Isothermal drying characteristics and kinetics of human faecal sludges

Gates Open Research

article

Athanasios Kolios¹  Chris Buckley²  Tosin Somorin³  Samuel Getahun²  Santiago Septien²  Ian Mabbet⁴ 

[1] Naval Architecture, Ocean & Marine Engineering, University of Strathclyde;Pollution Research Group, University of Kwazulu-Natal;Chemical and Process Engineering, University of Strathclyde;Department of Chemistry, Swansea University

关键词: Thermogravimetric Study;    Biomass Conversion;    Sanitation Intervention;    Kinetic Behaviour;    Sludge Treatment;   

DOI  :  10.12688/gatesopenres.13137.2

学科分类：电子与电气工程

来源: American Journal Of Pharmtech Research

【 摘 要 】

Background: Drying is an important step for the thermochemical conversion of solid fuels, but it is energy-intensive for treating highly moist materials. Methods: To inform the thermal treatment of faecal sludge (FS), this study investigated the drying characteristics and kinetics of various faecal wastes using thermogravimetric analysis and isothermal heating conditions. Results: The findings show that FS from the anaerobic baffled reactor (ABR) and ventilated improved pit latrines (VIP) exhibit similar drying characteristics, with maximum drying rates at 0.04 mg/min during a constant rate period that is followed by a distinct falling rate period. On the contrary, fresh human faeces (HF) and FS from urine diversion dry toilets (UDDT) exhibited a falling rate period regime with no prior or intermittent constant rate periods. The absence of a constant rate period in these samples suggested limited amounts of unbound water that can be removed by dewatering and vice versa for VIP and ABR faecal sludges. The activation energies and effective moisture diffusivity for the sludges varied from 28 to 36 kJ/mol and 1.7·10-7 to 10·10-7 m2/s at 55°C and sludge thickness of 3mm. The Page model was consistent in modelling the different sludges across all temperatures. Conclusions: These results presented in this study can inform the design and development of innovative drying methods for FS treatment.

【 授权许可】

CC BY