MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China; Center for Hypergravity Experimental and Interdisciplinary Research, Zhejiang University, Hangzhou 310058, China.
MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China; Center for Hypergravity Experimental and Interdisciplinary Research, Zhejiang University, Hangzhou 310058, China.
Waste Manag. 2022 May 1;144:144-152. doi: 10.1016/j.wasman.2022.03.017. Epub 2022 Mar 29.
Ventilating solid waste landfills with an oxygen supply can effectively accelerate the degradation of waste, achieve rapid stabilization, and realize the sustainable utilization of landfills. Aiming to understand and verify the aerobic degradation process in landfills, this paper proposed a biochemical-thermal-hydro-mechanical coupling model. The model considers aerobic biochemical reactions, dissolved solute migration, heat transport, two-phase flow, and skeleton deformation. The model was verified by comparison with an in-situ experiment at Jinkou landfill. The results showed the model could accurately represent the observed degradation phenomena during the experiment. The modelling results indicated that the rate of temperature increase and peak temperature of the upper layer, which were lower than those of the middle layer, were affected by heat exchange at the landfill surface. The lowest temperatures occurred near the bottom because of high water content and low oxygen concentrations. The high temperature zone migrated out from the injection well during degradation, reflecting the degradation of degradable organic matter associated with oxygen diffusion rates and aerobic degradation reactions. The initial accumulated settlement value was fast, but slowed and finally stabilized. The surface subsidence also developed from the center around the injection well to the surrounding area, and 70% of the total subsidence occurred within 150 days. This newly developed model provides a theoretical framework for analyzing the multi-field coupling of aerobic degradation of landfilled municipal solid waste (MSW).
用氧气供应来通风固体废物填埋场可以有效地加速废物的降解，实现快速稳定，并实现填埋场的可持续利用。本文旨在了解和验证填埋场中的好氧降解过程，提出了一个生化-热-水-力耦合模型。该模型考虑了好氧生化反应、溶解溶质迁移、热传递、两相流和骨架变形。通过与金口垃圾填埋场的现场实验进行比较验证了模型。结果表明，该模型可以准确地表示实验过程中的观测到的降解现象。模拟结果表明，由于与垃圾填埋场表面的热交换，上层的温度升高速率和峰值温度低于中层的温度升高速率和峰值温度。由于含水量高和氧气浓度低，底部附近的温度最低。在降解过程中，高温区从注入井中迁移出来，反映了与氧气扩散速率和好氧降解反应相关的可降解有机物的降解。初始累积沉降值很快，但随后减缓并最终稳定。地表沉降也从注入井周围的中心向周围地区发展，总沉降的 70%发生在 150 天内。这个新开发的模型为分析垃圾填埋场中城市固体废物（MSW）好氧降解的多场耦合提供了一个理论框架。
