Biosorption of Pb(II) and Fe(III) from Aqueous Solutions Using Oil Palm Biomasses as Adsorbents Shabnam Khosravihaftkhany & Norhashimah Morad & Tjoon Tow Teng & Ahmad Zuhairi Abdullah & Ismail Norli Received: 27 August 2012 / Accepted: 15 January 2013 / Published online: 8 February 2013 # Springer Science+Business Media Dordrecht 2013 Abstract The removal of lead (II) and iron (III) from aqueous solutions using empty fruit bunch (EFB), oil palm leaves (OPL), oil palm frond (OPF), and oil palm bark (OPB) as biosorbents was investigated. The bio- sorbents were characterized through scanning electron microscopy, Brunauer–Emmett–Teller analysis, and Fourier transform infrared spectroscopy. Variables such as pH (2–12), biosorbent particle size (200– 1,400 μm), adsorbent dosage (0.25–1.75 g/l), and agitation time (5–80 min) were investigated. The suit- able pH range, particle size, adsorbent dosage, and agitation time for the removal of both metals were 5 to 6, 200 μm, 1 g/l, and 40 min, respectively. Under optimum conditions, OPB showed the highest adsorp- tion efficiency of 80 % and 78 % for lead and iron, respectively. The adsorption equilibrium data were fitted to three adsorption isotherm models. The Langmuir isotherm showed the best result for both metals. The kinetics of the biosorption process was analyzed using pseudo-first-order and pseudo-second- order models. The latter showed a better fit for both metals. OPB biomass introduced the lowest chemical oxygen demand into the treated solution, with an average amount of 32.9 mg/l. Keywords Biosorption . Lead . Iron . Oil palm biomasses . Isotherms . Kinetic model 1 Introduction The discharge of industrial effluents to the water resour- ces is one of the major environmental problems that need to be properly addressed. Heavy metals such as iron, copper, lead, zinc and nickel are among the most common inorganic pollutants found in industrial waste- water (Al-Rub 2006; Reddy et al. 2011). Heavy metals are toxic pollutants that can accumulate in living tissues and cause various diseases and disorders (Witek- Krowiak et al. 2011). The content of heavy metals in industrial wastewater is a worldwide environmental problem (Amarasinghe and Williams 2007). Heavy metals can be removed from wastewater using a variety of technologies depending on water quality expectation, economic concerns, and local leg- islation. Waste stabilization ponds (Shpiner et al. 2009), chlorination and thermal treatment (Nowak et al. 2010), electrochemical-switchable polymer film (Le et al. 2009), chitosan and chitosan derivatives (Miretzky and Cirelli 2009), flocculation/precipitation (Bratskaya et al. 2009), and adsorption methods (Mansour et al. 2011; Nasef and Yahaya 2009; Water Air Soil Pollut (2013) 224:1455 DOI 10.1007/s11270-013-1455-y S. Khosravihaftkhany : N. Morad (*) : T. T. Teng : I. Norli School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysia e-mail: nhashima@usm.my A. Z. Abdullah School of Chemical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia