Dating of mine waste in lacustrine sediments using cesium-137

For over a century Medicine Lake in northern Idaho has received heavy-metal-laden tailings from the Coeur d'Alene mining district. Establishing the depositional chronology of the lake bottom sediments provides information on the source and rate of deposition of the tailings. Cesium-137, an isotope produced in the atmosphere by nuclear bomb tests, was virtually absent in the environment prior to 1951, but reached its apex in 1964. Our analysis of cesium-137 in the sediments of Medicine Lake revealed that 14 cm of fine-grained tailings were deposited in the lake from 1951 to 1964 and tailing deposition downstream was greatly reduced by the installation of tailings dams in the district in 1968. Cesium-137 analysis is accomplished by a fairly simple gamma-ray counting technique and should be a valuable tool for analyzing sedimentation in any lacustrine environment that was active during the 1950s and 1960s.     

核废物处置试验场环境地质研究综述

介绍了国外核废物处理试验场有关环境地质研究现状与进展。据核废物的放射性不同，目前或未来处置的方式不一样：中－低放射性废物（ＩＬＷ－ＬＬＷ）一般采用浅层处置，多置于粘土层或沉积岩层中；高放射性废物（ＨＬＷ）一般通过竖井或平巷处置于深部的花岗岩或岩盐中。根据母岩的类别不同，本文分花岗岩、岩盐、粘土及其它四部分，对不同的试验场的研究计划、内容、方法、进展等进行了评述。     

甘肃西部地区高放废物处置库场址预选调查

本文根据高放废物处置库场址选择的基本要求，对区域地质及深部构造特征、新构造运动及地震分布规律进行了调查，确定北山南带地区为稳定区。在稳定区内根据处置库有利围岩的出露情况，结合岩体工程地质特征分析，初步选出了４个以花岗岩为主体的场址预选区。经综合分析，认为在４个场址预选区中，以Ｉ号预选区的条件最优，其次是Ⅱ号预选区，再次是Ⅲ号和Ⅳ号预选区。场址区的最后确定尚待进一步调查和论证。     

Emission of aliphatic amines from animal husbandry and their reactions: Potential source of N2O and HCN

We measured the emissions of volatile aliphatic amines and ammonia produced by the manure of beef cattle, dairy cows, swine, laying hens and horses in livestock buildings. The amine emissions consisted almost exclusively of the three methylamines and correlated with those of ammonia. The molar emission ratios of the methylamines to ammonia, and data on NH₃ emissions from animal husbandry in Europe, together with global statistics on domestic animals, were used to estimate the global emissions of amines. Annual global methylamine-N input to the atmosphere from animal husbandry in 1988 was 0.15±0.06 TgN (Tg=10¹² g). Almost 3/4 of these emissions consisted of trimethylamine-N. This represents about half of all methylamine emissions to the atmosphere. Other sources are marine coastal waters and biomass burning.Possible reaction pathways for atmospheric methylamines are shown. Among various speculative but possible products N₂O and HCN are of interest because the emission of methylamines could contribute to the global budgets of these compounds. Maximum atmospheric N₂O production from methylamines are below 0.4 Tg N/year, which is less than 10% of the annual N₂O growth rate. Although we do not expect the methylamine emissions to contribute in a major way to the atmospheric N₂O budget, more studies are needed to establish this conclusion beyond doubt. Similar conclusions hold for HCN.     

废物资源化利用的理论与方法——基于沱牌集团的应用分析

文章通过对废物资源化利用的历史回忆，从能量一经济－环境的复合系统，论述了能量的投入推动着经济的发展，经济发展又会带来环境的破坏，要在经济发展的同时减少环境的污染程度，不能采取简单的末端治理方式，而应从能量投入的源头开始治理，为此，要采取清洁的生产方式，减少废物排放量，并把真正的废物进行资源化利用，确保系统的完备性，做到能量投入减量化，经济发展,高速化，环境污染低量化，由此，结合沱牌集团的计划项目，我们模拟了沱牌集团废物资源化利用的框架，并用具体实例进行分析。     

London: a sustainable city?

Observations include:
Ian Livingstone, London: a sustainable city?, p.77
Michael Parkinson, Key challenges for European cities: achieving competitiveness, cohesion and sustainability, p.78
Chris Hamnett, London's housing, p.80
Sarah Curtis, Health in London, p.84
Martin Frost, London's transport—investing for sustainability, p.92
Chris Birks, Mike Owen and Brian Arkell, London's water resources: threat or opportunity, p.92
Sean D Beevers, David C Carslaw and Gary W Fuller, London's air quality: nitrogen dioxide and particles (PM10) in London's air—present and future, p.97
Adam D Read, Where there's muck there's brass—the 'cost' of London'swaste?, p.103     

KN系列难降解有机废水处理新药剂的研制及应用

KN系列污水处理剂对不同污水采用多孔、层状非金属矿经活化复配而成，不仅对难降解有机废水具有良好的处理效果，也可用于易生物降解废水，并且价格低，相关工艺具有占地少、投资省、运转费用低的特点。所产生的污泥脱水性能好，并可无害化最终处理，不产生二次污染。     

Hydrogeologic studies for nuclear-waste disposal in Sweden

Safety Report 1997 (SR 97) of the Swedish Nuclear Fuel and Waste Management Company is a comprehensive performance assessment of three hypothetical radioactive waste repositories in Sweden. It includes hydrogeologic studies (data compilation, parameter synthesis, and groundwater flow modeling) to determine groundwater flow and the associated uncertainties for the three sites. This report reviews and compares the hydrogeologic characterization programs, the site characteristics, and the groundwater flow models used in the SR 97 performance assessment. Although differences in site-characterization programs tend to mask differences in site characteristics, the sites do have notable differences that affect the results of the performance assessment. The effects of model uncertainties evaluated by the variant cases appear to be smaller than the variability of results for the base case (best estimate of site conditions) of each site. Electronic Publication     

伊乐藻,轮叶黑藻净化养鱼污水效果试验

在实验室条件下.对伊乐藻及轮叶黑藻净化养鱼污水的能力进行了比较研究。结果表明:(1)伊乐藻和轮叶黑藻对养鱼污水中的N、P等物质有较好的净化效果。在96h内,它们对TN、TP、PO_4~(3-)-P、NH_4~+-N、NO_3~--N、COD_(Mn)的平均净化率分别为:60.7％,53.6％.74.4％.59.7％,75.1％,63.2％;61.8％,54.2％.85.3％,81.8％,31.4％,33.5％。(2)水生植物在净化过程中,其效率受温度、光照、及水体中营养盐浓度等外界条件的制约。(3)微生物在水生植物净化养鱼污水的过程中起着重要的作用。     

Mineralogical and geochemical behavior of mill tailing material produced from lead-zinc skarn mineralization,Hanover, Grant County,New Mexico,USA

Mineral extraction and processing, especially metal mining, produces crushed and milled waste; such material, exposed to weathering, poses the potential threat of environmental contamination. In this study, mill tailings from inactive Pb-Zn mines in New Mexico, southwest USA, have been examined for their potential environmental impacts by means of detailed mineralogical and geochemical characterization. The principal ore minerals remaining in the tailings material are sphalerite, chalcopyrite, and very minor galena, smithsonite, and cerrusite, accompanied by the gangue minerals pyrite, pyrrhotite, magnetite, hematite, garnet, pyroxene, quartz, and calcite. White precipitate occurring on tailings surfaces is composed of gypsum and hydrated magnesium sulfates. Pyrite is mostly unaltered or shows only micron-scale rims of oxidation (goethite/hematite) in some surface samples. This iron oxide rim on pyrite is the only indication of weathering-derived minerals found by microscopy. There are variations in element concentrations with depth that reflect primary variations through time as the tailings ponds were filled. Cadmium and Zn concentrations increase with depth and Ag and Pb are low for the uppermost core samples, while Cu, Ni, and Co concentrations are generally high for the uppermost core samples. These elemental distributions indicate that little or no leaching has taken place since emplacement of the tailings because no accumulation or enrichment of these metals is observed in Hanover tailings, even in reducing portions of tailings piles. Element concentrations of surface samples surrounding the tailings reflect underlying mineralized zones rather than tailings-derived soil contamination. We observed no successive decreasing metal concentrations in prevalent wind directions away from the tailings. Stream sediment samples from Hanover Creek have somewhat elevated Zn, Cd, and Pb concentrations in areas that receive sediments from erosion of the tailings. However, input from tributaries downstream of the ponds appears to be principal source of heavy metals in Hanover Creek. The results of this study indicate that there is low risk for groundwater heavy-metal contamination from Hanover tailings. Tailings material do not show significant geochemical oxidation/alteration or metal leaching with depth. Our studies indicate that neutralizing minerals present in the tailings are sufficient to keep the tailings material chemically stable. Geochemically, however, tailings materials are being eroded and may pose a threat to Hanover Creek via siltation.