 13.99, 21.20, 29.15 and 42.56 min, respectively. By separation and identification of photoproducts using GC-MS, it could be concluded that HW-02 was photolyzed through ester cleavage, photo-dechlorination and photoisomerization of the molecule itself.     

光离子化检测技术在重油泄漏检测中的应用

介绍了PID检测技术原理、特点,及在重油输送装置的对比试验,结果表明,PID比催化燃烧式可燃气体检测仪灵敏度高。     

福州市建筑用地地质环境优化利用评价

在对福州市建筑用地地质环境适宜性评价的基础上,进一步对宜建区高层(重型)建筑用地与普通民用及工业建筑用地进行了优化利用评价,即:首先采用敏感因子—模糊综合评价模型确定福州市建筑用地宜建区;然后依据建筑物高度对地质环境要求的差异,建立建筑用地优化利用评价的指标体系;最后采用模糊多属性决策模型对两种方案进行排序择优,实现两种建筑用地基于地质环境的优化利用。评价结果表明:基于地质环境的福州市建筑用地优化利用评价结果基本符合实际,采用的评价方法是切实可行的。