Numerical simulation to optimize passive aeration strategy for semi-aerobic landfill

Shuai Guo; Wenbo Yu; Hongyang Zhao; Changfei Lai; Shijie Bian; Pan Jin; Sha Liang; Shushan Yuan; Liang Huang; Songlin Wang; Huabo Duan; Feifei Wang; Jiakuan Yang

doi:10.1016/j.wasman.2023.10.015

Numerical simulation to optimize passive aeration strategy for semi-aerobic landfill

Waste Manag. 2023 Oct 20:171:676-685. doi: 10.1016/j.wasman.2023.10.015. Online ahead of print.

Authors

Affiliations

¹ School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
² School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycle Technology, Wuhan, Hubei 430074, China; Hubei Provincial Research Center of Water Quality Safety and Water Pollution Control Engineering Technology, Wuhan, Hubei 430074, China. Electronic address: yuwenbo@hust.edu.cn.
³ School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycle Technology, Wuhan, Hubei 430074, China; Hubei Provincial Research Center of Water Quality Safety and Water Pollution Control Engineering Technology, Wuhan, Hubei 430074, China.

PMID: 37866111
DOI: 10.1016/j.wasman.2023.10.015

Abstract

Passive aeration has been proven to be efficient for oxygen supply in landfill. The combination of passive aeration and semi-aerobic landfill offers a cost-effective and energy-efficient approach to solid waste (SW) treatment. However, determining the optimal strategy for this combination has remained unclear. This study aimed to investigate the strategy of passive aeration in a semi-aerobic landfill using numerical simulation methods. A model coupled hydrodynamic model and compartment model for degradation of SW was implemented. The accuracy was well validated by comparing measured and simulated results in a pilot-scale landfill. Compared with natural convection, passive aeration by funnel caps could increase air input by 20 %. By simulating volumetric fraction distribution of CO₂, CH₄ and O₂ in landfill, an orthogonal experiment including 4 factors was designed to identify that the diameter of tubes (D_T), the spacing between tubes (S_T) and the landfill depth (LD) have substantial impacts on aerobic zone ratio (AZR) of landfill. But the diameter of gas ports (D_GP) has an indiscernible effect. The optimized factors were determined to be as follows: D_T = 0.3 m, S_T = 15.0 m, D_GP = 0.05 m, and LD = 4.0 m, under which the semi-aerobic landfill could enhance SW degradation. Large diameter and spacing of tubes are favorable to improve the AZR at the top of the landfill, and the aerobic zone mainly exists near the ventilation tubes. These findings contribute to the development of more efficient and sustainable solid waste treatment strategies in semi-aerobic landfill.

Keywords: Aeration strategy; Computational fluid dynamics; Numerical simulation; Passive aeration; Semi-aerobic landfill.