高浓度氨氮废水好氧反硝化反应的基本条件

文章通过室内实验,对高浓度氨氮废水(垃圾渗滤液)间歇曝气,在只存在有机碳、无机氮的条件下进行好氧反硝化脱氮研究。实验结果表明:垃圾渗滤液中存在好氧反硝化土著微生物菌落;发生好氧反硝化的基本条件为在溶解氧充足的条件下间歇曝气;碳源不仅是厌氧反硝化所必须的,同样也是好氧反硝化的必要条件。     

原位生物修复硝酸盐污染地下水的模拟实验

对硝态氮污染地下水微生物修复的实验方法进行了介绍。实验采用注入法,从活性污泥中筛选出一株优势反硝化菌,利用室内模拟柱模拟地下含水层,并在进水中添加少量营养碳源。考察了模拟NO3-污染地下水的修复效果及其影响因素,实验结果显示硝酸盐最高去除率可达85.20%。     

两段SBR工艺脱氮规律实验研究

基于对生物硝化反硝化原理的分析,本实验选用两段SBR工艺生物脱氮技术,解决了高浓度工业废水有机物去除效率高而氨氮去除率不高的难题。同时对其脱氮规律作了研究,找到SBR2是脱氮的关键环节,并分别对SBR2硝化反硝化阶段p H和DO的变化规律进行了研究,得出用这两个参数作为系统自动控制的依据是完全可行的。     

短程硝化--反硝化生物脱氮工艺的研究进展

短程硝化反硝化生物脱氮工艺是将硝化控制在形成亚硝酸阶段,阻止亚硝酸的进一步硝化,然后直接进行反硝化。本文结合国内外的研究,对短程硝化脱氮技术的实现途径进行了概括和探讨,对该工艺的开发应用（如SHARON工艺、OLAND工艺、CANONT艺和生物膜／活性污泥法结合的短程硝化反硝化工艺）作了简要综述,并指出了该工艺的技术优势和应用价值。     

多孔颗粒载体-膜生物反应器脱氮效果研究

实验探索了高MLSS(溶液悬浮固体浓度)下多孔颗粒载体—膜生物反应器发生短程硝化、反硝化的可能性。研究了溶解氧(DO)、C/N、氨浓度及氨负荷、pH等因素对短程硝化、反硝化和TN去除的影响。实验发现,当控制pH=7.5、DO=1.0mg/L、C/N为6时,该反应器能同时达到较高的NH4 —N和TN出除率。     

同步硝化好氧反硝化生物脱氮机理分析及其研究进展

通过对比传统生物脱氮理论，提出同步硝化好氧反硝化技术优点，对好氧反硝化的机理进行了初步探讨，并从不同角度做了理论分析。同时阐述了同步硝化反硝化技术的控制因素及其研究进展。并对好氧反硝化的应用前景作了展望，提出了好氧反硝化今后的研究方向。     

利用反硝化聚磷菌实现城市污水的脱氮除磷

阐述了反硝化除磷的机理,对现有反硝化除磷工艺进行介绍,并进一步讨论了反硝化除磷的影响因素和未来发展新思路。利用DPBs进行反硝化除磷实现了污水处理的资源化和能源化,代表了当前污水处理可持续发展战略的发展趋势,成为目前脱氮除磷技术研究的热点和重点。     

利用反硝化聚磷茵实现城市污水的脱氮除磷

阐述了反硝化除磷的机理,对现有反硝化除磷工艺进行介绍,并进一步讨论了反硝化除磷的影响因素和未来发展新思路。利用DPBs进行反硝化除磷实现了污水处理的资源化和能源化,代表了当前污水处理可持续发展战略的发展趋势,成为目前脱氮除磷技术研究的热点和重点。     

废水生物脱氮低温反硝化研究进展

反硝化过程是废水生物脱氮的关键,低温下废水生物处理的反硝化效率显著降低.本文从低温对微生物反硝化处理效果的影响、低温对反硝化微生物的影响机制以及低温下反硝化效果的强化策略等方面的研究展开综述,并提出了可能的研究方向,以期为微生物低温反硝化进一步的机理研究与技术强化提供参考.     

短程硝化-反硝化生物脱氮技术研究

将短程硝化-反硝化生物脱氮技术与传统生物脱氮技术进行了比较,论述了短程硝化-反硝化生物脱氮技术的机理及特点。分析了实现亚硝酸盐积累的影响因素,包括温度、溶解氧浓度、pH值、分子态游离NH3浓度和泥龄。结合典型工艺,提出了目前短程硝化-反硝化脱氮技术存在的问题及改进建议。     

低负荷状态下CAST工艺脱氮特性的研究

在征润洲污水处理厂CAST工艺处理城市污水运行实践的基础上,开展了两个阶段的对比生产性试验;对城市污水处理过程中,低负荷运行状态下CAST工艺脱氮特性进行研究。研究结果表明:通过对F/M、DO、MLSS、SRT等工艺参数的优化控制,可实现同步硝化反硝化、短程硝化反硝化和传统硝化反硝化有机结合的耦合脱氮模式。该耦合脱氮模式下各出水水质指标稳定达标的情况下,出水NH3-N的去除率达到90%以上,出水TN去除率在55%以上,取得了良好的脱氮效果。     

Identification and quantitative evaluation of nitrogen-converting organisms in a full-scale leachate treatment plant

The presence of ammonia nitrogen in landfill leachates poses a significant problem for treatment plant operators. The nitrification-denitrification process mostly carries out the nitrogen conversion in biological treatment systems. However, recent research shows that other processes by anaerobic ammonia-oxidizing bacteria (Anammox) and ammonia-oxidizing archaea (AOA) were also responsible for the removal of nitrogen in biological systems. In this study, the nitrogen-converting microorganisms in the Bursa Hamitler Leachate Treatment Plant were identified and monitored by using molecular tools. Fluorescent in situ hybridization (FISH) and slot-blot hybridization results showed that the Nitrosomonas and Nitrospira species were the dominant ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), respectively. Quantitative real-time PCR results indicated that AOB, NOB, AOA and Anammox bacteria exist in the leachate treatment plant. However, the removal of ammonia can be ascribed mainly to nitrification because AOB (1.5%) and NOB (11.3%) were predominant among all nitrogen-converting bacteria. The results of the phylogenetic analysis based on amoA and 16S rDNA gene revealed that the uncultured bacterium clone 4-24, Kuenenia stuttgartiensis genome fragment KUST_E and the uncultured Crenarchaeota clone NJYPZT-C1 belong to AOB, Anammox and AOA populations, respectively, and were the dominant species in their cluster.     

Nitrification and denitrification rates of Everglades wetland soils along a phosphorus-impacted gradient

Little information is available on the effect of phosphorus (P) enrichment on nitrogen (N) biogeochemical cycling in wetland soil. Of particular importance are the coupled nitrification-denitrification reactions that regulate the microbially mediated loss of N from wetland systems. Soils from the northern Florida Everglades have been affected by P loading from surface waters over the past 40 years. Elevated P levels have been show to have an effect on the size and activity of the microbial pool and a decrease in the N to P ratio of the microbial biomass. The objective of the study was to determine if P enrichment in soils affected microbial activities related to nitrification and denitrification in these flooded, peat soils. Potential nitrification rates of soil and detritus were determined using constantly stirred reactors under aerobic conditions while denitrification rates were determined from anaerobic incubations of slurry. Nitrification rates showed two distinct linear phases, a slower initial rate, signifying activity of nitrifiers present, followed by a sharp increase in the NH4+ conversion rate indicative of maximum potential rates. Initial rates of nitrification were highest in the surficial detrital layer decreasing with soil depth and did not correlate to soil total P. The potential rates of nitrification were 13 times greater than the initial rates. Potential denitrification rates were highest in the detritus and 0- to 10-cm soil interval with significantly lower values in the 10- to 30-cm soil interval, significantly correlated to total P of the soil. A significant (P < 0.01) relationship was seen between potential denitrification rates and soil total P suggesting an increased rate of N removal from P-enriched regions of the northern Everglades.     

电子产品环境试验概述

电子产品环境试验是将产品置于典型的自然或人工环境条件下,用以鉴定产品在运输、贮存和使用中的环境适应性。环境试验在产品研制和生产各个阶段得到了广泛的应用,了解环境试验对设计人员和试验人员有着重要的作用。文中着重介绍了环境试验的分类与试验项目、环境试验的顺序的选择、环境试验的实施及国内环境试验存在的问题与建议。     

Modeling military trampling effects on glacial soils in the humid continental climate of southern New York

The purpose of this research is to create a baseline model of soil compaction response to trampling and a methodology to model the effects of trampling on soil. Although trampling studies have been conducted in the past, the analysis of military training in part provides a different perspective and approach. The data showed bulk densities remained relatively constant for a time and then began to increase at an increasing rate for several hundred passes and finally leveled and remained at or below 1.30 g/cm3 through the remainder of the experiment. Mathematical models were created based on empirical data from a trampling experiment using a more standard logistical growth curve as well as curves based on Weibull and gamma cumulative distribution functions (CDFs). The experiment and the resulting models give quantifiable continuous inference on the effects of trampling, as opposed to the existing qualitative assessments. These baseline models will be the foundation for future studies of land management when trampling occurs.     

扩展阴极型膜电解法处理含铜废水的数学模型

采用均匀设计法,研究离子膜扩展阴极电解法对低浓度含铜废水的处理效果,得到了反应条件与回收效果之间的线性模型,并比较了线性预测模型和BP网络的预测效果。结果表明,线性模型有较强的定性分析作用但预测能力不强,而BP网络具有很强的预测能力。两法结合,具有很强的理论和实践指导意义。模型预测结果和实验结果均表明,扩展阴极型膜电解法可带来很好的社会效益和经济效益。     

New tools in local energy planning: experimenting with scenarios,public participation and environmental assessment

This article presents a model for local energy planning and its application in a full-scale experiment in a Swedish municipality. The model is based on legal requirement, research findings and standards of good practice and includes a combination of analytical and procedural tools intended to support rational decision-making: external scenarios, a citizens’ panel, life cycle analysis and qualitative environmental assessment (EA). The application of the model indicates that the decision-support tools selected can give several new and valuable inputs to local energy planning, such as local knowledge and values through citizen dialogue and comprehensive EAs. However, the experiment also shows that there are several challenges involved in applying the tools, for example, it is difficult to get citizens and the industry to participate and that it is complicated to combine several different tools for decision-making into a single planning process. Moreover, the experiences from the application suggest that the model for local energy planning show great potential but needs to be improved before it can be used as a standard of good practice.