300 MW等级燃煤机组煤粉炉与循环流化床锅炉汞排放特性比较

选取某地330 MW煤粉炉(PC炉)和350 MW循环流化床锅炉(CFB)的燃煤电厂进行汞排放特性的研究。采用30B法和安大略法对两个燃煤电厂的除尘器入口、除尘器出口、脱硫塔出口和湿式电除尘器出口的烟气进行了取样和汞浓度分析,采集了入炉煤和副产物底渣、飞灰及脱硫石膏样品。通过样品中汞含量的分布,探讨了PC炉与CFB锅炉机组现有污染物控制设备对汞的协同脱除作用。结果表明,350 MW CFB电厂除尘器出口烟气平均汞浓度降低至0.43μg/m~3,布袋除尘器对汞的捕获效率达到98.9%,相应的燃烧副产物中飞灰是汞的主要富集对象。对于330 MW PC炉电厂,除尘器入口和除尘器出口烟气汞浓度均高于350 MW CFB电厂,烟气汞浓度从除尘器入口、除尘器出口到脱硫塔出口依次降低,在脱硫塔出口烟气汞浓度降低至0.42μg/m~3,静电除尘器和湿式脱硫塔对烟气汞的捕获效率分别为75.0%和22.4%,相应的产物中飞灰和脱硫石膏中汞都有一定程度的富集。     

Development of a headspace-gas chromatography (HS-GC-PID-FID) method for the determination of VOCs in environmental aqueous matrices: Optimization, verification and elimination of matrix effect and VOC distribution on the Fortaleza Coast, Brazil

An analytical protocol combining a headspace technique with gas chromatography and detection by photoionization detector and flame ionization detector (HS-GC-PID-FID) was developed. This procedure was used to measure volatile organic compounds (VOCs) in environmental aqueous matrices and was applied in determination of VOCs on the coast of Fortaleza, Brazil. At optimum operating conditions, analytical figures of merit such as linearity (R ranged from 0.9983 to 0.9993), repeatability (5.62 to 9.63% and 0.02 to 0.19% for the quantitative and qualitative analyses, respectively), detection limits (0.22 to 7.48 μg L⁻¹) and sensibility were estimated. This protocol favors a fast sampling/sample preparation (in situ), minimizes the use of laboratory material, eliminates the matrix effect from environmental samples, and can be applied to river, estuarine and oceanic waters. The advantage of detectors in series is that a low sensitivity in detection in one is compensated by the other. Toluene was the most abundant VOC in the studied area, with an average concentration of 1.63 μg L⁻¹. It was followed by o-xylene (1.15 μg L⁻¹), trichloroethene (1.08 μg L⁻¹), benzene (0.86 μg L⁻¹), ethylbenzene (0.74 μg L⁻¹), carbon tetrachloride (0.55 μg L⁻¹), m/p-xylene (0.48 μg L⁻¹) and tetrachloroethene (0.46 μg L⁻¹), compounds which are very commonly detected in urban runoff from most cities. The results of the VOC distribution showed that port activity was not the main source of VOCs along the Fortaleza Coast, but that the contribution from urban runoff seemed more significant.     

水中镉含量的激光诱导击穿光谱高灵敏快速检测

 为了对水中的痕量镉进行高灵敏快速检测,实验采用一种未受污染的薄木片作为基底来吸收水样品,将其晾干后再用激光诱导击穿光谱（LIBS）技术对其进行分析,克服了用LIBS技术直接分析水样品时灵敏度低和稳定性差等问题。实验中选择214.44 nm的镉离子线作为分析线以提高光谱检测的灵敏度,建立了用于定量分析的校正曲线,镉的检出限达到55 μg/L,重复测量的信号相对标准偏差小于5%,单次测量的时间短于5 min。     

镉污染水稻高光谱诊断分析与建模

为了快速、准确地探测自然环境下水稻镉污染胁迫状况,提出了一种基于可见光-近红外光谱小波分析技术的快速识别和估算水稻镉污染的方法。根据野外实测水稻高光谱数据、水稻叶片主要生化参数及重金属含量等数据,利用Daubechies小波系的db5小波函数对350～1300nm水稻高光谱反射率进行9层分解,并提取小波能量系数进行镉含量回归建模。结果显示:第5层小波分解(d5)的奇异范围为550～810nm,奇异幅度为0.04,模极大值的中心位于700nm处,对识别水稻镉污染效果最佳;以第3层小波能量系数作为自变量的回归模型对水稻镉含量估算精度最高,其决定系数R2高达0.958,均方根误差RMSE为0.122。小波奇异性分析可以较准确的诊断水稻镉污染胁迫状况,基于小波能量系数的建模能有效估算水稻镉污染胁迫水平。     

选矿药剂二次污染对尾矿重金属释放与迁移的影响

利用柱淋溶实验模拟研究了硫化矿尾矿在不同选矿药剂淋溶条件下的铜、铅、锌、铬重金属离子的污染规律;利用光降解实验模拟研究了选矿药剂二次污染物的产生问题。选矿药剂二次污染对重金属离子的释放与迁移起着重要作用。     

Numerical models for vehicle exhaust dispersion in complex urban areas

Two numerical models are presented for predicting vehicle exhaust dispersion in complex urban areas with or without the wind field. The models not only reflect the effect of building and street canyon configuration on the pollutant propagation, but also are able to predict the turbulent energy produced by moving vehicles on the road. In particular, in the discrete model, turbulent energy and pollutant concentration produced by each vehicle are dynamically described in the Lagrangian method. The pollutant propagation is calculated with the advection–diffusion equation. The Reynolds averaged Navier–Stokes equations are numerically solved for the wind flows. The movement and heat release rate of the vehicles are treated as sources of the turbulent energy equation for the computation of turbulent energy produced by the moving vehicles. This paper reports the detailed implementation of the models. Four typical numerical tests were carried out to represent the performance of the proposed numerical models. Copyright © 2010 John Wiley & Sons, Ltd.     

Noise effects of reducing traffic flow through a Spanish city

Towards the end of 1999, the building of one of the main communication routes in Spain was finished, the A-3 motorway, which connects Madrid and Valencia. So far, this road was running through the town Motilla de Palancar, province of Cuenca. The opening of the last section of the motorway on 3 December 1999, re-routes all the traffic passing through the town. This study makes a comparative of the noise levels before and after the opening of the motorway that goes through Motilla de Palancar.     

基于GIS的杭州市地面水有机污染可视化研究

通过利用地理信息系统（GIS）的空间分析功能，对杭州市地面水中的有机污染现状（用高锰酸盐指数CODMn表示）进行区域分析，使环境信息数据定性、定位、可视，并能便捷地找出环境信息在时间上和空间上所呈现的规律性，为GIS深入应用于环境科学领域作了有益的尝试。     

CO2 dial for monitoring atmospheric pollutants at the University of Calabria

Summary In this report we introduce the infrared lidar-dial apparatus developed at the University of Calabria. It has been carried out as a tool in the investigation of both the atmospheric pollution of trace gases and other atmospheric parameters as water vapour. The general scheme of the station is described, as well as the performances of the home-made CO₂ laser sources. Finally preliminary measurements of average concentration of ozone and water vapour over a range of about 3 km are presented and discussed in the report.     

Boundary layer parametrization for atmospheric diffusion models by meteorological measurements at ground level

Summary Over recent years several theoretical and experimental works have made it possible to evaluate the basic parameters describing the atmospheric boundary layer by means of elementary meteorological measurements in proximity to the ground. This has opened up the possibility of utilizing atmospheric pollutant dispersion models able to use direct evaluations of atmospheric turbulence through friction velocity and the Monin-Obukhov length. The present paper provides an application of these new techniques in the Milan area.