外文翻譯--市政污水生物膜處理系統(tǒng)的模型化（英文）

1、Journal of Membrane Science 216 (2003) 55–65Modelling of a membrane bioreactor system for municipal wastewater treatmentT. Wintgens a,?, J. Rosen a, T. Melin a, C. Brepols b, K. Drensla b, N. Engelhardt ba Department of

2、Chemical Engineering, Institut für Verfahrenstechnik, Rheinisch-Westfälische Technische Hochschule Aachen, Turmstrasse 46, 52056 Aachen, Germany b Erftverband, Bergheim, GermanyReceived 3 May 2002; received in

3、revised form 14 January 2003; accepted 16 January 2003AbstractWithin the presented study a model to describe the filtration performance of submerged capillary hollow fibre modules in membrane bioreactor applications for

4、wastewater treatment was developed. The model was implemented in a software platform for simulation and calibrated using operating data of the full-scale municipal wastewater treatment plant Rödingen, which is opera

5、ted by the Erft River Association (Erftverband) and equipped with activated sludge treatment and microfiltration units for biomass retention. Mathematical expressions for filtration resistances like cake layer forming an

6、d fouling are presented and combined with an activated sludge model (ASM) to describe the biological treatment processes. The model proved successful in simulating the long-term decrease in permeability of the membranes

7、and the final effluent quality in terms of standard parameters. © 2003 Elsevier Science B.V. All rights reserved.Keywords: Membrane bioreactor; Wastewater treatment; Fouling model; Microfiltration; Simulation1. Intr

8、oductionMembrane bioreactor systems are increasingly applied for municipal wastewater treatment, with submerged membrane units featuring rather low trans-membrane pressure (TMP) differences and feed-sided air pulsing pre

9、dominantly being employed. The combination of activated sludge units and mem- brane filtration for biomass retention generally results in high effluent qualities and compact plant configu- rations. While investment costs

10、 are already lower than for conventional wastewater treatment plants with secondary clarification, operating costs are still higher? Corresponding author. Tel.: +49-241-80-96-233; fax: +49-241-80-92-252. E-mail address:

11、wintgens@ivt.rwth-aachen.de (T. Wintgens).due to membrane replacement costs and high-energy demand for aeration [1]. Fouling phenomena on the membrane surface and within the pores reduce the long-term stability of flux p

12、erformance. Permeate back flushing and chemical cleaning are standard procedures applied to minimise these effects and stabilise overall permeability of the membrane systems, but result in losses of net filtra- tion effi

13、ciency and possible damage the membrane by cleaning agents. Neither the evolution of membrane permeability under certain operating conditions nor the effect of cleaning measures can nowadays be pre- dicted. These uncerta

14、inties cause considerable diffi- culties in plant layout, design and operation. For many industrial processes as well as for conven- tional wastewater treatment models are used to sim- ulate process performance and to de

15、rive optimisation0376-7388/03/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0376-7388(03)00046-2T. Wintgens et al. / Journal of Membrane Science 216 (2003) 55–65 572.1. Activate

16、d sludge modelThe activated sludge model 3 (ASM3) was fre- quently used as a basis for the description of pro- cesses in the biological stage. Like the first version of the activated sludge model (ASM1), the ASM3 has bee

17、n designed as a tool for description and simulation of aerobic and anoxic stages in municipal wastewater treatment [5]. Unlike in ASM1, the endogenous respiration con- cept is used, introducing storage substances as majo

18、r components. They were used in ASM2 for the first time and are specifically important for cell metabolism in conditions of low organic loads, which are typically encountered in the operation of membrane bioreactors for

19、municipal wastewater treatment in order to min- imise excess sludge production. Extra-cellular poly- meric substances (EPS), produced by micro-organisms in biological wastewater treatment systems, exert a critical influe

20、nce on the flux-rate achieved in mem- brane filtration of activated sludge suspensions and are not yet included in the description of biotransfor- mation processes. Their generation is supposed to be strongly dependent o

21、n the metabolic stage, which cor- relates with the organic loading rate of the biological treatment system [6]. The ASM3 in its basic version considers 12 micro- bial transformation processes with 13 dissolved andFig. 1.

22、 Metabolic pathways according to activated sludge model 3 [1].particular components involved in the decomposition of carbon and nitrogen compounds in wastewater. The biochemical processes undergone by the ASM3 com- ponen

23、ts are visualized in Fig. 1. While autotrophic or- ganisms use inorganic substances as the main energy source, heterotrophic organisms utilise reduced carbon sources for growth and endogenous respiration. The reactions d

24、escribed by ASM3 represent a system of coupled ordinary differential equations, which can be numerically solved for a given set of initial concentrations in the bioreactor. Hence, a dynamic calculation of the time-depend

25、ent concen- tration schemes for the individual components can be accomplished.2.2. Modelling of the filtration process in membrane bioreactorsIn membrane bioreactor configurations for mu- nicipal wastewater treatment mic

26、ro- or ultrafiltration membranes are used to retain the biomass in the sys- tem, leading to a considerably high total suspended solid concentration in the bioreactors. The filtration performance, namely, the permeability

27、 and its evo- lution of long periods of time, is the main focus of interest due to its crucial importance for system reliability and economic feasibility [1]. The under- standing and quantitative description of performan