title: Periphyton biofilms: A novel and natural biological system for the effective removal of sulphonated azo dye methyl orange by synergistic mechanism.
abstract: Due to their large scale use, azo dyes are adversely affecting aquatic fauna and flora as well as humans. The persistent nature of sulphonated azo dyes makes them potential ecotoxic hazards. The aim of the present study was to employ a proficient, locally available biomaterial, viz. periphyton (i.e. epiphyton, epilithon or metaphyton), for removal of the azo dye, methyl orange (MO). Results showed that the periphytic biofilms are capable of completely removing comparatively high concentrations (up to 500 mg L-1) of MO from wastewater. The removal of MO occurs by a synergistic mechanism involving bioadsorption and biodegradation processes. The adsorption of MO by periphyton can be described by pseudo-second order kinetics. Elovich and intraparticle diffusion models as well as Langmuir equations fit well to the MO adsorption process. FTIR analysis of MO and its metabolites demonstrated biotransformation into simpler compounds within 72 h. GC-MS/MS analysis showed the conversion of MO into simpler compounds such as phenol, ethyl acetate and acetyl acetate. The results indicated that periphyton is a promising biomaterial for the complete removal of MO from wastewater and that the treatment process has the potential for in situ removal of MO at contaminated sites.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing, 210008, Jiangsu, People's Republic of China; Department of Microbiology, Quaid-i-Azam University, 3rd Avenue, 45320, Islamabad, Pakistan.
authors.forename: Sadaf
authors.initials: S
authors.lastname: Shabbir
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing, 210008, Jiangsu, People's Republic of China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Faheem
authors.affiliation: Department of Microbiology, Quaid-i-Azam University, 3rd Avenue, 45320, Islamabad, Pakistan.
authors.forename: Naeem
authors.initials: N
authors.lastname: Ali
authors.affiliation: School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Kerr
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing, 210008, Jiangsu, People's Republic of China. Electronic address: yhwu@issas.ac.cn.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D018441:Biofilms; D001711:Biotransformation; D004396:Coloring Agents / Q000302:isolation & purification*; D007700:Kinetics; D008962:Models, Theoretical; D053719:Tandem Mass Spectrometry / Q000379:methods; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D062065:Wastewater; D014874:Water Pollutants, Chemical; C100258:methyl orange
keywords: Aliphatic hydrocarbons; Bioremediation; Methyl orange; Periphyton; Synergistic