Optimization of lead (II) biosorption in an aqueous solution using chemically modiﬁed aerobic digested sludge R. Darvishi Cheshmeh Soltani, A. Rezaee, Gh Shams Khorramabadi and K. Yaghmaeian ABSTRACT Biosorption of Pb(II) by using digested sludge obtained from a municipal wastewater treatment plant in Tehran was examined. The aims of this investigation were biosorption of Pb(II) ions onto chemically treated digested sludge with hydrogen peroxide (H 2 O 2 ) solution and determination of kinetic and isotherm of biosorption. Biosorption capacity of two types of sludge (treated and untreated) for biosorption of Pb(II) ions was investigated as function of initial Pb(II) concentration and pH using batch biosorption systems. The equilibrium biosorption capacity increased with increasing of initial metal ion concentrations and pH for both of digested sludge. The pseudo- second order kinetic model was found to be slightly suitable than the pseudo-ﬁrst order kinetic model to correlate the experimental data for two types of digested sludge (R 2 40.9). Regarding the applicability of the isotherm models, the freundlich model was found to be suitable than the other isotherm models. According to obtained q max from Langmuir isotherm, biosorption of Pb(II) by H 2 O 2 treated digested sludge was found to perform better than untreated digested sludge. The maximum biosorption capacity was given 185.19 and 144.93 mgg 1 for H 2 O 2 treated and untreated digested sludge, respectively. Also, the constant of energy (B) between the Pb(II) ions and the adsorbent surface, calculated using BET isotherm model, obtained 5401 and 3401 for H 2 O 2 treated and untreated digested sludge, respectively. These results indicate the usefulness of H 2 O 2 treated digested sludge as a biosorbent for Pb(II) biosorption. Key words 9 biosorption, digested sludge, isotherm, kinetic, Pb(II) INTRODUCTION Heavy metal ions present in some industrial efﬂuents have detrimental effects on the environments such as water and soil (Gulnaz et al. 2005; Kargi & Cikla 2006; Yunus Pamu- koglu & Kargi 2006). Lead causes severe damage to kidney, liver, brain and reproductive system in human. Lead contam- ination exists in efﬂuent of many industries, such as battery manufacturing, printing and pigment, metal ﬁnishing, glass industries and steel manufacturing (Kumar Naiya et al. 2009). Conventional methods for removal of heavy metals from industrial wastewater such as: chemical precipitation, ion- exchange, adsorption, solvent extraction were found to be ineffective or expensive and require high capital and operat- ing costs, also may result large volumes of sludge causing disposal problems (Utgikara et al. 2000; Aksu et al. 2002; Al-Qodah 2006; Kargi & Cikla 2006). Therefore, recent researches have been focused on use of non-conventional alternative including different biomaterials such as: waste sludge, algae, yeast and fungal biomass (Kargi & Cikla 2006; Tokcaer & Yetis 2006; Yunus Pamukoglu & Kargi 2006). Biomaterials are ecosystem-friendly, cost-effective, R. Darvishi Cheshmeh Soltani (corresponding author) A. Rezaee Environmental Health Dept, Faculty of Medical Sciences, Tarbiat Modarres University, P.O.Box: 14115-178, Tehran, Iran E-mail: rezadarvish86@yahoo.com; abbasrezaee@yahoo.com Gh Shams Khorramabadi Environmental Health Dept, Faculty of Health, Lorestan University of Medical Sciences, P.O.Box: 441, Khorramabad, Iran E-mail: shams_lums@yahoo.com K. Yaghmaeian Environmental Health Dept, Faculty of Health, Semnan University of Medical Sciences, P.O.Box: 373, Damghan, Iran E-mail: k_yaghmaeian@yahoo.com doi: 10.2166/wst.2011.022 129 & IWA Publishing 2010 Water Science & Technology 9 63.1 9 2011 Downloaded from https://iwaponline.com/wst/article-pdf/63/1/129/445051/129.pdf by guest on 08 November 2018