Influence of Stand-Alone Vertical Gas Vents on Aeration and Denitrification of Organic Municipal Waste Assessed by Two-Dimensional (2D) Lysimeters  

作　　者：Tadis Dillon Takayuki Shimaoka Teppei Komiya Tadis Dillon;Takayuki Shimaoka;Teppei Komiya(Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan)

机构地区：[1]Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan

出　　处：《Journal of Geoscience and Environment Protection》2023年第12期209-228,共20页地球科学和环境保护期刊(英文)

摘　　要：Landfilled organic waste, in the presence of oxygen, can undergo aerobic decomposition facilitated by heterotrophic microorganisms. Aerobic degradation of solid waste can quickly consume available oxygen thus curtailing further degradation. The aim of this study was the investigation of a low-cost method of replenishing oxygen consumed in landfilled waste. Three 2D lysimeters were established to investigate the effectiveness of stand-alone, vertical ventilation pipes inserted into waste masses. Two different configurations of ventilation were tested with the third lysimeter acting as an unventilated control. Lysimeters were left uninsulated and observed over the course of 6 months with regular collection of gas and leachate samples. Lysimeters were then simulated for Oxygen (O₂) and Nitrous oxide (N₂O) to analyze the denitrification contributions of each. The experiment revealed that a single ventilation pipe can increase the mean oxygen level of a 1.7 m × 1.0 m area by up to 13.5%. It also identified that while increasing the density of ventilation pipes led to increased O₂ levels, this increase was not significant at the 0.05 probability level. A single vent averaged 13.67% O₂ while inclusion of an additional vent in the same area only increased the average to 14.59%, a 6.7% increase. Simulation helped to verify that lower ventilation pipe placement density may be more efficient as in addition to the effect on oxygenation, denitrification efficiency may increase. Simulations of N₂O production estimated between 8% - 20% more N₂O being generated with lower venting density configurations.Landfilled organic waste, in the presence of oxygen, can undergo aerobic decomposition facilitated by heterotrophic microorganisms. Aerobic degradation of solid waste can quickly consume available oxygen thus curtailing further degradation. The aim of this study was the investigation of a low-cost method of replenishing oxygen consumed in landfilled waste. Three 2D lysimeters were established to investigate the effectiveness of stand-alone, vertical ventilation pipes inserted into waste masses. Two different configurations of ventilation were tested with the third lysimeter acting as an unventilated control. Lysimeters were left uninsulated and observed over the course of 6 months with regular collection of gas and leachate samples. Lysimeters were then simulated for Oxygen (O₂) and Nitrous oxide (N₂O) to analyze the denitrification contributions of each. The experiment revealed that a single ventilation pipe can increase the mean oxygen level of a 1.7 m × 1.0 m area by up to 13.5%. It also identified that while increasing the density of ventilation pipes led to increased O₂ levels, this increase was not significant at the 0.05 probability level. A single vent averaged 13.67% O₂ while inclusion of an additional vent in the same area only increased the average to 14.59%, a 6.7% increase. Simulation helped to verify that lower ventilation pipe placement density may be more efficient as in addition to the effect on oxygenation, denitrification efficiency may increase. Simulations of N₂O production estimated between 8% - 20% more N₂O being generated with lower venting density configurations.

关 键 词：Organic Waste Waste Stabilization Passive Aeration 2D Lysimeter COMSOL Multiphysics In-Situ Aeration 

分 类 号：X70[环境科学与工程—环境工程]