Model testing using data on 137Cs from Chernobyl fallout in the Iput River catchment area of Russia

Data collected for 10 years following the Chernobyl accident in 1986 have provided a unique opportunity to test the reliability of computer models for contamination of terrestrial and aquatic environments. The Iput River scenario was used by the Dose Reconstruction Working Group of the BIOMASS (Biosphere Modelling and Assessment Methods) programme. The test area was one of the most highly contaminated areas in Russia following the accident, with an average contamination density of 137Cs of 800,000 Bq m-2 and localized contamination up to 1,500,000 Bq m-2, and a variety of countermeasures that were implemented in the test area had to be considered in the modelling exercise. Difficulties encountered during the exercise included averaging of data to account for uneven contamination of the test area, simulating the downward migration and changes in bioavailability of 137Cs in soil, and modelling the effectiveness of countermeasures. The accuracy of model predictions is dependent at least in part on the experience and judgment of the participant in interpretation of input information, selection of parameter values, and treatment of uncertainties.     

Quantitative assessment of the long term behaviour of 90Sr in Lake Uruskul,Southern Urals,Russia

The present paper is aimed at assessing the long term behaviour of 90Sr migration from water to bottom sediments of Lake Uruskul, Southern Urals, Russia. The lake was contaminated following the nuclear accident at the Mayak nuclear complex in 1957 (the Kyshtym accident). Some transfer parameters relevant to the behaviour of 90Sr in the water-sediment system were evaluated: a) the radionuclide migration velocity from the water column to the bottom sediment, b) the radionuclide migration rate from bottom sediment to water, and c) the radionuclide migration rate from bottom sediment to deep sediment. The estimated values of the above parameters were 6.4 x 10(-1) m s(-1), 5.7 x 10(-10) s(-1) and 5.2 x 10(-10) s(-1), respectively. These values were compared with data obtained for some Italian lakes contaminated by 90Sr after the nuclear weapons tests fallout. The relatively low radionuclide migration from water to sediment of these lakes is reflected by the values of the ratio migration velocity/migration rate from sediment to water (4 m and 12 m) that are significantly lower than the corresponding value in the Russian lake (112 m). The peculiar hydrochemical conditions of Lake Uruskul (high pH, high mineralisation, etc.) are considered to be responsible for the high radionuclide migration from water to sediment.     

利用废锂渣制备碳酸锂

介绍了用生产丁基过程中的渣制备碳酸锂的工艺过程及最佳工艺条件,在碳酸钠加入量为理论需要量的110％、pH为9－10、陈化时间为12h、干燥温度为450℃、干燥时间为2h的条件下,碳酸锂的总收率为70.3%左右,产品的纯度为98％左右,产品质量达到GB11075－89的三级标准。     

异波折板高效水解酸化废水的处理技术

提出了异波折板高效水解酸化废水处理技术.通过水力学措施实现水解酸化系统内湍流涡旋以加速传质,并改善系统内pH值条件以增强微生物活性.试验结果表明,对浓度范围在450～900mg/L之间的溶解性COD的去除率为40%±4%.     

组合曝气MBR处理高速公路服务区污水试验

将微孔曝气和穿孔管曝气的组合曝气方式应用于膜生物反应器(MBR)中所形成的组合曝气MBR,采用该工艺处理高速公路服务区生活污水的试验进行了研究。结果表明:该系统处理效果良好,当水力停留时间(HRT)为12 h,其中缺氧区和好氧区均为3.5 h,膜滤区为5 h,泥龄(SRT)为20 d,气水比为22:1时,在进水COD为201.60⁷45.92 mg/L,NH3-N为15.46745.92 mg/L,NH3-N为15.46⁴0.25 mg/L,TP为3.3240.25 mg/L,TP为3.32⁸.26 mg/L,浊度为34.248.26 mg/L,浊度为34.24⁹3.86 NTU的条件下,系统对COD、NH3-N、TP及浊度的去除率分别为93.33%93.86 NTU的条件下,系统对COD、NH3-N、TP及浊度的去除率分别为93.33%⁹9.55%、81.97%99.55%、81.97%⁹6.90%、54.14%96.90%、54.14%⁷3.61%和98.08%73.61%和98.08%⁹9.37%。出水水质达到《城市污水再生利用城市杂用水水质》(GB/T 18920-2002)标准中的冲厕、车辆冲洗水质要求。     

松花江上游夹皮沟金矿土壤与大气汞污染特征

在松花江上游夹皮沟金矿开采区内,混汞法提金工艺已使用180余年,导致严重的环境介质汞污染问题.为研究土壤和大气汞污染特征,使用塞曼效应汞分析仪(Zeeman RA915+)测定了大气汞含量,使用冷原子吸收分光光度法(GB/T17136-1997)测定了土壤汞含量,使用动态通量箱法测定了老金厂、二道沟、二道岔和夹皮沟镇小区四处土/气间汞交换通量;对土壤汞含量和大气汞含量进行了线性回归分析;并对土/气间汞交换通量与气象因子进行了相关性分析.结果表明:①区域大气汞含量均值为(71.08±38.22)ng.m-3.②区域土壤汞含量均值为(0.913 1±0.040 8)mg.kg-1;土壤汞含量与大气汞含量显著正相关.③各采样点土/气间汞交换通量为:老金厂(129.13±496.07)ng.(m2.h)-1,二道沟(98.64±43.96)ng.(m2.h)-1,二道岔(23.17±171.23)ng.(m2.h)-1,夹皮沟镇小区(7.12±46.33)ng.(m2.h)-1.④太阳辐射是老金厂、二道岔和夹皮沟镇小区土/气间汞交换通量主要影响因子,太阳辐射、大气温度和土壤温度共同控制二道沟土/气汞交换通量过程;地形条件的干扰,形成三类迥异的土/气间汞交换通量日变化特征形态.     

石油污染土壤富集前后细菌群落组成和共现网络分析

为了探究石油污染土壤中细菌群落在富集过程中的演替规律,试验采用平板划线法、菌落PCR和高通量测序技术,分析了富集前后细菌群落结构、共现网络和核心菌属组成,并对富集后体系中的微生物进行分离鉴定,筛选石油降解菌.研究表明富集体系中可培养微生物隶属于34个属53个种,其中3个为潜在新种微生物,Dietzia maris OS33和Rhodococcus qingshengii OS62-1具有降解石油的能力.高通量测序结果显示,在门分类水平上,富集前后丰度较高的菌门均为Proteobacteria和Actinobacteria,富集后两菌门的丰度可达到97.98%,占据绝对优势;丰度较高菌属由Pseudomonas、Rhodococcus、Bacillus和Xanthomonas转变为Dietzia、Unspecified_Idiomarianceae和Halomonas,标志微生物转变为与石油降解有关的Dietzia.细菌群落共现网络在富集后,网络结构进一步简化且更加稳定,核心微生物转变为与石油降解有关的Pseudomonas、Lysinibacillus、Pseudochrobactrum、Agrobacterium、Lactobacillus,且非石油降解菌P.songnenensis P35可协同石油降解菌D.maris OS33降解石油.     

碱渣对土壤中镉有效性的影响

用盆栽试验研究碱渣及其用量对小白菜(Brassica chinesis)产量、镉吸收量,土壤pH及有效态镉含量的影响,以期为碱渣的利用提供新的途径。结果表明:碱渣对小白菜生长有促进作用,用量3 g/kg时增产效果最佳,与对照相比,增加了48.1%,继续增加用量小白菜产量增加幅度降低;施用碱渣显著提高土壤pH,且pH与施用量呈显著正相关(R=0.792,P<0.05)关系,但土壤有效态镉含量随着碱渣用量的增加呈递增趋势,与对照处理相比,用量为6 g/kg时增加22.0%,达显著水平;碱渣促进根系对镉吸收累积,与对照相比,碱渣处理根系镉含量增加了29.7%~61.0%,达显著水平,并有增加小白菜地上部镉含量的趋势。这说明碱渣能提高土壤镉有效性,促进植物对镉吸收,可用来强化镉污染土壤的植物修复。     

好氧-低氧生物滤池对低碳氮比污水脱氮研究

针对我国大多数城市污水低碳氮比的水质特点,提出以好氧-低氧淹没式生物滤池对其进行深度脱氮处理.试验过程中,保持好氧段DO为3.5～4.3 mg/L、低氧段DO为0.9～1.1 mg/L,通过调节2段进水分流比、水力停留时间（HRT）、进水碳氮比（C/N）实现深度脱氮效果.进行了3个阶段的试验研究：首先,以低C/N城市污...     

基于撞击法的喷雾射流粒径研究*

为解决我国光学法仪器价格昂贵,操作复杂,在消防领域未能大范围应用的问题。基于撞击法的采样原理,提出新测试方法,并将其应用于消防领域喷雾射流现场测试。在不同的喷孔数量条件下,通过改变喷雾射流出口压力,观察并统计水雾携带的雾滴在载玻片上留下的印记,根据其直径和数量得出雾滴粒径的分布。研究结果表明:喷雾射流雾滴粒径值与平均直径预测模型的预测值和马尔文粒度仪测得的粒径值相近,水雾粒径随着出口压力的增大而减小,研究结果可为喷雾水枪性能测试和优化改造提供技术支持。