A degradation model for high kitchen waste content municipal solid waste.
Municipal solid waste (MSW) in developing countries has a high content of kitchen waste (KW), and therefore contains large quantities of water and non-hollocellulose degradable organics. The degradation of high KW content MSW cannot be well simulated by the existing degradation models, which are mostly established for low KW content MSW in developed countries. This paper presents a two-stage anaerobic degradation model for high KW content MSW with degradations of hollocellulose, sugars, proteins and lipids considered. The ranges of the proportions of chemical compounds in MSW components are summarized with the recommended values given. Waste components are grouped into rapidly or slowly degradable categories in terms of the degradation rates under optimal water conditions for degradation. In the proposed model, the unionized VFA inhibitions of hydrolysis/acidogenesis and methanogenesis are considered as well as the pH inhibition of methanogenesis. Both modest and serious VFA inhibitions can be modeled by the proposed model. Default values for the parameters in the proposed method can be used for predictions of degradations of both low and high KW content MSW. The proposed model was verified by simulating two laboratory experiments, in which low and high KW content MSW were used, respectively. The simulated results are in good agreement with the measured data of the experiments. The results show that under low VFA concentrations, the pH inhibition of methanogenesis is the main inhibition to be considered, while the inhibitions of both hydrolysis/acidogenesis and methanogenesis caused by unionized VFA are significant under high VFA concentrations. The model is also used to compare the degradation behaviors of low and high KW content MSW under a favorable environmental condition, and it shows that the gas potential of high KW content MSW releases more quickly.
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China. Electronic address: chenyunmin@zju.edu.cn.
Yunmin
Y
Chen
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Ruyang
R
Guo
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Yu-Chao
YC
Li
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Hailong
H
Liu
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
Tony Liangtong
TL
Zhan
Degradation; Kitchen waste; Landfill; Model; Municipal solid waste; VFA inhibition