Experimental and simulated evaluations of airborne contaminant exposure in a room with a modified localized laminar airflow system

Environmental Science and Pollution Research - The traditional mixing ventilation is not an energy effective approach to remove indoor air pollutants, maintain breath zone air quality, and control...     

Removal of ammonia nitrogen from water by mesoporous carbon electrode–based membrane capacitance deionization

Environmental Science and Pollution Research - The removal of ammonia nitrogen from wastewater is always a focus in current water treatment. In this study, a combination of mesoporous carbon...     

非线性回归法计算曝气设备清水氧传递系数

分析对比作图法、线性回归法和非线性回归法计算曝气设备清水氧传递系数(KLa)各自的优缺点。指出在实际测定曝气设备性能中,使用非线性回归法计算KLa更加可靠．而且可以使测试过程更加容易控制。所以在实际测试过程中,推荐使用非线性回归法计算KLa。     

单甲脒农药对模型池塘生态系统藻类群落结构的影响

在１．５－５０．０ｍｇ／Ｌ的浓度范围内，单甲脒农药对模型池塘生态系统中的浮游植物群落结构有明显影响。尤其在加药的头４ｄ内，藻类种类、数量、多样性指数、种类数比及增长率明显下降，优势比显著上升，敏感种及清洁种减少甚至消失，高浓度（５０．０ｍｇ／Ｌ）的单甲脒在２ｄ内可把藻类全部杀灭。随试验时间的延长，药物不断降解，６ｄ后藻类种类、数量、多样性指数又不断回升。随加药次数的增多，药物对藻类抑制作用明显减弱，藻类的种类、数量、多样性指数等指标不断上升，尤其是藻类数量增加明显，试验后期，藻类数量高低主要受Ｎ、Ｐ浓度大小的影响。     

Comparison of the daily global solar radiation from different data sources in Northwest China climate

The solar radiation data are of high importance to the solar energy systems. Conventional methods to obtain the solar radiation data are from weather stations, solar radiation models, commercial software databases, and field measurements. In the present study, a new daily global solar radiation model is proposed, by combining the quadratic function of sunshine fraction and sine function of the day of the year. The solar radiation model calculated data are then compared with China Meteorological Data Sharing System (CMDSS) data, TRNSYS data, and field-measured data in Northwest China climate. It is found that the newly proposed solar radiation model has better performance than the other nine solar radiation models in the literature. The solar radiation model calculated data fit well with the CMDSS annually average data. The TRNSYS data are a bit larger than the CMDSS annually average data in summer half year and a little smaller than those in winter half year. The solar radiation model and the CMDSS annually average data have the best correlation, whereas the TRNSYS data and the field-measured data have the worst correlation. The solar radiation model calculated data have the best correlation with the other three data sources.     

Modeling the fate of benzo[a]pyrene in the wastewater-irrigated areas of Tianjin with a fugacity model

A Level III fugacity model was applied to characterize the transfer processes and environmental fate of benzo[a]pyrene in wastewater-irrigated areas of Tianjin, China. The physical-chemical properties and transfer parameters of benzo[a]pyrene were used in the model and the concentration distribution of benzo[a]pyrene in sediment, soil, water, air, fish, and crop compartments, as well as transfer fluxes across the compartments, were then derived under steady-state assumptions. The calculated results were compared with monitoring data for air, soil, water, and sediment collected from the literature. The results indicate that there was generally good agreement and the differences were within an order of magnitude for air, soil, and sediment. The concentration of benzo[a]pyrene in the ambient air in the area was very low with a majority present sorbed to aerosol. In the water compartment, approximately 70% of benzo[a]pyrene dissolved in water phase. Relatively high concentrations of the compound were found in the soil and sediment, with the soil serving as the dominant sink in the area. Benzo[a]pyrene, with a slow metabolic rate, was found to accumulate in fish in the area.     

论代表性的涵义及工业废水重点源采样方案的设计原则

数据代表性是指监测结果在表征被监测对象特性时所能达到的真实程度;样品代表性是指局部体现整体时所能达到的真实程度。加密监测是重点原调查的质量基础,不能简化行事。监督性监测中,通过测定流量比例混合样来获取总量控制所必需的漉量加权平均值浓度数据,并以此来减小工作量。为满足浓度控制需要,时间—浓度确定型废水的峰浓度样应单独测定。     

伊宁市饮用水源地水质变化动态趋势分析

根据近10年的监测数据，对伊宁市饮用水源地水质变化进行动态趋势分析，无显著变化。     

Quantitative method to determine the regional drinking water odorant regulation goals based on odor sensitivity distribution：Illustrated using 2-MIB

Taste and odor （T/O） in drinking water often cause consumer complaints and are thus regulated in many countries. However, people in different regions may exhibit different sensitivities toward WO. This study proposed a method to determine the regional drinking water odorant regulation goals （ORGs） based on the odor sensitivity distribution of the local population. The distribution of odor sensitivity to 2-methylisobomeol （2-MIB） by the local population in Beijing, China was revealed by using a normal distribution function/model to describe the odor complaint response to a 2-MIB episode in 2005, and a 2-MIB concentration of 12.9 ng/L and FPA （flavor profile analysis） intensity of 2.5 was found to be the critical point to cause odor complaints. Thus the Beijing ORG for 2-MIB was determined to be 12.9 ng/L. Based on the assumption that the local FPA panel can represent the local population in terms of sensitivity to odor, and that the critical FPA intensity causing odor complaints was 2.5, this study tried to determine the ORGs for seven other cities of China by performing FPA tests using an FPA panel from the corresponding city. ORG values between 12.9 and 31.6 ng/L were determined, showing that a unified ORG may not be suitable for drinking water odor regulations. This study presents a novel approach for setting drinking water odor regulations.     

喷射时刻对柴油甲醇组合燃烧发动机颗粒物排放的影响

为了进一步减少甲醇掺烧后的柴油机颗粒物排放,在一台由增压中冷的高压共轨柴油机改造成的柴油甲醇组合燃烧(DMCC—diesel/methanol compound combustion)发动机上详细研究了柴油喷射时刻对两种燃料共燃时的颗粒物生成及其排放的影响.试验工况选择重型柴油机常用的A50工况.试验结果表明,当柴油在上止点后喷射时,颗粒物排放的数量浓度随着甲醇替代率的增加而减少,当上止点前喷射时,颗粒物的数量浓度先减少后增加.随着喷射时刻的提前,颗粒中超细颗粒所占比例增大.随着喷射时刻的推迟,甲醇替代率降低颗粒物质量浓度的作用增强,同时甲醇替代率降低颗粒物几何平均直径的作用减弱.