经济高效的污水生物脱氮除磷新技术研究

控制污水中氮和磷的排放,对于防治水体富营养化是十分重要的。针对常规生物脱氮除磷技术和工艺中存在的问题,研究开发出从不同类型污水中去除氮和磷的生物膜与活性污泥结合工艺、亚硝酸型脱氮技术、新型膜生物反应器和立体循环一体化氧化沟等。这些技术和工艺发挥了不同微生物苗群的优势,使其分别处于各自最佳状态,可提高处理效率、简化操作、降低处理费用。     

烟气同时脱硫脱氮的高活性吸收剂的表征及脱除机理研究

以飞灰、工业用石灰、少量锰盐添加剂为原料制备了具有同时脱硫脱氮性能的“富氧型”高活性吸收剂, 在烟气循环流化床(CFB)上对“富氧型”吸收剂的脱硫脱氮性能进行了试验, 试验结果表明, “富氧型”吸收剂能够实现高达94.5%的脱硫效率和64.2%的脱氮效率. 利用扫描电子显微镜和X射线能谱仪对飞灰、工业用石灰、普通高活性吸收剂、“富氧型”高活性吸收剂和反应后的“富氧型”高活性吸收剂进行了表面微区分析, 结果表明, 普通高活性吸收剂和“富氧型”高活性吸收剂颗粒表面可以观察到白色薄层状物质; 钙元素在二者表面的平均含量高于吸收剂主体的钙含量; 反应后的“富氧型”高活性吸收剂颗粒表面具有多孔特性; 氧化性添加剂主体元素锰在“富氧型”高活性吸收剂表面分布均匀; 脱硫脱氮反应后的吸收剂中出现了硫元素的峰. 化学分析方法对吸收剂的脱硫脱氮产物进行的成分分析表明, 反应后的吸收剂中除了硫物种外还有大量氮物种. 由X射线能谱分析和化学分析结果表明, CFB内的主要脱除过程为化学吸收, 脱硫产物主要为硫酸盐; NO首先被快速氧化为NO₂, 进而发生化学吸收反应, 脱氮产物主要为亚硝酸盐.     

微波辐射法快速制备龙虾壳聚糖工艺的研究

以地产龙虾壳为原料．探讨微渡辐射法快速制备壳聚糖的工艺。着重时微波辐射法制备壳聚糖的加热时间、碱液浓度等对壳聚糖脱乙酰度、粘度等性质的影响进行研究，并和酸碱法制备壳聚糖的方法进行比较。结果表明：微波辐射法制备龙虾壳聚糖的适宜工艺为：碱液浓度45％；微波加热15min；微波功率280W；具高效性。用该法制备的龙虾壳聚糖的红外光谱和X射线衍射谱图与市售生化级壳聚糖的图谱基本一致，且工艺设备简单，操作方便，具有较强的推广性。     

厌氧氨氧化微生物学机制及其在污水脱氮工艺中的应用进展

厌氧氨氧化反应(Anammox)是指将NH_4~+-N和NO_2~--N直接转变为N_2去除的生物氧化过程,近年来成为新型生物脱氮技术研究的热点。在厌氧氨氧化反应中起关键作用的厌氧氨氧化细菌是一类对生态环境要求极为苛刻的微生物类群。目前,对于厌氧氨氧化生物转化过程的生物学理论与机制研究虽取得一定的突破,但有关厌氧氨氧化微生物代谢与调控机制的关键科学问题研究还不够深入,严重制约了该技术的工程化应用与推广。本文着重阐述了厌氧氨氧化菌的微生物学原理、生理特性,以及参与中心代谢途径的关键酶基因等,进而讨论了典型的厌氧氨氧化反应的化学与生化反应模型、影响厌氧氨氧化生物代谢过程的主要生态因子。最后,针对厌氧氨氧化技术在国内外典型的污水脱氮工艺中的应用现状与运行效果,深入剖析了产业化工程应用与推广的瓶颈,并对厌氧氨氧化技术未来的理论机制研究与产业化工程应用进行了前景展望。     

应用于微结构制造自治系统的第Ⅰ类工艺缺陷诊断

在集成电路制造中，通常采用各电学参数的测试值来衡量和评价工艺效果。一种可能的工艺后果是，出现了测量结果偏离预定目标的第1类工艺缺陷。传统上的基于SPC的工艺控制技术，不含工艺诊断的内容，在寻找造成工艺失效的原因时，存在着巨大的困难。本文对集成电路制造过程中所涉及到的几类重要参数间的关系，进行了详细的分析，由此确定造成诊断问题困难的根本原因，在于测试现象与工艺故障因素之间是多对多的关系。通过正交化的方法。可以将测试参数转化成为一组广义参数。广义参数与故障因素之间存在着一对一的联系。这样就找到了一种有效的，从异常的广义参数值确定失效原因的工艺诊断方法。本文对第Ⅰ类工艺诊断的技术进行了讨论。在集成电路制造自自治系统中，对于Ⅰ类工艺缺陷的纠正过程，也就是工艺结果不断向工艺目标趋近的过程。     

应用于微结构制造自治系统的第I类工艺缺陷诊断

在集成电路制造中,通常采用各电学参数的测试值来衡量和评价工艺效果。一种可能的工艺后果是,出现了测量结果偏离预定目标的第I类工艺缺陷。传统上的基于SPC的工艺控制技术,不含工艺诊断的内容,在寻找造成工艺失效的原因时,存在着巨大的困难。本文对集成电路制造过程中所涉及到的几类重要参数间的关系,进行了详细的分析,由此确定造成诊断问题困难的根本原因,在于测试现象与工艺故障因素之间是多对多的关系。通过正交化的方法,可以将测试参数转化成为一组广义参数。广义参数与故障因素之间存在着一对一的联系。这样就找到了一种有效的,从异常的广义参数值确定失效原因的工艺诊断方法。本文对第I类工艺诊断的技术进行了讨论。在集成电路制造自自治系统中,对于I类工艺缺陷的纠正过程,也就是工艺结果不断向工艺目标趋近的过程。     

突出煤样与非突出煤样低温氮吸附实验研究

为研究煤样吸附能力和煤与瓦斯动力现象的关系,针对突出煤与非突出煤的吸附能力差异问题,应用物理化学吸附仪对6组突出与非突出煤进行低温氮吸附实验,得到低温氮吸附等温线,运用BET吸附理论对实验数据进行分析。实验及分析结果表明:突出煤吸附量、拐点斜率、脱附滞后量大于非突出煤,突出煤吸附等温线变化趋势为单调递增,非突出煤样局部范围内出现下降趋势;突出煤样C值较非突出煤样C值低,突出煤样孔隙中的吸附质更容易脱附。以此为依据来判断煤是否具有突出性,可为预防煤与瓦斯突出事故提供技术方法。     

氮同位素示踪技术在研究地下水硝酸盐污染中的应用

氮是重要的生源要素之一，地下水中硝酸盐污染问题不容忽视；由于不同氮污染源的同位素组成不同，所以氮同位素示踪技术应用于地下水硝酸盐污染研究具有重要意义。本文重点介绍了氮同位素示踪的基本原理及其测定方法，并归纳总结了氮同位素示踪技术在地下水中硝酸盐污染研究中的应用现状，指出了今后研究工作中值得重视的有关问题。     

COF(chip on film)技术现状和发展前景

随着当今电子产品朝着更小,更轻方向发展,各种平板显示器得到了广泛的应用,LCD面板就是其中的典型代表。COF技术凭借自身的许多优点,成为了LCD驱动IC的主要封装形式。本文就COF的结构,特点,所用材料,关键工艺,应用状况及其发展趋势进行了综述。     

激光聚变靶球充气微孔扫描探针加工技术研究

为解决核聚变激光靶球诊断气体充气问题及满足充气微孔良好的堵胶工艺性, 基于扫描探针显微镜的金刚石探针为工具, 采用接触力扫描方式对靶球充气微孔进行了微加工工艺研究. 研究了金刚石针尖扫描方向、扫描速度及扫描接触压力等工艺参数对微孔形成的影响, 得到了较准确的锥状孔型, 其孔型尺寸与加工精度满足微孔充气及其堵胶工艺性的要求. 实验结果表明, 利用扫描探针显微镜作为工具并通过加工工艺研究, 可以实现靶球充气锥型微孔的精确加工, 为靶球高Z气体的注入提供了一种新的实用技术.     

Nitrate and nitrite transport in bacteria

The topological arrangements of nitrate and nitrite reductases in bacteria necessitate the synthesis of transporter proteins that carry the nitrogen oxyanions across the cytoplasmic membrane. For assimilation of nitrate (and nitrite) there are two types of uptake system known: ABC transporters that are driven by ATP hydrolysis, and secondary transporters reliant on a proton motive force. Proteins homologous to the latter type of transporter are also involved in nitrate and nitrite transport in dissimilatory processes such as denitrification. These proteins belong to the NarK family, which is a branch of the Major Facilitator Superfamily. The mechanism and substrate specificity of transport via these proteins is unknown, but is discussed in the light of sequence analysis of members of the NarK family. A hypothesis for nitrate and nitrite transport is proposed based on the finding that there are two distinct types of NarK.     

苯酚在氨氮体系中的氧化降解研究

研究了氨氮存在下次氯酸钠处理苯酚模拟废水的氧化特性,探讨了苯酚在氨氯体系中的反应途径。实验结果表明:在含氨氮的苯酚废水中加入次氯酸钠,氨氮将与苯酚发生竞争反应。折点加氯曲线表现为当氯与氨氮质量比由5.35上升到27.67时,氨氮去除率的变化趋势滞后;而余氯量则不断减小,没有折点出现。随着氨氮浓度增加,苯酚的氧化降解受到抑制:一方面,苯酚的去除率不断下降;另一方面,体系中检测到一系列氯酚中间产物,其生成量和种类先增加后减少。HPLC分析结果显示体系中生成的氯酚中间产物至少有2种(2-氯酚和4-氯酚),至多有5种(2-氯酚、4-氯酚、2,6-二氯酚、2,4-二氯酚和2,4,6-三氯酚)。其中,2-氯酚和4-氯酚是导致三卤甲烷产生的最有效前体物质,而2,6-二氯酚、2,4-二氯酚和2,4,6-三氯酚则是生成卤乙酸的高活性物质。实验结果对次氯酸钠处理含氨氮的难生化或有毒有机废水具有一定的参考价值。     

Microbial potential in deep-sea sediments

Summary In spite of high pressures and low temperatures in abyssal sediments of the North Atlantic Ocean, bacterial activity is evident and highest in the top 10 cm. At these locations the input of degradable organic material to the deep-sea bottom is low. Oxygen, therefore, remains the dominant oxidant in surface sediments. Although alternative electron acceptors like nitrate, oxidized manganese and sulfate are present in large amounts, they are not utilized in this natural habitat. In sediment cores which were collected from the site for laboratory perturbation studies, it was possible to stimulate microbially mediated processes which are dormant in situ. When the oxygen supply was cut off, nitrate and manganese reduction occurred. Denitrification was the major process observed in the upper anoxic layers, while nitrate-ammonification and manganese reduction occurred in deeper sediment strata (4–8 cm). This is evidence for the presence of a variety of different bacteria and of an anaerobic heterotrophic potential. Most of the activity is located in the top 10 cm of these sediments. The shift to anaerobiosis initiates microbial activities through which metals are converted into their mobile species at the lowered redox potential. Evaluation of the suitability of the deep sea as a repository for waste materials will have to account for the large dormant potential of microbial activities and the consequences of their release by changing the environmental conditions at the sea floor.     

Fenton试剂的发展及在废水处理中的应用

Fenton在废水处理中具有独特的优势，是一种很有应用前景的废水处理技术。文章介绍了该技术的发展过程、主要类型，尤其介绍了和其它方法联合的优势，以及应用情况，并对各类型的优势、问题、发展趋势作出评述。     

河岸缓冲带不同植被配置对铵氮去除效果研究

在沈阳市郊浑河和蒲河两岸开展不同植被配置方式下，开展河岸植被缓冲带对地表径流中铵氮污染消减研究。结果表明：河岸植被缓冲带越宽，水中铵氮浓度越高，其对地表径流中铵氮的消减作用越明显；天然植被比人工植被能更好的去除铵氮污染物；当污染浓度升高时，林草混合配置的植被带对铵氮表现出较好的消减率；人工林草地和天然林草地对铵氮的平均消减率分别为31％和25．9％，最高消减率分别为57．9％和63．3％，最高消减率均发生在7m宽度河岸带上，而人工林地对铵氮的消减效果较差。实验结果能够应用于指导自然河岸带的生态保护与人工河岸植被带的建设。     

Assimilation of mineral nitrogen and ion balance in the two partners of ectomycorrhizal symbiosis: Data and hypothesis

Summary Assimilation pathways of mineral nitrogen and ion balances of the two partners of ectomycorrhizal symbiosis (fungi and woody plants) are reviewed. Data are presented about the partners both in pure culture and in mycorrhizal association. The two forms of mineral nitrogen, ammonium and nitrate, differ in their mobility in the soil, their transport into the cells, their uptake rates by plants and their assimilation pathways. These metabolic differences are related to differences in adjustment of ion balances and carbon metabolism under conditions of nitrate or ammonium nutrition. The data obtained on the partners of ectomycorrhizal symbiosis are discussed from this point of view and the observations composed with those on herbaceous angiosperms.     

微生物燃料电池与常规污水处理技术结合的研究进展

通过总结近年来微生物燃料电池(MFC)与常规污水处理技术的结合案例,发现与MFC结合的污水处理技术主要集中在物理化学法、生物法及高级氧化法三类。与物理化学法的结合侧重于利用MFC的产电特性,如电吸附法和电渗析法;与生物法的结合分为好氧和厌氧法两种方式,主要利用MFC的多重系统特性,大大提升除污性能:与高级氧化法的结合体现在光催化法、电化学法和电Fenton法三方面,其中,与电benton法的结合是研究的热点。将MFC与常规污水处理技术从产能和净化的双重角度进行结合,既为节能型污水处理技术的发展奠定基础,同时也扩大了MFC的应用范围,为今后MFC与其他技术的结合研究提供了借鉴和依据。     

Uptake of NO2 by plants grown at different salinity levels

Summary It is demonstrated that the uptake of nitrogen dioxide (NO₂) byPhaseolus vulgaris L. is decreased by the addition of sodium chloride (NaCl) to the root medium, as a result of increased diffusive resistance of the leaves. The NO₂-uptake rate constant measured kinetically was in agreement with the nitrite content of the leaves after the fumigation.     

Does ammonium uptake influence xylem sap composition inPhaseolus vulgaris L. andGlycine max (L.) Merill?

The question of whether ammonium uptake influences the occurrence of ureides in legumes has been addressed in this study by investigating threeP. vulgaris genotypes as well as one cultivar ofGlycine max. All plants were raised in sand culture during the dry season in northern Thailand and irrigated daily with nitrogen-free nutrient solution, or the same solution containing 12 mol m^–3 nitrogen in the form of (NH₄)₂SO₄ or KNO₃, each treatment consisting of different proportions of either compound. Regression analyses of xylem sap composition relative to ammonium vs. nitrate supply of plants harvested at V4, R1 and R6 indicated close positive correlations of xylem amino nitrogen content and negative correlations with xylem nitrate content and ammonium supply. Statistically significant correlations between relative xylem ureide content and ammonium availability could be established for theP. vulgaris cultivar Brilliant up to stage R1, but not for the other plants investigated. It was concluded that at least for some genotypes of common bean a relationship exists between ureide production and ammonium uptake by the root system. Since the extent to which ureide production is stimulated remains quite small, its relevance to the xylem solute technique for measurement of N₂ fixation may be limited. Nevertheless, due to the possibility of large genotypic differences in the impact of ammonium on ureide production, this factor must be considered in calculations if N₂ fixation is to be determined in soils containing significant amounts of ammonium, e.g. in paddy fields.