Sadia Ilyas

Bioleaching of copper, aluminum, magnesium and manganese from brown shale by Ganoderma lucidum

The present study was done to check the bioleaching feasibility of brown shale for the recovery of copper (Cu), aluminum (Al), magnesium (Mg) and manganese (Mn) ions using Ganoderma lucidum. Different experimental parameters were optimized for the enhanced recovery of metals ions. Effect of different substrates like glucose, molasses, saw dust and cotton seed cake on the recovery of metals ions was investigated under shaking as well as non-shaking conditions. Significant difference in leaching of metal ions by G. lucidum was observed under shaking and non shaking conditions. Maximum leaching of Al (90.7%), Mg (96.46%), Mn (66.3%) and Cu (73.45%) was observed using glucose under shaking conditions with 5, 3, 4 and 3% pulp densities respectively. The results show that maximum solubilization up to 68.89, 77.03 and 38.37% was achieved for Cu, Al and Mg ions respectively using molasses as substrate, whereas, 57.74% recovery of Mn was achieved with saw dust. The recovery of metal ions indicated that this low grade discarded ore may be a potential source of metal ions in future.

Bio-extraction of metal ions from laterite ore by Penicillium chrysogenum

The main objective of this study was to find a more feasible and economical method to extract metal ions from laterite ore by Penicillium chrysogenum. The effect of different substrates on microbial recovery of metal ions from laterite ore using indigenous strain of P. chrysogenum was observed. Maximum recovery of aluminum (86.78%), iron (97.78%), manganese (77.61%), nickel (57.31%) and chromium (34.32%) was recorded in case of shaking flasks experiments up to 24 days of incubation. Metal ions solubilization was also compared with the samples, which were not shaken and maximum recovery of Al (83.54 %), Fe (96.12 %), Mn (88.56 %), Ni (46.53 %) and Cr (37.82 %), were attained up to 24 days of incubation period. Enhanced recovery of Fe and Al may be due to the result of the acidic effect of the environment and the chelating capacity of organic acids.

Removal of copper from an electroplating industrial effluent using the native and modified spirogyra

In the present study, biosorption behavior of a green filamentous alga, spirogyra in its native and modified states was investigated for copper removal from an electroplating industrial effluent. For this, the effluent containing 194 mg·L-1 Cu2+ in sulfate medium was contacted with both forms of spirogyra, under the parametric variations of effluent pH, adsorbent dosage, contact time, and sorption temperature. The study revealed spirogyra as a prominent candidate for removing contaminant metal cation; however, at the same condition, biosorption capacity of modified biomass in gel form was higher than the native spirogyra. At the optimized condition with 6 g sorbent dosage treated to 100 mL effluent for 30 min at pH 6.0 and temperature 20 °C, the maximum 82.8% and 96.4% copper could be adsorbed by the native and modified spirogyra, respectively. The batch sorption data using native biomass followed pseudo-first-order kinetic; exhibiting the multilayer sorption mechanism via surface diffusion could be defined by the Freundlich model. In contrast, the sulfuric acid treated modified spirogyra followed pseudo-second-order kinetics and intra particle diffusion as the rate-limiting step.