使用紫外闪光灯处理受污染的水,气,土壤

本文介绍了一种新的有效的处理挥发性有机化合物(VOC′S)、聚氯联苯化合物(PCB′S)和其他有机毒物的方法。这个新方法是采用高强宽谱的紫外光线(UV)直接光解有机物,分解的最终产物是无毒的单质物质。新方法的效靛优于使用中压汞灯做光源的传统 UV 处理工艺。     

西澳大利亚布罗克曼火山岩型稀有金属矿床──奈厄比厄姆凝灰岩的矿物学和地球化学

西澳大利亚布罗克曼稀有金属矿化，是富含挥发份和不相容元素（例如Zr、IJf、Nb、Ta、Be、Y和REE及Ga等）的粗面岩岩浆发生早期火山碎屑喷发的结果。矿化呈三。粒状（＜20μm），是由于相对简单的岩浆前身矿物（如铌铁矿和钻石），在岩浆喷发后保存于灰流凝灰岩［奈厄比厄姆（Niobium）凝灰岩］中的岩浆期后富F溶液的作用下，发生蚀变和再活化的结果。球粒陨石标准化的REE分布模式显示，矿体强烈富集HREE。胶质锆石是HREE主要载体，浸染状氟碳铈矿（±氟碳钙铈矿和直氟碳钙铈矿）是LREE的载体，晚期方解石脉中的羟硅滚石是Be的载体。Ga赋存于基质K云母中。上覆于奈厄比厄姆凝灰岩的粗面岩流含有许多类似的矿石矿物，但含量略有不同。     

Effect of nickel on some aspects of protein metabolism in the gill and kidney of the freshwater fish, Cyprinus carpio L

Nickel has an adverse effect on some aspects of protein metabolism of the freshwater fish, Cyprinus carpio. The main changes observed were: (a) Decrease in soluble, structural and total proteins, AlAT and AAT activities with an increase in the levels of free amino acids, protease and GDH activities and ammonia in the gill and kidney at 1, 2, 3, and 4 days of exposure to a lethal concentration, 40 mg litre(-1) of nickel; (b) Increase in soluble, structural and total proteins, free amino acids and the activities of protease, AlAT, AAT and GDH with a decrease in ammonia and urea in these organs at 1, 5, 10 and 15 days of exposure to sublethal concentration, 8 mg litre(-1); (c) The magnitude in these changes increased over time with both concentrations of the metal, and was more marked in gill than in kidney.     

Fluxes of ions in precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia

A study was carried out to determine the chemical composition of bulk precipitation, throughfall and stemflow in an urban forest in Kuala Lumpur, Malaysia. The mean weekly rainfall recorded during the period of study was 63.2 mm. Throughfall, stemflow and canopy interception of incident precipitation were 77.1%, 1.2% and 21.7% respectively. Bulk precipitation, througfall and stemflow were acidic, the pH recorded being 4.37, 4.71 and 4.15 respectively. In all cases the dominant ions were NO3, SO4, Cl, NH4, K, Ca and Na. Of the ions studied Ca, K, Cl, SO4, Mg and Mn showed net increases in passing through the forest canopy, while NH4, Na, NO3, Zn, H and Fe showed net retention. This study shows that the urban environment of Kuala Lumpur contributes considerable amounts of materials to the atmosphere, as reflected by the high ionic contents in bulk precipitation, throughfall and stemflow.     

Impacts of afforestation on water quality trends in two catchments in mid-Wales

The impact of afforestation on stream-water chemistry for two catchments in central Wales is investigated. Trends in water chemistry are evaluated with forest age progressing at 8-15 years and 20-27 years. To assess the possible exacerbating effect of afforestation on surface-water acidification two moorland catchments are used as controls. Absolute differences in inter-catchment streamwater chemistry are evident. Differences in acidity between the moorland and the young forest site reflect site preparation and modifications to water pathways. Differences in the observed present day chemistry between the young and old forest result from past interactions between deposition changes during forest development. An estimate of the future impact of forest growth was attained from model predictions. The model was calibrated to present day stream-water chemistry and incorporates, cation uptake, evapotranspiration/ concentration effect and increased scavenging of occult and dry deposition. Predictions suggest the pH will decline to 5.3 when the young forest progresses to 20 years of age, which is still much higher than the pH recorded at the older forest site at the age of 20 years.     

Treatability studies of naphthalene in soil,water and air with persulfate activated by iron(Ⅱ)

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO₄], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO₄] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.     

洞庭湖近30年水环境演变态势及影响因素研究

水量、泥沙和污染物交换作为河流与湖泊之间的关键过程,对湖泊生态环境演变具有复杂而深远的影响.以长江中游典型通江湖泊洞庭湖为研究对象,着眼于“江湖”“河湖”“人湖”三重作用关系变化,从水文情势、水质、富营养化3个层面剖析了近30年洞庭湖水环境演变态势及主控因素.结果表明:①“江湖”关系变化影响了洞庭湖水沙交换及其年内分配,是湖泊枯水期提前和延长、水沙关系突变等现象的主控因素;“河湖”“人湖”关系变化协同加剧了该现象.②“河湖”关系的失衡和“河湖”统筹管理措施缺位,造成入湖河流长期输送大量营养物质,是湖体氮磷污染较重的根源;“江湖”“人湖”关系变化协同影响着营养盐分布格局,但影响范围及程度有限.③在“江湖”“河湖”作用关系复合影响下,藻类生长条件更为有利,增加了洞庭湖富营养化及水华风险.为保障洞庭湖水环境安全,建议:针对“江湖”作用主导的低枯水位问题,以水资源调控为核心,推进长江与流域上游水库联合生态调度,保障湖泊生态流量;针对“河湖”作用主导的水质恶化问题,以水污染防治为核心,强化流域污染控制,统筹“河湖”一体化监测管理模式,保障湖泊水环境质量;对于“人湖”作用主导的生态破坏问题,以生态空间管控为核心,划定并坚守生态红线,保障生态空间.      

The Spitak (Armenia, USSR) Earthquake: Residential Building Typology and Seismic Behaviour

The 1988 earthquake in Armenia was the most serious seismic disaster since the 1976 earthquake in Tangshan, China. At least 25,000 people lost their lives in a tremor of moderate magnitude and the USSR suffered a loss of more than 2.5 per cent of 1988's GDP. Research at the Martin Centre on the effects of earthquakes on human lives has shown an increase in global earthquake mortality rate, despite the well known improvements in some countries. The Armenian disaster was a warning to all of us concerned with natural or man-made disasters. Areas of potential high hazard are pointed out for the sub-Caucasian region. Construction practices similar to those in Armenia are certainly found in many other parts of the world, with some regional variations, and the fast assimilation of the lessons is an important target. The structural characteristics of all the residential building types existing in the affected area are presented in terms of their seismic vulnerability. Vulnerable points are discussed with a view to low cost interventions that will drastically improve the seismic safety of new buildings.     

Recycling of petroleum-contaminated sand

The environmental impact of using petroleum-contaminated sand (PCS) as a substitute in asphalt paving mixtures was examined. An appreciable component of PCS is oily sludge, which is found as the dregs in oil storage tanks and is also produced as a result of oil spills on clean sand. The current method for the disposal of oily sludge is land farming. However, this method has not been successful as an oil content of < 1% w/w is required, and difficulty was encountered in reaching this target. The reuse of the sludge in asphalt paving mixtures was therefore considered as an alternative. Standard tests and environmental studies were conducted to establish the integrity of the materials containing the recycled sludge. These included physical and chemical characterization of the sludge itself, and an assessment of the mechanical properties of materials containing 0%, 5%, 22% and 50% oily sludge. The blended mixtures were subjected to special tests, such as Marshall testing and the determination of stability and flow properties. The experimental results indicated that mixtures containing up to 22% oily sludge could meet the necessary criteria for a specific asphalt concrete wearing course or bituminous base course. To maximize the assay from the recycled material, the environmental assessment was restricted to the 50% oily sludge mixture. Leachates associated with this particular mixture were assayed for total organic residue and certain hazardous metal contaminants. The results revealed that the organics were negligible, and the concentrations of the metals were not significant. Thus, no adverse environmental impact should be anticipated from the use of the recycled product. Our research showed that the disposal of oily sludge in asphalt paving mixtures could possibly yield considerable savings per tonne of asphalt concrete, and concurrently minimize any direct impact on the environment.