http://nopr.niscair.res.in/handle/123456789/13007 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/13036 Title: Removal of Ni (II) from aqueous solutions by adsorption onto <i style="">Cajanus cajan L </i>Milsp seed shell activated carbons <br/> <br/>Authors: Thamilarasu, P; Sivakumar, P; Karunakaran, K <br/> <br/>Abstract: The adsorptive removal of Ni(II) from aqueous solution using <i>Cajanus cajan L </i>Milsp seed shells activated carbon (CCC) and polypyrrole coated <i>Cajanus cajan L </i>Milsp seed shells activated carbon (PPy/CCC) has been carried out under various experimental conditions. Quantity of Ni(II) uptake at 50 mg of activated carbon is 25.75 mg/g for CCC and 29.60 mg/g for PPy/CCC. Adsorption data are modeled with Freundlich, Langmuir and Temkin adsorption isotherms. Thermodynamics parameters, such as <img src='/image/spc_char/delta.gif' border=0>H^o, <img src='/image/spc_char/delta.gif' border=0>S^o, and <img src='/image/spc_char/delta.gif' border=0>G^ohave been calculated and the findings indicate that the adsorption is spontaneous and endothermic. Enthalpy change values range from 8.90 kJ/mol to 23.04 kJ/mol, and based on these values the adsorption of Ni(II) by CCC could be a physisorption. A mechanism involving intra particle diffusion and surface adsorption has been proposed for the adsorption of Ni(II) onto the adsorbent. Adsorbent used in this study is also characterized by FT-IR and SEM before and after the adsorption of metal ions. <br/> <br/>Page(s): 414-420 http://nopr.niscair.res.in/handle/123456789/13035 Title: Removal of arsenic ions and bacteriological contamination from aqueous solutions using chitosan nanospheres <br/> <br/>Authors: Singh, P; Bajpai, J; Bajpai, A K; Shrivastava, R B <br/> <br/>Abstract: This paper reports study on the removal of As (V) by chitosan nanospheres following batch studies conducted as a function of dosage, contact time and temperature. The kinetic investigation of the removal process reveals that the uptake of As (V) ions by chitosan is very rapid in the first 40 min and then an equilibrium adsorption is achieved in next 20 min. The adsorption data has been applied to Langmuir and Freundlich isotherm equations and various experimental parameters such as solid to liquid ratio, <i style="">p</i>H, temperature and contact time are varied to optimize the conditions for the removal of arsenic ions. Antibacterial studies are also performed on native chitosan and silver nanoparticles loaded chitosan nanospheres and dissolved oxygen is calculated in water samples treated with chitosan and Ag-chitosan nanospheres. <i style="">Escherichia coli</i> is used to test the bactericidal efficacy of synthesized Ag-chitosan nanospheres. These nanospheres are found to have significantly higher antibacterial activity than the native chitosan nanospheres. <br/> <br/>Page(s): 403-413 http://nopr.niscair.res.in/handle/123456789/13034 Title: Hexavalent chromium removal by gingelly oil cake carbon activated with zinc chloride <br/> <br/>Authors: Nagashanmugam, K B; Srinivasan, K <br/> <br/>Abstract: An activated carbon has been prepared from gingelly oil cake (GOC) by zinc chloride treatment and its Cr(VI) removal capacity is compared with that of commercial activated carbon (CAC). The effect of experimental parameters such as <i>p</i>H, initial concentration, contact time and adsorbents dose for Cr(VI) removal has been studied. Langmuir, Freundlich and Temkin models are tested to describe the equilibrium isotherms. The maximum adsorption capacity of the adsorbents calculated from Langmuir isotherm is found to be 62.5 mg/g and 25.13 mg/g for zinc chloride treated gingelly oil cake carbon (ZTGOC) and CAC respectively. R² values show that both Langmuir and Freundlich models fit well to explain the adsorption phenomenon for ZTGOC and CAC. The kinetic data fits best to pseudo-second order model. FT-IR analysis has been used to obtain information on the nature of possible interaction between carbon adsorbents and metal ions. SEM images confirm the adsorption of Cr(VI) onto these adsorbents through morphological observations. Thermodynamic study shows the feasibility of process and spontaneous nature of the adsorption. The carbon adsorbents have also been tested for the removal of Cr(VI) from chrome plating wastewater and &nbsp;are found to remove Cr(VI) effectively.<i style=""></i> <br/> <br/>Page(s): 391-402 http://nopr.niscair.res.in/handle/123456789/13033 Title: Influence of <i>Ficus religiosa</i> leaf powder on bisorption of cobalt <br/> <br/>Authors: Krishna, B; Venkateswarlu, P <br/> <br/>Abstract: The batch-wise biosorption of cobalt by <i style="">Ficus religiosa</i> (peepul) leaf powder has been carried out. The optimum biosorbent dosage is 60 g/L for an equilibrium agitation time of 90 min. Percentage removal of cobalt is increased from 70.9 to 97.2 (0.96 to 1.45 mg/g) with decrease in acidity in the <i style="">p</i>H range from 2 to 7. The experimental data are well represented by Freundlich (<i style="">n</i>=0.42, <i style="">K_f</i>=0.83 L/g, <i style="">R²</i>=0.948), Langmuir (<i style="">R_L</i>=0.566, <i>q</i>_m= 3.60 mg/g, <i style="">R²</i>=0.991), Redlich-Peterson(<i style="">R²</i>=0.98) and Temkin (<i style="">R²</i>=0.98, b_T =784.52) isotherms, indicating favourable biosorption. The biosorption of Co(II) is described by the pseudo-second order rate equation (<i style="">K</i>=0.418 g/mg-min, <i style="">R²</i>=0.99) preferably than first order rate equation (<i style="">R²</i>=0.89). The biosorption is exothermic, irreversible and spontaneous. <br/> <br/>Page(s): 381-390