酸阻滞法处理含酸及其相应盐的废液

本文主要介绍在含酸及其相应盐的废液中分离酸和盐的一种方法。将含酸及其相应盐的废液，通过装有强碱性阴离子交换树脂柱，其中的酸受到阻滞，而相应的盐能顺利通过，然后用水洗脱，则流出的是含酸的溶液，使酸和相应的盐得到了分离。经ＦｅＳＯ４－Ｈ２ＳＯ４和ＺｎＳＯ４－Ｈ２ＳＯ４两组废液的试验，均能使酸和金属得到回收。分离后的废水，可达标排放，废液得到了处理。酸阻滞法简单易行，易于投产使用，不受规模大小的限制。     

多氯苯生产中有机氯化物的分析

在气相色谱和色谱-质谱分析的基础上,对以六六六为原料生产多氯苯的两种工艺的产品及废渣进行了分析。结果表明:伴随多氯苯的生成,尚有多种氯化物产生。在水解生产工艺中,产品和废渣中有微量PCDDs和PCDFs,但产品中还有少量PCBs。在热解工艺中,废渣内发现大量的PCBs,PCDDs和PCDFs,最毒的异构体,2,3,7,8-TCDD含量高达24ppm。     

贵州省雷公山自然保护区发展现状及其对策

雷公山自然保护区以秃杉等珍稀濒危物种和中亚热带山地森林生态系统为主要保护对象。１０多年来，保护区在认真做好自然保护工作的同时，引导地方群众发展生产、脱贫致富，探索了许多适度开发当地资源的实用技术和有效的经济发展模式，促进了地方经济发展，改善了当地群众生活，增强了保护区经济活力。在分析保护区发展现状的基础上，针对目前存在问题，提出保护区今后发展的对策措施。     

Small-scale co-management for the sustainable use of Xilingol biosphere reserve, inner Mongolia

There exists a negative externality of livestock breeding due to the difference between private and social breeding cost in Xilingol Biosphere Reserve (XBR), Inner Mongolia, that has caused extensive ecological degradation of the grassland. The property rights regime, the household production responsibility system (HPRS), was adopted in the 1980s to increase livestock production in XBR. Although HPRS has successfully increased production by promoting private economic interests, it has led to grassland degradation due to inefficient enforcement of stock rate. Through interviews conducted with government representatives and herding families in all management units of XBR, we elucidate the shortfalls of the current management regime and the Fencing Grassland and Moving Users policy initiated in 2002 to restore grassland. We propose an alternative property rights regime, small-scale co-management, to concurrently promote both individual economic interests and grassland conservation by improving the enforcement of stock rate.     

A review of effects and control methods of particulate matter in animal indoor environments

This paper reviews the effects and control methods for particulate matter (PM) in animal indoor environments. PM in animal indoor environments represents a particular threat to the health of countless animals and millions of workers around the world. Because air in animal facilities has a higher portion of biological content than does air in other environments, the adverse health impact is much greater than it is for the same amount of PM in other environments. Source control, ventilation, and internal air cleaning can reduce PM concentration in animal indoor environments. Source control is typically the most economical method for PM control. Ventilation is the most widely applied technology, although uncertainties remain as to its effectiveness for PM control. Most internal air cleaners require frequent maintenance because of the high concentration and stickiness of PM in animal environments. Filtration is the most well-studied and widely used technology for internal air cleaning because of its low capital cost and high efficiency. Several trials using electrostatic precipitators have shown efficiencies of approximately 50% in removing PM concentration, but improvements are needed before they can be used widely. No report using wet collectors or centrifugals as internal air cleaners has been found.     

环境外部不经济性分析及其进展

本文从经济学角度分析了环境外部不经济的内涵、特点、解决途径及其发展方向。     

An active region model for capturing fractal flow patterns in unsaturated soils: model development

Preferential flow commonly observed in unsaturated soils allows rapid movement of solute from the soil surface or vadose zone to the groundwater, bypassing a significant volume of unsaturated soil and increasing the risk of groundwater contamination. A variety of evidence indicates that complex preferential patterns observed from fields are fractals. In this study, we developed a relatively simple active region model to incorporate the fractal flow pattern into the continuum approach. In the model, the flow domain is divided into active and inactive regions. Flow occurs preferentially in the active region (characterized by fractals), and inactive region is simply bypassed. A new constitutive relationship (the portion of the active region as a function of saturation) was derived. The validity of the proposed model is demonstrated by the consistency between field observations and the new constitutive relationship.     

The characterisation of polycyclic aromatic hydrocarbons emissions from burning of different firewood species in Australia

Four kinds of woods used for residential heating in Australia were selected and burned under two burning conditions in a domestic wood heater installed in a laboratory. The selected wood species included pine (Pinus radiata), red gum (Eucalvptus camaldulensis), sugar gum (Eucalyptus cladocalyx) and yellow box (Eucalyptus melliodora). The two different burning conditions represented fast burning and slow burning, with the air inlet of the combustion chamber respectively 'full open' and 'half open'. By sampling and analysing particulate and gaseous emissions from the burning of each load of wood under defined experimental conditions, PAHs emissions and their profiles in the particulate and gaseous phases were obtained. 16 species out of the 18 selected PAHs were detected. Of these, seven species were detected in the gaseous phase and most were lower molecular weight compounds.Similarly, more than 10 species of PAHs were detected in the particulate phase and these were mostly heavier molecular weight compounds. Under both burning conditions, emission levels for total PAHs and total genotoxic PAHs were the highest for pine and lowest for sugar gum, with red gum being the second highest, followed by yellow box. Using the specific sampling method, gaseous PAHs accounted for above 90% mass fraction of total PAHs in comparison to particulate PAHs (10%). The majority of the genotoxic PAHs were present in the particulate phase. PAHs emission levels in slow burning conditions were generally higher than those in fast burning conditions.     

Photodegradation of surfactants on the nanosized TiO2 prepared by hydrolysis of the alkoxide titanium

Nanosized TiO(2) was synthesized by hydrolysis of titanium tetraisopropoxide in the nanodroplets of microemulsions. The microemulsion provided by functionalized surfactants derived from the mixture of the commercially available sodium dodecylbenzensulfonate (DBS) and sodium dodecyl sulfate (DS). The resulting TiO(2) nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, and differential thermal analysis. Nanosized TiO(2) of anatase was found to show good photocatalytic properties in the photodegradation of DBS and DS surfactants. The cleavage of the aromatic moiety, the intermediate products and ultimate mineralization to CO(2) were examined in the process of photodegradation. A mechanism is also proposed on the basis of these experimental results.