Hydrothermal carbonization of acerola (Malphigia emarginata D.C.) wastes and its application as an adsorbent. (15th July 2019)

• Record Type: Journal Article
• Authors: Nogueira, Geraldo D.R.; Duarte, Claudio R.; Barrozo, Marcos A.S.
• Is Part Of: Waste management. Volume 95(2019)
• Page Start: 466
• Page End: 475
• Publication Date: 2019-07-15
• Subjects: Biomass waste -- Carbonization -- Hydrochar -- Adsorption -- Cationic dyes -- Oxygen-containing groups; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2019.06.039
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Hydrothermal carbonization (HTC) of acerola wastes was investigated. An optimization study was performed to maximize the solid yield and OFG. The hydrochar produced under optimum conditions was analyzed for MB adsorption. The conditions necessary for the maximum removal and adsorption capacity were identified. The adsorption process is endothermic and spontaneous at optimal conditions. Abstract: Hydrothermal carbonization (HTC) is a promising technique for the improved management and better use of agro-industrial wastes. In this study, the effects of temperature, reaction time, biomass/water ratio, feed-water pH, and agitation speed on the HTC of acerola wastes were investigated. The effects of these independent variables on process yield and on the total oxygenated functional groups of hydrochars were quantified. The best process conditions were obtained using the desirability function and the chemical-morphological properties of the hydrochar produced in these optimal conditions were investigated. The total number of oxygenated functional groups were found to be higher than those described in the literature for similar biomasses. The effects of temperature, solution pH, initial dye concentration, and adsorbent dosage on the adsorption of methylene blue using the obtained hydrochar were also investigated and the conditions necessary for the maximum removal and adsorption capacity were determined. Adsorption isotherms and thermodynamic studies have shown that methylene blue adsorption on the obtained hydrochar is endothermic and spontaneous. Thus, the HTC of acerola wastes may be a sustainable technology for the modification of underutilized wastes and their application as adsorbents of environmental contaminants.