城市垃圾问题及处理对策

中国的城市垃圾问题已经成为比较严重的环境问题之一,目前的垃圾处理存在很多问题.以全过程控制思想为基础,在可持续发展和"三化"原则的指导下,运用环境管理的经济、法律、行政等方法,提出解决城市垃圾问题的城市垃圾管理对策和技术对策,提出了城市生活垃圾多元化综合处理的设想,以求建立适合中国国情的城市垃圾管理体系和垃圾产业化体系.     

Environmental reporting for global higher education institutions using the World Wide Web

Voluntary environmental reporting on the progress achieved against policy objectives is an emerging trend in industry and business and is recognized as a valuable aid in implementing policy and improving environmental management systems. Environmental reporting in the UK, has a whole range of formats including PERI, GEMI, WICE and EMAS, with the last, in particular, aiming to improve the level of environmental stewardship and to increase the flow of environmental information to audiences both internally and externally. Higher education institutions globally have been slow to respond in this respect and there is much that they can learn from corporate environmental reporting. An environmental policy is not sufficient proof of commitment for those institutions who have signed the global Talloires Declaration or the European COPERNICUS Charter: demonstrable progress in policy implementation is essential. The environmental management systems that higher education institutions adopt or create and the ways in which their environmental information is collated are of great significance, but the medium selected for the report is perhaps one of the most important aspects to consider. Those institutions such as the University of Sunderland, UK who are using the World Wide Web have been able to produce a flexible, hypertext-linked service on request with inbuilt feedback mechanisms containing varied, up-to-date, comprehensive and well-structured environmental information signposted to external pro-active institutions and agencies. These reports have unique educational angles and reveal links and networks that are naturally more pervasive and far-reaching in their scope and impact and could well provide a key way forward to practical and sustainable environmental reporting into the millennium.     

Understanding the fate and transport of petroleum hydrocarbons from coal tar within gasholders

Coal tars have been identified as posing a threat to human health due to their toxic, mutagenic and carcinogenic characteristics. Workers involved in former gasholders decommissioning are potentially exposed to relevant concentrations of volatile and semi-volatile hydrocarbons upon opening up derelict tanks and during tar excavation/removal. While information on contaminated sites air-quality and its implications on medium-long term exposure is available, acute exposure issues associated with the execution of critical tasks are less understood. Calculations indicated that the concentration of a given contaminant in the gasholder vapour phase only depends on the coal tar composition, being only barely affected by the presence of water in the gasholder and the tar volume/void space ratio. Fugacity modelling suggested that risk-critical compounds such as benzene, naphthalene and other monocyclic and polycyclic aromatic hydrocarbons may gather in the gasholder air phase at significant concentrations. Gasholder emissions were measured on-site and compared with the workplace exposure limits (WELs) currently in use in UK. While levels for most of the toxic compounds were far lower than WELs, benzene air-concentrations where found to be above the accepted threshold. In addition due to the long exposure periods involved in gasholder decommissioning and the significant contribution given by naphthalene to the total coal tar vapour concentration, the adoption of a WEL for naphthalene may need to be considered to support operators in preventing human health risk at the workplace. The Level I fugacity approach used in this study demonstrated its suitability for applications to sealed environments such as gasholders and its further refining could provide a useful tool for land remediation risk assessors.     

Conservation through different lenses: reflection, responsibility, and the politics of participation in conservation advocacy

This essay considers the arenas of advocacy, politics, and self-reflection in strengthening conservation and resource management initiatives. It frames key questions that reflective conservation practitioners may address in seeking to enhance the results of conservation projects, including equity and more inclusive participation by nonprivileged groups. The essay touches on the importance of understanding conservation work within particular political and historic dynamics, including the need to understand non-Western and/or indigenous or traditional perspectives on conservation. The author makes the case that Western or privileged conservation practitioners are uniquely situated to advocate effectively for change.     

基于RuO2-IrO2/Ti和Fe0电极的电氧化-电絮凝处理含Tl废水

基于RuO₂-IrO₂/Ti形稳电极和Fe⁰牺牲电极实现电氧化-电絮凝(EO-EC)一体化处理含Tl (I)废水,并与单一的电絮凝(EC)进行比较,探讨了EO-EC处理含Tl废水的机理.结果表明,相较于单一EC,EO-EC (1:1)组合技术适应于宽pH (4-10)以及电流密度范围(5-20mA/cm²)下含Tl废水高效处理,且不易发生钝化;活性氯以及氧化还原电位在Tl (I)间接氧化Tl (III)过程中扮演重要角色,沉淀分析表明生成的Tl (OH)_3(s)与絮体Fe (OH)_3(am)共沉淀,纤铁矿位点可吸附残留Tl (I).EO-EC一体化技术可满足实际含Tl废水达标处理(<2µg/L)且具有经济可行性.     

Diagenesis of Upper Carboniferous rocks in the Ouachita foreland shelf in mid-continent USA: an overview of widespread effects of a Variscan-equivalent orogeny

Diagenesis of Upper Carboniferous foreland shelf rocks in southeastern Kansas took place at temperatures as high as 100–150° C at a depth of less than 2 km. High temperatures are the result of the long distance (hundreds of kilometers) advection of groundwater related to collisional orogeny in the Ouachita tectonic belt to the south. Orogenic activity in the Ouachita area was broadly Late Carboniferous, equivalent to the Variscan activity of Europe. Mississippi Valley-type Pb-Zn deposits and oil and gas fields in the US midcontinent and elsewhere are commonly attributed to regional groundwater flow resulting from such collisional events. This paper describes the diagenesis and thermal effects in sandstone and limestone of Upper Carboniferous siliciclastic and limestone-shale cyclothems, the purported confining layer of a supposed regional aquifer. Diagenesis took place in early, intermediate, and late stages. Many intermediate and late stage events in the sandstones have equivalents in the limestones, suggesting that the causes were regional. The sandstone paragenesis includes siderite cement (early stage), quartz overgrowths (intermediate stage), dissolution of feldspar and carbonates, followed by minor Fe calcite, pore-filling kaolinite and sub-poikilotopic Ca ankerite (late stage). The limestone paragenesis includes calcite cement (early stage); megaquartz, chalcedony, and Fe calcite spar (intermediate stage); and dissolution, Ca-Fe dolomite and kaolinite (late stage). The R _m value of vitrinite shows a regional average of 0.6–0.7%; Rock-Eval T _maX suggests a comparable degree of organic maturity. The T _h of aqueous fluid inclusions in late stage Ca-Fe-Mg carbonates ranges from 90 to 160° and T _mice indicates very saline water (>200000 ppm NaCl equivalent); ¹⁸O suggests that the water is of basinal origin. Local warm spots have higher R _m, T _max, and T _h. The results constrain numerical models of regional fluid migration, which is widely viewed as an artesian flow from recharge areas in the Ouachita belt across the foreland basin onto the foreland shelf area. Such models must account for heating effects that extend at least 500 km from the orogenic front and affect both supposed aquifer beds and the overlying supposed confining layer. Warm spots indicate either more rapid or more prolonged flow locally. T _h and T _mice data show the highest temperatures coincided with high salinity fluids.     

Distribution of enzymes of glycolysis and gluconeogenesis in fish tissues

Gluconeogenesis in fishes has been demonstrated in whole animals and liver preparations. However, at present, the relative physiological importance of possible substrates such as lactate, pyruvate and amino-acids or the precise sites of gluconeogenesis are unclear. In mammals, gluconeogenesis takes place in the liver and kidney, and the same could occur in fishes although it has been proposed that fish red muscle is also capable of reconverting lactate (derived from white muscle) to glucose. In this present study, the activities of 3 key glycolytic (hexokinase, phosphofructokinase and pyruvate kinase) and 2 key gluconeogenic (fructose diphosphatase and phosphoenolpyruvate carboxykinase) enzymes were investigated in tissues of the rainbow trout Salmo gairdneri, the cod Gadus morhua, and the plaice Pleuronectes platessa in order to elucidate the relative glycolytic/gluconeogenic capacities of the individual fish tissues. The glycolytic enzymes were found in all tissues, the relative potential being skeletal muscle>heart, brain >kidney, gills>liver. The gluconeogenic enzymes were not present in all tissues, and were mainly concentrated in the liver and kidney. Hence the results indicate that the liver, and to a lesser degree, the kidney are the major sites of gluconeogenesis in fishes, and that the process is unlikely to occur in skeletal muscle.     

Tissue accumulation of aluminium is not a predictor of toxicity in the freshwater snail, Lymnaea stagnalis

The amount of toxic metal accumulated by an organism is often taken as an indicator of potential toxicity. We investigated this relationship in the freshwater snail, Lymnaea stagnalis, exposed to 500 μg l⁻¹ Al over 30 days, either alone or in the presence of phosphate (500 μg l⁻¹ P) or a fulvic acid surrogate (FAS; 10 mg l⁻¹ C). Behavioural activity was assessed and tissue accumulation of Al quantified. Lability of Al within the water column was a good predictor of toxicity. FAS increased both Al lability and behavioural dysfunction, whereas phosphate reduced Al lability, and completely abolished Al-induced behavioural toxicity. Tissue accumulation of Al was not linked to toxicity. Higher levels of Al were accumulated in snails exposed to Al + P, compared to those exposed to Al alone, whereas FAS reduced Al accumulation. These findings demonstrate that the degree of tissue accumulation of a metal can be independent of toxicity.