Nature and Science, 2012;10(3) http://www.sciencepub.net/nature 1 Investigation of Heavy Metals Binding to Jatropha Curcas Husk Adelaja O. A*, Okoronkwo A.E., Abass L.T Department of Chemistry, Federal University of Technology, P.M.B 704 Akure, Nigeria. seunmt@gmail.com Abstract: Seed coat of Jatropha curcas was investigated for the removal of some selected metals from aqueous solutions. The selected metal ions are Cu, Ni and Cr. In this work, impact of pH of solution and sorption time on sorption capacity was investigated. At a pH of 5.0, 6.0 and 5.0 relatively to sorption time of 120mins, 60mins and 120mins respectively, 88.88%, 99.78% and 97.81% of Ni, Cu, and Cr were removed accordingly. Adsorption data analyzed using Langmuir and Freundlich models shows that Cu and Cr however followed Langmuir isotherms and not Freundlich while Ni adsorption conforms to both Langmuir and Freundlich models. This study shows that prepared biomass of Jatropha curcas husk can be used as an adsorbent for removal of Cu, Ni and Cr from wastewater or any industrial effluent. Nature and Science 2012;10(3):1-6]. (ISSN: 1545-0740). http://www.sciencepub.net . 1 Keywords: Adsorption, Jatropha Curcas, pH –profile, time dependency. 1. Introduction The primary source of heavy metal contamination has resulted from industrial activities such as energy and fuel production, mining and smelting of metaliferous ores and post production use that contains wastes (Sarwoko and Surahmaida, 2008).Due to increased industrial activities, an alarming amount of toxic heavy metal has been released into the environment endangering natural ecosystem and public human health (Gardea –Torresday et al, 1996). Usually, the most common heavy metal contaminants are Cadmium, Chromium, Cobalt, Copper, Lead, Mercury, Nickel and Zinc. Because of their adverse effects on natural ecosystem, their removal has become of major concern (Okoronkwo and Olasehnde, 2007). Hexavalent chromium is widely used in many industrial processes such as electroplating, wood preservation, etc. Commercially available forms of hexavalent chromium (Cr(VI)) are potassium chromate and potassium dichromate. The chromium manufacturing industry produces a large quantity of solid and liquid waste containing hexavalent chromium. The treatment of these wastes is essential before discharging them to the environment. Cr(VI) compounds are highly water soluble, toxic and carcinogenic in mammals. In contrast, trivalent chromium is considered to be non-toxic as it precipitates at pH higher than 5.5 with the formation of insoluble oxides and hydroxides in soil and water systems (Chen and Hao, 1998; Jeyasingh and Philip, 2005). Copper is a very common substance in the environment and it long term exposure can cause irritation of the nose, mouth and eyes. High intake of copper can cause liver and kidney problems which could eventually lead to death. Copper does not breakdown in the environment and because of this it can accumulate in plants and animals. On copper-rich soil only limited numbers of plants has a chance of survivals because copper interrupt the activities of the soil as it negatively influence the activities of microorganism, earthworms and the decomposition of organic matter (Lenntech, 2011). Nickel is used majorly in the preparation of alloys. In human, Nickel uptake will boost when people eat large quantities of vegetable from polluted soil. High uptake of Nickel is associated with respiration system. It is essential to remove heavy metals from waste water, so that their disposal into water bodies does not cause toxicity to inhabiting body. The conventional methods of metal removals from waste water, such as precipitation, adsorption and ion exchange are expensive and may not work well at low concentration of metal ions (Ahluwalia and Goyal, 2005; Alpana et al, 2007). Many researchers have generated considerable interest to pursue better methods or techniques which could be cost effective to remove heavy metals from the environment of which great attention has been given to the use of both living and non- living biological materials for the remediation of toxic metals ions from industrial waste water, (Okoronkwo and Olasehinde, 2007; Volesky and May-Philips, 1995; Carvalho et al., 1994). One of these technologies is bioremediation, which is the use of biological system (such as plants, bacteria, fungi, etc) in various applications of waste treatment and remediation of pollutants. Bioremediation can be engaged for specific contaminants or general approach, such as reduction of BOD and odour from organic rich sediment (Chang et [Adelaja O. A, Okoronkwo A.E., Abass L.T. Investigation of Heavy Metals Binding to Jatropha Curcas Husk. according to the World Health Organization (WHO) associated with high chance of development of cancer