差示分光光度法在水质监测中的应用

通过测定高浓度氨氮标准品(GSBZ20005—88)的试验,验证了差示分光光度法在测定高浓度样品时的准确度和精密度,说明差示分光光度法在一定情况下能减少多次稀释所带来的误差,可以快速测定高浓度样品。     

碱性消解-伏安极谱法测定土壤中六价铬

分析了汞滴尺寸、支持电介质等因素对碱性消解-伏安极谱法测定土壤中六价铬的影响。在优化实验条件下,该方法检出限为7.65μg/L,相对标准偏差(n=7)为4.6%。以2个样品为例,每个浓度进行6次平行测定,加入六价铬浓度为10μg/L,六价铬的回收率为91.4%~120%,RSD≤5%。与二苯碳酰二肼分光光度法进行比较,2种方法测定值基本一致。     

Reduction and immobilization of chromium(VI) by nano-scale Fe0 particles supported on reproducible PAA/PVDF membrane

A new class of nano-scale Fe0 particles (NZVI) supported on a PAA/PVDF membrane (NZVI-PAA/PVDF) were synthesized and the feasibility of using NZVI-PAA/PVDF for reductive immobilization of Cr(VI) in water was investigated through laboratory batch tests. The results showed that the Cr(VI) removal capacity of NZVI-PAA/PVDF was 181 mg Cr/g Fe at an initial Cr(VI) concentration of 20 mg L(-1) under pH 6.5 +/- 0.1. XPS results showed that Cr(VI) was converted to nontoxic Cr(III). Interfering ions exerted various degrees of impact on NZVI-PAA/PVDF's Cr(VI) removal capacity. Specifically, Ca2+ alone showed the mildest impact while the presence of ions (Mg2+ and HCO3-) exerted the greatest impact. An advantage of NZVI-PAA/PVDF is that the nano-scale Fe0 and resultant particles were combined within a PAA/PVDF membrane, which prevents secondary pollution. Moreover, a piece of PAA/PVDF membrane (4.7 cm diameter) can still support 6.51 mg of nano-scale Fe0 particles after being renewed.     

Composition, sources, and potential toxicology of polycyclic aromatic hydrocarbons (PAHs) in agricultural soils in Liaoning, People’s Republic of China

Surface soil (0–20 cm) samples (n?=?143) were collected from vegetable, maize, and paddy farmland used for commercial crops in Liaoning, China. Sixteen priority polycyclic aromatic hydrocarbons (PAHs) listed in US Environmental Protection Agency were analyzed by high-performance liquid chromatography using a fluorescence detector. The soil concentrations of the 16 PAH ranged from 50 to 3,309 ng/g with a mean of 388 ng/g. The highest concentration of total PAHs found in soil of the vegetable farmland was 448 ng/g in average, followed by maize and paddy with total PAHs of 391 and 331 ng/g, respectively. Generally, the low molecular weight PAHs were more predominant than the high molecular weight PAHs in most of the soils. The evaluation of soil PAH contamination based on the Canadian criterion indicated that only naphthalene, phenanthrene, and pyrene were over the target values in several sampling sites. Isomer pair ratios and principal component analysis indicated that biomass and coal combustion were the main sources of PAHs in this area. And the average value of total B[a]Peq concentration in vegetable soils was higher than paddy and maize soils. We suggest that biomass burning should be abolished and commercial farming should be carried out far from the highways to ensure the safety of food products derived from commercial farming.     

水平潜流人工湿地系统处理微污染原水的研究

采用水平潜流人工湿地系统处理微污染原水,同时考察了水力停留时间、温度、水力负荷以及植物的生长状况等对人工湿地系统处理效果的影响。结果表明,水平潜流人工湿地系统对微污染原水有较好的处理效果,COD、TP、TN、NH⁺₄-N、NO^-₃-N和NO^-₂-N的平均去除率分别为51.55%、49.90%、51.74%、 47.36%、52.67%和63.23%。按照国家地表水环境质量标准（GB3838-2002）,经过湿地处理后,出水COD平均值达到Ⅰ类;出水TP平均值达到Ⅱ类;出水TN平均值基本接近Ⅳ类;出水NH⁺₄-N平均值达到Ⅱ类。另外,研究表明, 本系统在水力停留时间为3 d时,水力负荷为0.2 m/d处理效果最好,温度的变化与污染物的去除率呈正相关关系,植物生长旺盛程度直接影响着整个系统的处理效果。     

武器装备防雷标准体系及应用研究

从国际防雷标准体系的研究入手,梳理了国内武器装备防雷标准的技术来源,对比了不同体系标准在雷电关键参数、标准内容、实际应用等方面的差异,分析了存在的问题,并提出协调与选择应用的建议,可作为各类型装备开展雷电防护工作及后续标准规范制定的参考依据.     

抚仙湖流域生态系统结构与功能分析

从湖泊地质结构、湖泊水文、湖泊生态系统的不稳定性、湖泊水环境承载能力特征进行了分析，结果表明：抚仙湖的生态系统不稳定，水环境的承载能力有限，湖水补给水量较小，水资源消耗量大。湖泊的功能是由各种资源相互作用而维系的，直观的资源过度利用造成对其功能的危害。全面实施抚仙湖保护，成为关系玉溪市社会经济可持续发展的头等重大问题。必须实现湖泊资源利用和经济的可持续发展，保护湖泊的生态服务功能，确保湖泊的生态安全。     

微生物絮凝剂的研究、应用及存在的问题

介绍了微生物絮凝剂的研究及应用现状,包括产生絮凝剂的微生物种类、微生物絮凝剂的絮凝机理,以及微生物絮凝剂的应用。同时提出了微生物絮凝剂在研究、应用中存在的问题和今后的发展方向。     

办公室内可吸入颗粒物污染初析

测定了普通办公室内空气中可吸入颗粒物的质量浓度，分析了粒径分布，并考察了吸烟对可吸入颗粒物污染的影响，研究表明，办公室内可吸入颗粒以细颗粒为主，ＰＭ〈７．０μｍ的颗粒物占９５％以主，ＰＭ〈１．１μｍ的颗粒物占５０￣７０％，吸烟和室外大气可吸入颗粒物的污染是普通办公室内窃据中可吸入颗粒物污染的重要来源。     

泸州市区域环境噪声监测优化布点

本文利用数理统计中有关数学工具进行监测布点的优化工作。把泸州市区域环境噪声普查的294个监测点位优化为67个。经验证,该优化布点方法合理、科学。