Biosorption of fluoride from aqueous solution by white—rot fungus Pleurotus eryngii ATCC 90888

AbstractIn present study the biosorption characteristics of fluoride anions from aqueous solution using white rot fungus (Pleurotus eryngii) were investigated as a function of pH, initial fluoride concentration, biosorbent dose, temperature, and contact time. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models were applied to describe the biosorption isotherm of fluoride ions by P. eryngii biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The monolayer biosorption capacity of P. eryngii biomass for fluoride ions was found to be 66.6mgg−1. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° indicate that the removal of fluoride ions by fungal biomass was endothermic and spontaneous in nature. Experimental data were also analyzed in terms of kinetic characteristics and it was found that biosorption process of fluoride ion followed well pseudo-second order model, where intra-particle diffusion was not the only rate-controlling step. The surface and sorption characteristics were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and Fourier transform infrared (FTIR) spectrometry. In order to check the practical utility of the studied biosorbent, batch studies were carried out with fluoride contaminated water samples collected from a fluoride-endemic area. Eventually, this fungal biomass recommended to be used as a suitable, environment friendly and low cost biosorbent for removal of fluoride ion concentration to standard permissible limit

Efficient entrapping of toxic Pb(II) ions from aqueous system on a fixed-bed column of fungal biosorbent

The present research dealt with the successful viability and practicality of Pleurotus eryngii packed bed column for Pb(II) ions biosorption. To achieve the aim of the project, the impact of different parameters including flow rate, initial concentration of Pb(II) ions and bed height were optimized. The column models, i.e.,Thomas and Bed Depth Service Time (BDST) were investigated to assess the column efficiency towards entrapping targeted ion. The adsorption capacity, rate constant and correlation coefficient related to each model for column sorption were also calculated. The adsorption capacity enhanced by increasing the bed height and decreasing initial Pb(II) metal ion concentration along with the flow rate. The maximum Thomas model adsorption (entrapping) capacity was obtained 3.30 mg g−1 for initial concentration of 20 mg L−1 at a constant flow rate of 1 ml min−1, bed height of 3 cm and pH 7. The experimental results implied and affirmed the suitability of the P. eryngii fungal biosorbent for Pb(II) ion biosorption with its nature being favourable, efficient and environment friendly

Geant4 step towards the durability and smooth response of silicon based neutron dosimeter, and protection from thermal neutrons

Responses and durability of energy independent neutron dosimeters based on proton detector microchips covered with segmented multi-Thickness polythene (PE) layers are badly affected by the slow neutrons produced in the process. Here, we report the shielding of slow neutrons by using 0.9 cm thick cadmium layer, which is transparent to fast neutrons. This is achieved by using 15 MeV beam of 10 7 number of neutrons incident on poly methyl methacrylate-Aluminum-cadmium (PMMA-Al-Cd) multiple layers by means of a Monte Carlo method. The results can be used in real time dosimeters for measuring the tissue equivalent neutron doses, and for optimizing the shielding of thermal neutrons in the vicinity of proton therapy centers. © 2018 IEEE

Fabrication of cadmium tagged novel ion imprinted polymer for detoxification of the toxic Cd2+ ion from aqueous environment

The present study describes a simple and facile precipitation polymerization technique. For the synthesis of Cd(2+)ion-imprinted polymer for the selective detoxification of toxic Cd2+ ions from the aqueous samples. The resultant Cd2+-imprinted polymer was characterized by the EDX, SEM, and FTIR. Different parameters were optimized during the adsorption study to achieve the maximum adsorption capability i.e. pH, equilibrium time, temperature shaking speed, and adsorbent dose. The maximum adsorption capacity of Cd2+ ion-imprinted polymer was 62.9 mg. g(-1) at pH 6. The kinetic study was best defined by pseudo-second-order, while the Langmuir isotherm model well fitted to present data. Good linearity was achieved in (10-100 mu g. L-1) concentration range with LOD 0.88 mu g. L-1 and LOQ 2.95 mu g. L-1. The relative selective factor (K') of Cd2+-ion and interfering ions was greater than 1 due to the imprinting effect. The developed method was validated by the spiking addition method and obtained good results in accordance with spiking values in real samples. The synthesized ion-imprinted polymer shown higher adsorption capacity than previously reported methods for the selective removal of Cd2+-ions from aqueous samples

Biogenic Silver Nanoparticles for Trace Colorimetric Sensing of Enzyme Disrupter Fungicide Vinclozolin

We report a novel, simple, efficient, and green protocol for biogenic synthesis of silver nanoparticles (AgNPs) in aqueous solution using clove (Syzygium aromaticum) extract as a reducing and protecting agent. Ultraviolet-visible (UV-Vis) spectroscopy was employed to monitor the localized surface plasmon resonance (LSPR) band of clove extract-derived AgNPs prepared under various conditions. Fourier-transform infrared (FTIR) spectroscopy analysis provided information about the surface interaction of the clove extract with the AgNPs. Ultrahigh-resolution transmission electron microscopy (UHRTEM) results confirmed the formation of spherical, uniformly distributed clove extract-capped AgNPs with sizes in the range of 2–20 nm (average size: 14.4 ± 2 nm). Powder X-ray diffractometry analysis (PXRD) illustrated the formation of pure crystalline AgNPs. These AgNPs were tested as a colorimetric sensor to detect trace amounts of vinclozolin (VIN) by UV-Vis spectroscopy for the first time. The AgNP-based sensor demonstrated very sensitive and selective colorimetric detection of VIN, in the range of 2–16 µM (R2 = 0.997). The developed sensor was green, simple, sensitive, selective, economical, and novel, and could detect trace amounts of VIN with limit of detection (LOD) = 21 nM. Importantly, the sensor was successfully employed for the determination of VIN in real water samples collected from various areas in Turkey