Atmospheric alcohols and aldehydes concentrations measured in Osaka,Japan and in Sao Paulo,Brazil

The use of alcohol fuel has received much attention since 1980s. In Brazil, ethanol-fueled vehicles have been currently used on a large scale. This paper reports the atmospheric methanol, ethanol and isopropanol concentrations which were measured from May to December 1997, in Osaka, Japan, where alcohol fuel was not used, and from 3 to 9 February 1998, in Sao Paulo, Brazil, where ethanol fuel was used. The alcohols were determined by the alkyl nitrite formation reaction using gas chromatography (GC-ECD) analysis. The concentration of atmospheric alcohols, especially ethanol, measured in Sao Paulo were significantly higher than those in Osaka. In Osaka, the average concentrations of atmospheric methanol, ethanol, and isopropanol were 5.8±3.8, 8.2±4.6, and 7.2±5.9 ppbv, respectively. The average ambient levels of methanol, ethanol, and isopropanol measured in Sao Paulo were 34.1±9.2, 176.3.±38.1, and 44.2±13.7 ppbv, respectively. The ambient levels of aldehydes, which were expected to be high due to the use of alcohol fuel, were also measured at these sampling sites. The atmospheric formaldehyde average concentration measured in Osaka was 1.9±0.9 ppbv, and the average acetaldehyde concentration was 1.5±0.8 ppbv. The atmospheric formaldehyde and acetaldehyde average concentrations measured in Sao Paulo were 5.0±2.8 and 5.4±2.8 ppbv, respectively. The C₂H₅OH/CH₃OH and CH₃CHO/HCHO were compared between the two measurement sites and elsewhere in the world, which have already been reported in the literature. Due to the use of ethanol-fueled vehicles, these ratios, especially C₂H₅OH/CH₃OH, are much higher in Brazil than these measured elsewhere in the world.     

Atmospheric mercury concentrations and speciation measured from 2004 to 2007 in Reno, Nevada, USA

Atmospheric elemental, reactive and particulate mercury (Hg) concentrations were measured north of downtown Reno, Nevada, USA from November 2004 to November 2007. Three-year mean and median concentrations for gaseous elemental Hg (Hg⁰) were 1.6 and 1.5 ng m⁻³ (respectively), similar to global mean Hg⁰ concentrations. The three-year mean reactive gaseous Hg (RGM) concentration (26 pg m⁻³) was higher than values reported for rural sites across the western United States. Well defined seasonal and daily patterns in Hg⁰ and RGM concentrations were observed, with the highest Hg⁰ concentrations measured in winter and early morning, and RGM concentrations being greatest in the summer and mid-afternoon. Elevated Hg⁰ concentrations in winter were associated with periods of cold, stagnant air; while a regularly observed early morning increase in concentration was due to local source and surface emissions. The observed afternoon increase and high summer values of RGM can be explained by in situ oxidation of gaseous Hg⁰ or mixing of RGM derived from the free troposphere to the surface. Because both of these processes are correlated with the same environmental conditions it is difficult to assess their overall contribution to the observed trends.     

工业废水中多金属离子的吸附净化

以含有Si、Al、Ca、C元素的矿物材料作为基质,经特定条件处理后造粒成型加工成轻质多孔Si-Al-Ca-C结构的吸附材料。研究了该吸附材料对工业废水中多种金属离子的吸附性能,探讨了影响吸附性能的因素。研究结果表明,在一定条件下,Si-Al-Ca-C吸附材料对工业废水中Al3+、Ca2+、Mn2+、Cu2+、Fe3+、Mg2+、As3+和Zn2+的净化率分别高达99.34%、99.82%、98.26%、98.16%、97.76%、97.01%、100%和89.09%。金属离子残留浓度分别为0.152、0.07、0.012、0.02、0.119、0.311、0和0.259 mg/L,均低于国家污水综合排放标准(GB8978-1996)一级标准。     

VOC concentrations measured in personal samples and residential indoor,outdoor and workplace microenvironments in EXPOLIS-Helsinki,Finland

Thirty target volatile organic compounds (VOC) were analyzed in personal 48-h exposure samples and residential indoor, residential outdoor and workplace indoor microenvironment samples as a component of EXPOLIS-Helsinki, Finland. Geometric mean residential indoor concentrations were higher than geometric mean residential outdoor concentrations for all target compounds except hexane, which was detected in 40% of residential outdoor samples and 11% of residential indoor samples, respectively. Geometric mean residential indoor concentrations were significantly higher than personal exposure concentrations, which in turn were significantly higher than workplace concentrations for compounds that had strong residential indoor sources (d-limonene, alpha pinene, 3-carene, hexanal, 2-methyl-1-propanol and 1-butanol). 40% of participants in EXPOLIS-Helsinki reported personal exposure to environmental tobacco smoke (ETS). Participants in Helsinki that were exposed to ETS at any time during the 48-h sampling period had significantly higher personal exposures to benzene, toluene, styrene, m,p-xylene, o-xylene, ethylbenzene and trimethylbenzene. Geometric mean ETS-free workplace concentrations were higher than ETS-free personal exposure concentrations for styrene, hexane and cyclohexane. Geometric mean personal exposures of participants not exposed to ETS were approximately equivalent to time weighted ETS-free indoor and workplace concentrations, except for octanal and compounds associated with traffic, which showed higher geometric mean personal exposure concentrations than any microenvironment (o-xylene, ethylbenzene,benzene, undecane, nonane, decane, m,p-xylene, and trimethylbenzene). Considerable differences in personal exposure concentrations and residential levels of compounds with mainly indoor sources suggested differences in product types or the frequency of product use between Helsinki, Germany and the United States.     

吸附氧化/纳滤/吸附组合工艺处理丙烯腈工业废水

针对高浓度丙烯腈工业废水,采用絮凝、吸附氧化、纳滤以及吸附的组合工艺进行处理,考察了不同工艺过程处理高浓度丙烯腈工业废水的效果和费用。结果表明,废水经过絮凝-纳滤-吸附氧化处理工艺,使废水的COD降低到1 000 mg/L以下,氨氮含量低于25 mg/L,CN-含量降低至5 mg/L以下,满足丙烯腈工业废水处理出水指标要求,且操作费用适中,为实现丙烯腈生产工业废水的循环利用奠定了坚实的技术基础。     

Tropospheric concentrations of the chlorinated solvents,tetrachloroethene and trichloroethene,measured in the remote northern hemisphere

A fully automated twin ECD gas chromatograph system with sample enriching adsorption–desorption primary stage was deployed on two field campaigns – Ny-Ålesund, Svalbard, Arctic Norway (July–September 1997), and the RRS Discovery CHAOS cruise of the northeast Atlantic (April–May 1998). Concentrations of an extensive set of halocarbons were detected at hourly intervals at pptv levels. We present here the results obtained for the chlorinated solvents, tetrachloroethene (PCE) and trichloroethene (TCE). Average baseline PCE and TCE concentrations of 1.77 and 0.12 pptv, respectively, were recorded in Ny-Ålesund. During pollution incidences, concentrations rose to 5.61 (PCE) and 3.18 pptv (TCE). The cruise data showed average concentrations ranging from 4.26 (PCE) and 1.66 pptv (TCE) for air masses originating over the North Atlantic and Arctic open oceans, to maxima of 15.59 (PCE) and 17.51 pptv (TCE) for polluted air masses from Northern Europe. The data sets emphasise the difficulties in defining remote sites for background tropospheric halocarbon measurements, as Ny-Ålesund research station proved to be a source of tetrachloroethene. The data also suggest possible oceanic emissions of trichloroethene in the sub-tropical ocean.     

BAF-MBR用于污水深度处理与同步化学除磷

以南方城镇生活污水为研究对象,对BAF-MBR组合系统进行研究。BAF-MBR组合系统运行稳定,去污完全,出水COD、NH4+-N、TN、TP的浓度分别达到7.11、0.16、8.85和0.34 mg·L-1,均达到了污水回用的最高要求。在后置MBR池内进行同步化学除磷时,FeSO4·7H2O的投加量为20 mg·L-1时,出水TP达到0.34 mg·L-1,一定程度上加剧了膜污染;Al2（SO4）3·18H2O的投加量为30 mg·L-1,出水TP达到0.33 mg·L-1,能有效减缓膜污染进程。     

Supramolecular interactions of humic acids with organic and inorganic xenobiotics studied by capillary electrophoresis

Methodology based on capillary electrophoresis (CE) to study humic acids (HAs)-xenobiotics interactions is proposed. The interactions of HAs with organic and inorganic xenobiotics like paraquat, diquat, p,p(')-DDE, p,p(')-DDT, potassium ferrocyanide, potassium ferricyanide, chloride, 4-nitrocatechol and other organic compounds were studied. They were found to be of different kind depending on the structure of the xenobiotic molecule and on its charge (neutral, positive or negative). Ion binding, hydrogen bonding, van der Waals forces, ligand exchange, hydrophobic and hydrophilic adsorption, charge-transfer complexes and sequestration are some of the different mechanisms proposed to bind inorganic and organic compounds to HAs.It was also observed that some of the pollutants are strongly complexed (bound) only with some of the HA fractions forming quite stable entities of supramolecular kind, which can migrate independently. In addition, the stability constant of HA-Cl (negatively charged species) was estimated to be logk=3.1+/-0.95. In order to explain the interaction between negatively charged HAs and inorganic anions (like Cl(-), [Fe(CN)(6)](3-) and [Fe(CN)(6)](4-)), it is proposed that macropolycyclic polyamine structures are present in HA supramolecules, and that they are responsible for such strong binding.     

Biopesticide and formulation processes based on starch industrial wastewater fortified with soybean medium

Abstract

The aim of this study was to produce Bacillus thuringiensis-based biopesticide using starch-producing industry wastewater (SIW) fortified with soybean medium and optimize the formulated product using different adjuvants. This study was necessary as low endotoxin concentration is obtained in formulated biopesticide when SIW alone is used as fermentation medium. The fermentation runs were conducted using SIW alone and SIW fortified with 25% soybean (w/v) medium in 2000?L and 150?L bioreactor, respectively. SIW supplemented with soybean medium showed an increase in cell count (from 1.95?×?10⁸ to 1.65?×?10⁹ CFU mL^–1), spore synthesis (from 1.5?×?10⁸ to 1.35?×?10⁹ CFU mL^–1) and endotoxin concentration (from 436 to 1170?μg mL^–1) when compared to SIW medium alone. The fermented broth was concentrated using continuous centrifugation and adjuvants were added for biopesticide formulation in order to enhance its resistance against UV rays and rainfastness. Entomotoxicity of the formulation produced using fermented broth of SIW fortified with soybean (38,000?IU μL^–1) was higher than that obtained by SIW medium alone (21,000?IU μL^–1), commercial biopesticide Foray 76B (20,000?IU μL^–1) and Btk sander’s (12,500?IU μL^–1).     

切削液废水处理技术研究进展

在机械加工和制造业中,切削液被广泛应用于工件的冷却、清洗、防锈和润滑,产生大量废切削液。切削液废水中含有大量乳化油、添加剂(表面活性剂、缓蚀剂、消泡剂),以及废油、粉尘和金属屑等杂质,排放前需经过严格的处理。切削液废水处理大致分为物理、化学和生物法3大类。不同的处理方法有各自的优缺点。物理法中的膜分离技术具有效率高、占地小、无二次污染等优点,是处理切削液废水的有效技术;但膜污染问题限制了膜过滤技术的大规模引用,开发机械强度高、亲水性的新型膜材料是重要的研究方向。传统的混凝法处理成本较低,然而混凝产生的大量矾花沉淀还需进行二次处理。氧化法能够将污染物矿化为无害无机物,但处理成本很高。由于切削液废水的成分复杂,具有生物毒性,无法对其进行单独的生物处理;可将生物处理单元与氧化过程联用,先通过氧化法提高废水的可生化性,再进行成本低廉的生物处理;这样既能够节约氧化剂用量,也可完成切削液废水的深度处理。本文在综述切削液废水处理技术的研究进展基础上,提出了现有处理工艺中存在的问题,探讨了解决的思路,可为切削液废水处理技术的发展提供参考。     

污水处理工艺系统优化设计理论的研究与发展

综述了污水处理工艺系统优化设计理论研究的发展历史 ,分析总结了优化设计模型研究的发展规律以及需要解决的关键性问题 ;详细介绍了几个具有典型代表性的非线性系统优化模型的结构及寻优方法 ;从 6个特征方面横向比较了部分优化数学模型的研究成果 ;结合国内研究动态提出了对该领域研究前景的展望     

Estimation of ambient PM2.5 concentrations in Maryland and verification by measured values

In 1997, Maryland had no available ambient Federal Reference Method data on particulate matter less than 2.5 microm in aerodynamic diameter (PM23), but did have annual ambient data for PM smaller than 10 microm (PM10) at 24 sites. The PM10 data were analyzed in conjunction with local annual and seasonal zip-code-level emission inventories and with speciated PM2.5 data from four nearby monitors in the IMPROVE network (located in the national parks, wildlife refuges, and wilderness areas) in an effort to estimate annual average and seasonal high PM2.5 concentrations at the 24 PM10 monitor sites operating from 1992 to 1996. All seasonal high concentrations were estimated to be below the 24-hr PM2.5 National Ambient Air Quality Standards (NAAQS) at the sites operating in Maryland between 1992 and 1996. The estimates also indicated that 12 monitor sites might exceed the 3-year annual average PM2.5 NAAQS of 15 microg/m3, but Maryland's air quality shows signs that it has been improving since 1992. The estimates also were compared with actual measurements after the PM2.5 monitor network was installed. The estimates were adequate for describing the chemical composition of the PM2.5, forecasting compliance status with the 24-hr and annual standards, and determining the spatial variations in PM2.5 across central Maryland.     

Ambient isoprene and monoterpene concentrations in a Greek fir (Abies Borisii-regis) forest. Reconciliation with emissions measurements and effects on measured OH concentrations

Ambient biogenic hydrocarbons were monitored in a forested site in Northern Greece during the summer of 1997 as part of the AEROBIC campaign. Significant concentrations of isoprene were observed, consistent with enclosure measurements presented in the previous paper (Harrison et al., 2001, Atmospheric Environment 35, 4687–4698). In addition, significant concentrations of monoterpenes were observed (nighttime maximum of 2.9 ppbv for total monoterpene concentration). Isoprene and the monoterpenes exhibited pronounced, but different, diurnal cycles which are interpreted via enclosure and OH measurements. The combination of relatively high emission rates at a time when OH concentrations are significantly lower leads to peak isoprene concentrations (∼3.0 ppbv) during the late evening. The temporal behaviour of the biogenic hydrocarbons is used to interpret the radical chemistry at the site and may indicate the presence of high (∼1×10⁶ cm⁻³) nighttime concentrations of the OH radical. Biogenic hydrocarbon measurements were supported by a range of organic and inorganic measurements which are also presented in this paper.     

A method for mapping the air pollution in cities with the combined use of measured and calculated concentrations

The aim of this paper is to develop the technique for mapping the air pollution in cities using measured and computed concentrations. It is based on the combined use of deterministic and stochastic modelling. Two different approaches are applied to extrapolate the measurements to the regular grid points covering the city. The first uses the method of the principal components, and the second is based on optimal interpolation or 'kriging' of meteorological fields. The results of the application of this model for the mapping of air pollution in the city of Pskov, Russia, are given.     

Statistical inferences from measured data on concentrations of naturally occurring radon,thoron, and decay products in Kumaun Himalayan belt

Environmental Science and Pollution Research - Regional averages of radon, thoron, and associated decay product concentration are reported to be higher than their respective global averages in...     

Response of Ceriodaphnia dubia to ionic silver: discrepancies among model predictions, measured concentrations and mortality

Silver thiosulfate, often a waste product of photoprocessing, is less bioavailable or toxic to aquatic organisms than is ionic silver. We conducted duplicate 48-h Ceriodaphnia dubia tests in reconstituted laboratory water using treatments of 92.7 nM Ag+ with various concentrations of thiosulfate. Expected Ag+ concentrations were generated for thiosulfate treatment levels using MINEQL + chemical equilibrium modeling. Ag+ concentrations in treatments were determined using a novel silicon-based sensor. Based on predicted Ag+ and published 48-h LC50 values for C. dubia, we did not expect to observe adverse effects. Yet, 100% mortality was observed at low thiosulfate treatments, whereas > 85% and > 95% survival was observed at higher thiosulfate treatment levels, respectively. Our results indicate that biotic responses match the sensor-based Ag+ concentrations. However, there is a discrepancy between these empirical results and responses expected to occur with Ag+ concentrations as predicted by MINEQL + chemical modeling. By correlating silicon sensor data with toxicity results obtained from our laboratory, our work clearly relates a specific chemical form (Ag+) to toxicity results.     

人工神经网络和专家系统在污水生物处理系统中的应用

对近年来国内外污水生物处理系统中人工神经网络和专家系统的应用进行了简要的回顾。分析了废水生物处理工艺难于控制的原因及人工神经网络和专家系统的结构和特点。结果表明．国外智能控制发展迅速,并且应用领域遍及污水生物处理的各个方面,国内尚处于起步阶段。简要探讨了废水生物处理智能控制今后应深入研究的问题及方向。     

Acetic acid and formic acid concentrations in the museum environment measured by SPME-GC/MS

A method is described to sample and quantify acetic and formic acid vapours within 35 min. The detection limits are 5.3 and 28.9 μg/m³, respectively, and the technique used is manual SPME collection of the sample followed by analysis on a gas chromatography/mass spectrometry system. In both cases linearity between the standards prepared and the results measured are found. The technique can be used to analyse air in small confined areas, as the total volume of air sampled is <4 l.     

Effects of pH and iron concentrations on sulfide precipitation in wastewater collection systems.

Sulfide precipitation by addition of iron salts is a widely used strategy for sulfide control in wastewater collection systems. Several parameters, such as pH, oxidation-reduction conditions, and reactant concentrations, are known to affect the feasibility of the method. However, their combined effects are difficult to predict for complex media, such as wastewater. This study investigates the effect of pH and reactant concentrations on the efficiency of iron sulfide precipitation in anaerobic municipal wastewater. Laboratory experiments showed that, when the pH was below 7, typically less than 40% of the added ferrous iron reacted by sulfide precipitation, although sulfide was in excess. However, when the pH was above 8, almost complete precipitation of all the added ferrous iron was observed. Varying the ferric-iron-to-ferrous-iron ratio demonstrated that improved efficiency could be achieved when using a 1:1 mixture of ferric chloride and ferrous sulfate.