Adsorptive removal of direct dyes by low cost rice husk: Effect of treatments and modifications

In the present study, free, carboxymethyl cellulose (CMC)-immobilized, polyvinyl alcohol (PVA)-alginate immobilized and chemically treated rice husk biomass was used for the biosorption of Everdirect Orange-3GL and Direct Blue-67 dyes. Maximum biosorption capacity of free, immobilized and hydrochloric acid treated biomass was observed for both dyes at low pH. Comparative study of free, immobilized and HCl treated biomass showed that, the HCl treated biomass exhibited more biosorption capacity (29.98 and 37.92 mg/g) for Everdirect Orange-3GL and Direct Blue-67, respectively. Equilibrium time was less for HCl treated biomass when compared with immobilized biomass. The Langmuir type 1 and 2 models were best fitted to experimental data for free, CMC, polyvinyl alcohol-alginate immobilized and HCl treated biomass in case of Everdirect Orange-3GL, while the equilibrium data of Direct Blue-67 followed the Langmuir type 2 isotherm. Pseudo-second-order and Elovich kinetic models illustrated good fitness to all types of biomasses showing chemisorption nature of biosorption. The amount of dyes sorbed (mg/g) increased with increase in temperature. The values of Gibbs free energy (ΔG°) showed that reaction was spontaneous at high temperature.Key words: Biosorption, kinetics, thermodynamics, direct dyes, immobilization, pretreatments

Biosorption of Foron turquoise SBLN using mixed biomass of white rot fungi from synthetic effluents

In the present study, biosorption of Foron turquoise SBLN using mixed biomass of white rot fungi was investigated in batch mode. The effect of process parameters such as pH of solution, medium temperature, biosorbent concentration, dye initial concentration, contact time etc. was investigated for enhanced removal of the dye. Maximum dye removal was observed at pH 2, biosorbent dose, 0.1 g/100 ml and temperature 30°C. The equilibrium data were analyzed by commonly employed Langmuir and Freundlich isotherm equations. The results show that the equilibrium data were better described by Freundlich isotherm model as compared to Langmuir equation. The biosorption kinetic data were found to follow the pseudo-second-order model. The results therefore indicated that mixed biomass of whiterot fungi could be used as natural biosorbent to remove dyes from aqueous effluents.Key words: Biosorption, disperse dye, Ganoderma lucidum, Coriolus versicolor

Bioleaching of metal ions from low grade sulphide ore: Process optimization by using orthogonal experimental array design

The present work was aimed at studying the bioleachability of metal ions from low grade sulphide ore containing high amount of carbonaceous materials by selected moderately thermophilic strain of acidophilic chemolothotrophic bacteria, Sulfobacilllus thermosulfidooxidans. The bioleaching process was optimized by constructing L25 Taguchi orthogonal experimental array design and optimization of variable proportions of process parameters. Five factors were investigated and twenty five batchbioleaching tests were run under lower, medium and higher levels of these factors. The parameters considered for shake flask leaching experiments were initial pH (1.8, 2, 2.5, 3, 3.5), particle size, (50, 100, 120, 200, 270 m), pulp density (1, 5, 10, 15, 25%), temperature (40, 45, 47, 52, 57oC) and agitation (100, 120, 180, 220, 280 rpm). Statistical analysis (ANOVA) was also employed to determine significant relationship between experimental conditions and yield levels. The experimental results for selective leaching showed that under engineered leaching conditions; pH 1.8, particle size 120 m, pulp density 10%, temperature 47°C and agitation 180 rpm, the percent bioleachabilities of metals were Zn 72%, Co68%, Cu 78%, Ni 81% and Fe 70% with an inoculum size of 1.0 ×107 /mL

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.Key words: Bioleaching, Penicillium chrysogenum, agriculture wastes, laterite ore

Optimization of growth parameters for lipase production by Ganoderma lucidum using response surface methodology

Lipases comprise a group of hydrolytic enzymes which catalyze reversibly the hydrolysis and synthesis of triacylglycerides in the oil water interface. In this study, a response surface approach was used to study the production of extracellular lipase from Ganoderma lucidum which has diverse applications in various fields. Interactions were studied for five different variables (moisture, canola oil cake, olive oil, pH and time of incubation) which were found influential for lipase production. Using the statistical approach (response surface methodology), the maximum yield of lipase (4838 U/gds) by G. lucidum was observed under optimum conditions. The optimum values of these parameters were as follows: canola oil cake (12.50 g), moisture level (60%), pH (4.5), olive oil as inducer (2.0%) and incubation period (96 h) at 30°C. Exploration of fungal diversity for improved production of lipases using statistical models makes it a high-profile area for novel discovery with enormous potential of massive returns.Key words: Lipases, Ganoderma lucidum, statistical approach, solid state fermentation, incubation period, canola oil cake

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.Key words: Recovery, brown shale, Ganoderma lucidum, organic acids, pulp density

Quantum Imaging with Incoherently Scattered Light from a Free-Electron Laser

The advent of accelerator-driven free-electron lasers (FEL) has opened new avenues for high-resolution structure determination via diffraction methods that go far beyond conventional x-ray crystallography methods. These techniques rely on coherent scattering processes that require the maintenance of first-order coherence of the radiation field throughout the imaging procedure. Here we show that higher-order degrees of coherence, displayed in the intensity correlations of incoherently scattered x-rays from an FEL, can be used to image two-dimensional objects with a spatial resolution close to or even below the Abbe limit. This constitutes a new approach towards structure determination based on incoherent processes, including Compton scattering, fluorescence emission or wavefront distortions, generally considered detrimental for imaging applications. Our method is an extension of the landmark intensity correlation measurements of Hanbury Brown and Twiss to higher than second-order paving the way towards determination of structure and dynamics of matter in regimes where coherent imaging methods have intrinsic limitations

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns