Solar Drying of Landfill-Leachate Sludge: Differential Results Through the Use of Peripheral Technologies

摘要

Sludge disposal, an indispensable element of waste management, is commonly achieved via landfilling, which requires sludge management. To this end, the drying process is critical in reducing sludge mass and volume, thereby lowering transport and storage costs. Solar energy is an alternative for minimizing costs of the drying process. This study evaluated drying landfill leachate-derived sludge using a solar still with and without peripheral systems to enhance thermal heat input. Sludge drying was most successful when using all peripheral systems (i.e., solar air preheater, extractor, and solar collector), where an accumulated solar energy of 241.6 kJ/kg produced 20 g of sludge mass. When only using the solar air preheater and extractor, 226.1 kJ/kg were needed to achieve 35 g of sludge mass. Results were poorer and took comparatively longer to reach suitable dryness levels when no peripheral systems were used (310 kJ/kg, 28 g) or when drying took place outside of the solar still (751 kJ/kg, 28 g). Notably, the base of the solar drier was hotter (49.6 degrees C peak) when the solar collector was used, and the thermal efficiency of the solar air preheater was 20.7%. (c) 2018 American Institute of Chemical Engineers Environ Prog, 38: 345-353, 2019