Incorporation of the concept of microbial product formation into ASM3 and the modeling of a membrane bioreactor for wastewater treatment

Abstract

-This paper proposes a modification of ASM3 in a way that takes into account the process of production and consumption of microbial products (MPs) in a submerged membrane bioreactor fed with the effluent of a particular precoagulation sedimentation unit. A comparative representation of the modeling results obtained with ASM3 and ASM1 is performed and it highlights the importance of considering the process of storage of organic substrate, including MPs, as a prior step to bacterial growth. In addition to the suspended solids and microorganisms, various soluble organic substances, which might be either undecomposed organic substances contained in the raw water or MPs, are assumed to be selectively retained within the bioreactor. The results show that the carbonaceous materials are more accurately estimated by ASM3, while ASM1 performs slightly better than ASM3 in the estimation of nitrate. The estimated MP concentration in the mixed liquor and permeate agrees with the experimental evidence, and as expected, MPs play a role in supplying organic substrate to heterotrophs in both ASM1 and ASM3.

Soluble Microbial Products from Water Biological Treatment Process: A Review

“…Their model is used to predict SMP and EPS production in an activated sludge system under various operating conditions. Oliveira-Esquerre et al (2006) incorporated the concept of microbial product formation to ASMs and compared modeling results with ASM3 and ASM1 in a submerged hollow-fiber MBR. Their results show that carbonaceous materials are more accurately estimated by ASM3, whereas ASM1 performs slightly better than ASM3 in estimating nitrates.…”

A review towards finding a simplified approach for modelling the kinetics of the soluble microbial products (SMP) in an integrated mathematical model of membrane bioreactor (MBR)

“…However the model description was limited for the modelling of the bioprocesses only without any correlation of the SMP with the physical membrane fouling phenomena. Oliveira-Esquerre et al (2006) presented the ASM3-MP model based on ASM3 (Gujer et al, 1999) but introduced in the model a new state variable termed as MP (microbial products). The UAP and BAP were lumped into a general term MP for which only the decay products of the biomass was considered.…”

“…UAPs are produced from the substrate degrada-tion only but BAPs are assumed to be produced by the decay of the active biomass (Namkung and Rittmann, 1986;Furumai and Rittmann, 1992) or by the hydrolysis of bound extracellular poly-meric substances (EPS) (Laspidou and Rittmann, 2002a,b) or by the combination of both (Aquino and Stuckey, 2008). Due to the high membrane fouling potential of SMPs, mathematical models have been developed introducing these kinetics into the bioprocess of MBR either separately (de Silva et al, 1998) or with the extension of basic Activated sludge models (ASMs) (Lu et al, 2001;Oliveira-Esquerre et al, 2006;Jiang et al, 2008). As the physical mecha-nism of the membrane plays a vital role in describing the mem-brane fouling of MBR, ASMs-SMP models have also been integrated with the resistance-in-series models in various forms (inter alia Lee et al, 2002;Di Bella et al, 2008;Mannina et al, 2011;Mannina and Di Bella, 2012).…”

Development of mechanistically based model for simulating soluble microbial products generation in an aerated/non-aerated SBR

“…Therefore, due to increasing understanding of the reactions among the microorganisms, more and more researchers have developed or modified activated sludge models No. 1-3 (ASMs) [5] trying to explore a true picture of activated sludge process [6][7][8][9][10][11][12][13][14][15][16].…”