活性污泥模型ASM1与ASM3比较和研究进展

比较了活性污泥模型1号(ASM1)和活性污泥模型3号(ASM3)的共同性和差异性,总结了模型的最新进展情况,预测了可能的发展趋势,从而促进污水处理厂的设计、改造及运行管理,以及更好地选择和应用模型.     

活性污泥法数学模型的研究与应用

在总结IAWQ（国际水质协会）活性污泥模型的基础上,建立了适合于普通推流式活性污泥法的碳氧化数学模型;应用MATLAB数学软件,在WINDOWS操作平台上开发出模拟系统。该模拟系统考虑了8个组分和3个生化过程。应用该模拟系统模拟了天津纪庄子污水处理厂的实际运行资料,模拟结果与实测数据吻合较好。     

活性污泥法数学模型的发展及应用

综述了IWA(国际水质协会)推出的活性污泥法数学模型(ASM系列)的理论基础、使用限制、相互之间的关系和基于ASM系列而开发的程序和软件，并指出了ASM系列在使用中的两个难题。     

深圳市宝安区观澜污水处理厂SBR法工艺调试及运行

概述了深圳市宝安区观澜污水处理厂工程概况和工艺概况,重点介绍了工程调试及试运行情况,最后结合实际对SBR工艺特点谈了自己的看法。     

活性污泥系统仿真软件的研究进展

近年来,基于活性污泥数学模型的系统仿真软件在国内外许多污水处理厂的模拟仿真、升级评估、运行优化和故障诊断等方面得到了广泛应用。介绍了活性污泥系统中常用的通用仿真软件和污水处理专业仿真软件,对仿真软件在城市污水处理厂中的应用经验进行总结,并提出了仿真软件今后的发展方向。     

IWA活性污泥法模型的应用研究

对于污水处理厂（WWTP）的方案选择、工艺设计、最佳状态运行控制，数学模型是一种很有用的工具。综述了IWA（国际水质协会）推出的活性污泥法数学模型（ASMs）的理论基础、使用限制之间的关系和基于ASMs的程序和软件，并指出了ASMs使用中的两个主要问题：一是进水水质的分析和测定；二是模型参数的实际校正。     

模糊控制技术在SBR工艺中的应用与发展

针对SBR污水处理工艺,提出用模糊控制方法实现SBR污水处理的自动控制方法,并详细介绍了模糊控制系统的结构和原理,分析了SBR工艺模糊控制技术的发展方向,以推广该技术的广泛应用。     

投加天然沸石粉末强化SBR活性污泥工艺的运行效能

采用SBR反应器和SBR反应器+天然沸石粉末两种不同的运行方式处理城市污水,研究表明沸石粉末的投加能够提高活性污泥的活性,与对比SBR反应器中的活性污泥相比,活性污泥的比好氧速率(SOURs)有了较大幅度提高,而且改善了活性污泥的沉降性能,强化了活性污泥的硝化性能.此外,通过冲击负荷试验,发现沸石粉末的投加能够提高SBR系统抵抗有机物、氨氮冲击负荷的能力,能够在较短的时间内完成对COD、氨氮、总氮和总磷的去除.     

SBR工艺的发展类型及其应用特性

对各种类型SBR工艺的发展和应用进行了综述，分析了其发展演变情况，归纳了经典及新型SBR工艺的特点。     

Performance evaluation of an oily industrial wastewater treatment system using the application of activated sludge model No. 3

The purpose of the present study was to adapt the activated sludge model No. 3 (ASM3) to the characteristics of oily industrial wastewater, determining the utmost significant and appropriate kinetic as well as stoichiometric parameters. An oily industrial wastewater treatment system was simulated to assess ASM3 validation and perform sensitivity analysis using the STOAT program. The obtained results revealed that the ASM3 model, which was calibrated after adding the Arrhenius equation into consideration, provided strong correlations with the analytical results of chemical oxygen demand (COD), total suspended solids (TSS), mixed liquor volatile suspended solids (MLVSS) and total suspended solids in the return activated sludge flow (TSS in RAS) concentrations. The values of modelled effluent COD and TSS are very close to those corresponding real values of the treated wastewater by a difference of between 0.5% and 1.5%. Thus, this model becomes successful in representing oily industrial wastewater treatment as a new trend added to the traditional modelling of sewage treatment.     

Parameter and state estimation of the activated sludge process: On-line algorithm

The Linearized Maximum Likelihood (LML) method for the simultaneous estimation of activated sludge states and parameters from noisy process measurements (Kabouris and Georgakakos, 1996a, Wat. Res., 30, 2853–2865) is simplified, in terms of its memory storage and computational requirements, for efficient on-line implementation. This is achieved by processing only the four most recent sets of 5-min on-line measurements at each estimation instance, along with the utilization of simplified estimation equations for tracking state and parameter variations, following the initial convergence period. The algorithm is tested in a computational case study involving a nitrifying activated sludge process, modelled by the IAWQ Activated Sludge Model 1 and incorporating a dynamic settling and clarification model. The on-line LML algorithm is capable of tracking the process states and parameters under dynamic conditions of process inputs and model parameters.     

Evaluating sludge minimization caused by predation and viral infection based on the extended activated sludge model No. 2d

The Activated Sludge Model No. 2d (ASM2d) was extended to incorporate the processes of both predation and viral infection. The extended model was used to evaluate the contributions of predation and viral infection to sludge minimization in a sequencing batch reactor (SBR) system enriching polyphosphate-accumulating organisms (PAOs). Three individual decay processes formulated according to the general model rules were used in the extended model. The model was firstly calibrated and validated by different experimental results. It was used to evaluate the potential extent of predation and viral infection on sludge minimization. Simulations indicate that predation contributes roughly two times more to sludge minimization than viral infection in the SBR system enriching PAOs. The sensitivity analyses of the selected key parameters reveal that there are thresholds on both predation and viral infection rates, if they are too large a minimal sludge retention time is obtained and the effluent quality is deteriorating. Due to the thresholds, the contributions of predation and viral infection to sludge minimization are limited to a maximal extent of about 21% and 9%, respectively. However, it should be noted that the parameters concerning predation and viral infection were not calibrated separately by independent experiment in our study due to the lack of an effective method, especially for the parameters regarding viral infection. Therefore, it is essential to better evaluate these parameters in the future.     

Cost-efficient operation of a denitrifying activated sludge process

In this paper, the choice of optimal set-points and cost minimizing control strategies for the denitrification process in an activated sludge process are treated. In order to compare different criterion functions, simulations utilizing the COST/IWA simulation benchmark are considered. By means of operational maps the results are visualized. It is found that it is easy to distinguish set-point areas where the process can be said to be efficiently controlled in an economic sense. The characteristics of these set-point areas depend on the chosen effluent nitrate set-point as well as the distribution of the different operating costs. It is also discussed how efficient control strategies may be accomplished.     

Kinetic model of excess activated sludge thermohydrolysis

Thermal hydrolysis of excess activated sludge suspensions was carried at temperatures ranging from 423 K to 523 K and under pressure 0.2-4.0 MPa. Changes of total organic carbon (TOC) concentration in a solid and liquid phase were measured during these studies. At the temperature 423 K, after 2 h of the process, TOC concentration in the reaction mixture decreased by 15-18% of the initial value. At 473 K total organic carbon removal from activated sludge suspension increased to 30%.It was also found that the solubilisation of particulate organic matter strongly depended on the process temperature. At 423 K the transfer of TOC from solid particles into liquid phase after 1 h of the process reached 25% of the initial value, however, at the temperature of 523 K the conversion degree of ‘solid’ TOC attained 50% just after 15 min of the process.In the article a lumped kinetic model of the process of activated sludge thermohydrolysis has been proposed. It was assumed that during heating of the activated sludge suspension to a temperature in the range of 423-523 K two parallel reactions occurred. One, connected with thermal destruction of activated sludge particles, caused solubilisation of organic carbon and an increase of dissolved organic carbon concentration in the liquid phase (hydrolysate). The parallel reaction led to a new kind of unsolvable solid phase, which was further decomposed into gaseous products (CO₂). The collected experimental data were used to identify unknown parameters of the model, i.e. activation energies and pre-exponential factors of elementary reactions. The mathematical model of activated sludge thermohydrolysis appropriately describes the kinetics of reactions occurring in the studied system.     

Determination of activated sludge biological activity using model corrected CO2 off-gas data

Carbon dioxide (CO(2)) online off-gas monitoring is useful to detect changes in biological activity for activated sludge systems especially under limited oxygen conditions like under simultaneous nitrification-denitrification (SND) where respirometric measurements are not applicable. So far, the influence of the bicarbonate system on the liquid-gas transfer of CO(2) prevented the wider use of off-gas CO(2) for monitoring purposes in wastewater treatment. The objective of the paper is to demonstrate a practical method to correct measured off-gas CO(2) as an indicator of biological activity by taking into account pH shifts (resulting in CO(2) release or retention) and changes in influent alkalinity. The simple model is based on the physicochemical system of the bicarbonate/CO(2) equilibrium and the liquid-gas mass transfer for aerated systems. Standard on-line measurements (pH, temperature, flow rates) and periodical alkalinity titration serve as input data to estimate the influence of the carbonate system on the CO(2) off-gas concentrations measured on-line. For a particular plant the CO(2) mass transfer coefficients are derived from measurements compared to the theoretical calculation from oxygen mass transfer. The model estimates the biological carbon dioxide production rate (CPR; heterotrophic activity) by the correction of the measured carbon dioxide transfer rate (CTR; C-flux by the off-gas) with the calculated inorganic carbon dioxide transfer rate (r(F)) considering bicarbonate consumption (autotrophic activity).     

A nitrification model for the contact stabilization activated sludge process

A kinetic model of the contact stabilization process has been developed and experimentally verified with the aid of bench-scale activated sludge units treating domestic sewage. The model provides information on the relationship between the design parameters (process loading, temperature, residence time distribution) and process performance (sludge, production, oxygen uptake, COD-removal, organic nitrogen conversion, nitrification and effluent suspended solids). An oxygen equivalence mass balance equation, which is applicable to all activated sludge process modifications is proposed and may be used in the design and operation of these processes.     

The activated sludge process—IV: Application of the general kinetic model to anoxic-aerobic digestion of waste activated sludge

This paper discusses the application of the general activated sludge model as set out by Dold et al. (Prog. Wat. Technol.12, 47–77, 1980) and extended by Van Haandel et al. (Wat. Res.15, 1135–1152, 1981), to anoxic-aerobic digestion of waste activated sludge. The laboratory scale experimental investigation comprised a 6 day sludge age activated sludge process, the waste sludge from which was fed to a number of digesters operated as follows: single reactor flow-through digesters at 4 or 10 days sludge age (retention times) under aerobic or anoxic-aerobic conditions (with 1.5 and 4 h cycle times) and 3-in-series flow-through aerobic digesters each with 4 days sludge age; all digesters were fed draw-and-fill wise once per day. The general kinetic model simulated accurately all the experimental data without the need to change the values of the kinetic constants. Both theoretical simulations and experimental data indicate that (i) the rate of volatile solids destruction is not affected by the incorporation of anoxic cycles and (ii) the specific denitrification rate constant in a digester is about two-thirds of that in the secondary anoxic reactor of the single sludge activated sludge system; this allows definition of a fourth denitrification rate constant K₄ for the anoxic-aerobic digester with K₄T = 0.046(1.029)^(T-20) mg(NO₃-N) (mgAVSS d)⁻¹, a constant independent of sludge age. An important consequence of (i) and (ii) above is that the denitrification can be integrated readily into the steady state digester model of Marais and Ekama (Wat. SA2, 163–200, 1976) and used for design purposes.     

The characteristics of the bacterial community structure and population dynamics for phosphorus removal in SBR activated sludge processes

The characteristics of the bacterial community structure and population dynamics for phosphorus removal in activated sludge were investigated using laboratory-scale sequencing batch reactor (SBR) activated sludge processes fed with four different carbon sources. Phosphorus removal activity, quinone profile of the activated sludge and isolated bacterial strains were monitored. An enhanced phosphorus removal activity was accompanied by the increase in ubiquinone-9 (Q-9). The relationships between phosphorus removal activity and Q-9 contents of the isolated bacterial strains were dependent neither on the organic substrates nor on the species of isolated bacterial strains. The enhanced phosphorus removal capability of activated sludge seemed to be due to the increase in the populations of bacteria with activity of phosphorus removal, i.e. species succession of bacteria in activated sludge ecosystems, rather than the increase in the phosphorus removal capability of phosphorus removal bacteria. Not only Acinetobacter but also Pseudomonas identified from isolated strains were regarded as representative polyphosphates-accumulating organisms and predominant species to the whole of bacterial population in activated sludge for phosphorus removal.