活性污泥和生物膜复合模型的建立与模拟

针对近年来出现的城市污水处理厂活性污泥和生物膜复合工艺,首先建立了能同时描述碳氧化、脱氮和除磷的修正ASM1(Activated Sludge Model No.1),以及与ASM1中微生物生长过程速率方程结构形式相同、物理意义明确的生物膜模型。然后将该生物膜模型与修正的ASM1相结合,形成了活性污泥和生物膜复合模型,利用VB6.0编写了相应的模拟软件。以西安市第五污水处理厂复合工艺为对象,对其碳、氮和磷的去除进行模拟,结果表明该模型可以较好地反映出水各污染指标的变化规律。通过对进水流量、填料区的位置及填料区填料的投加率进行模拟,为填料区的优化和系统运行提出了建议。     

生物脱氮除磷活性污泥系统复合模拟方法

为避免繁琐的参数校核工作,提出了活性污泥2 d号模型(ASM2d)和人工神经网络(ANNs)相结合的复合模拟方法。考察了复合方法在某污水处理厂生物脱氮除磷工艺中的应用情况。研究表明,ANNs能够准确地模拟出水实测值与未经校核的ASM2d机理模型的估计值之间的差值。利用Levenberg-Marquardt算法,对出水氨氮、总氮和总磷分别建立网络结构为5-12-1、5-8-1和5-8-1的ANNs子模型,将这些子模型输出同ASM2d机理模型输出相加便得到复合模型输出。复合模型估计值对前10.4 d(ANNs子模型训练数据时段)出水氨氮、总氮和总磷浓度的拟合平均绝对百分比误差分别为0.267、0.055和0.048;其对后2.6 d(ANNs子模型测试数据时段)出水氨氮、总氮和总磷浓度的预测平均绝对百分比误差分别为0.332、0.083和0.069。均方根误差、平均绝对误差等评价指标也表明复合模型能够给出合理的模拟结果。     

基于成本-效能分析的氧化沟工艺运行条件优化

在利用ASM2d模型对城市污水处理厂氧化沟工艺进行动态模拟的基础上,将曝气能耗、污泥产量与出水水质超标率整合为一个综合效能指数,对该工艺进行了成本-效能分析。最优运行策略为:3～10月温度高于15℃时运行8台曝气转刷,其余时间段运行10台转刷,同时剩余污泥排放量控制在250 m3/d。这一策略能够使出水NH4-N和TN的超标率分别低于5%和2%,保证出水TP的持续达标,与常规运行策略相比,在明显降低氮磷超标率的同时,节省曝气能耗约12%。     

基于TUD模型模拟优化MSBR工艺反硝化脱氮除磷

基于TUD模型（delftuniversityoftechnologymodel）对实验室MSBR（modifiedsequencingbatchreactor）工艺进行了模拟与优化，强化反硝化除磷，以提高系统脱氮除磷效率。结果表明，工艺运行参数为厌氧池90min、好氧池90min、SBR池缺氧段150min、污泥回流比1．0和污泥龄15d时，MSBR工艺COD、TN以及磷酸盐去除效率达95％，92％和83％；SBR池缺氧段吸磷量达到23．20mg／L，占系统总吸磷量43％左右；好氧池和SBR池缺氧段平均吸磷速率分别为0．35—0．42和0．12～0．17mgPO4^3-P／（L·min）。TUD模型能够较好模拟各水质组分在MSBR工艺空间和时间上的浓度分布，COD和NH4＋-N的模拟误差低于15％，PO4^3-P模拟值高于实测值5％左右。     

生物脱氮与甲烷化耦合的EGSB-BAF工艺模拟

以活性污泥3号模型(ASM3)为平台,通过引入厌氧氨氧化和甲烷化过程、以2步硝化-反硝化取代1步硝化-反硝化过程以及区分硝酸盐和亚硝酸盐条件下的内源呼吸过程,建立了同时具有甲烷化、厌氧氨氧化和2步硝化反硝化功能的EGSB-BAF工艺模型.该模型包括5种微生物、28个生物过程,同时考虑了温度、pH值和抑制性物质对生物过程的影响.以实验室EGSB-BAF集成工艺的实验数据,结合灵敏度分析对部分模型参数进行了校核.采用校核后的模型对集成工艺EGSB段和BAF段出水的COD、NH4+-N、NO2--N和NO3--N浓度进行模拟,结果表明,EGSB段和BAF段的出水中COD、NH4+-N、NO2--N和NO3--N浓度的模拟值与实测值的误差在可接受范围内.表明模型能够描述工艺的主要生物反应过程,可以作为指导工艺研究、设计和运行优化的手段.     

生物膜与A/O工艺耦合快速降解氨氮

应用由城市污水处理厂序批式间歇反应器(SBR)中筛选得到的4株特殊氨氧化菌,分别在SBR和有回流的生物膜与A/O工艺耦合体系培养中,考察其降解低碳高氨氮废水的功能.结果表明,自养硝化与异养氨氧化菌的混合菌群较单一自养硝化菌株降解氨氮速率快;在生物膜与A/O工艺耦合系统中,自养硝化与异养氨氧化菌协同代谢加速氨氮氧化脱除,氨氮脱除速率远比SBR系统快.对生物膜与A/O工艺耦合系统中氨氮脱除动力学进行了研究,模拟了NH4 、NO2-质量浓度与氨氮脱除比速率之间的关系,模型得到了较好的验证.     

污泥转移SBR工艺处理低浓度生活污水

污泥转移SBR工艺是一种通过内部污泥回流实现污泥在不同SBR隔室间转移,从而增加污泥利用效率,提高系统除污效能的新工艺。以设计规模为240 m3/d、处理低浓度生活污水的工艺系统为对象,研究了新工艺在不同泥转移量(污泥回流比)下的除污性能,并与系统以传统SBR方式运行的情况进行了对比。结果表明,新工艺可以有效提高SBR反应器的容积利用率;采用30%的污泥回流比进行污泥转移,新工艺的处理能力比传统SBR工艺提高近1/2,除磷效率从46%提升至85%。出水各项水质指标均能达到国家排放标准的要求。     

基于ASM2D模型对奥贝尔氧化沟工艺的模拟研究

基于活性污泥数学模型ASM2D,对西安市某污水厂奥贝尔氧化沟工艺进行模拟研究。根据实际工艺构建模型,输入实测模型组分与模型参数。参照实测出水水质对所建模型进行校准与验证。之后,通过调节污泥回流比与BOD5污泥负荷对氧化沟工艺进行优化,使其取得更好的污染物去除率。     

活性污泥模型研究及其工艺软件的发展

本文综述了活性污泥模型从基于Monod方程的稳态模型到以ASM1、ASM2、ASM3为代表的动态模型的发展过程 ,介绍了各代表性模型的特点并对当前典型的活性污泥工艺软件作了评述 ,提出其研究方向及发展趋势     

ASM3模型研究与运用

根据国际水质协会推出的ASM3利用MATLAB建立模型,通过实验确定进水水质及模型初值,通过模拟结果与污水处理厂实测结果对比,确定重要模型参数范围,并用结果对其他污水处理厂进行模拟,模拟结果与实测结果吻合较好.     

Relative efficacy of intrinsic and extant parameters for modeling biodegradation of synthetic organic compounds in activated sludge: dynamic systems.

The utility of intrinsic and extant kinetic parameters for simulating the dynamic behavior of a biotreatment system coupled with a distributed, unstructured, balanced microbial growth model were evaluated against the observed response of test reactors to transient loads of synthetic organic compounds (SOCs). Biomass from a completely mixed activated-sludge (CMAS) system was tested in fed-batch reactors, while a sequencing batch reactor (SBR) was tested by measuring SOC concentrations during the fill and react period. Both the CMAS system and the SBR were acclimated to a feed containing biogenic substrates and several SOCs, and the transient loading tests were conducted with biogenic substrates along with one or more SOCs. Extant parameters more closely reflect the steady-state degradative capacity of activated-sludge biomass than intrinsic parameters and, hence, were expected to be better predictors of system performance. However, neither extant nor intrinsic parameters accurately predicted system response and neither parameter set was consistently superior to the other. Factors that may have contributed to the inability of the model to predict system response were identified and discussed. These factors included the role of abiotic processes in SOC removal, disparity in the bases used to evaluate parameter estimates (substrate mineralization) and reactor performance (substrate disappearance), inhibitory substrate interactions under the severe loading conditions of the SBR, changes in the physiological state of the biomass during the transient loading tests, and the presumed correlation between the competent biomass concentration and the influent SOC concentration.     

Effect of dissolved oxygen concentration on nitrite accumulation in nitrifying sequencing batch reactor.

A mathematical model based on Activated Sludge Model No. 3 (International Water Association, London) and laboratory-scale experiments were used to investigate ammonia conversion by nitrification in a sequencing batch reactor (SBR). The purpose of the study was to assess the effect of dissolved oxygen concentration on nitrite accumulation in the SBR. As the dissolved oxygen concentration in the SBR depends on the balance between oxygen consumption and oxygen transfer rates, ammonium conversion was measured for different air flowrate values to obtain different dissolved oxygen concentration profiles during the cycle. The ammonia concentration in the feeding medium was 500 mg ammonium as nitrogen (N-NH4(+))/L, and the maximum nitrite concentration achieved during a cycle was approximately 50 mg nitrite as nitrogen (N-NO2)/L. The air flow supplied to the reactor was identified as a suitable parameter to control nitrite accumulation in the SBR. This identification was carried out based on experimental results and simulation with a calibrated model. At a low value of the volumetric mass-transfer coefficient (kLa), the maximum nitrite concentration achieved during a cycle depends strongly on k(L)a, whereas, at a high value of k(L)a, the maximum nitrite concentration was practically independent of kL(a).     

超声波处理回流剩余污泥对SBR工艺的污泥减量效能

在SBR中试系统中,采用较高声能密度较短时间的超声波处理剩余污泥后回流至系统连续运行20 d的方式进行污泥减量,通过分析测定系统MLSS、累计排泥量以及系统出水水质指标,考察了系统污泥减量效果及污泥回流对系统污水处理效果的影响。结果表明,对SBR系统2/3的剩余污泥用声能密度为1 W/mL的超声波预处理6 min后回流至SBR系统。SBR系统最终需处置的污泥量减少了45.64%,获得了理想的污泥减量效果。污泥回流后SBR系统对SS、COD、TN以及NH4+-N的去除效果均无明显变化,仅出水TP含量略高于对照的SBR,出水水质仍能达到《城镇污水处理厂污染物排放标准》(GB18918-2002)一级B标准。     

基于神经网络的污水处理指标软测量研究

污水处理厂目前广泛使用序批式活性污泥法.该方法处理污水过程是一种典型的复杂动态生物反应工程系统,具有非线性、时变性、随机性和不确定性等特点,难以建立准确的数学模型.同时,该方法的污水处理指标在线测量仪表价格昂贵.为从工程应用角度将人工神经网络软测量方法应用于污水水质指标的实时检测,分别建立BP神经网络和RBF神经网络污水指标软测量模型.仿真结果表明,建立的神经网络软测量模型能很好地实现污水处理指标的COD、BOD、N等参数的实时测量和估计,为污水指标的实时检测提供了新的思路.     

SBR工艺数学模型研究进展及其应用

SBR法具有操作简单、运行方式灵活、占地面积小等优点，用于处理间歇排放的工业废水及中小城镇污水取得了巨大成功，并在全世界范围内迅速得到发展和推广应用。随着自控技术的飞速发展和对SBR工艺机理的深入认识，围绕SBR工艺数学模型的研究引起各国学者的重视。回顾了目前SBR法数学模型的研究进展和应用现状，并总结和比较了各种数学模型的优势和不足，特别是对机理模型（白箱模型）和统计模型（黑箱模型）进行了分类、归纳和分析。所有这些数学模型建模与仿真的目的都是为了实现SBR工艺优化控制，为实际SBR污水处理厂的运行提供依据和技术支持。虽然以前的研究有力地推动了数学模型在SBR工艺中的应用，但是在实际应用中还存在很多值得深入研究的问题。最后对SBR工艺数学模型尚待解决的问题进行了总结，并指出今后SBR数学模型的发展方向。     

Evidence for the Stepwise Behavioral Response Model (SBRM): the effects of Carbamate Pesticides on medaka (Oryzias latipes) in an online monitoring system

The Stepwise Behavioral Response Model (SBRM), which is a conceptual model, postulated that an organism displays a time-dependent sequence of compensatory Stepwise Behavioral Response (SBR) during exposure to pollutants above their respective thresholds of resistance. In order to prove the model, in this study, the behavioral responses (BRs) of medaka (Oryzias latipes) in the exposure of Arprocarb (A), Carbofuran (C) and Methomyl (M) were analyzed in an online monitoring system (OMS). The Self-Organizing Map (SOM) was utilized for patterning the obtained behavioral data in 0.1 TU (Toxic Unit), 1 TU, 2 TU, 5 TU, 10 TU and 20 TU treatments with control. Some differences among different Carbamate Pesticides (CPs) were observed in different concentrations and the profiles of behavior strength (BS) on SOM were variable depending upon levels of concentration. The time of the first significant decrease of BS (SD-BS) was in inverse ratio to the CP concentrations. Movement behavior showed by medaka mainly included No effect, Stimulation, Acclimation, Adjustment (Readjustment) and Toxic effect, which proved SBRM as a time-dependence model based on the time series BS data. Meanwhile, it was found that SBRM showed evident stress-dependence. Therefore, it was concluded that medaka SBR was both stress-dependent and time-dependent, which supported and developed SBRM, and data mining by SOM could be efficiently used to illustrate the behavioral processes and to monitor toxic chemicals in the environment.     

(AO)_2SBR同步脱氮除磷的研究

以人工配水为研究对象,采用厌氧/好氧/缺氧/好氧交替运行的序批式反应器,研究了(AO)2SBR系统同步脱氮除磷的效果,并结合批式实验讨论了同步脱氮除磷的反应机理。研究结果表明,该系统以厌氧1.5 h、好氧1 h、缺氧3h、好氧0.5 h的方式运行,在DO=2.5 mg/L,SRT=15 d的条件下,具有良好的脱氮除磷效果,配水中的总氮、总磷、COD和总有机碳的去除率分别为96.26%、99.87%、90.46%和85.57%。批式实验表明,合成的内碳源越多,氨氮的硝化越充分,反硝化除磷越多。     

反硝化除磷颗粒污泥的活性恢复及对生活污水处理能力

实验利用序批式反应器(SBR)考察反硝化除磷颗粒污泥搁置1个月后重新投入运行,其活性恢复能力及对实际生活污水的处理效果。结果表明,颗粒污泥搁置后外观由淡黄色转变为灰黑色,颗粒重新投入反应器,11 d后颜色基本恢复,污泥浓度及活性迅速增加;对COD处理能力的恢复历时14 d,去除率稳定在80.32%以上;颗粒污泥对NH4+-N和PO34--P的去除在40 d时也恢复到正常水平;反硝化聚磷菌(DNPAOs)活性恢复期为50 d。颗粒污泥对低碳氮比的实际生活污水处理结果显示,当C/N<5.1时(生活污水比例>60%),无法满足系统内微生物生长要求,需要外加适量碳源进行补充。