Response surface methodology for lead biosorption on Aspergillus terreus

Abstract

ABSTRACT:A central composite face-centered design was used to study and to optimize lead biosorption from aqueous solution on Aspergillus terreus biomass. Four factors such as stirring speed, temperature, solution pH and biomass dose at different levels were studied.The hierarchical quadratic model were established by adding replicates at the central point and axial points to the initial full factorial design (2 4 ). The percentage removal of lead was affected by biomass dose, pH, and interactions between pH and biomass dose, pH and stirring speed, pH and temperature. The hierarchical quadratic model described adequately the response surface based on the adjusted determination coefficient (R 2 Adj = 0.97) and the adequate precision ratio (42.21). According to this model, the optimal conditions to remove lead completely from aqueous solutions (at initial lead concentration of 50 mg/L and solutions of 100 mL) with Aspergillus terreus were at pH 5.2, 50 °C, stirring speed of 102/min and a biomass dose of 139 mg.The response surface methodology can be used to determine the optimal conditions for metal adsorption on several adsorbents. In addition, results reported in this research demonstrated the feasibility of employing A. terreus as biosorbent for lead removal.

Identification of potential soil adsorbent for the removal of hazardous metals from aqueous phase

“…Various improved and innovative methods such as reverse osmosis, precipitation, coagulation, ion exchange, solvent extraction, adsorption, membrane filtration, ultra-filtration and photoreduction have been developed to remove metal pollutants from contaminated water and wastewater (Bailey et al 1999;Barron-Zambrano et al 2002;Chen and Wang 2000;Hunsom et al 2005;Kentish and Stevens 2001;Pacheco et al 2006). Among the above-mentioned processes, adsorption plays a pivotal role in removing metals from the aqueous phase using various biomaterial sorbents, algae (Holan et al 1993), fungi, sugar cane bagasse (Cerino Córdova et al 2011;Peterlene et al 1999), rice husk, wheat barn (Nouri et al 2007), pine bark, olive cake (Doyurum and Celik 2006), coconut husk, chitin (Benguella and Benaissa 2002), ash, activated carbon (Jusoh et al 2007;Onundi et al 2011;Zavvar Mousavi and Seyedi 2011), etc. Clays, zeolite, calcite, manganese nodule residue (Agrawal and Sahu 2006;Tashauoei et al 2010), perlite (Hasan et al 2006) and peat (Gabaldon et al 2006) have also been employed to remove metals from the water phase.…”

Application of central composite design for optimization of the removal of humic substances using coconut copra

“…The regression coefficients, R 2 and adjusted R 2 , were calculated to determine the variation between the model and the experimental data [22]. According to Weinberg and Abramowitz [26], R 2 often overestimates the model fit with excessive predictors therefore adjusted R 2 is recommended.…”

“…This design has been widely employed for process optimization involving dye removal [16][17][18], antibiotic production [19] and humic acid and heavy metal adsorption [20,21]. Cerino Cordova et al [22] conclude that it is necessary to study the interaction effects of various parameters on the optimal biosorption process. Therefore in this paper, inscribed CCD and response surface methodology were employed to examine the optimum conditions for removal of humic substances from peat swamp runoff using coconut copra.…”

Preparation and characterization of biosorbents and copper sequestration from simulated wastewater

“…The pH of the biosorption medium affects the solubility of metal ions and the ionization state of the functional groups. Cerino Córdova et al (2011) stated that functional groups of biosorbents can be protonated or deprotonated depending on their dissociation constant that is function of the solution pH. Because of high proton concentration at lower pH, heavy metal biosorption decreases due to the positive charge density on metal binding sites, that is, hydrogen ions compete effectively with metal ions in binding to the sites.…”