title: Hydrothermal conversion of urban food waste to chars for removal of textile dyes from contaminated waters.
abstract: Hydrothermal carbonization of urban food waste was carried out to prepare hydrochars for removal of Acridine Orange and Rhodamine 6G dyes from contaminated water. The chemical composition and microstructure properties of the synthesized hydrochars were investigated in details. Batch adsorption experiments revealed that hydrochars with lower degree of carbonization were more efficient in adsorption of dyes. Operational parameters such as pH and temperature had a strong influence on the dye uptake process. The adsorption equilibrium data showed excellent fit to the Langmuir isotherm. The pseudo-second-order kinetic model provided a better correlation for the experimental kinetic data in comparison to the pseudo-first-order kinetic model. Thermodynamic investigations suggested that dye adsorption onto hydrochars was spontaneous and endothermic. The mechanism of dye removal appears to be associated with physisorption. An artificial neural network (ANN)-based modelling was further carried out to predict the dye adsorption capacity of the hydrochars.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Republic of Singapore.
authors.forename: Ganesh K
authors.initials: GK
authors.lastname: Parshetti
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Republic of Singapore.
authors.forename: Shamik
authors.initials: S
authors.lastname: Chowdhury
authors.affiliation: Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576, Republic of Singapore. Electronic address: ceerbala@nus.edu.sg.
authors.forename: Rajasekhar
authors.initials: R
authors.lastname: Balasubramanian
mesh_terms: D000165:Acridine Orange / Q000302:isolation & purification*; D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D005735:Garbage; D006358:Hot Temperature; D007700:Kinetics; D016571:Neural Networks, Computer; D012235:Rhodamines / Q000302:isolation & purification*; D013783:Textile Industry; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D012235:Rhodamines; D014874:Water Pollutants, Chemical; C026188:rhodamine 6G; D002606:Charcoal; D000165:Acridine Orange
keywords: Adsorption; Artificial neural network; Dyes; Food waste; Hydrochars