Microbiological characteristics in a zero-valent iron reactive barrier

Zero-valent iron (Fe⁰)-based permeable reactive barriertreatment has been generating great interest for passivegroundwater remediation, yet few studies have paid particularattention to the microbial activity and characteristics withinand in the vicinity of the Fe⁰-barrier matrix. The presentstudy was undertaken to evaluate the microbial population andcommunity composition in the reducing zone of influence byFe⁰ corrosion in the barrier at the Oak Ridge Y-12 Plantsite. Both phospholipid fatty acids and DNA analyses were usedto determine the total microbial population and microbialfunctional groups, including sulfate-reducing bacteria,denitrifying bacteria, and methanogens, in groundwater andsoil/iron core samples. A diverse microbial community wasidentified in the strongly reducing Fe⁰ environment despitea relatively high pH condition within the Fe⁰ barrier (up topH 10). In comparison with those found in the backgroundsoil/groundwater samples, the enhanced microbial populationranged from 1 to 3 orders of magnitude and appeared to increase from upgradient of the barrier to downgradient soil. Inaddition, microbial community composition appeared to change overtime, and the bacterial types of microorganismsincreased consistently as the barrier aged. DNA analysisindicated the presence of sulfate-reducing and denitrifyingbacteria in the barrier and its surrounding soil. However, theactivity of methanogens was found to be relatively low,presumably as a result of the competition by sulfate/metal-reducing bacteria and denitrifying bacteria because of the unlimited availability of sulfate and nitrate in the site groundwater. Results of this study provide evidenceof a diverse microbial population within and in the vicinity ofthe iron barrier, although the important roles of microbial activity, either beneficially or detrimentally, on the longevityand enduring efficiency of the Fe⁰ barriers are yet to be evaluated.     

螯合树脂在线富集——火焰原子吸收光度法测定水中微量Cu,Pb,Zn,Cd

对螯合树脂在线富集，火焰原子吸收光度法进行了条件试验。试验证实方法对Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ４个元素检出浓度可达μｇ／Ｌ级，校准曲线性、样品重现性及准确度可满足测定要求。     

Modeling photocatalytic destruction of the organic contaminants in continuous stir flow reactor

Thin-film technique is becoming an industry standard for the preparation of TiO₂-based photocatalyst for organic destruction. The catalyst provides several advantages over the conventional powder TiO₂ in the treatment of wastewater and groundwater. In this study, a continuous stir flow reactor model is developed capable of describing the photocatalytic process. The model incorporates the following fundamental mechanisms: adsorption, diffusion, liquid-film transfer, UV attenuation, and photocatalytic reaction. All of the simulation results indicate that there exists a highly nonlinear relation between each of these parameters and the destruction rate. Various incident light intensities also are incorporated to simulate the energy efficiency. The simulations illustrate that the photocatalytic model can be used to elucidate the effect of process variables. It is also possible to “custom-design” a catalyst for the treatment of a particular waste stream.     

铁路运输业污水治理系统分析

研究了乌鲁木剂铁路局系统污水治理污染控制方法及途径，提出了主要污染物为石油类，其最佳治理对策是：确定重点污染单位、污染源、用最低的治理投入，选择斜板隔油气浮工艺治理重点污染和次重点污染部门，得到较好的治理效果，否定盲目追求“零排放”的高投入方案。     

无剩余污泥的多级活性生化处理工艺

介绍了多级活性生化处理 (MSABP)这项新的废水处理技术的原理、技术特点及两个实例运用。这是此项技术在国内的首次运用 ,其最大的优点是无剩余污泥产生 ,不需要沉淀池     

Application of PCR and probe hybridization techniques in detection of airborne fungal spores in environmental samples

Specific PCR amplification and probe hybridization techniques were applied to examine the compositions of airborne fungi in samples from three different environments. The results from microscopic and CFU counting were compared to those of the molecular-based detections. The detection sensitivity for PCR amplifications was 9 to 73 spores and 1.3 to 19.3 CFUs per PCR reaction. The hybridization detection limit was 2 to 4 spores and 0.2 to 1.2 CFU. The hybridization method was more sensitive than PCR amplification and showed less variation among samples. Using specific PCR primers and probes we identified the presence of several fungal groups and species in the air samples. Specific detections through probe hybridization to PCR products amplified with universal or group-specific fungal primers have promising applications in the examination of air samples for environmental monitoring.     

有机磷酸酯诱导迟发性神经毒性及其对神经毒性酯酶（NTE）活性影响的动态研究

以成年产卵来航母鸡为试验动物，研究了三甲基苯基磷酸酯（Ｔｒｉ－ｏ－ＣｒｅｓｙｌＰｈｏｓ－ｐｈａｔｅ，ＴＯＣＰ）诱导的迟发性神经毒性．试验发现，母鸡口服ＴＯＣＰ（７５０ｍｇ／ｋｇ）后，经过大约８－１０ｄ的潜伏期开始出现中毒症状，其表现为以步态失调为主要特征的运动障碍呈进行性加重，至第２１ｄ开始便发展为瘫痪，对鸡脑神经病损靶标酯酶（ＮｅｕｒｏｐａｔｈｙＴａｒｇｅｔＥｎｚｙｍｅ，ＮＴＥ）活性的测定表明，有机械诱导的迟发性神经毒性（Ｏｒｇａｎｏｐｈｏｓｐｈａｔｅ－ＩｎｄｕｃｅｄＤｅｌａｙｅｄＰｏｌｙｎｅｕｒｏｐａｔｈｙ，ＯＰＩＤＰ）与ＮＴＥ活性抑制之间的关系不平行，其毒性症状的轻重与ＮＴＥ活性被抑制的强弱也不呈正相关，很可能，在给药后２４ｈ，体内ＯＰＩＤＰ已被触发，此外，实验观察到给予ＴＯＣＰ后被试鸡的体重明显下降。     

汽车尾气污染及其净化处理技术

本文详细阐述了汽车尾气的有害成份及其对人类健康的危害。为此 ,应该采取净化处理措施 ,减少或者消除有害气体的产生 ,为大气环境洁净而创造条件。     

多环芳烃的几种理化参数与LC_(50)的相关性研究

对多环芳烃(PAHS)4种理化参数(K;W、Sw。X Vv。)与 LCO的相关关系进行了研究,建立了 4种一元线性回归方程。结果表明,4种参数的相关系数分别为:0.刀66、08083、09488、0.9570,经r检验,后两种属高度显著相关.用所建立的一元线性回归方程对7种PAHS的LC。进行估算,估算值与实测值相比,平均相对误差分别为58.84％、32.23％、1761％、198％,用l和V＊.H对LClj进行估算的估算精度也较高。经比较,提出用(。估算P＊比对麦穗鱼＊CO的新方法。     

Observation of atmospheric nitrous acid with DOAS in Beijing, China

Measurements of nitrous acid （HONO） and nitrogen dioxide （NO2） in Beijing City have been performed by means of a developed differential optical absorption spectroscopy （DOAS） system based on photodiode array （PDA）, during the autumn of 2004. HONO and NO2 were simultaneously identified by their characteristic absorption bands in the spectral region between 337 nm and 372 nm with high sensibility and time resolution. The concentrations of HONO exhibit obviously diurnal variation with a nocturnal maximum and a daytime minimum. The highest HONO value up to 11.8 μg/m^3 was observed during the night of 2/3 September. Possible sources of the observed HONO were discussed. Good correlation to NO2 indicates that NO2 is a main source component. The measurement also shows direct emission of HONO is an imnortant source in strongly polluted urban area.