循序间歇式生物脱氮除磷工艺

本文报道了循序间歇式生物脱氮除磷工艺在不同工况下的处理效果,分析了此工艺去除有机物和脱氮除磷的特点。     

芳香化合物的光催化-臭氧联用降解研究

研究了几种芳香化合物的光催化 臭氧联用降解。探讨了光催化 臭氧联用技术降解有机物作用机理,分析了芳香化合物结构与反应活性的关系。实验结果表明,光催化 臭氧联用对芳香化合物的降解都存在一定的协同效应,而且符合表观准一级反应动力学规律;203#膜光催化臭氧的作用机理是催化臭氧产生了更多的高活性氧化剂,芳香化合物结构对其光催化 臭氧联用降解活性有很大影响。     

中国西南酸雨区降水化学特征研究进展

西南酸雨区为我国主要酸雨沉降区,且是全球三大喀斯特集中分布区之一.本文将该区9个地点的降雨资料进行了总结、整理和分析,数据包括pH值和主离子成分(Cl~-、SO_4~(2-)、NO_3~-、Ca~(2+)、NH_4~+、Mg~(2+)、K~+、Na~+).该地区降雨中的主要阴离子为SO_4~(2-)和NO_3~-,主要阳离子为Ca~(2+)和NH_4~+.与我国其它地区相比,其酸性离子、碱性离子和总离子浓度均普遍高于东南地区、而低于我国北方地区.西南酸雨区主要以pH值为4.5~5.6的弱酸性降雨为主,占总降雨频次的58%左右.根据酸、碱性离子的相关性、中和因子等分析结果,该区雨水中的酸性物质可能受到了碱性离子的中和作用,其中起主要中和作用的离子为Ca~(2+)和NH_4~+.将该区雨水pH值和酸、碱性离子浓度与我国其它地区进行对比研究发现,西南酸雨区降雨受到的中和作用要强于东南地区,但弱于北方地区的降雨.通过对西南酸雨区降雨中主要离子来源的分析和估算,降雨中的酸性离子SO_4~(2-)和NO_3~-主要来自于人为污染;99.7%的Ca~(2+)和84.0%的Mg~(2+)为陆源贡献,这可能与西南地区碳酸盐岩广泛分布有关.     

离子阱质谱库的建立与研究

该质谱库建有510种环境中常见有机化合物的质谱数据,其中含中国环境优先控制污染物名单中列入的有机化合物63种,U．S．EPA清洁水法中规定的重点有机污染物95种,覆盖率达80％～90％,该谱库可应用于离子阱检测系统的谱库检索,提高了对未知化合物鉴定的可靠性。      

某些太古界岩石的金含量及其与后生含金石英脉矿床的可能关系

<正> 引言 太古界花岗岩-绿岩地体中的金矿化每年可提供大约200t金。现在世界金年产量大约为1300t。 太古界金矿床包括块状硫化物、古砂矿和条带状铁建造,其中最重要的一类是与石英脉伴生的后生矿化。 在空间上与太古界绿岩有密切关系的含金石英脉,已知在世界范围内都有产出。例如南非的巴伯顿山地、西澳大利亚卡尔古利矿区的戈尔登迈尔以及加拿大苏必利尔构造省的阿比蒂比绿岩带。 直至约25年前,人们乐于用来解释金矿脉     

基于概率神经网络的西安地区地下水水质评价

为了检验概率神经网络在地下水水质评价中的适用性,论文分别采用综合评价法和概率神经网络评价法对西安地区地下水水质进行了评价,结果表明概率神经网络法能综合考虑各因子对水质的影响,剔除不良数据造成的干扰,能很好地反应地下水的水质状况。同时分析了西安地区地下水水质变化趋势和空间分布情况,结果显示：西安地区地下水水质年际变化不大,大部分地区水质较好;2001~2004年潜水多为Ⅱ类和Ⅲ类水,承压水多为Ⅰ类水。     

Trees as bioindicator of heavy metal pollution in three European cities

Concentrations of four heavy metals were determined in tree leaves and bark collected from polluted and non-polluted areas of three European cities (Salzburg, Belgrade and Thessaloniki) for a comparative study. Platanus orientalis L. and Pinus nigra Arn., widespread in urban northern and southern Europe, were tested for their suitability for air quality biomonitoring. Leaves and barks were collected uniformly of an initial quantity of about 30 g of each sample. Analysis was accomplished by electrothermal atomic absorption spectrometry after total digestion. Site-dependent variations were found with the highest concentration level measured in Belgrade, followed by Thessaloniki and Salzburg. A higher accumulation of heavy metals was found in bark compared to leaves. Pine tree bark, accumulating higher concentrations of trace metals compared to plane tree bark, shows a higher efficiency as bioindicator for urban pollution. Both indicator species are suitable for comparative studies on bioindication of urban air pollution.     

Heavy metal concentrations in the liver of three duck species: influence of species and sex

To investigate interspecific and intersex differences in heavy metal levels, we analysed concentrations of cadmium, cobalt, chromium, copper, lead, mercury, manganese, nickel and zinc in the livers of male and female black duck (Anas rubripes), mallard (A. platyrhynchos) and greater scaup (Aythya marila) collected in Raritan Bay, New Jersey in December 1980 and January 1981. Certain metal levels varied significantly by species and sex. In all species, Zn and Cu had the highest concentrations, and Cd, Co, and Hg were lowest in all three species. Scaup had significantly higher levels of Cu than black ducks and mallards, and mallards had significantly higher levels of Mn and Zn than black duck and scaup. Overall, eight of nine metal levels were higher in male than female black duck. In scaup, females had significantly higher levels of Pb and Mn than males. In black ducks, males had significantly higher levels of Cu, Mn and Zn than females. The sample of mallard was too small to test intersex differences.     

Boreal bog plants: nitrogen sources and uptake of recently deposited nitrogen

The main goals of this study were to determine the delta15N signature of quantitatively important boreal bog plants as basis for discussing their N sources, and to assess the effects of five different 3 year N treatments (i.e. 0, 5, 10, 20 and 40 kg N ha(-1) year(-1)) on the bog plants and surface peat at different depths (i.e. 0, 5, 10, 20 and 40 cm) by using 15N as tracer. Plants and peat were analyzed for N concentration, 15N natural abundance and 15N at.%. From the results we draw three main conclusions: First, the relative importance of different N sources is species-specific among bog plants. Second, an annual addition of 5 kg N ha(-1) year(-1) was sufficient to significantly increase the N concentration in Sphagnum mosses, liverworts and shallow rooted vascular plants, and an annual addition of 40 kg N ha(-1) year(-1) during 3 years was not sufficient to increase the N concentration in deep rooted plants, although the 15N content increased continuously, indicating a possible longer term effect. Third, an annual addition of 40 kg N ha(-1) year(-1) during 3 years increased the N content in surface peat at depths of 5 and 10 cm, but not at depths of 20 and 40 cm, indicating the capacity of the living Sphagnum mosses and the surface peat to take up deposited N, and thereby function as a filter.     

Estimation and characterization of PCDD/Fs and dioxin-like PCBs from Chinese iron foundries

The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper.In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupolas. When iron ore lump and sinter were used as raw material, the emission factors were about 250 ng TEQ t⁻¹ of product. However, if the raw material was scrap, the emission factors varied owing to the different contents of organic materials in the raw materials. It was found that the mean WHO-TEQ values of PCDD/Fs and DL-PCBs were 144 and 34.2 pg Nm⁻³ in stack gas and 20.0 and 1.58 pg g⁻¹ in fly ash. In multiple tests, it was estimated that the mean emission factors of PCDD/Fs and DL-PCBs were 365 and 10.9 ng WHO-TEQ t⁻¹ released to residue and 2719 and 555 ng TEQ t⁻¹ released to air. The total emission amounts of PCDD/Fs and DL-PCBs from Chinese iron foundries with cupola furnaces released to residue and air were 16.8 and 146 g WHO-TEQ in 2008, respectively.