Chemical Science Review and Letters ISSN 2278-6783 Chem Sci Rev Lett 2015, 4(15), 827-834 Article CS02204607 827 Research Article Biosorption of Heavy Metals by Aquatic Weeds Ashok K Jha 1* , Ujjwal Kumar 2 and Yogesh Chandra Gupta 3 1 Department of Chemistry, G.B. college, Naugachia, Bihar and supervisor for Ph. D, Bhagwant University Ajmer, Rajasthan 2 Research Scholar, Department of P. G. Biotech, T.M. Bhagalpur University, Bhagalpur 3 Department of Chemistry, M.S. College, Alauli and Research scholar, Bhagwant University Abstract The aqueous solution of Cr(VI) and As(III) have been tested in the laboratory for biosorption by different aquatic weeds of this area. In addition to this, biosorption kinetics have been studied also for fluoride. The aquatic weeds taken were Eicchornea Crassipes, Lemna Minor and Azolla Microfilla. Eicchornea Crassipes was found to be a good adsorbent of Arsenic (III) aqueous solution where as Azolla Microfilla has been found to be effective in biosorption of heavy metals. Aquatic weeds were not very effective in removal of fluoride from aqueous solution. Different mass of aquatic weeds were taken in 100ml 2ppm solution up to a certain period (3 days) and the experiment is done with a fixed mass of bio absorbent up to different interval of time e.g. 1day, 2day and 3days. Heavy metal removal capacity increases up to a certain time interval and after that the release of heavy metals also takes place. It has been found that the removal of heavy metal by biosorbents follow a first order kinetics. The studies show that aquatic weeds found in abundance in this area can be exploited as an alternative source of removal of heavy metals from aqueous medium but longer duration of time taken in removal and release after certain time are impediments of bioremediation. Keywords: Bioremediation, Arsenic(III), Cr(VI), Aquatic weeds. *Correspondence Author: Ashok K Jha Emails: ashokjha39@gmail.com Introduction Arsenic, a common contaminant of water, is mobilized through a no of natural processes e.g. weathering processes, biological activity and anthropogenic activities [1]. Heavy metal ions emitted into the environment are hazardous to human health [2]. Heavy metals find their way in ground, industrial and waste water [3]. Arsenic is one of the most toxic elements which exist as arsenite (AsO 3 3- ) and arsenate (AsO 4 3- ) in water [4]. Arsenic contamination in ground water has been reported over the world and in the doab land of Bhagalpur district and in the southern part of the Ganges River where patients having skin pigmentation, liver and lung cancer have been reported [5, 6, 7]. This worsening situation of ground water arsenic contamination necessitated the methods of eco-friendly and cheap methods of removal of arsenic. Several techniques e.g., ion exchange, reverse osmosis and adsorption by bentonite minerals are in practice [8, 9, 10]. It is important to note that this doab land between the Koshi and the Ganga has a variety of aquatic weeds e.g. Eicchornea crassipes, Azolla microfila and Lemna minor. These aquatic weeds have been tried for removal of arsenic from aqueous solution. Efforts have been made to select the aquatic weeds which can lower the arsenic concentration below the permissible limit [11, 12]. Another toxic element_found in the ground water sample of this area is Cr(VI) [13]. Chromium (VI) is toxic and carcinogenic in nature. The deaths due to liver cancer by the ingestion of Cr(VI) contaminated ground water have