Biosorption studies on powder of stem of Acacia nilotica: Removal of arsenic from surface water

• Published in: Journal of hazardous materials Vol. 178; no. 1; pp. 941 - 948
• Main Authors: Baig, Jameel A., Kazi, Tasneem G., Shah, Abdul Q., Kandhro, Ghulam A., Afridi, Hassan I., Khan, Sumaira, Kolachi, Nida F.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.06.2010; Elsevier
• Subjects: Acacia - chemistry; Acacia nilotica; Adsorption; Algorithms; Applied sciences; Arsenic; Arsenic - isolation & purification; Biological and medical sciences; Biomass; Biosorption; Biotechnology; Chemical engineering; Contact; Continental surface waters; Endothermic reactions; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Indicators and Reagents; Isotherms; Kinetics; Mathematical analysis; Mathematical models; Methods. Procedures. Technologies; Microscopy, Electron, Scanning; Natural water pollution; Others; Plant Stems - chemistry; Pollution; Powders; Sorption; Spectroscopy, Fourier Transform Infrared; Surface water; Temperature; Thermodynamics; Various methods and equipments; Water Purification - methods; Water Supply - analysis; Water treatment and pollution; Acacia nilotica; Biosorption; Arsenic; Surface water; Correlation coefficient; Second order; Adsorption isotherm; Biomass; Modeling; Uptake; Powder; Sorption; First order equation; Thermodynamic parameter; Lakes; pH; Stream; Kinetics
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2010.02.028

In present study a biomass derived from the stem of Acacia nilotica has been investigated to remove As ions from surface water samples of different origins (lake, canal and river). The effects of various parameters viz. pH, biosorbent dosage, contact time and temperature on the biosorption processes were systematically studied. Experimental data were modeled by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms. It was observed that As biosorption best fitted to the Langmuir and Freundlich isotherms. The mean sorption energy ( E) calculated from D–R model, indicated physico-chemical biosorption. Study of thermodynamic parameters revealed the endothermic, spontaneous and feasible nature of biosorption process. The pseudo-second-order rate equation described better the kinetics of As biosorption with good correlation coefficients than pseudo-first-order equation. The biomass of A. nilotica was found to be effective for the removal of As with 95% sorption efficiency at a concentration of <200 μg/L of As solution, and thus uptake capacity is 50.8 mg As/g of biomass. The A. nilotica biomass could be used as a low-cost biosorbent for As ion removal.