{"references": ["\n\tK. Periasamy, C. Namasivayam, (1996), Removal of Copper (II) by adsorption onto peanut hull carbon from water and copper plating industry waste water, Chemosphere, 32(4) pp769-789.\n\tSafia A Cavaco, Sandra Fernandes, (2007), Margarida M Quina, Licinio M. Ferreira, Removal of chromium from electroplating industry effluents by ion exchange resins, J.Hazard.Mater. 144, pp 634-638.\n\tL.Koene, L.J.J.Janseen, (2001), Removal of nickel from industrial process liquids, Electrochimica acta, 47, pp 695-703.\n\tISI, Tolerance limits for industrial effluents prescribed by Indian Standard Institution, IS: 2490 (part I) 1982.\n\tB.M. Kim, P.A.Amodeo, (1983), Calcium sulphide process for treatment of metal containing wastes, Environ. Prog, 2, pp 175-180.\n\tMohamed Kheireddine Arova, S.P.P. Leong, L.Y.Teo, Chun Yang Yin, Wan Mohd Ashri Wan Daud, (2008), Real time determination of kinetics of adsorption of lead (II) onto palm shell-based activated carbon using ion selective electrode, Biores Technol, 99, pp 5786-5792.\n\tF.Hassaine-sadi, L.Sadoun, (2005), Treatment of industrial wastes containing toxic metals (Chromium), Purification by liquid membranes, Desalination, 185, pp 335-340.\n\tDiwakar Tiwari, Hyoung-Uk Kim, Seung-Mok Lee, (2007), Removal behavior of Sericite for Cu(II) and Pb (II) from aqueous solutions: Batch and column studies, Sep.Puri.Technol, 57, pp 11-16.\n\tZouboulis,A.L, Mastisk. A, (1997), Removal of metal ions from dilute solutions by sorption flotation, Critical review in Environmental, pp195-235.\n\tVirendra Kumar Mishra, B.D.Tripathi, (2008), Concurrent removal and accumulation of heavy metals by the three aquatic macrophytes,Biores. Technol. 99, pp 7091-7097.\n\tJ.Deans, B. Dixon, Uptake of Pb2+ and Cu2+ by novel biopolymers, (1992) Water Res, 26, pp 469-472.\n\tGregorio Crini, (2005), Recent developments in polysaccharide–based materials used as adsorbents in waste water treatment, Prog. Polym. Sci. 30, pp 38-70.\n\tBabel. S, Kurniawan T.A, (2004), Chromium removal from electroplating waste water using chemically treated zeolite, Proceedings of the 9th world Filtration Congress, 18-22, April, New Orleans, USA, pp 1-14.\n\tAli Hakan Oren, Abidin Kaya, (2006), Factors affecting adsorption characteristics of Zn2+ on two natural zeolites, J. Hazard.Mater, B131, pp59-65.\n\tDinesh Mohan, Subhash Chander, (2006), Removal and recovery of Metal ions from acid mine drainage using lignite, A low cost sorbent, J. Hazard.Mater. B137, pp1545-1553.\n\tG. Skodras, Ir.Diamantopoulou, A.Zabaniotou, G.Stavropoulos, G.P.Sakellaropoulas, (2007), Enhanced mercury adsorption in activated carbons from biomass materials and waste tires, Fuel process. Technol. 88, pp 749-758.\n\tDonmez.G.C, Aksu.Z, Ozturk.A, Kutsal.T, (1997), A comparative study on heavy metal biosorption characteristics of some algae, Process BioChem, 34, pp 885-892.\n\tSwapna Pradhan, Shyam. S. Shukla, Kenneth L Dorris,(2005) Removal of nickel from aqueous solutions using crab shells, J. Hazard. Mater, B 125, pp 201-204.\n\tDinesh Mohan, Charles U. Pittman Jr, Philip H. Steele, (2006), Single, binary and multi- component adsorption of copper and cadmium from aqueous solutions on kraft lignin-a biosorbent, J.Colloid Interface Sci,297, pp 489-504.\n\tShaobin Wang, T.Terdkiatburana, M.O.Tade, (2008) Single and Co-adsorption of heavy metals and humic acid on fly ash, Sep. Purif.Technol, 58 (3), pp 353-358.\n\tHeechan Cho, Dalyoung Oh, Kwanho Kim, (2005),A study on removal characteristics of heavy metals from aqueous solution by fly ash, J.Hazard.Mater. B127, 9, pp187- 195.\n\tS.K.Banerjee, M.D.Mathew, (1985), Carbonization of jute, an agricultural waste, Agricultural waste, 15, pp 225-229.\n\tD.Mohan, K.P.Singh, (2002) Single and Multicomponent adsorption of cadmium and zinc using activated carbon derivated from bagasse-an agricultural waste, Water Res . 36, pp2304- 2318.\n\tHarshala Parab, Shreeram Joshi, Niyoti shenoy, Arvind Lali, U.S.Sarma, M. Sudersanan, (2006) Determination of kinetic and equilibrium parameters of the batch adsorption of Co(II), Cr(III) and Ni(II) onto coir pith, Process Biochem, 41, pp 609-615.\n\tC.Namasivayam, D.Sangeetha, (2006), Recycling of agricultural solid waste, coir pith: Removal of anions, heavy metals, organics and dyes from water by adsorption onto ZnCl2 activated coir pith carbon, J. Hazard. Mater, B 135, pp 449-452.\n\tDinesh Mohan, Kunwar P.Singh, Vinod K. Singh, (2006) Trivalent Chromium removal from waste water using low cost activated carbon derived from agricultural waste material and activated carbon fabric cloth, J. Hazard. Mater, B135, pp 280-295.\n\tK.Kadirvelu, M. Kavipriya, C.Karthika, M. Radhika, N. Vennilamani, S. Pattabhi, (2003), Utilization of various agricultural wastes for activated carbon preparation and application for the removal of dyes and metal ions from aqueous solutions, Biores.Technol, 87, 129-132.\n\tI. Gaballah, G. Kilbertus, (1998), Recovery of heavy metal ions through decontamination of synthetic solutions and industrial effluents using modified barks. J. Geochem.Explor. 62, pp 241-286.\n\tB. R.Reddy, N.Mirghaffari, I.Gaballah, (1997), Removal and recyclingof copper from aqueous solutions using treated Indian barks, Resour Conserv Recycle, 21, pp227-245.\n\tE. Nehrenheim, J. P. Gustafsson, Kinetic sorption modelling of Cu, Ni, Zn, Pb and Cr ions to pine bark and blast furnace slag by using batch experiments, (2008), Biores Technol, 99, (6), pp 1571-1577.\n\tK.Karunakaran, P. Thamilarasu, (2010), Removal of Fe (III) from aqueous solutions using Ricinus Communis seed shell and polypyrrole coated ricinus communis seed shell activated carbons, International. J.of Chem Tech. Research, 2 (1), pp 26-35.\n\tJ.U.Deshmukh, E. Ambore, J. S. Pulle, (2007), Heavy metal Pollution of Godvari River due to industrial effluents from M.I.D.C Nanded, Maharastra, India, Jr. of Industrial Pollution Control, 23(1), pp 107-111.\n\tVenkateshwarh. V, Manikya Reddy. P, Rajkumar. B, (1994), Heavy metal pollution in the rivers at A.P. India. J. Environ. Biol. 15 (4), pp 275-282.\n\tChopade V V, Tankar A N, Pande V V, Tekade A R, Gowekar N M, Bhandari S R, Khandake S N, (2008), Pongamia pinnata: Phytochemical constituents, traditional uses and pharmacological properties: A review, Int. J. Green Pharm, 2, pp 72-75.\n\tAPHA. 1985, Standard methods for examination of water and waste water, American Public Health Association, Washington, 18th edition.\n\tY N Hao, Zhang Si, Jun Wu and Nan Haihan, (2006), Dihydro pyranoflavones from Pongamia pinnata, J. of the Brazilian Chemical Society, 17, 1432-1435.\n"]}

One of the causes of water pollution is the presence of heavy metals in water. In the present study, an adsorbent prepared from the raw bark of the Pongamia pinnata tree is used for the removal of ferrous or ferric ions from aqueous and waste water containing heavy metals. Adsorption studies were conducted at different pH, concentration of metal ion, amount of adsorbent, contact time, agitation and temperature. The Langmuir and Freundlich adsorption isotherm models were applied for the results. The Langmuir isotherms were best fitted by the equilibrium data. The maximum adsorption was found to 146mg/g in waste water at a temperature of 30°C which is in agreement as comparable to the adsorption capacity of different adsorbents reported in literature. Pseudo second order model best fitted the adsorption of both ferrous and ferric ions.