Analysis and modelling of predation on biofilm activated sludge process: Influence on microbial distribution, sludge production and nutrient dosage. (November 2016) - Revilla, Marta
Graphical abstract: Highlights: Complete Biofilm Activated Sludge (BAS) process is modeled incorporating predation. Predation is the predominant mechanism in the Activated Sludge (AS) of BAS process. Modeled microbial distribution profile in biofilm and AS stages are different. The unified model explains the efficiency of COD removal under low nutrient dosage. The influence of predation in the sludge reduction is evaluated. Abstract: The influence of predation on the biofilm activated sludge (BAS) process is studied using a unified model that incorporates hydrolysis and predation phenomena into the two stages of the BAS system: moving bed biofilm reactor pre-treatment (bacterial-predator stage) and activated sludge (predator stage). The unified model adequately describes the experimental results obtained in a cellulose and viscose full-scale wastewater plant and has been used to evaluate the role and contribution of predator microorganisms towards removal of COD, nutrient requirements, sludge production and microbial distribution. The results indicate that predation is the main factor responsible for the reduction of both nutrient requirements and sludge production. Furthermore, increasing the sludge retention time (SRT) does not influence the total biomass content in the AS reactor of a BAS process in two different industrial wastewater treatments.