PEM式臭氧消毒在地上游泳池水处理中的应用

采用臭氧法水处理系统对地上游泳池的循环水进行灭菌消毒,研究了臭氧用量、循环水流量和运行时间等因素对臭氧法灭菌效果的影响。结果表明,3组PEM臭氧发生器应用于21.2 m3的地上游泳池,在4 m3/h的循环水流量下运行12 h后,水中的细菌总数与大肠杆菌群数达到国家标准,去除率均在99%以上。与盐电解法水处理系统相比较,臭氧法水处理系统的优势在于:杀菌快速高效、出水水质的理化指标较好和运行费用低廉。     

Bioaccessibility of polychlorinated biphenyls in workplace dust and its implication for risk assessment

Human exposure to bioaccessible PCBs via indoor dust is limited around the world. In the present study, the workplace dust sample from commercial office, hospital, secondary school, shopping mall, electronic factory and manufacturing plant were collected from Hong Kong for PCBs analyses. Total PCBs concentrations ranged from 46.8 to 249 ng g⁻¹, with a median of 107 ng g⁻¹. Manufacturing plant showed the highest concentration among all of sampling sites. PCB 77 was found as the dominant congeners. The bioaccessibility of PCBs in small intestinal juice ranging from 8.3% to 26.0% was significantly higher than that in gastric condition, ranging from 4.8% to 12.4%. In addition, significant negative correlations (p < 0.05) were observed between K_OW and bioaccessibility for all workplace dust samples. Risk assessment indicated that the averaged daily dose of dioxin-like PCBs via non-dietary intake of workplace dust, considering the bioaccessibility of PCBs, were much lower than the TDI of dioxins (2.3 pg WHO-TEQ kg bw⁻¹ d⁻¹) established by Joint FAO/WHO Expert Committee on Food Additives.     

Precipitation of Charged Dust Particles on Electrostatic Screen

The purpose of this paper is to present collection performance dependence upon the parameters of channeled electrodes in a twostage precipitator. The practical channeled electrostatic screens are classified into two types and the respective theoretical collection efficiency equations are obtained by employing idealized models. It is shown that In normal operating conditions the most effective particle collection mechanism in the device is electrostatic precipitation rather than the Inertlal separation. It is also pointed out that the channeled electrode, in comparison with the plate-type, should be a narrow width. An empirical efficiency equation is recommended and the agreement between experimental data and empirical equation is within 6%.     

CNTs/TiO2/CS光降解苯的动力学

综合光催化氧化苯的动力学过程、光辐射场模型和质量守恒定律,采用平板型反应器建立了碳纳米管/二氧化钛/壳聚糖(CNTs/TiO2/CS)催化薄膜光催化氧化气相苯的数学模型;该模型考虑了光强、相对湿度、初始浓度与气体流速对气相苯光降解的影响。结果表明,建立的数学模型与实验结果吻合较好。     

Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM_2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ₁₅PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM₁₀ (Particulate Matter up to 10 μm in size) bounded Σ₁₅PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ₁₅PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones.     

采用水解酸化-复合好氧处理制药工业废水的工艺评价

以制药工业综合废水处理为例对其采用的两级水解酸化复合好氧工艺的处理效果进行评估。按常规指标进行评估,该工艺对于制药综合废水的处理效果达到了设计目的,COD去除率可达到78.2%以上,NH+4-N的去除率达到99.3%,出水质量基本满足"污水综合排放标准(GB8978-1996)"二级标准和"辽宁省污水综合排放标准(DB21.1627-2008)";急性毒性的检测表明,经过该工艺处理后出水为低毒性;三维荧光谱分析(EEM)表明,制药综合废水经生物处理后的可溶性有机物中仍然存在难降解物质,建议增加物化处理以提高处理效果;并且制药废水经处理后的出水中的盐度对排入的生态系统存在风险,建议纳入排放标准以加强管理。     

Detection of tritium sorption on four soil materials

In order to measure groundwater age and design nuclear waste disposal sites, it is important to understand the sorption behavior of tritium on soils. In this study, batch tests were carried out using four soils from China: silty clays from An County and Jiangyou County in Sichuan Province, both of which could be considered candidate sites for Very Low Level Waste disposal; silty sand from Beijing; and loess from Yuci County in Shanxi Province, a typical Chinese loess region. The experimental results indicated that in these soil media, the distribution coefficient of tritium is slightly influenced by adsorption time, water/solid ratio, initial tritium specific activity, pH, and the content of humic and fulvic acids. The average distribution coefficient from all of these influencing factors was about 0.1-0.2 mL/g for the four types of soil samples. This relatively modest sorption of tritium in soils needs to be considered in fate and transport studies of tritium in the environment.     

Effects of prenatal exposure to bisphenols on newborn leucocyte telomere length: a prospective birth cohort study in China

Environmental Science and Pollution Research - Telomere length (TL) at birth is related to diseases that may arise in the future and long-term health. Bisphenols exhibit toxic effects and can cross...     

环境电磁污染和防治

本文对环境电磁污染的现状,危害及产生作了部份介绍;同时阐述了污染的防治技术和目前该项工作尚存在问题。     

基于神经网络的温度预测

室内温度与诸多影响因素之间的非线性、复杂性等关系 ,给建模、预测带来了难度 ,引入了人工神经网络 ;利用人工神经网络的非线性、并行计算和自学习特性进行建模 ,实现了对温度模拟