title: Modified ADM1 for modeling free ammonia inhibition in anaerobic acidogenic fermentation with high-solid sludge.
abstract: Anaerobic acidogenic fermentation with high-solid sludge is a promising method for volatile fatty acid (VFA) production to realize resource recovery. In this study, to model inhibition by free ammonia in high-solid sludge fermentation, the anaerobic digestion model No. 1 (ADM1) was modified to simulate the VFA generation in batch, semi-continuous and full scale sludge. The ADM1 was operated on the platform AQUASIM 2.0. Three kinds of inhibition forms, e.g., simple inhibition, Monod and non-inhibition forms, were integrated into the ADM1 and tested with the real experimental data for batch and semi-continuous fermentation, respectively. The improved particle swarm optimization technique was used for kinetic parameter estimation using the software MATLAB 7.0. In the modified ADM1, the Ksof acetate is 0.025, the km,acis 12.51, and the KI_NH3is 0.02, respectively. The results showed that the simple inhibition model could simulate the VFA generation accurately while the Monod model was the better inhibition kinetics form in semi-continuous fermentation at pH10.0. Finally, the modified ADM1 could successfully describe the VFA generation and ammonia accumulation in a 30m3full-scale sludge fermentation reactor, indicating that the developed model can be applicable in high-solid sludge anaerobic fermentation.
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: wxbaijie@163.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Bai
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: liuhe@jiangnan.edu.cn.
authors.forename: He
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yin
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Ma
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Xinchun
authors.initials: X
authors.lastname: Chen
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis; D019149:Bioreactors; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation / Q000502:physiology*; D007700:Kinetics; D008962:Models, Theoretical; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D005232:Fatty Acids, Volatile; D000641:Ammonia
keywords: ADM1; Free ammonia inhibition; Full scale; High-solid sludge; Semi-continuous