International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 02 Issue: 03 | June-2015 www.irjet.net p-ISSN: 2395-0072 © 2015, IRJET.NET- All Rights Reserved Page 1677 REMOVAL OF LEAD (II) FROM AQUEOUS SOLUTION USING NATURAL AND ACTIVATED RICE HUSK Rajkumar V. Raikar 1 , Sefra Correa 2 , Praveen Ghorpade 3 1 Professor, Department of Civil Engineering, KLE Dr. MSSCET, Belgaum, Karnataka, India 2 M. Tech. Scholar, Department of Civil Engineering, KLE Dr. MSSCET, Belgaum, Karnataka, India 3 Assistant Professor, Department of Civil Engineering, KLE Dr. MSSCET, Belgaum, Karnataka, India, Abstract This paper presents the experimental results on the use of rice husk in the removal of lead (II) from the aqueous solution. In this study, rice husk is used in four different forms, namely, natural un-activated form (RH), rice husk ash acquired after carbonizing rice husk without pretreatment (RHA), rice husk pretreated with phosphoric acid (PRH) and acetic acid (ARH) separately and then followed by carbonization. Through batch adsorption studies the effect of various parameters such as pH of the aqueous medium, contact time of agitation, adsorbate concentration, and adsorbent dosage were examined. The results obtained show that the adsorption of the metal ion is pH, contact time, adsorbent dosage and adsorbate concentration dependent. The maximum percentage removal of lead (II) ions is 93.36%, 94.8%, 96.72% and 99.35% with adsorbents RH, RHA, PRH and ARH, respectively. It is found that RH, RHA and PRH followed Freundlich isotherm model whereas ARH followed Langmuir isotherm model. Further, both RH and RHA follow pseudo-second order kinetics. Key Words: Adsorption, Lead, Natural Adsorbents, Rice husk, Isotherms, Reaction kinetics … --------------------------------------------------------------------***---------------------------------------------------------------------- 1. INTRODUCTION Amongst the present day’s environmental issues, water scarcity and water pollution rank equal to climate change [1]. The industrial effluents have serious concern as they contain heavy metals like iron (Fe), lead (Pb), zinc (Zn), copper (Cu) etc., which are hazardous to human health. Heavy metals being non-biodegradable cause various diseases and disorders through bioaccumulation. Many methods have been developed to remove heavy metals from wastewater, such as adsorption, chemical oxidation / reduction, precipitation, ion exchange, electrochemical processes, membrane filtration and reverse osmosis. These methods tend to be expensive and often impracticable in remote regions where heavy metal contaminants originate from geogenic sources. On the contrary, adsorption technique has proved to be an efficient and cost effective among all the methods [2, 3]. Demirbas presented a review on heavy metal adsorption onto agro-based waste materials [4]. Lead as Pb (II) is released into the environment from various industrial processes: industries engaged in lead acid batteries, pulp and paper, petrochemicals, refineries, printing, pigments, photographic materials, explosive manufacturing, ceramics, glass, paint, oil, metal, phosphate fertilizer, electronics, wood production and also combustion of fossil fuel, forest fires, mining activity, automobile emissions, sewage wastewater, sea spray and many more [5]. Hashem [6] studied the sorption of Pb (II) using okra wastes, Singh et al. [7] used maize bran in the adsorption of lead using maize bran, while El-Ashtoukhy et al. [8] employed pomegranate peel as a adsorbent in the removal of lead (II) and copper (II) from aqueous solution. Yoshita et al. [9] carried out the study on the removal of lead by spent tea leaf residue after instant tea extraction. Imamoglu and Tekir [10] have studied removal of copper (II) and lead (II) ions from aqueous solution by adsorption on activated carbon from a new precursor hazelnut husks. The thermodynamic study on the adsorption of Pb (II) and Zn (II) from aqueous solution by human hair was done by Ekop and Eddy [11]. Adie et al. [12] carried out the comparative analysis of the adsorption of Pb (II) and Cd (II) in wastewater using Borrassus aethiopium and Cocos nucifera. The adsorption of lead from aqueous solution onto untreated orange barks was studied by Azouaou et al. [13]. Wahi et al. [14] studied the removal of mercury, lead and copper from aqueous solution by activated carbon of palm oil empty fruit bunch. Chairgulprasert et al. [15] studied phytoremediation of synthetic wastewater by adsorption of lead and zinc onto Alpinia galangal Willd. However, the studies on the use of activated rice husk in the removal of lead (II) are very few. Hence, the present study emphasizes on the use activated rice husk in the removal of lead (II) cations from aqueous solution. The study also include fitting of isotherms and reaction kinetics.