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Presence of heavy metals in the aquatic systems has become a serious problem. As a result, there has been a great deal of attention given to new technologies for removal of heavy metal ions from contaminated waters. Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from industrial wastewater. The aim of the present study was to utilize the locally available agricultural waste materials for heavy metal removal from industrial wastewater. The wastewater containing lead and hexavalent chromium was treated with biomass prepared from ficus religiosa leaves. It was fund that a time of one hr was sufficient for sorption to attain equilibrium. The equilibrium sorption capacity after one hr was 16.95 ± 0.75 mg g -1 and 5.66 ± 0.43 mg g -1 for lead and chromium respectively. The optimum pH was 4 for lead and 1 for chromium. Temperature has strong influence on biosorption process. The removal of lead decreased with increase in temperature. On the other hand chromium removal increased with increase in temperature up to 40ºC and then started decreasing. Ion exchange was the major removal mechanism along with physical sorption and precipitation. The biosorption data was well fitted to Langmuir adsorption model. The kinetics of biosorption process was well described by the pseudo 2 nd order kinetics model. It was concluded that adsorbent prepared from ficus religiosa leaves can be utilized for the treatment of heavy metals in wastewater.

Abbreviations: FTIR: Fourier transform infrared rpm: rotations per minute SEM: scanning electron microscopeThe biosorption of lead(II) and chromium(VI) on groundnut hull was investigated. Batch biosorption experiments were conducted to find the equilibrium time and biosorption capacity. Effect of parameters like pH, temperature and initial metal concentration was studied. The maximum biosorption capacity of lead(II) and chromium(VI) was found to be 31.54 ± 0.63 and 30.21 ± 0.74 mg g -1 , respectively. The optimum pH for lead(II) and chromium(VI) removal was 5 ± 0.1 and 2 ± 0.1, respectively. The temperature change, in the range of 20 -45ºC affected the biosorption capacity. The maximum removal of lead(II) was achieved at 20 ± 2ºC, where as maximum uptake of chromium(VI) was observed at 40 ± 2ºC. The biosorption data was fitted to the Langmuir and the Freundlich isotherm models. The Langmuir model showed better representation of data, with correlation coefficient greater than 0.98. The kinetics of biosorption followed the pseudo second order kinetics model. The thermodynamics parameters were evaluated from the experimental data.

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The effects of cork powder loadings on selected physicomechanical, thermal and ablative properties of ethylene propylene diene monomer (EPDM) based thermal insulations were studied in comparison to asbestos filled EPDM thermal insulation. Ethylene propylene diene monomer was compounded with other ingredients, such as fillers, process aid and curing package, and characterised for required properties. It was observed that increasing cork loading up to 33 parts per hundred parts of rubber caused an increase in hardness and tensile strength. Elongation at break, however, decreased with increasing cork percentage in the formulations. Thermal and ablation properties of the thermal insulations were studied by ballistic evaluation motors and oxyacetylene torch. Cork filled vulcanisates had more ablation and better insulative properties than asbestos filled vulcanisates. About 39% reduction in density of the thermal insulation was possible using cork filled insulation instead of asbestos filled insulations.