A dynamic model for the prediction of malodorous compounds production from anaerobic methanogenic biofilm

Abstract

A dynamic 1-D mathematical model for production and emission of a group of malodorous Volatile Sulphurous Compounds (VSCs) and volatile fatty acids from anaerobic microbial biofilms was herein formulated, calibrated, and validated. Mathematically, the biofilm was modelled using a multispecies approach, while microbial activity was modelled using the well-established Anaerobic Digestion Model 1 framework, amended with biochemical and physico-chemical processes to accurately represent the kinetics and compounds transportation in anaerobic methanogenic sulphate reducing biofilms. The model was formulated as an integrated Anaerobic Biofilm Reactor Model (ABRM) that provides a combined a dynamic output based on the processes taking place in the biofilm, liquid, and gas phases. Published experimental data representing the production of the targeted malodorous compounds obtained from a multi-reactor, lab-scale, anaerobic biofilm containing system fed with real wastewater was used to calibrate the model's parameters and to validate its predictions. ABRM predicted sulphite reduction and methanogenesis kinetics with R2 values ≥0.916 and matched the trends of spatial and temporal variations of the experimental targeted malodorous compounds concentrations inside the reactors with Spearman's rank correlation coefficients ≥0.922. Simulation results for ABRM predicted spatial variations in the anaerobic biofilm's microbial species distribution, abundance, growth, substrate competition and uptake, hydrogen sulphate inhibition, and the levels of targeted malodorous compounds production and emissions in response to changes in operational conditions. In an integrated approach for odour control strategies, ABRM can play a great role in predicting malodorous emissions from microbial biofilms in wastewater treatment processes.