循环序批式活性污泥反应器的调试及运行

介绍了循环序批式活性污泥反应器的工艺流程及设计参数、调试和运行情况,分析探讨了系统运行中出现的一些问题。稳定运行期间的检测结果表明,反应器对COD和NH3-N具有较好的去除效果,平均去除率分别达到86.2%和92.1%,但对TP的去除率有待提高。     

Oxidative stress and DNA damages induced by cadmium accumulation

Experimental evidence shows that cadmium （Cd） could induce oxidative stress and then causes DNA damage in animal cells, however, whether such effect exists in plants is still unclear. In the present study, Vicia faba plants was exposed to 5 and 10 mg/L Cd for 4 d to investigate the distribution of Cd in plant, the metal effects on the cell lipids, antioxidative enzymes and DNA damages in leaves. Cd induced an increase in Cd concentrations in plants. An enhanced level of lipid peroxidation in leaves and an enhanced concentration of H2O2 in root tissues suggested that Cd caused oxidative stress in Vicia faba. Compared with control, Cd-induced enhancement in superoxide dismutase activity was significant at 5 mg/L than at 10 mg/kg in leaves, by contrast, catalase and peroxidaseactivities were significantly suppressed by Cd addition. DNA damage was detected by neutral/neutral, alkaline/neutral and alkaline/alkaline Comet assay. Increased levels of DNA damages induced by Cd occurred with reference to oxidative stress in leaves, therefore, oxidative stress induced by Cd accumulation in plants contributed to DNA damages and was possibly an important mechanism of Cd-phytotoxicity in Vicia faba plants.     

基于生态—经济协调发展的乡镇空间功能分区

按提供产品的类别,乡镇尺度空间由生态空间、农业空间和建设空间组成,这3部分空间共同承载着乡镇社会经济发展的重任。坚持生态保护对发展的约束与支撑功能并存的理念,建立以生态约束为前提,并与开发建设协同推进的分区指标体系、技术方法及应用模式,是生态文明战略下空间功能分区的有益探讨。以南京市六合区雄州街道为案例,借助Arc GIS空间分析工具,采用互斥性矩阵分类法,通过对生态约束、农业发展、工业发展与人居环境等建设开发适宜性的单项与综合评价的集成,构建生态、农业和建设空间布局的总体架构,实现了街镇空间功能的整合与科学定位;划分禁止建设区、限制建设区、适宜建设区和已建设区等四大类功能区,并提出各功能区的生态环境保护措施与产业发展导向,为实施区域发展与生态保护的协同推进提供了依据。     

经济发达地区土地利用结构变化预测 --以江苏省江阴市为例

结构决定功能，把握土地利用结构变化的趋势，调整社会经济发展的策略。优化土地利用结构是土地可持续利用的关键。以经济发达地区江苏省江阴市为例，运用马尔柯夫链的理论与方法，构建土地利用结构转移的概率矩阵，预测江阴市2005年和2010年的土地利用结构，并分析其变化特征，以此来研究经济发达地区近期内可能的土地利用结构变化规律。模拟结果表明，经济发达地区土地利用结构变化存在着非农化趋势加快．农地数量减少加速的现象，如果为保证耕地的数量平衡，则可能导致农地内部结构极其不合理。根据研究结果，提出适当释放农地，促进经济发展；运用经济杆杠，提高非农用地利用效率；重视耕地质量，改善生态环境的政策建议。     

Combined use of molecular biology taxonomy, Raman spectrometry, and ESEM imaging to study natural biofilms grown on filter materials at waterworks

DNA-based population analysis was applied in combination with Raman spectrometry and Environmental Scanning Electron Microscopy for the characterisation of natural biofilms from sand and activated carbon filters operated for a long term at a municipal waterworks. Whereas the molecular biology polymerase chain reaction combined with denaturing gradient gel electrophoresis approach provides a deeper insight into the bacterial biofilm diversities, Raman spectrometry analyses the chemical composition of the extracellular polymer substances (EPS), microorganisms embedded in EPS as well as other substances inside biofilm (inorganic compounds and humic substances). Microscopy images the spatial distribution of biofilms on the two different filter materials. In addition, bacterial bulk water populations were compared with biofilm consortia using the molecular fingerprint technique mentioned.Population analysis demonstrated the presence of more diverse bacterial species embedded in a matrix of EPS (polysaccharides, peptides, and nucleic acids) on the sand filter materials. In contrast to this, activated carbon granules were colonised by reduced numbers of bacterial species in biofilms. Besides α-, β-, and γ-Proteobacteria, a noticeable specific colonisation with Actinobacteria was found on activated carbon particles. Here, the reduced biofilm formation came along with a decreased EPS synthesis. The taxonomy profiles of the different biofilms revealed up to 60% similarity on the same filter materials and 32% similarity of different materials. Similarity of adherent communities from filter materials and bulk water populations from the filter effluent varied between 36% and 58% in sand filters and 6–40% in granular activated carbon filters.The biofilm investigation protocols are most crucial to subsequent acquisition of knowledge on biofilm dynamics and bacterial contributions to transformation or adsorption processes in waterworks facilities.     

Assessment Tools for Urban Catchments: Defining Observable Biological Potential1

Abstract: Urbanization represents a strong and increasingly more prevalent impact on stream quality worldwide. One of the characteristic effects of increased urbanization is a consistent decline in biological stream condition. The characterization of this biological degradation with increasing urbanization presents a number of advantages for the study and management of urban streams and catchments. In this paper, the limitation of biological condition with urbanization, called observed biological potential, is characterized. Using an urban intensity index and a biological index developed specifically for urban systems in the Baltimore, Maryland; Cleveland, Ohio; and San Jose, California regions, two principal techniques were compared (quantile regression and bin regression) to define observed biological potential along urban gradients. Quantile regression was selected as the preferable tool for describing observed biological potential given the consistency with which it can be applied and its statistical efficiency, however, bin quantile regression performed similarly. Having identified a numeric approximation of observed biological potential, two methods for identifying factors related to distance from potential as a way of identifying critical environmental factors affecting biological condition in urban areas were explored. The results of this work can be used for identifying benchmarks for urban stream biological condition, identifying limiting catchment characteristics, and prioritizing urban stream management efforts.     

石墨炉法测定铅的基体改进剂的选择

通过一系列实验,选择了石墨炉法测定铅的最佳基体改进剂,并确定了使用该基体改进剂的最佳灰化温度和原子化温度。     

A New Approach to Plant Diversity Assessment Combining HPLC Data, Simplex Mixture Design and Discriminant Analysis

The quantitative assessment of plant diversity and its monitoring with time represent a key environmental issue for management and conservation of natural resources. Assessment of plant diversity could be based on chemical analyses of secondary metabolites (e.g. flavonoids, terpenoids), because of the substantial quantitative and qualitative between-individual variability in such compounds. At a geographical scale, the plant populations become widely dispersed, and their monitoring from numerous routine individual analyses could become restricting. To overcome such constraint, this study develops a multivariate calibration model giving the relative frequency of a particular taxon from a simple high-performance liquid chromatography (HPLC) analysis of a plant mixture. The model was built from a complete set of mixtures combining different taxons, according to an experimental design (Scheffé’s matrix). For each mixture, a reference HPLC pattern was simulated by averaging the individual HPLC profiles of the constitutive taxons. The calibration models, based on Bayesian discriminant analysis (BDA), gave statistical relationships between the contributions of each taxon in mixtures and reference HPLC patterns of these mixtures. Finally, these models were validated on new mixtures by using outside plants. This new biodiversity survey approach is illustrated on four chemical taxons (four chemotypes) of Astragalus caprinus (Fabaceae). The more differentiated the taxon, the better predicted its contributions (in mixtures) were by BDA calibration model. This new approach could be very useful for a global routine survey of plant diversity.     

炭催化剂吸附剂标准物质的研制

本文介绍了炭催化剂吸附剂标准物质的研制过程。对标准物质的制备技术、均匀性检验、稳定性考察及定值和不确定度进行了逐项分析。采用活性炭浸渍、煅烧技术制得炭催化剂吸附剂标准物质。试验结果表明,该标准物质定值结果准确,均匀性、稳定性良好。铜含量的标准值为11．06％,扩展不确定度为0．13％。     

环境监测用5种氯代烯烃混合气体标准样品研制

介绍了1μmol/mol氮气中5种氯代烯气体标准样品的研制方法。这5种氯代烯包括氯乙烯、1,1-二氯乙烯、顺1,2-二氯乙烯、三氯乙烯、四氯乙烯,其中氯乙烯常温下为气态,其他4种为液态,并且沸点低,将这几种氯代烯制备成气体标准样品存在制备精度低、气液转换不完全等困难。经研究,采用2步称量法制备5种氯代烯气体标准样品,重复制备的相对标准偏差小于1.6%。建立了5种氯代烯标准气体瓶内均匀性的实验方法,并通过考察样品量值伴随样品压力的变化来评价样品的均匀性。结果显示,5种氯代烯标准气体是均匀的,最低使用压力为1 MPa。依照ISO 15000.3来考察样品的时间稳定性,样品有效期为12个月。相对扩展不确定度为3%(置信度为95%)。