%A C.S. Liew
%A R. Raksasat
%A H. Rawindran
%A W. Kiatkittipong
%A J.W. Lim
%A W.H. Leong
%A M.K. Lam
%A M. Mohamad
%A Y.W. Cheng
%A C.C. Chong
%I Elsevier Ltd
%V 292
%T Hydrolysis kinetics for solubilizing waste activated sludge at low temperature thermal treatment derived from multivariate non-linear model
%R 10.1016/j.chemosphere.2021.133478
%D 2022
%L scholars16952
%J Chemosphere
%O cited By 4
%K Biodegradability; Biodegradable polymers; Chemical oxygen demand; Hydrolysis; Kinetics; Nonlinear systems; Solubility, Hydrolysis kinetics; Low temperature thermal pre-treatment; Lows-temperatures; Modeling; Non-linear modelling; Sludge hydrolysis; Sludge solubilization; Thermal pre-treatment; Treatment duration; Waste activated sludges, Temperature, bovine serum albumin; carbohydrate; protein, activated sludge; hydrolysis; low temperature; reaction kinetics; solubility; temperature effect, activated sludge; anaerobic digestion; Article; biodegradability; chemical oxygen demand; dry weight; humic substance; hydrolysis kinetics; low temperature; Lowry assay; moisture; multivariate non linear model; nonhuman; oxygen consumption; particulate chemical oxygen demand; pH; physical chemistry; prediction; sludge hydrolysis; solubilization; soluble chemical oxygen demand; suspended particulate matter; temperature; thermal pre treatment; thermostability; treatment duration; waste solubilizing; waste water management; wet weight; anaerobic growth; hydrolysis; kinetics; nonlinear system; sewage, Anaerobiosis; Hydrolysis; Kinetics; Nonlinear Dynamics; Sewage; Temperature; Waste Disposal, Fluid
%X Low temperature thermal pre-treatment is a low-cost method to break down the structure of extracellular polymeric substances in waste activated sludge (WAS) while improving the sludge biodegradability. However, previous models on low temperature thermal pre-treatment did not adequately elucidate the behaviour of sludge hydrolysis process for the duration ranging from 5 to 9 h. Therefore, this work had developed an inclusive functional model to describe the kinetics of sludge hydrolysis for a wide range of treatment conditions (30 °C�90 °C within 0 and 16 h). As compared with treatment duration, the treatment temperature played a greater impact in solubilizing WAS. Accordingly, the 90 °C treatment had consistently produced WAS with the highest degree of solubility. Nonetheless, the mediocre discrepancies between 90 °C and 75 °C may challenge the practicality of increasing the treatment temperatures beyond 75 °C. The effects of treatment duration on soluble chemical oxygen demand, soluble carbohydrate and soluble protein were only significant during the first 4 h, except for humic substances release that continued to increase with treatment duration. Finally, a good fit with R2 > 0.95 was achieved using an inclusive multivariate non-linear model, substantiating the functionality to predict the kinetics of sludge hydrolysis at arbitrary treatment conditions. © 2021 Elsevier Ltd