工业废水中锑污染物排放标准制定的原则与依据

通过对我国不同工艺、不同规模涉锑企业生产工艺、治理现状进行调查并对不同生产环节排放废水锑浓度监测的基础上,结合区域环境背景值和环境目标的可达性等方面进行分析论证,得出涉锑企业外排废水中锑的标准值为0.5mg/L。研究发现,本标准制定的主要依据除了治理技术的可达性和经济性外,其纳污水体下游饮用水源地水质达到GB5749-2006《生活饮用水卫生标准》规定限值也是一个重要的约束条件。     

Application and Quality Assessment of an Instantaneous Vehicle Emission Model at Fleet Level

A developed instantaneous emission model is applied to predict emission factors for small vehicle fleets for quality assessment. Extensive vehicle measurements of pre-Euro-1 gasoline, Euro-3 gasoline, and Euro-2 diesel vehicles are available. The data were used to develop individual vehicle emission models for each car. The prediction quality for each vehicle category was determined by averaging the results obtained from the individual vehicle models. The results show that the prediction quality is improved in comparison with the individual vehicles, even with a small number of vehicles in a specific category. This indicates that the errors in the individual models are mainly random and that prediction quality, when applied to fleets of cars, is exceptionally high.     

双怠速法机动车尾气排放检测结果的影响因素分析

针对双怠速法机动车尾气排放检测过程中经常大量出现过量空气系数(λ)不合格现象,结合相关标准和工作实践对影响检测结果的因素进行分析。结果显示,取样管路的气密性差、系统响应时间未达标准、测试软件程序设置错误、高怠速转速设置不合理及由于车辆特性导致的选用标准及操作错误均会导致λ测试结果超标,影响双怠速检测法的准确性。     

青藏高原典型城市拉萨市大气颗粒物污染源成分谱建立研究与特征分析

系统研究建立高原典型城市拉萨市开放源(土壤风沙尘、道路扬尘、施工扬尘、采矿扬尘),移动源(机动车尾气尘),固定源(工业烟粉尘、生物质燃烧尘及餐饮油烟)共3类8种大气颗粒物(PM_(2.5)、PM_(10))污染源化学成分谱。研究结果表明:开放源以地壳类元素为主,自然背景特征明显;移动源源成分谱中元素碳含量明显高于其他城市,在PM_(2.5)、PM_(10)源谱中分别占60.15%、51.86%,有机碳含量也相对较高,均超过20%;固定源中,牛粪和松柏枝两类生物质燃烧污染源的有机碳含量显著高于其他组分,工业烟粉尘中Ca远高于其他组分,在PM_(2.5)、PM_(10)源谱中分别占21.32%、21.21%。移动源、固定源源成分谱均显示出高原城市的独特特征。     

Accumulation and relationship of metals in different soil aggregate fractions along soil profiles

Different aggregates vary in their ability to retain or adsorb metals in soil. Five soil profiles were sampled from different soil horizons and grouped, and the concentrations of Al, Mg,Ca, Fe, Mn, Cd, Cu and Pb were determined in six sizes of aggregates(> 2, 2-1, 1-0.6, 0.6-0.25,0.25-0.053, < 0.053 mm). Significantly high(p < 0.05) structural stability indexes(SSI) and aggregate stability indexes(ASI) were recorded in the topsoil horizon, which may be attributed to the high soil organi...     

汽油车尾气遥感检测结果统计分析与限值制定

选取汽油车尾气中CO、HC、NO等3种气态污染物,以稳态工况法为基准,与车辆实际行驶时的遥感测试结果比对,从而制定相应的排放控制限值。建议遥感检测法对于CO、HC、NO的限值,2001年10月1日前注册登记的汽油车分别为3．0％、1000×10-6、3500×10-6,2001年10月1日起注册登记的汽油车分别为2．0％、500×10-6、2000×10-6。提出当机动车所有人对检测结果有异议时,可在规定期限内至指定机构按年检方法复检。     

苏州高新区典型行业VOCs排放特征及控制对策探讨

通过资料收集和现场调研估算苏州高新技术产业园区VOCs排放量,对区内典型行业VOCs污染物特征组分做分析,并简述其区域内典型行业VOCs治理技术的现况,分析了排放现状特征和控制难点。基于对国内外工业VOCs污染控制措施研究,提出对VOCs污染控制的对策和建议。     

机动车尾气VOCs排放特征及减排措施研究

分析了机动车尾气挥发性有机物(VOCs)的排放特征,发现尾气VOCs排放具有明显的日变化和季节变化特征。不同区域不同车型机动车尾气VOCs成分谱略有差异,轻型汽油车尾气VOCs中芳香烃和烷烃含量较高,柴油车烷烃含量较高。尾气排放受机动车保有量、行驶里程、维护保养水平、行驶速度和燃油标准、排放标准等因素影响。从优先控制汽油车、加快机动车更新、采取本地化减排措施、加强多元管理措施、提高科研水平等方面提出了针对性的减排措施。     

Studies on the drug resistance profile of Enterococcus faecium distributed from poultry retailers to hospitals

The multidrug resistant Enterococcus faecium (MEF) strains originating from farm animals are proliferating at a substantial pace to impact downstream food chains and could reach hospitals. This study was conducted to elucidate the drug susceptibility profile of MEF strains collected from poultry products in Ann Arbor, MI area and clinical settings from Michigan State Lab and Moffitt Cancer Center (MCC) in Florida. Presumptive positive Enterococcus isolates at species level were identified by Matrix Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) analysis. The antibiotic susceptibility profile for both poultry and clinical strains was determined by the Thermo Scientific's Sensititre conform to the National Committee for Clinical Laboratory Standards (NCCLS) and validated via quantitative real-time PCR (qPCR) methods. Out of 50 poultry samples (Turkey: n = 30; Chicken: n = 20), 36 samples were positive for Enterococcus species from which 20.83% were identified as E. faecium. All the E. faecium isolates were multidrug resistant and displayed resistance to the last alternative drug, quinupristin/dalfopristin (QD) used to treat vancomycin resistant E. faecium (VRE) in hospitals. Results indicate the presence of MEF strains in food animals and clinical settings that are also resistant to QD.     

Copper and cadmium effects on growth and extracellular exudation of the marine toxic dinoflagellate Alexandrium catenella: 3D-fluorescence spectroscopy approach

In this study, metal contamination experiments were conducted to investigate the effects of copper and cadmium on the growth of the marine toxic dinoflagellate Alexandrium catenella and on the production of dissolved organic matter (Dissolved Organic Carbon: DOC; Fluorescent Dissolved Organic Matter: FDOM). This species was exposed to increasing concentrations of Cu²⁺ (9.93 × 10⁻¹⁰–1.00 × 10⁻⁷ M) or Cd²⁺ (1.30 × 10⁻⁸–4.38 × 10⁻⁷ M), to simulate polluted environments. The drastic effects were observed at pCu²⁺ = 7.96 (Cu²⁺: 1.08 × 10⁻⁸ M) and pCd²⁺ = 7.28 (Cd²⁺: 5.19 × 10⁻⁸ M), where cyst formation occurred. Lower levels of Cu²⁺ (pCu²⁺ > 9.00) and Cd²⁺ (pCd²⁺ > 7.28) had no effect on growth. However, when levels of Cu²⁺ and Cd²⁺ were beyond 10⁻⁷ M, the growth was totally inhibited. The DOC released per cell (DOC/Cell) was different depending on the exposure time and the metal contamination, with higher DOC/Cell values in response to Cu²⁺ and Cd²⁺, comparatively to the control. Samples were also analyzed by 3D-fluorescence spectroscopy, using the Parallel Factor Analysis (PARAFAC) algorithm to characterize the FDOM. The PARAFAC analytical treatment revealed four components (C1, C2, C3 and C4) that could be associated with two contributions: one, related to the biological activity; the other, linked to the decomposition of organic matter. The C1 component combined a tryptophan peak and a characteristic humic substances response, and the C2 component was considered as a tryptophan protein fluorophore. The C3 and C4 components were associated to marine organic matter production.