title: Biosorption of arsenite (As(+3)) and arsenate (As(+5)) from aqueous solution by Arthrobacter sp. biomass.
abstract: In this study we investigated the role of arsenic-resistant bacteria Arthrobacter sp. biomass for removal of arsenite as well as arsenate from aqueous solution. The biomass sorption characteristics were studied as a function of biomass dose, contact time and pH. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm. The Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The biosorption capacity of the biomass for As(+3) and As(+5) was found to be 74.91 mg/g (pH 7.0) and 81.63 mg/g (pH 3.0), respectively using 1 g/L biomass with a contact time of 30 min at 28 degrees C. The mean sorption energy values calculated from the D-R model indicated that the biosorption of As(+3) and As(+5) onto Arthrobacter sp. biomass took place by chemical ion-exchange. The thermodynamic parameters showed that the biosorption of As(+3) and As(+5) ions onto Arthrobacter sp. biomass was feasible, spontaneous and exothermic in nature. Kinetic evaluation of experimental data showed that biosorption of As(+3) and As(+5) followed pseudo-second-order kinetics. Fourier transform infrared spectroscopy (FT-IR) analysis indicated the involvement of possible functional groups (-OH, -C=O and -NH) in the As(+3) and As(+5) biosorption process. Bacterial cell biomass can be used as a biosorbent for removal of arsenic from arsenic-contaminated water.
authors: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India. suranjit@gmail.com
authors: Kumar Suranjit
authors: KS
authors: Prasad
authors: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
authors: A L
authors: AL
authors: Ramanathan
authors: School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
authors: Jaishree
authors: J
authors: Paul
authors: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
authors: Vaidyanathan
authors: V
authors: Subramanian
authors: Amity Institute of Microbial Technology, Amity University, Noida, India.
authors: Ram
authors: R
authors: Prasad
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000302:isolation & purification*; D018053:Arsenites / Q000302:isolation & purification*; D001173:Arthrobacter / Q000737:chemistry* / Q000166:cytology; D018533:Biomass; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D001149:Arsenates; D018053:Arsenites; D014874:Water Pollutants, Chemical; C015001:arsenite; C025657:arsenic acid