Indoor particle dynamics in a school office: determination of particle concentrations,deposition rates and penetration factors under naturally ventilated conditions

Recently, the problem of indoor particulate matter pollution has received much attention. An increasing number of epidemiological studies show that the concentration of atmospheric particulate matter has a significant effect on human health, even at very low concentrations. Most of these investigations have relied upon outdoor particle concentrations as surrogates of human exposures. However, considering that the concentration distribution of the indoor particulate matter is largely dependent on the extent to which these particles penetrate the building and on the degree of suspension in the indoor air, human exposures to particles of outdoor origin may not be equal to outdoor particle concentration levels. Therefore, it is critical to understand the relationship between the particle concentrations found outdoors and those found in indoor micro-environments. In this study, experiments were conducted using a naturally ventilated office located in Qingdao, China. The indoor and outdoor particle concentrations were measured at the same time using an optical counter with four size ranges. The particle size distribution ranged from 0.3 to 2.5 μm, and the experimental period was from April to September, 2016. Based on the experimental data, the dynamic and mass balance model based on time was used to estimate the penetration rate and deposition rate at air exchange rates of 0.03–0.25 h^?1. The values of the penetration rate and deposition velocity of indoor particles were determined to range from 0.45 to 0.82 h^?1 and 1.71 to 2.82 m/h, respectively. In addition, the particulate pollution exposure in the indoor environment was analyzed to estimate the exposure hazard from indoor particulate matter pollution, which is important for human exposure to particles and associated health effects. The conclusions from this study can serve to provide a better understanding the dynamics and behaviors of airborne particle entering into buildings. And they will also highlight effective methods to reduce exposure to particles in office buildings.     

壳聚糖-活性炭复合物水冲前后吸附性及其抑菌性能的研究

将3种不同分子量(Mw)壳聚糖(50 000、100 000及高分子量(粘度为50～800 mPa·s))分别与活性炭制成壳聚糖活性炭复合物.考察自来水冲洗前后,壳聚糖-活性炭复合物的吸附性能及其对大肠杆菌和金黄色葡萄球菌抑制性能的变化.结果表明,经水流冲洗后,3种壳聚糖制备的壳聚糖-活性炭复合物的吸附性能上升,而抑菌性能下降;其中,高分子量壳聚糖制备而成的壳聚糖-活性炭复合物对两种细菌仍有较强的抑制能力.即高分子量壳聚糖制备而成的壳聚糖-活性炭复合物更适于在实际水处理中应用.     

纳米TiO2花式分层微球的合成及其对Pb(Ⅱ)的吸附性能

利用仿生合成的方法,以甘氨酸为模板剂、钛酸正四丁酯作钛源,水热合成一种新型纳米TiO₂花式微球,并对其进行了表征。通过考察pH值、温度和Pb(Ⅱ)溶液的初始浓度对吸附效果的影响,研究了TiO₂花式微球对水溶液中Pb(Ⅱ)的吸附性能及其吸附动力学特性。结果表明,纳米TiO₂花式微球直径约2 μm,平均孔径约56 nm,比表面积约是270.3 m²/g;当pH值为4.0时TiO₂花式微球对溶液中Pb(Ⅱ)吸附率达到最高,210 min时基本达到吸附平衡,20、30和40℃的最大吸附量分别为75.64、76.34 和77.52 mg/g。吸附过程遵循准二级速率方程,与Langmuir等温式拟合更好。     

Supercritical water oxidation of tannery sludge: Stabilization of chromium and destruction of organics

The supercritical water oxidation (SCWO) of industrial tannery sludge was investigated to understand the simultaneous destruction of organic pollutants and recovery of high content chromium. Experiments were performed in a batch reactor at temperatures of 350–500 °C, reaction time of 150–300 s and different oxygen ratios, to exhibit the effect of operation conditions. Results showed that removal efficiency of chemical oxygen demand (COD) increased with higher temperature, larger oxidant amount and reaction time; a maximum value of 96% was obtained. Meanwhile, destruction yield was much higher under supercritical conditions than that in subcritical water. In addition, removal efficiency of Cr from sludge reached more than 98% under all conditions; higher temperature played a positive role. Further, leaching toxicity tests of heavy metals in solid products were conducted based on toxicity characteristic leaching procedure. All heavy metals except nickel showed a greatly reduced leaching toxicity through their stabilization. The chromium oxide recovered in ash was amorphous below 550 °C, so that the structure of Cr could not be identified by X-ray diffraction pattern. Special attention should be paid on nickel as its leaching toxicity increased due to the corrosion of reactor surface under severe reaction conditions.     

MVC设计模式在水环境模拟中的应用

采用MVC软件设计模式能够有效的提高软件的可扩展性、可维护性和代码复用率。并在此思想基础上探讨了利用该方法实现可灵活配置的水质模型系统,为实现动态的水质预测过程提供了一种新途径。     

苏鲁边界区域水资源保护与利用的协同机制探讨——以南四湖为例

通过对苏鲁界湖南四湖水源保护与利用状况的详细考察,全面系统分析了湖域水资源现状、存在的关键问题、影响因素等。针对湖域水资源现状,探讨了南四湖流域水资源保护与利用的协同机制,即建立湖域水资源协同规划与管理机制、湖区经济协同发展机制、生态修复与补偿协同机制、群众协同参与与监督机制、水危机协同处置机制和湖域界面冲突协同控制机制等,以促进跨界区域水资源的保护与利用,统筹区域协同发展,增强南四湖湖域的可持续发展能力。     

含聚污水悬浮固体含量测定方法改进

采用石油天然气行业标准推荐的滤膜法测定油田含聚合物采出水(简称含聚污水)中悬浮固体含量时,过滤时间长而测定值偏高。文章分析了新疆油田含聚污水中固相颗粒物的分布特点,考察了滤膜法存在的问题及影响因素:残余聚合物含量、聚合物分子量、温度等,考察了水中残余聚合物浓度与滤膜截留量的关系,建立了适合含聚污水中悬浮固体含量的测定方法——高速剪切法,验证了该方法的精密度,并以新疆油田现场聚驱和二元复合驱采出水为对象,评价新方法的有效性。     

Landscape ecology of the region around Qinghai Lake,Qinghai Province of China based on romote sensing

１ＩｎｔｒｏｄｕｃｔｉｏｎＡｓａｖｅｒｙｈｉｇｈａｎｄｃｏｌｄｒｅｇｉｏｎ，ｔｈｅＱｉｎｇｚａｎｇＰｌａｔｅａｕ（ＴｉｂｅｔＱｉｎｇｈａｉＰｌａｔｅａｕ）ｉｓｖｅｒｙｐｅｃｕｌｉａｒｉｎｅｃｏｌｏｇｉｃａｌｌａｎｄｓｃａｐｅｆｅａｔｕｒｅ．Ａｌｔｈ...     

SBR-混凝沉淀处理织棉漂白废水研究

研究了SBR－混凝沉淀工艺对织棉漂白废水的处理效果，结果表明，进水CODcr为1060mg/L，经SBR工艺处理，CODcr去除率达到79％。以聚铁－PAM作后续处理，可进一步把CODcr降到100mg/L以下，并能有效去除色度，去除度达94％，出水达到排放标准。该工艺是一种经济有效的可行方法。     

Retrospective assessment of air quality management practices in Taiwan

In 1995, Taiwan's Environmental Protection Administration (EPA/TW) instituted a policy of levying emission taxes on polluters in order to combat the rampant national issue of pollution. Since that time, pollution control strategies, tightening exhaust emission standards for industry, improvements in fuel quality, and new stricter vehicle emission standards, etc., have been implemented. This study evaluates the effectiveness of these measures and examines the improvement of Taiwan's air quality. In this paper, we conduct a detailed analysis of change in the concentrations of pollutants (SO₂, NO_x and particulate matter [PM]) between two three-year periods (from 1996 to1998 and from 2000 to 2002). The pollution levels were generally lower in the latter period. Concentrations at 14 EPA/TW stations in central Taiwan were simulated and source apportionment analyses in three of Central Taiwan's largest cities were conducted using a trajectory transfer-coefficient air quality model. Correlation coefficients (r) between simulations and observations for the monthly means of the concentrations of SO₂, NO_x, PM_2.5 and PM₁₀ during the study periods at the 14 stations are 0.56, 0.63, 0.70 and 0.31, respectively. The sulfur control policy greatly reduced SO₂ concentration island-wide, a stringent emission standard put into place for gasoline vehicles reduced NO_x concentration along highways, and an emissions tax placed on construction sites, as well as a regular program for road-dust sweeping, reduced primary particulate matter. Among all of the pollution abatement policies implemented, the most effective method for reducing PM_2.5 concentrations in the three largest cities involved the reduction of fine ammonium sulfate aerosols from point sources (56–63% of net PM_2.5 reduction). The next largest reduction was attributed to a diminishment in primary PM_2.5 emanating from point sources (27–56% of net PM_2.5 reduction). Secondary particulate matter, especially sulfate, was reduced from distances up to 150 km leeward of major pollution point sources such as Taichung Power Plant.