污水生物脱氮新技术研究现状与发展方向

综述了国内外生物脱氮领域最近开发出的短程硝化反硝化、同步硝化反硝化和厌氧氨氧化等新技术,指出了这些新技术的特点以及存在的不足.重点论述了目前实现短程硝化反硝化生物脱氮技术的方法,如控制温度、溶解氧浓度和pH值,并提出应用序批式反应器(SBR)实现短程硝化-反硝化生物脱氮工艺今后研究的发展方向和开发应用的前景.建议加强同步硝化反硝化和厌氧氨氧化生物脱氮工艺反应机理方面的研究.     

游离氨对污水生物脱氮的影响综述

总结了游离氨(FA)抑制生物脱氮过程(BNR)的最新研究。主要介绍了FA对氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)的抑制阈值、抑制机理和抑制模型以及FA对反硝化菌的抑制作用。同时探讨了如何利用FA选择性抑制来实现短程硝化反应,并且展望了FA对BNR影响的研究方向。     

游离氨对污水生物脱氮的影响综述

总结了游离氨(FA)抑制生物脱氮过程(BNR)的最新研究。主要介绍了FA对氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)的抑制阈值、抑制机理和抑制模型以及FA对反硝化菌的抑制作用。同时探讨了如何利用FA选择性抑制来实现短程硝化反应,并且展望了FA对BNR影响的研究方向。     

新型污水脱氮工艺研究进展

阐述了污水脱氮的反应工艺,综述对比了厌氧氨氧化(ANAMMOX)工艺、短程硝化反硝化(SHARON)工艺、限氧自养硝化-厌氧反硝化(OLAND)工艺、短程硝化-厌氧氨氧化(SHARN-ANAMMOX)工艺和单相CANON(SHARON-ANAMMOX)这五种生物脱氮工艺工作原理,脱氮效果和工艺的优缺点。     

基于厌氧氨氧化技术处理垃圾渗滤液的研究综述

由于中老龄垃圾渗滤液的氨氮含量高、碳氮比低且难降解等特点,高效且低耗的处理渗滤液是十分困难的。近年来,厌氧氨氧化生物脱氮技术的出现为处理此类废水开辟了一条新道路。本文着重综述了几种基于厌氧氨氧化技术处理垃圾渗滤液的新型方法,主要包括短程硝化-厌氧氨氧化(SHARN-ANAMMOX)工艺、一体化部分亚硝化和厌氧氨氧化(CANON)工艺、限氧自养硝化-厌氧反硝化(OLAND)工艺、部分亚硝化-厌氧氨氧化(PN-ANAMMOX)耦合工艺、短程硝化反硝化-厌氧氨氧化联合工艺。     

一体化生物脱氮技术研究进展

废水氨氮污染已成为环境领域的热点问题。针对废水氨氮污染,国际上研发了一批高效废水生物脱氮技术。本文将3种典型工艺--同步硝化-反硝化(SND)工艺、短程硝化-反硝化(SHARON)工艺、基于亚硝氮的全自养脱氮(CANON)工艺归类并命名为一体化生物脱氮技术,分别对其原理、特征、效能和应用进行了分析评述,以期为该技术的深度研发提供参考。总结了与传统脱氮技术相比,一体化生物脱氮技术具有工艺流程短、系统操作易、占地面积小、运行费用低等优势。其中以氨氧化菌和厌氧氨氧化菌等自养型微生物作为脱氮功能菌的一体化自养型生物脱氮工艺的研发将成为一体化生物脱氮技术的研究前沿,一体化自养型生物脱氮工艺的研发将集中于优质菌种的培育和反应器的优化。     

生活污水实时控制策略实现短程脱氮研究

短程脱氮工艺可减少25%的曝气量和40%的有机碳源。然而,对于低C/N比的城市生活污水常温下较难实现短程脱氮以及维持稳定。本研究利用实时控制策略常温下处理生活污水经过30 d的驯化实现了短程脱氮。SBR曝气结束后亚硝氮积累率超过95%,成功的将大部分亚硝化细菌(NOB)从系统中淘洗掉,氨氧化菌(AOB)成为了优势菌属。SEM分析结果表明,活性污泥系统中大部分以杆状亚硝化单胞菌(约为1μm)为主。     

污水生物脱氮除磷新技术

概述了传统生物脱氮除磷原理,分析了传统生物脱氮除磷工艺的不足,并介绍了同时硝化反硝化、短程硝化反硝化、厌氧氨氧化、反硝化除磷等几种经济、高效的生物脱氮除磷新技术的原理和研究现状.     

短程反硝化的微生物富集策略及应用研究进展

污废水的高效节能脱氮技术一直以来都是研究和应用的焦点。短程反硝化-厌氧氨氧化耦合工艺因具有能耗低、产泥少、温室气体减排和脱氮效果好等优点,已成为废水脱氮领域研究和应用的热点。其中,短程反硝化被认为是厌氧氨氧化菌获取底物(NO₂^--N)的重要途径之一,对其进行研究具有重要的科学和工程意义。基于此,综述了短程反硝化的工艺原理,总结了硫自养短程反硝化和异养短程反硝化微生物的富集方法,并探讨了短程反硝化-厌氧氨氧化耦合工艺处理城市污水、高浓度氨氮废水和硝酸盐废水的工程应用。最后对短程反硝化及其耦合厌氧氨氧化工艺的研究和应用方向进行了展望,以期为短程反硝化-厌氧氨氧化耦合工艺处理实际污水提供参考。     

高氨氮垃圾渗滤液SBR法短程深度生物脱氮

以实际垃圾填埋场渗滤液为研究对象,应用SBR系统对该类废水短程生物脱氮的可行性进行研究,重点考察了短程生物脱氮实现、稳定及系统的脱氮性能.结果表明,经过95天的运行,SBR系统成功实现并维持了稳定短程生物脱氮,平均亚硝积累率在92.5%以上.获得了稳定的脱氮性能,NH4+-N,TN平均去除率分别在97.2%和91.7%以上.DO、ORP和pH曲线的特征点能够准确判断硝化和反硝化终点,可作为SBR处理垃圾渗滤液短程生物脱氮过程的控制参数.相对于氨氧化菌,亚硝酸盐氧化菌对FA、FNA更敏感,因此两者协同作用抑制亚硝酸盐氧化菌活性,再辅以过程控制,能够准确判断硝化终点,实现NOB从系统硝化菌群中逐渐被淘洗,AOB成为优势菌种的目标,这是系统长期维持稳定短程生物脱氮的决定因素,FISH检测结果证明了这一点.     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。