title: Elimination of textile dyes using activated carbons prepared from vegetable residues and their characterization.
abstract: In this study, three mesoporous activated carbons prepared from vegetable residues were used to remove acid, basic, and direct dyes from aqueous solutions, and reactive and vat dyes from textile wastewater. Granular carbons obtained by chemical activation at 673 K with phosphoric acid from prickly pear peels (CarTunaQ), broccoli stems (CarBrocQ), and white sapote seeds (CarZapQ) were highly efficient for the removal of dyes. Adsorption equilibrium studies were carried out in batch systems and treated with Langmuir and Freundlich isotherms. The maximum adsorption capacities calculated from the Langmuir isotherms ranged between 131.6 and 312.5 mg/g for acid dyes, and between 277.8 and 500.0 mg/g for basic dyes at 303 K. Our objective in this paper was to show that vegetable wastes can serve as precursors for activated carbons that can be used for the adsorption of dyes. Specifically CarBrocQ was the best carbon produced for the removal of textile dyes. The color removal of dyes present in textile wastewaters was compared with that of a commercial powdered carbon, and it was found that the carbons produced using waste material reached similar efficiency levels. Carbon samples were characterized by bulk density, point of zero charge, thermogravimetric analysis, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, methylene blue adsorption isotherms at 303 K, and nitrogen adsorption isotherms at 77 K (SBET). The results show that the activated carbons possess a large specific surface area (1025-1177 m(2)/g) and high total pore volume (1.06-2.16 cm(3)/g) with average pore size diameters between 4.1 and 8.4 nm. Desorption and regeneration tests were made to test the viability of reusing the activated carbons.
authors.affiliation: Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla, Edificio ING1, Ciudad Universitaria, CP. 72570 Puebla, Mexico. Electronic address: alejandra.pelaez@correo.buap.mx.
authors.forename: Alejandra-Alicia
authors.initials: AA
authors.lastname: Peláez-Cid
authors.affiliation: Área Académica de Ciencias de la Tierra y Materiales, Universidad Autónoma del Estado de Hidalgo, Ciudad del Conocimiento, CP. 42184 Hidalgo, Mexico.
authors.forename: Ana-María
authors.initials: AM
authors.lastname: Herrera-González
authors.affiliation: Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla, Edificio ING1, Ciudad Universitaria, CP. 72570 Puebla, Mexico.
authors.forename: Martín
authors.initials: M
authors.lastname: Salazar-Villanueva
authors.affiliation: Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla, Edificio ING1, Ciudad Universitaria, CP. 72570 Puebla, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Bautista-Hernández
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification*; D008751:Methylene Blue / Q000737:chemistry / Q000302:isolation & purification; D009584:Nitrogen / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013783:Textile Industry; D014675:Vegetables / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D014866:Waste Products; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D004396:Coloring Agents; D010756:Phosphoric Acids; D014866:Waste Products; D014874:Water Pollutants, Chemical; D002606:Charcoal; D002244:Carbon; C030242:phosphoric acid; D009584:Nitrogen; D008751:Methylene Blue
keywords: Activated carbons; Broccoli stem; Characterization; Prickly pear peel; Textile dyes removal; White sapote seed