饮用水反硝化脱氮方法研究

为去除饮用水中的硝酸盐氮(NO3ˉ-N)，采用上流式厌氧污泥床(UASB)反应器和固定化微生物进行异养反硝化；自制固定化反硝化菌涂层电极和生物电化学脱氮装置，并用于自养反硝化。试验结果表明。若以甲醇为碳源。当碳氮比(C／N)≥1．o时，室温下经UASB处理4h，NO3ˉ-N去除率为97．7％；若以乙酸为碳源。当C／N≥1．0时，30C下经固定化微生物处理6h，N03ˉ-N去除率为98．6％；在无外加碳源的条件下处理东湖现场水样，30C下经60h后。N03ˉ-N去除率达93．5％。生物电化学脱氮装置可迅速建立自养反硝化菌所需的厌氧环境，水样在室温下经72h处理，脱氮率达96．3％。     

Microbial cycling of iron and sulfur in acidic coal mining lake sediments

Lakes caused by coal mining processes are characterized by low pH, low nutrient status, and high concentrations of Fe(II) and sulfate due to the oxidation of pyrite in the surrounding mine tailings. Fe(III) produced during Fe(II) oxidation precipitates to the anoxic acidic sediment, where the microbial reduction of Fe(III) is the dominant electron-accepting process for the oxidation of organic matter, apparently mediated by acidophilic Acidiphilium species. Those bacteria can reduce a great variety of Fe(III)-(hydr)oxides and reduce Fe(III) and oxygen simultaneously which might be due to the small differences in the redox potentials under low pH conditions. Due to the absence of sulfide, Fe(II) formed in the upper 6 cm of the sediment diffuses to oxic zones in the water layer where itcan be reoxidized by Acidithiobacillus species. Thus, acidic conditions are stabilized by the cycling of iron which inhibits fermentative and sulfate-reducing activities. With increasing sediment depth, the amount of reactive iron decrease, the pH increases above 5, and fermentative and as yet unknown Fe(III)-reducing bacteria are also involved in the reduction of Fe(III). Sulfate is reduced apparently by the activity of spore-forming sulfate reducers including new species of Desulfosporosinus that have their pH optimum similar to in situconditions and are not capable of growth at pH 7. However, generation of alkalinity via sulfate reduction is reduced by the anaerobic reoxidation of sulfide back to sulfate. Thus, the microbial cycling of iron at the oxic-anoxic interface and the anaerobic cycling of sulfur maintains environmental conditions appropriate for acidophilic Fe(III)-reducing and acid-tolerant sulfate-reducing microbial communities.     

Comparing Environmental Conditions Using Indicators of Pollution Hazard

/ Land use/land cover classifications for 1973 and 1991, derived from the interpretation of satellite imagery, are quantified on the basis of biophysical land units in a study area in southeastern Australia. Nutrient export potentials are estimated for each land unit based on their composition of land use/land cover classes. Spatial and temporal comparisons are made of the land units based on the calculated pollution hazard indicators to provide an insight into changes in the state of the environment and the regional significance of land use changes. For example, one ecosystem, unique to the study, showed a large increase in pollution hazard over the study period as a manifestation of an 11-fold rise in cleared area and an expansion of cropping activities. The benefits to environmental management in general are discussed.KEY WORDS: Land cover change; Nutrient export; Environmental condition; Pollution hazard; Agricultural pollution; Nonpoint source pollution; Diffuse pollution; Environmental degradation     

生态条件和瘤胃菌丛密度与纤维分解的关系

在自行设计装配的人工模拟瘤胃发酵装置内，用90523-1瘤胃菌丛进行瘤胃体外发酵试验，结果表明纤维素的分解与瘤胃细菌的密度及其类群变化有着密切关系，都受生态环境条件的制约。在发酵温度40℃，搅拌速度为60～70r／min的条件下搅动20min／h，C／N为10：1的生态条件环境中的细菌密度和纤维素分解率都高于相同生态条件的其它梯度组。     

太阳能光催化降解法去除水中罗丹明染料的研究

在太阳光的紫外线辐射下，应用载有ＴｉＯ２薄层的平板式光催化反应器，进行了光催化降解法去除水中罗丹明染料的试验，结果表明，当紫外线辐射强度平均为３３Ｗ／ｍ＾２，反应时间为１８ｍｉｎ时，水中罗丹明染料浓度由１０ｍｇ／Ｌ降至０．０１ｍｇ／Ｌ，在室国家排放标准，探讨了太阳能光催化反应系统的改进方向及工业化应用的有关问题。     

石油污染生物修复技术研究

本文概述了影响石油污染物生物降解修复处理的多种因素，对石油污染生物处理技术的发展进行了展望。其中主要影响因素包括：菌种的影响，菌种在不同的环境中和对不同碳链长度的碳氢化合物表现出不同的降解效率；石油物质本身物理化学特性的影响，如石油物质在水体或土壤中的浓度以及石油的粘度、沸点、折射率等特性；生存环境条件的影响，在接种入高效率的降解菌或利用土著微生物进行降解时，降解率受到生存环境中各种条件的影响，如表面活性剂、光照条件、吸附剂的利用、营养盐、共代谢底物、氧气、温度、盐度等。     

石油污染土壤的生物修复技术研究及其前景

根据污染土壤的生物修复技术具有高效、无二次污染和操作管理简便的优点，本文介绍谊类技术在石油污染治理领域的应用。在概述石油的组成成分及其对环境造成的污染的基础上，重点论述了微生物和植物修复技术有效去除有机污染物的应用条件，并就目前两种技术的最新研究成果即基因技术的应用作了介绍，同时指出了石油污染土壤生物修复技术的发展趋势和应用前景。     

TiO2光催化氧化的研究进展

概述了TiO2光催化氧化降解水中污染物的原理及TiO2光催化剂的制备，提出了增强其活性的途径。TiO2光催化氧化可应用于印染、农药、造纸等工业废水及饮用水处理中，研制高效的负栽型纳米TiO2光催化剂、解决太阳能利用问题、开发多功能光催化反应器是今后TiO2光催化氧化的发展趋势。     

UV/O3复合降解水中2,4-二氯酚的试验研究

以紫外光源为主要依托,变换反应器中的不同工艺条件,分别对紫外光、臭氧和紫外/臭氧三种不同于工艺条件对水中污染物2,4-二氯酚(2 ,4-DCP)的降解规律进行研究.结果表明,UV/O3复合对2,4-DCP的降解较UV、O3单独作用效果好;溶液的酸碱度影响UV/O3对2 ,4-DCP的降解;此外,溶液中含有细菌时,E. coli的杀灭效果仍表现为UV/O3＞O3＞UV.细菌的杀灭和2,4-DCP的降解均消耗羟基自由基,形成竞争反应,从而影响到2,4-DCP的降解效果.     

ENHANCING FECAL COLIFORM TOTAL MAXIMUM DAILY LOAD MODELS THROUGH BACTERIAL SOURCE TRACKING1

ABSTRACT: Surface water impairment by fecal coliform bacteria is a water quality issue of national scope and importance. In Virginia, more than 400 stream and river segments are on the Commonwealth's 2002 303(d) list because of fecal coliform impairment. Total maximum daily loads (TMDLs) will be developed for most of these listed streams and rivers. Information regarding the major fecal coliform sources that impair surface water quality would enhance the development of effective watershed models and improve TMDLs. Bacterial source tracking (BST) is a recently developed technology for identifying the sources of fecal coliform bacteria and it may be helpful in generating improved TMDLs. Bacterial source tracking was performed, watershed models were developed, and TMDLs were prepared for three streams (Accotink Creek, Christians Creek, and Blacks Run) on Virginia's 303(d) list of impaired waters. Quality assurance of the BST work suggests that these data adequately describe the bacteria sources that are impairing these streams. Initial comparison of simulated bacterial sources with the observed BST data indicated that the fecal coliform sources were represented inaccurately in the initial model simulation. Revised model simulations (based on BST data) appeared to provide a better representation of the sources of fecal coliform bacteria in these three streams. The coupled approach of incorporating BST data into the fecal coliform transport model appears to reduce model uncertainty and should result in an improved TMDL.