国内旅游地水环境研究综述

水环境问题是旅游环境研究的重点领域之一。本文从研究理论、方法、区域和内容方面对国内水环境研究作一系统综述,并指出目前我国旅游水环境的研究理论较侧重水环境专业理论,与旅游结合的理论运用不足;研究方法注重一般的环境影响评价方法,社会方法运用较少;研究区域注重水域型旅游地,海滨海岛及山岳、古村落等旅游地较少;研究内容侧重旅游对水环境的自然影响,水资源利用及社会影响研究较少。     

电化学传感器法监测室内空气中甲醛

通过用国家标准GB/T 18204.26-2000酚试剂分光光度法与电化学传感器原理的PPM-400 ST甲醛检测仪（PPM-Tech）相对比,并对可能影响甲醛检测仪监测结果的环境因素如空气中干扰物、风速、温度、湿度等进行研究。在95%置信度下,两种方法所得数据配对t检验的结果,差别无显著性意义;并将两种方法测得的数据进行相关分析,其回归方程式：y（传感器法）=0.004 6＋1.03x（酚试剂法）,相关系数为r=0.993 4。研究结果表明PPM-400 ST甲醛快速检测便携式仪器具有轻巧、方便、快捷、可靠、实时检测甲醛浓度的优点,检测结果与现有国家标准方法具有好的可比性。     

2,4-D异辛脂原药生产废水处理工艺的研究

针对2,4D异辛脂原药生产中产生的工艺废水化学需氧量和异辛脂污染物浓度高、毒性大。废水日产量和排放量相对较少,排放周期短、气温低等特性,研究废水在较短周期内,克服低气温条件,以一套处理工艺,采用多种方法协同作用,使多组分污染物经处理后都能够实现达标排放。通过实验室研究,确定化学絮凝、活性炭吸附铁炭等多种技术方法应用于同一废水中对多组分污染物处理时的最佳药剂的投放量和最佳停留时间。并用数理统计理论分析了处理效果的相关性,制定了铁-炭还原-混凝-MPAC处理工艺,并使其成功地应用于实际废水处理中,取得了预期的处理效果。     

兰州市冬季高校教室环境状况调查分析

为了研究兰州市冬季高校大学生上课期间的教室内环境状况。对兰州市某高校22间教室的室内空气干球温度、相对湿度、风速、CO2浓度等环境参数进行了现场测试,并按照ASHRAE 7点标度对学生热感觉进行主观调查。测试结果表明,教室内相对湿度都低于50%;95.5%的教室空气温度都满足16℃-24℃国家标准要求;上课期间54.5%的被调查教室内的CO2浓度超过卫生标准的3-4.5倍。问卷调查结果表明,80%以上的学生对所处教室的热环境表示满意,78.1%的学生认为室内空气干燥。兰州市冬季高校教室环境状况有待改善,建议采用人工加湿和开窗通风等手段,改善教室室内空气品质。     

Intake of phthalates and di(2-ethylhexyl)adipate: results of the Integrated Exposure Assessment Survey based on duplicate diet samples and biomonitoring data

Phthalates are ubiquitous environmental chemicals with potential detrimental health effects. The purpose of our study was to quantify dietary intake of phthalates and of DEHA (Di-ethylhexyl adipate) using duplicate diet samples and to compare these data with the calculated data based on urinary levels of primary and secondary phthalate metabolites. 27 female and 23 male healthy subjects aged 14-60 years collected daily duplicate diet samples over 7 consecutive days. Overall, 11 phthalates were measured in the duplicates by GC/MS and LC/MS methods. Urinary levels of primary and secondary phthalate metabolites are also available. The median (95th percentile) daily intake via food was 2.4 (4.0) microg/kg b.w. (Di-2-ethylhexyl phthalate, DEHP), 0.3 (1.4) microg/kg b.w. (Di-n-butyl phthalate, DnBP), 0.6 (2.1) microg/kg b.w. (Di-isobutyl phthalate, DiBP) and 0.7 (2.2) microg/kg b.w. for DEHA. MEPH (Mono-2-ethylhexyl phthalate) was detectable only in minor concentrations in the samples, thus conversion of DEHP to MEHP and dietary intake of MEHP were negligible. When comparing back-calculated intake data of the DEHP metabolites with dietary DEHP intake from the day before significant correlations were observed for most of the metabolites. No correlation was found for DnBP and only a weak but significant correlation for DiBP. The median and 95th percentile daily dietary intake of all target analytes did not exceed the recommended tolerable daily intake. Our data indicated that food was the predominant intake source of DEHP, whilst other sources considerably contributed to the daily intake of DnBP and DiBP in an adult population.     

荆州市中心城区集中式饮用水源保护区优化研究

荆州市中心城区集中式饮用水源位于长江,为河流型水源地,在长江荆州城区段23 km范围内分布6个集中式饮用水源地,实际日取水量为设计规模的32.37%。为此提出将饮用水源保护区进行优化调整,将6个集中式饮用水源保护区减少为3个,保护区水域岸线长度从15.3 km缩减为9.9 km,一级保护区从8.3 km调整为3.3 km,并通过分析优化调整前后该江段水环境容量、减少饮用水源安全隐患和充分合理地发挥岸线资源功能等方面论证优化的合理性。     

地层对四氯化碳迁移影响的实验研究

四氯化碳（CT）在地下水中是一种持久性的有机污染物（POPs）,工业污水和残留在土壤中的CT一旦进入地下含水层,会长期影响人类的用水安全。了解土壤对CT的去除效能,以及CT在地层中的迁移规律,可以为地下水污染的风险评估和修复治理提供依据。为了研究CT在不同岩性地层中的运移规律,通过批量振荡平衡实验,对CT在地层中的吸附...     

Theoretical and Empirical Study on Urban Population Carrying Capacity: Case of Haidian District in Beijing

Abstract

The measurement of urban population carrying capacity is the basis for cities’ sustainable development. However, the traditional study on population carrying capacity which was based on food supply is not applicable to the single urban area. This paper built a model for the analysis of urban carrying capacity, and took Haidian District in Beijing as an example to calculate the urban carrying capacity of Haidian District in the future, which was the basis for the improvement of the population carrying capacity. This study would also provide a reference to the measurement of the urban population carrying capacity for other cities and districts in China.     

Experimental and numerical study of biogas,methane and carbon dioxide produced by pre-treated wheat straw and pre-digested cow dung

ABSTRACT

The biogas constituting majorly CH₄ and CO₂ has been produced by Ca(OH)₂ pre-treated wheat straw with pre-digested cow dung. Some of the key thermodynamic parameters like specific heat capacity, density and heating capacity of the biogas produced have also been calculated per day as well as throughout the hydraulic retention time. The governing equations of biogas with appropriate phase and interfacial conditions describing the physics of the biogas have been derived. The control volume approach has been used to predict the total volume (ml) of biogas, CH₄ and CO₂ throughout the experiment and on the daily basis. The effects of feedstock, temperature and pressure on the production of biogas, CH₄ and CO₂ in anaerobic digestion have also been studied. The average number of molar fraction and conversion ratio of CH₄ and CO₂ are correlated with number of carbon atoms available in feedstock. Numerical calculations by using developed model and Modified Gompertz model have shown proficient agreement with the experimental observations.