重庆地区大气干降尘化学组分及其在中和降雨酸度中的作用

用直径50cm 的聚乙烯漏斗,在冬夏两季分别截获了白天和夜间的干降尘。结果表明,干降尘中主要阳离子是钙,虽然它吸附二氧化硫,但不酸。计算表明城区干降尘能中和降水中11.8％的酸,四面山中和6.2％。     

固体通量法在沸石强化A/O脱氮工艺二沉池中的应用

分析了固体通量的理论基础及其在二沉池设计与运行控制上的应用。利用固体通量理论对某污水处理厂中试现场装置进行分析,结果表明：固体通量法可用于判断二沉池的运行控制是否正确合理;当负荷发生变化时,可以通过固体通量分析来改变操作条件,以保证二沉池正常运行。     

某核废液处理厂的火灾爆炸事故解析(Ⅱ) 氧化剂盐粒子的大小及微观结构对沥青固化物的固—液表面氧化还原反应特性的影响

就不同粒径及微观构造的氧化剂盐粒子制备的沥青固化物的氧化还原反应特性用高感度量热仪(C80微量量热仅)进行了测定.结果表明,当氧化剂盐粒子的微观构造基本相同时,随粒径的减小,制作的沥青固化物的反应开始温度向低温方向偏移,低温领域的发热量增大.当粒径的大小及其分布基本相同时,沥青固化物的氧化还原反应特性随粒子的微观构造的不同表现出较大的差异,由针状结晶构成的多孔状粒子制成的沥青固化物的反应开始温度低、低温领域的发热量较大.     

Pools and Fluxes of Cations,Anions and Doc in Two Forest Soils Treated With Lime and Ash

The effect of liming and ash treatment on pools, fluxes and concentrations of major solutes was investigated at two forestedsites (Norway spruce) in S. Sweden. One site was treated 15 yrprior to sampling (Hasslöv-Hs; dolomite: 3.45 and 8.75 t ha^-1) and the other 4 yr before (Horröd-Hd; dolomite: 3.25 t ha^-1; wood ash: 4.28 t ha^-1). Effects of limingwere most pronounced in the O horizon solutions where higher pH,elevated Ca (120–700 M) and Mg (50–600 M) were observed as compared to control plots. The impact on the mineralsoil was more moderate. Soil solution concentrations were combined with modelled hydrological flow to calculate mass flows,which largely followed the trends of the solution composition. Liming also resulted in large increases of both exchangeable Caand Mg as well as effective cation exchange capacity (CEC_E;2–5 times the controls). The base saturation (BS%) was raised to 60–100% in the O horizon while in the mineral soil elevated values were only seen at the Hs site (20–60%; down to 10–15 cm depth for 8.75 t ha^-1). Ash treatment did notaffect either the soil solution nor the exchangeable pool to thesame extent as lime. In general, the impact at the Hd site was less pronounced especially in the mineral soil, which might be due to shorter treatment time (4 vs. 15 yr) and also differentthickness of the O horizon. Budget calculations for Ca and Mg originating from the lime showed that a major part of the Ca (40–100%) was retained in the top 30 cm of the soil, of which30–95% was present in the O horizon. The mobility of Mg wasgreater and it was estimated that a significant part had been leached from the profile (30 and 50 cm depth) after 15 yr. Increased mass flows of NO₃ ^- due to nitrification resulting from liming at the Hs site were calculated in the range120–350 mmol m^-2 yr^-1 (or 1.2–3.5 kmol ha^-1 yr^-1). There was significant leaching of Al (25–60 mmol m^-2 yr^-1), of which about 70% was inorganic, in thelower B horizon at both sites with no influence of liming.     

Urban Metal Management The Example of Lead

The metal metabolism of an urban region, the City ofVienna, was investigated to discuss urban metal management strategies in view of environmental protection and resource conservation. About 90% of the metal stock is located in Vienna's buildings and infrastructure, whilst only 10% is in the landfills. The city stock represents a potential source for diffusive emissions. However, the control of the current environmental policy concentrates mainly on landfill emissions. Diffusive emissions resulting from the losses over the use of metal containing goods in the city are widely dispersed and cannot be easily controlled due to numerous non-point sources. First investigations indicate that for certain applications, the diffusive stock emissions are as significant as other sources. At present, Vienna's known diffusive and point source lead emissions into air and water are about 40 to 50 times higher than comparable past loadings from geogenic Vienna. Furthermore, a life cycle approach from acid car batteries indicates that sustainable lead management should consider flows and stocks in the hinterland of the city too. The city metal stock also represents a potential resource. Leaded water pipes built-in in Vienna's city stock have the potential to produce 1.6 million traditional car batteries. In future such city mining strategies can partly replace ore mining.     

BLEVE火球热辐射及其影响评价模型介绍

高压液化易燃、易爆化学品储罐易发生BLEVE,引起热辐射,会造成周围人员伤亡和设备损坏.介绍了BLEVE火球热辐射及其影响模型,通过该模型可以计算BLEVE火球的尺寸、持续时间、升空高度、热辐射通量及预测暴露在BLEVE火球热辐射通量下人的致死概率.     

Why Critical Loads of Acidity and N for Soils Should be Based on Pollutant Effective Concentrations Rather Than Deposition Fluxes

Numerous assumptions have been made over the past 17 years when calculating critical loads for soils, both for acidity (based upon base cation steady state mass balances (SMB)) and for N (eutrophication, based upon N mass balances), often without all the assumptions being explicitly stated. The tacit assumptions that the author believes to be implicit in the SMB approach are critically reviewed, with particular reference to upland regions where slope processes are highly significant. It is concluded that many of them cannot be justified, especially those that involve ignoring many key processes known to be important to biogeochemical cycling and soil evolution in upland catchments. The evidence presented suggests that critical loads of acidity and of N for soils should be based upon effective pollutant and, for acidity, also effective base cation deposition concentrations, rather than upon pollutant deposition fluxes. This is because of the dominant role of cation exchange equilibria, rather than weathering rate, in regulation of the pH and base status of the more acidification-sensitive soils, and because of the importance of transport down slope of base cations, alkalinity and N species.     

上升热流条件下木材表面温度的实验研究

本文利用热电偶对上升热流条件下不同种类木材的表面温度进行了实验测量。实验中选取的不同上升热流过程是为了更好的模拟实际室内火灾发展过程。实验结果表明,热流上升速率及木材密度都会影响木材的表面温升过程。点燃时刻表面温度随热流变化率的增加而降低,而木材密度对其影响不大。     

Production and emission of phosphine gas from wetland ecosystems

Phosphine is a part of an atmospheric link of phosphorus cycle on earth, which could be an important pathway for phosphorus transport in environment.Wetland ecosystems are important locations for global biogeochemical phosphorus cycle.In this study, production and emission fluxes of free phosphine from four wetlands types in southern China were observed in different seasons.The results showed that the concentration of phosphine liberated from wetlands was at pg/m3-ng/m3 level.The emission concentrations of different wetlands followed the sequence:paddy field(51.83 ± 3.06) ng/m3 marsh(46.54 ± 20.55) ng/m3 lake(37.05 ± 22.74) ng/m3 coastal wetland(1.71 ± 0.73) ng/m3, the positive phosphine emission flux occurred in rice paddy field(6.67 ± 5.18) ng/(m2·hr) and marsh(6.23 ± 26.9) ng/(m2·hr), while a negative phosphine flux of(-13.11 ± 35.04) ng/(m2·hr) was observed on the water-air interface of Lake Taihu, suggesting that paddy field and marsh may be important sources for phosphine gas in atmosphere, while lake may be a sink of atmospheric phosphine gas during the sampling period.Atmospheric phosphine levels and emission flux from Yancheng marsh and rice paddy field varied in different seasons and vegetational zones.Both diffusion resistance in aqueous phase and temperature were dominating factors for the production and transportation of phosphine to atmosphere.     

丹江口水库入库河流总氮通量监测

针对丹江口水库总氮超标问题,对作为主要集水区的汉库入库各河流进行了一整年的水量和水质同步监测。结果表明:(1)主要河流入汉库总氮量共24503t/a,湖北和陕西两省入库总氮量比例总体上与水资源量比例相当,其中,汉江干流上游陕西来水入库总氮量占68.2%,湖北主要支流包括十堰堵河(18%)、神定河(7%)、泗河(4%)、官山河(0.9%)、浪河(0.7%)剑河(0.5%)和天河(0.5%)。(2)入汉库总氮总量月变化与入库总水量变化一致,总氮入库量主要集中在5~9月,占全年的77%。(3)根据各河流水环境容量和纳污特征,可将入库河流划分为容量型、点源污染型、农业面源型和混合型等四种类型。建议对不同类型河流应采取不同控制对策,点面结合,综合防治。