title: Eco-friendly chitosan production by Syncephalastrum racemosum and application to the removal of acid orange 7 (AO7) from wastewaters.
abstract: Due to the existence of new methodologies that have reduced the production costs of microbiological chitosan, this paper puts forward the use of agro-industrial residues in order to produce microbiological chitosan and to apply chitosan as an innovative resource for removing acid orange 7 (AO7) from wastewaters. The best culture conditions were selected by a full 24 factorial design, and the removal of the dye was optimized by a 23 central composite rotational design. The results showed that corn steep liquor (CSL) is an agro-industrial residue that can be advantageously used to produce microbiological chitosan with yields up to 7.8 g/kg of substrate. FT-IR spectra of the product showed typical peak distributions like those of standard chitosan which confirmed the extracted product was chitosan-like. The efficiency of removing low concentrations of AO7 by using microbiological chitosan in distilled water (up to 89.96%) and tap water (up to 80.60%) was significantly higher than the efficiency of the control (chitosan obtained from crustaceans), suggesting that this biopolymer is a better economic alternative for discoloring wastewater where a low concentration of the dye is considered toxic. The high percentage recovery of AO7 from the microbiological chitosan particles used favors this biopolymer as a possible bleaching agent which may be reusable.
authors.affiliation: Rede Nordeste de Biotecnologia, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos-52171-900 Recife, PE, Brasil. abatista@ufersa.edu.br
authors.forename: Anabelle C L
authors.initials: AC
authors.lastname: Batista
authors.forename: Marta C Freitas
authors.initials: MC
authors.lastname: Silva
authors.forename: Jefferson B
authors.initials: JB
authors.lastname: Batista
authors.forename: Aline Elesbão
authors.initials: AE
authors.lastname: Nascimento
authors.forename: Galba M
authors.initials: GM
authors.lastname: Campos-Takaki
mesh_terms: D001391:Azo Compounds / Q000633:toxicity*; D001557:Benzenesulfonates / Q000633:toxicity*; D048271:Chitosan / Q000737:chemistry*; D005658:Fungi / Q000737:chemistry / Q000235:genetics; D006801:Humans; D017550:Spectroscopy, Fourier Transform Infrared; D062065:Wastewater / Q000737:chemistry* / Q000382:microbiology; D014874:Water Pollutants, Chemical; D018508:Water Purification
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D048271:Chitosan; D062065:Wastewater; D014874:Water Pollutants, Chemical; C014722:2-naphthol orange