A mechanistic model for anaerobic phototrophs in domestic wastewater applications: Photo-anaerobic model (PAnM)

Abstract

Purple phototrophic bacteria (PPB) have been recently proposed as a key potential mechanism for accumulative biotechnologies for wastewater treatment with total nutrient recovery, low greenhouse gas emissions, and a neutral to positive energy balance. Purple phototrophic bacteria have a complex metabolism which can be regulated for process control and optimization. Since microbial processes governing PPB metabolism differ from traditional processes used for wastewater treatment (e.g., aerobic and anaerobic functional groups in ASM and ADM1), a model basis has to be developed to be used as a framework for further detailed modelling under specific situations. This work presents a mixed population phototrophic model for domestic wastewater treatment in anaerobic conditions. The model includes photoheterotrophy, which is divided into acetate consumption and other organics consumption, chemoheterotrophy (including simplified fermentation and anaerobic oxidation) and photoautotrophy (using hydrogen as an electron donor), as microbial processes, as well as hydrolysis and biomass decay as biochemical processes, and is single-biomass based. The main processes have been evaluated through targeted batch experiments, and the key kinetic and stoichiometric parameters have been determined. The process was assessed by analyzing a continuous reactor simulation scenario within a long-term wastewater treatment system in a photo-anaerobic membrane bioreactor.

Control tools to selectively produce purple bacteria for microbial protein in raceway reactors

“…10–12 PNSB are characterized by high biomass yields (0.9-1.1 g COD biomass g -1 COD removed ) and have growth rates between 0.6-3.7 d -1 . 13–15 However, compared to AHB, there is a lack of full-scale PNSB facilities for microbial protein production, probably due to costs (expensive photobioreactor; PBR).…”

Purple bacteria as added-value protein ingredient in shrimp feed:Litopenaeus vannameigrowth performance, and tolerance againstVibrioand ammonia stress

“…There biomass shows high potential as nutritious feed as it is rich in essential vitamins and carotenoid pigments (Sasaki et al, 1998). These phototrophic bacteria can be produced highly selectively on wastewater for proteins due to their ability to grow under anaerobic conditions in the light (Hülsen et al, 2016a; Hülsen et al, 2016b; Puyol et al, 2017). To date, studies of PNSB as protein substitution in shrimp feed are limited.…”

Enriching and aggregating purple non-sulfur bacteria in an anaerobic sequencing-batch photobioreactor for nutrient capture from wastewater

“…PNSB can assimilate carbon (C), nitrogen (N), and phosphorus (P) from 104 wastewater at COD:N:P ratio of 100:7:2 m/m/m. with an elemental formula for purple 105 phototrophic biomass given as C1H1.8O0.38N0.18 (degree of reduction of 4.5 mol e -C-mol -1 XPPB) 106 (Puyol et al, 2017a). A ratio of 100 Stoppani et al, 1954), underlying the potential of populations of this guild for water 112 6 treatment.…”