|
1
|
Tao J, Liu Y, Kumar A, Chen G, Sun Y, Li J, Guo W, Cheng Z, Yan B. Effect of landfilling time on physico-chemical properties of combustible fractions in excavated waste. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170371. [PMID: 38280582 DOI: 10.1016/j.scitotenv.2024.170371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/19/2024] [Accepted: 01/20/2024] [Indexed: 01/29/2024]
Abstract
Excavated waste is a byproduct of microbial decomposition and fermentation following landfill disposal. The effective management and utilization of excavated waste offer broad prospects for environmental and resource protection, as well as economic growth. While current research predominantly focuses on plastics in landfills, the physico-chemical properties of excavated waste over extended landfilling time remain unclear. This study aimed to address this gap by excavating waste from a landfill in Tianjin, China, with a maximum landfilling time of 18 years. The findings revealed that, compared to municipal solid waste (MSW), the excavated waste exhibited increased calorific value, ash content, and fixed carbon content after screening the landfill-mined-soil-like-fine fraction. The average calorific value of the excavated waste could reach 57.8 MJ/kg. Additionally, the oxygen content in the excavated combustible waste exceeded that of MSW, increasing from 25.59 % to 34.22 %. This phenomenon is potentially linked to the oxidation of attached soil impurities and waste. The study identified polyethylene (PE), polypropylene (PP), expanded polystyrene (EPS), polyethylene terephthalate (PET), and wood as the primary combustible components. Notably, the excavated waste exhibited a significant decrease in surface gloss, adopting a rough texture with apparent holes, potentially attributed to the acidification and corrosion of organic matter during fermentation. Nevertheless, the breaking of molecular bonds could also contribute to waste fragmentation. Furthermore, an increase in landfilling time resulted in a more pronounced decrease in mechanical properties. For instance, the failure load of PE decreased from 15.61 N to 6.46 N, and PET reduced from 884.83 N to 186.56 N. The chemical composition of excavated waste has changed, with -OH and CO observed in PE with an 18-year landfilling time. In conclusion, these results provide a theoretical foundation for the recycling of excavated waste and contribute to the advancement of waste management and recycling technologies.
Collapse
Affiliation(s)
- Junyu Tao
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China; School of Ecology and Environment, Tibet University, Lhasa 850012, China
| | - Yuan Liu
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China
| | - Akash Kumar
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Guanyi Chen
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China.
| | - Yunan Sun
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin 300134, China
| | - Jian Li
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Wei Guo
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; CECEP Talroad Technology Co., Ltd., Beijing 100000, China
| | - Zhanjun Cheng
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; Tianjin Key Lab of Biomass Wastes Utilization/Tianjin Engineering Research Center of Bio Gas/Oil Technology, Tianjin 300072, China
| | - Beibei Yan
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; Tianjin Key Lab of Biomass Wastes Utilization/Tianjin Engineering Research Center of Bio Gas/Oil Technology, Tianjin 300072, China
| |
Collapse
|