A Depth‐Proportional Intake Device for Automatic Water Samplers1

Abstract: This paper describes the construction and testing of a device for pumping water samplers that collects suspended sediment samples by moving the intake vertically to keep it at the same proportion of flow depth. The device uses a simple sprocket mechanism that can be mounted vertically on the downstream side of culverts and bridge pilings to protect against damage from floating debris during storms. Suspended sediment samples collected from an urban stream with the depth‐proportional device were compared with manual samples taken with a depth‐integrated sampler. Scatter in the relationship between pumped and manual samples (R² = 0.76) are probably explained by horizontal variability in concentrations, poor mixing associated with lateral sediment inputs from construction site erosion, the downstream orientation of the intake, and the failure of the concentration at 60% of the flow depth to match the average vertical concentration.     

简易吸水式深水采样器的制作与应用

常用的直通式深水采样器不但价格较高,且使用不方便。本文介绍一种简单、实用的吸水式深水采样器,具有造价低廉、操作简单、方便实用的优点,尤其适用于河流湖库的深层水样采集,采水深度可达１００ｍ左右。     

Modelling Replicated Weed Growth Data using Spatially-varying Growth Curves

Weed growth in agricultural fields constitutes a major deterrent to the growth of crops, often resulting in low productivity and huge losses for the farmers. Therefore, proper understanding of patterns in weed growth is vital to agricultural research. Recent advances in Geographical Information Systems (GIS) now allow geocoding of agricultural data, which enable more sophisticated spatial analysis. Our current application concerns the development of statistical models for conducting spatial analysis of growth patterns in weeds. Our data comes from an experiment conducted in Waseca, Minnesota, that recorded growth of the weed Setariaspp. We capture the spatial variation in Setaria spp. growth using spatially-varying growth curves. An added challenge is that these designs are spatially replicated, with each plot being a lattice of sub-plots. Therefore, spatial variation may exist at different resolutions – a macro level variation between the plots and micro level variation between the sub-plots nested within each plot. We develop a Bayesian hierarchical framework for this setting. Flexible classes of models result which are fitted using simulation-based methods.     

发电厂附近大气气溶胶元素浓度的监测

用Ｓｔｒｅａｋｅｒ时间顺序采样器在火力发电厂附近连续收集大气气溶胶样品，这些样品在２×１．７ＭＶ串列加速器上用２．５ＭｅＶ的质子进行ＰＩＸＥ分析，得到了大气气溶胶粗，细颗粒物中２１个元素浓度及其时间的短时变化，显示了主要污染源方向的信息，结果表明，元素Ｓｉ，Ｋ，Ｚｎ和Ａｓ的浓度高于北京地区冬天的水平，Ｂｒ／Ｐｂ的比值为０．１６（ｎ＝４４），高于一般地区。     

Sampling atmospheric pesticides with SPME: Laboratory developments and field study

To estimate the atmospheric exposure of the greenhouse workers to pesticides, solid phase microextraction (SPME) was used under non-equilibrium conditions. Using Fick's law of diffusion, the concentrations of pesticides in the greenhouse can be calculated using pre-determined sampling rates (SRs). Thus the sampling rates (SRs) of two modes of SPME in the lab and in the field were determined and compared. The SRs for six pesticides in the lab were 20.4-48.3 mL min⁻¹ for the exposed fiber and 0.166-0.929 mL min⁻¹ for the retracted fiber. In field sampling, two pesticides, dichlorvos and cyprodinil were detected with exposed SPME. SR with exposed SPME for dichlorvos in the field (32.4 mL min^-1) was consistent with that in the lab (34.5 mL min^-1). SR for dichlorvos in the field (32.4 mL min⁻¹) was consistent with that in the lab (34.5 mL min⁻¹). The trends of temporal concentration and the inhalation exposure were also obtained.     

Spatio-Temporal Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Atmospheric Air of Tamil Nadu,India, and Human Health Risk Assessment

This study analyzed the seasonal distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs) in the atmospheric environment of Tamil Nadu, India. Passive air sampling was performed at 32 locations during the period from April 2009 to January 2010, and PAHs were quantified using a gas chromatograph-mass spectrometer. Analysis showed that the concentrations of PAHs were in the range of 5–47.5 ng/m³ with uniform distribution in urban areas in all seasons. Pre-monsoon season showed the highest cumulative concentration of PAHs in both agricultural and coastal areas. Among PAHs, phenanthrene, fluoranthene, and pyrene levels were found to be predominant in all the samples, contributing up to 36%, 35.5%, and 24.5% of total PAHs, respectively. The signature of the PAHs obtained through diagnostic ratio and principal component analysis revealed that diesel emissions was the probable source of PAHs in all locations. Based on Word Health Organization guidelines, the human lung cancer risk due to observed level of PAH concentration (i.e., PAHs exposure) is meager. However, the risk is predicted to be more in the coastal area during summer (18 individuals among 0.1 million people). To the knowledge of these authors, this report is the first on the seasonal analysis of PAHs using passive air sampling in India.     

北京市城市道路尘土残存量和湿式积尘量特征

道路扬尘是大气细颗粒物的来源之一,道路清扫保洁可以降低道路积尘量和道路扬尘排放。收集北京市2015年道路尘土残存量（d≤2 mm）数据,采用道路积尘湿式采样器采集秋季道路积尘量（d≤180 μm）,分析道路积尘的空间和道路类型分布特征,道路积尘中有机物和无机物含量等,并与瑞典斯德哥尔摩城市道路积尘特征进行比较。结果表明：春、夏、秋、冬和年均值道路尘土残存量分别为26.1、15.7、14.9、15.0和17.9 g·m-2,4类城市功能区的道路尘土残存量分别为13.8、15.0、24.8和20.6 g·m-2;秋季首都功能核心区和城市功能拓展区道路积尘量分别是道路尘土残存量的3.2和2.5倍,是斯德哥尔摩市道路积尘量的5.3和3.9倍;道路积尘量主要来自车辆遗撒、车轮带泥、非铺装路肩风蚀水蚀和大气降尘等无机物,无机物约占道路积尘量的（86.8±5.1）%,最高可达95.8%。建议严格控制渣土车遗撒和车轮带泥等污染源,并加强道路清扫保洁。     

呼吸性粉尘个体采样器气流脉动的研究

分析了个体呼吸性粉尘采样器气流脉动的形成原因,以及其对采样性能的影响,提出了解决这一问题的方法。     

Development of odorous gas sampler and investigation of its practicality

The existing gas sampler is deficient in regard to its efficiency, handling and ability. In order to solve these problems, a new gas sampler was developed and its function was investigated. The sampler is a vessel made of aluminium and contains a polyester bag inside the vessel. The vacuum method is employed for taking the gas. The maximum capacity of the gas volume that can be taken is about 15 liters and sampling time can be from 15 sec to 10 min per sample. In addition, many odor surveys were carried out and the practicality of the new sampler was investigated. It was concluded that the new sampler was easy to handle and was more efficient than the existing gas sampler.     

应急监测空气和废气中醋酸乙烯

醋酸乙烯作为重要的有机化工原料在扬州多家化工企业使用,在此针对醋酸乙烯的理化性质,采用便携式采样器采集气体样品,参考了EPA．625方法中采样罐采样热脱附气相色谱-质谱法进行分析,但是热脱附装置和采样罐价格昂贵．质谱分析时间较长．操作要求高．不便于常规监测分析,现采用活性炭吸附气相色谱分析醋酸乙烯。通过实验总结出一套采样时间短分析速度快．灵敏度高的快速分析方法．为环境监测工作中醋酸乙烯应急监测提供分析参考。