北京市近地层气象要素与大气细菌浓度分布规律的调查研究

以1998年10月的观测资料为例,分析了北京市某地气象要素的变化规律以及该地区大气细菌浓度的分布特征,对两者之间的相互关系进行了初步探讨,发现一天内气象要素及细菌浓度均是周期变化,且两者有一定的相关性。     

毛细柱气相色谱法测定废水中的三氯乙醛

讨论了用毛细柱气相色谱法测定废水中三氯乙醛的方法。该方法用(2+1)石油醚-乙醚萃取废水中的三氯乙醛,方法的相对标准偏差4.9％,回收率91.2％～101.1％,最低检出限4×10~(-2)ng。     

Determination of organophosphorus pesticides and related compounds in water samples by membrane extraction and gas chromatography

A membrane extraction-gas chromatography method was developed fordetermination of organophosphorus pesticides and related compounds including methamidophos, DDVP, dimethoate, methyl parathion, parathion, thiophosphoric acid trimethyl ester, and thiophosphoramidic acid dimethyl ester in water samples. In thismethod, surface-modified acetic cellulose membranes were used to extract the target analytes in water samples, the extracted analytes were back-extracted into a small amount of methanol, andgas chromatography with pulsed flame photometric detector (GC-PFPD) was used to determine the concentrations of targetanalytes in the extracts. The recoveries obtained for thetarget analytes spiked into the water samples ranged from 66to 94%. The method detection limit for each target analyte was 0.05 g L^-1. The method developed in this study had shown the advantages of being cheap, simple, fast, and reliable. It had been used successfully to determine the concentrations of target analytes in river water samples.     

Monitoring of Butter and Ghee (Clarified Butter Fat) for Pesticidal Contamination from Cotton Belt of Haryana, India

Butter (45) and ghee (55) samples were collected from rural and urban areas of cotton growing belt of Haryana and analysed for detecting the residues of organochlorine, synthetic pyrethroid and organophosphate insecticides. The estimation was carried out by using multi residue analytical technique employing GC-ECD and GC-NPD systems equipped with capillary columns. Butter samples were comparatively more contaminated (97%) than ghee (94%), showing more contamination with organochlorine insecticides from urban samples. About 11% samples of butter showed endosulfan residues above MRL value and 2% samples had residues of synthetic pyrethroids and organophosphates each above their respective MRL values. In ghee, residues of HCH & DDT both and of endosulfan exceeded the MRL values in 5 and 20% samples, respectively. Among organophosphates, only chlorpyriphos was detected with 9% samples showing its residue above MRL value. Irrespective of contamination levels, residues above the MRL values were more in ghee. More extensive study covering other agricultural regions/zones of Haryana has been suggested to know the overall scenario of contamination of milk products.     

Factors influencing Aerosol Characteristics over Urban Environment

Atmospheric aerosols are an important contributing factor to turbidity in urban areas besides having impact on health. Aerosol characteristics show a high degree of variability in space and time as anthropogenic share of total aerosol loading is quite substantial and is essential to monitor the aerosol features over long time scales. In the present study extensive observations of columnar aerosol optical depth (AOD), total columnar ozone (TCO) and precipitable water content (PWC) have been carried over a tropical urban city of Hyderabad, India. Significant variations of AOD have been observed during course of the day with low values of AOD during morning and evening hours and high values during afternoon hours. Spectral variation of AOD exhibits high AOD at smaller wavelengths and vice versa except a slight enhancement in AOD at 500 nm. Anomalies in AOD, particulate matter and black carbon concentrations have been observed during May, 2003. Back trajectory analysis of air mass during these episodes suggested variation in air mass trajectories. Analysis of the results suggests that air trajectories from land region north of study area cause high loading of atmospheric aerosols. The results are discussed in the paper.     

深圳市几种空气污染物浓度日变化特征分析

通过对深圳市2002年8月至2003年8月五种空气污染物浓度日变化特征、相互关系及不同天气条件下的变化,与人们活动的关系等进行分析,试图找出深圳空气污染的主要成因及变化规律,为环境规划决策提供科学依据。     

乌鲁木齐市汽车尾气排污现状及防治对策探讨

对乌鲁木齐市在用车辆进行了路抽检调查，通过大量数据分析，得出乌鲁木齐市目前汽车尾气排放情况仍令人担忧，治理工作不容忽视。     

Formation and Emission of N2O and CH4 from Compost Heaps of Organic Household Waster

Composting can be a source of N₂O andCH₄ production. In this investigation, differentcompost heaps of organic household waste weremonitored with the focus on potential formation ofCH₄ and N₂O in the heaps and emission ofthese gases from the heaps. The studied compost heapshad different compost ages, turning intervals andcompost sizes. The analysed compost gases containedbetween 1–3421 L of N₂O-N L^-1 and 0–470 mL of CH₄ L^-1. The emission rates ofN₂O and CH₄ from the compost heaps werebetween 1–1464 mg N₂O m^-2 day^-1 and0–119 000 mg CH₄ m^-2 day^-1. These verylarge differences in compost gas composition andemission indicate the importance of compostmanagement. The results also give an understanding ofwhere in the composting process an increasing emissionof N₂O and CH₄ can occur.     

毛细管气相色谱法测定烟草中有机氯农药残留

研究了烟草中六六六及滴滴涕异构体含量的气相色谱分析方法.样品以石油醚 丙酮在索氏提取器中提取,提取液以浓硫酸净化.采用DB-5弹性石英毛细管柱分离样品,GC-ECD检测农药六六六、滴滴涕的残留量.方法的线性范围为2.27×10-13～7.66×10-11g;最小检测量为1.3×10-8～3.0×10-7 μg,加标平均回收率为95.3%～103.3%,RSD为2.8%～4.5%.     

低浓度石油类监测与评价的问题探讨

分析表明,当地表水中石油类浓度很低时,受多方面因素影响,其监测结果的准确性和评价结论的可靠性会下降,应选用合适的监测方法,同时要注意引入污染问题。