自动跟踪动压平衡烟尘采样仪的研制

ＧＭ１００Ｃ动压平衡自动跟踪烟尘采样仪,跟踪精度高,响应时间快,无需换孔板,只要拨动波段开关就可换采样嘴。     

浅析被动采样器监测环境空气质量数据的可比性

对被动采样器与空气自动站监测环境空气质量进行了全年的对比实验,并对大量的监测数据进行了规范的处理分析。结果表明,被动采样器在环境条件持续稳定满足采样条件时,被动采样器与自动站监测结果无显著性差异;在环境条件不能持续稳定满足采样条件时,二者监测结果有显著性差异,但仍有较大的相关性。     

固定源可凝结颗粒物稀释采样器的设计

固定污染源烟气排放进入大气环境后稀释降温,气相中部分饱和蒸气压较低的组分转化为可凝结颗粒物,这部分颗粒物在固定源烟气颗粒物监测中通常被忽略.为评价固定源可凝结颗粒物的排放情况,本文设计开发并评测了一套稀释采样器.稀释采样器稀释比在10∶1～40∶1范围内,混合停留时间为5～10 s.实验室评测结果表明,稀释气颗粒物背景值低((～0.1±0.08)个·cm^-3),稀释采样器气密性良好,烟气和稀释气能够均匀混合,颗粒物损失较少,细颗粒物(PM_2.5)损失在5%以下.本稀释采样器能模拟烟气与环境空气混合降温过程,可用于固定源可凝结颗粒物的测量.     

顶空进样-气相色谱法测定大气中吡啶的研究

采用硫酸溶液为吸收液,顶空进样气相色谱法测定大气中的吡啶,毛细管柱分离,FID检测器分析。吡啶标准溶液在0～98.3 mg/L范围内线性良好,当采样体积为30 L时,最低检出质量浓度为0.006 mg/m³,标准溶液平行测定的RSD≤3.1%,加标回收率为95.3%～99.6%。     

油类废水采样器的优化研究

一般说来,在水体中油的分布是很不均匀的,除少部分乳化状油较为均匀地存在于水体,大部分多分散浮于水面,若用普通采水器完全不能满足要求.因此,油类的环境监测采样要求必须单独使用采样器或专用采样器,并应定容或定面积采样,且不得在实验室再行分样.该研究根据永州市废水污染源的特点,设计制作出水中不均匀分布污染物油类的专用采样器,研究结果表明,其精密度和准确度方面明显优于普通采水器.     

EVALUATION OF A DEPTH PROPORTIONAL INTAKE DEVICE FOR AUTOMATIC PUMPING SAMPLERS1

ABSTRACT: A depth proportional intake boom for portable pumping samplers was used to collect suspended sediment samples in two coastal streams for three winters. The boom pivots on the stream bed while a float on the downstream end allows debris to depress the boom and pass without becoming trapped. This equipment modifies point sampling by maintaining the intake nozzle at the same proportion of water depth regardless of stage. Data taken by pumping samplers with intakes mounted on the boom were compared with depth integrated hand samples. Pumped samples showed higher concentrations than depth integrated hand samples. Results suggested that cross-sectional sampling can give high precision with proper placement and calibration of a boom mounted intake.     

A DIGITAL CONTROLLER FOR DISCRETE STAGE ACTIVATION OF AUTOMATIC PUMPING SAMPLERS1

ABSTRACT: An electronic controller was developed to facilitate water sampling at discrete stage heights in perennial mountain streams of southeast Oklahoma. The controller operates in conjunction with an automatic pumping sampler and a magnetic, relay transducer. In response to changes in stage, the transducer generates an electrical pulse when relays are closed by a magnetic float. The controller monitors these relay closures and signals the sampler to pump a single sample at each desired water level during both rising and falling stages. After a sample is taken, additional switch closures at that stage axe ignored until the relay immediately above or below is closed. Inadvertent switch closures caused by turbulent stage fluctuations are not translated to the sampler thus eliminating duplicate or multiple samples at a given stage. Field testing has proven this device to be a reliable component with a range of applications for improving water quality sampling systems. The controller features battery operation, low power consumption, circuit simplicity and can be easily constructed for less than $100, including parts and labor.     

Application of a Dialysis Sampler to Monitor Phytoremediation Processes

A cylindrical dialysis sampler (1.2 m in length; 5 cm in diameter) was designed and constructed to sample small–scale phytoremediation processes in the root zone of poplar trees. The study site was a 183–tree plantation of hybrid poplars located at Aberdeen Proving Ground, Maryland, at the J–Field Area of Concern. The grove was planted in 1996 to intercept a chlorinated solvent plume containing 1,1,2,2–tetrachloroethane (1,1,2,2–TeCA, trichloroethene (TCE) and daughter products. Two dialysis samplers were installed: one directly in the poplar grove (approximately 0.3 m from the trunk of a mature tree) and the other outside of the grove but in the plume. Data collected included concentrations of chlorinated VOCs, organic acids, chloroacetic acids, Cl⁻, and dissolved gases (ethane, ethene, CH₄, CO₂). At the control location, the VOC profile was dominated by cis– 1,2–dichloroethene (cis–1,2–DCE) and trans–1,2–dichloroethene (trans–1,2–DCE) with concentrations ranging from 0.88-4.5 to 4.4-17.6 mg/L, respectively. Concentrations of VOCs were similar across the vertical profile. At the tree location, 1,1,2,2–TeCA and TCE were the dominant VOCs detected but as opposed to the control location were highly variable within the root zone, with the greatest variability associated with locations in the sampler where roots were observed. This highly variable profile at the tree location is indicative of VOC rhizosphere biodegradation and uptake near the active roots. This variability appears to be on the centimeter scale, emphasizing the importance of these high–resolution samplers for the study of rhizosphere influences.     

限流孔烟气采样器的研制及应用

介绍了限流孔烟气采样器的设计原理、主要技术指标、设计指标说明及采样器主要性能。通过测定ＳＯ２标准气体和比对试验，表明限流孔烟气采样器控制流量稳定，计量采气体积准确，应用结果满意。     

Estimating Air Quality in a Traffic Tunnel Using a Forecasting Combination Model

This study performs a field analysis of the diffusion collection rate coefficients of radial geometry passive samplers to measure NO₂ in a Mediterranean coastal area. The study shows that the collection rate coefficients are not constant and depend on certain environmental parameters as well as on the levels of some co-pollutants. A mathematical model, which explains the variation of the collection rate coefficient, has been established.