Further studies on the influence of zeolite type A on metal transfer in the activated sludge process

Investigations were carried out to determine the effect of zeolite type A on metal removal by activated sludge using laboratory activated sludge simulations. They were operated at constant aerator sludge age and settler surface loading. Different concentrations of raw zeolite and zeolite extracted from washing powder (0, 15, 30, 60, 120 mgl^?1) were introduced into the simulations. The zeolite was added at two degrees of calcium exchanged for sodium, 25 and 75% of the maximum exchange capacity. Metals were added at concentrations typical of mixed domestic-industrial waste waters. The results show that there was no adverse effect on metal removal by the laboratory activated sludge simulations in the presence of zeolite type A.     

Ease vs. noise: Long-run changes in the value of transport (dis)amenities

For a complete cost-benefit analysis of durable infrastructures, it is important to understand how the value of non-market goods such as transit time and environmental quality changes as incomes rise in the long-run. We use difference-in-differences and spatial differencing to estimate the land price capitalization effects of metro rail in Berlin, Germany today and a century ago. Over this period, the negative implicit hedonic price of rail noise tripled. Our results imply income elasticities of the value of noise reduction and transport access of 2.2 and 1.4, substantially exceeding cross-sectional contingent valuation estimates.     

制冷剂二氟甲烷热解生成氟化氢的实验研究

空调制冷剂二氟甲烷(R32)是R22的替代制冷剂之一,其分子中含有氟元素,受热可产生剧毒物质氟化氢(HF),一旦泄漏分解,将会对人员造成极大危害.首次通过实验研究了R32泄漏后的受热分解情况,利用激光气体分析仪,测量了不同工况下HF的实时浓度,分析了R32受热分解的影响因素.结果表明R32泄漏后,在受热状态下很容易产生HF,HF浓度随着泄漏量和受热状态的变化而异,浓度可达1000ppm以上；研究结果可为含氟制冷剂的应用提供技术支持.     

自然富硒土中Se对不同水稻籽粒吸收Cd的影响

通过水稻盆栽试验,在高低两种自然富硒土壤上种植3种水稻。结果发现,水稻籽粒Se含量与土壤中Se含量呈正相关,而土壤硒含量过高会降低水稻籽粒的产量。在添加Cd下,高富硒土种植的博优998、秋优998、金稻优998等水稻籽粒Cd含量比低富硒土分别降低了26.99%、10.28%、13.48%,说明土壤中适量的Se对水稻籽粒吸收Cd有拮抗作用。另外,秋优998富集Se、Cd的能力最强,生物产量最低,金稻优998达到富硒效果,而富集Cd的能力最弱,且生物产量较高,在筛选品种时,应优选金稻优998。     

沈阳商业城火灾及灾后修复

介绍了发生在沈阳商业城的火灾及灾后调查、检测和加固情况，从中得到一些有意义的看法。     

铬菁R分光光度法测定水和废水中痕量铍的方法评价

在方法研究的基础上 ,组织全国六个实验室对铬菁 R分光光度法测定水和废水中铍进行了方法验证。对统一标准样品、环境地表水、实际含铍废水进行了分析。以协作试验所得数据评价本方法的灵敏度、精密度、准确度和适用性     

Environmental impact assessment in the association of southeast Asian Nations

The Association of Southeast Asian Nations has agreed that environmental protection and sustainable use of natural resources are essential for sound economic development. The Environmental Impact Assessment is viewed as an important management tool and an ASEAN Experts Group on the Environment has been working for several years on a model especially adapted to the region and also on case studies of the implementation of EIA. Progress so far has been frustratingly slow due to misunderstanding, a lack of ecological data, inadequate trained manpower and institutional shortcomings for compliance. The author advocates collaboration on an ASEAN model for performing EIA as a means of accelerating acceptance and implementation. The concept of Adaptive Environmental Assessment and Management is proposed as a prototype.     

青海野生大黄的生态特征及其开发对策

文章通过对青海野生大黄的生态环境、分布状况、群落特征、开发现状、存在问题的分析和论述，提出未来青海野生大黄资源开发必须遵从生态保护为先，生态、生产、经济、社会效益共同持续的原则，强化资源保护和基础技术研究，加大人工驯化裁培力度，不断满足日益增长的市场需求。     

砼芯水泥土复合桩在基坑支护工程中的应用与研究

砼芯水泥土复合桩是一种新型的基坑支护方法,即在水泥土搅拌桩中插入钢筋混凝土预制小方桩,形成一种新的复合桩体,兼有受力和止水的双重作用,并采用两排中间用圈梁相连的门型结构提高了支护结构的受力特性。该支护方案在南京某深基坑工程中得到了成功应用。本文分析了该新方法的结构特点、简要介绍了其设计计算方法,并结合有限元数值模拟和实际的监测数据与排桩方案进行分析比较。研究结果表明,该新型基坑支护形式取得了良好的支护和经济效果,具有重要的应用前景。