A Bifunctional Electroactive Ti4O7-Based Membrane System for Highly Efficient Ammonia Decontamination

Herein, an electroactive filtration system, consisting of a Ti4O7 anode and a Pd-Cu co-modified nickel foam cathode, was developed and applied for the decontamination of ammonia from water. When assisted with an external electrical field, ClO• was generated on the surface of the Ti4O7 anode, which then reacted selectively with ammonia to generate N2. The anodic byproduct, NO3−, could also be reduced efficiently at the functional cathode to produce N2 as well. Electron paramagnetic resonance technique and radical scavenging tests synergistically verified the essential role of ClO• during the highly efficient ammonia conversion process. Relative to conventional batch systems, the developed flow-through design demonstrated enhanced ammonia conversion kinetics, thanks to the convection-enhanced mass transport. The proposed technology also showed desirable stability across a wide environmental matrix. This work provides new insights for the development of advanced and affordable continuous-flow systems towards effective decontamination of ammonia.

Green Synthesis of Silver Nanoparticles using Strobilanthes flaccidifolius Nees. Leaf Extract and its Antibacterial Activity

The leaf extract of Strobilanthes flaccidifolius Nees. was used for the synthesis of silver nanoparticles through a green technique of synthesis. The nanoparticles was characterized by UV-VIS spectroscopy which proves the formation silver nanoparticles. FTIR (Fourier Transmission infra red spectroscopy) study was carried out to assess the biomolecule as indigo precursors, Energy dispersion X-ray analysis(EDX) data further proves it. EPR (Electron paramagnetic resonance technique) shows the free radical in silver neutral state and XRD(X-ray diffraction technique) also repots silver neutral formation.The morphology and the shape of the silver nanoparticles were determined by Scanning electron microscopy(SEM) and Tunneling electron microscopy (TEM).The nanoparticles adopted spherical morphology and the size ranging from 6nm to 54.11nm and average size was determined as 12.15± 5.3nm.The nanoparticles had antimicrobial activity

EPR-Investigation of Irradiated Imported Foodstuffs and Parameters of EPR Signals

Study by EPR (electron paramagnetic resonance) technique of a wide range of food products imported to Kazakhstan and of analogous domestic foodstuffs has been carried out in order to develop a methodic that would make it possible to control the fact of radiation sterilization of food. Elaborated method of sample preparing for EPR-study included dividing into components, removing moisture by drying or lyophilizing then grinding till dimensional work fraction. Selection of optimal conditions for spectra recording and algorithm of spectra treatment enabled authors to allocate correctly initial EPR-signals and to obtain information on shape, intensities and parameters. Model gamma-irradiations of the initial whole products with subsequent study of prepared EPR-specimen have been carried out. Influence of irradiation on the intensities of EPR-signals and possible changes of EPR-characteristics have been studied in dose range (0.1-25) kGy. EPR-signals of free radicals (FR) of radiation origin were obtained from the EPR-spectra of gamma-irradiated delicious fruits, citrus, vegetables and others. Nonmonotonous dependences of FR concentration on a dose, along with linear ones were observed. Intensities of initial signals and of radiation-induced ones are much higher in solid components, than in pulp, dependences on dose are more close to linearity, which can be used in some cases for retrospective EPR-dosimetry. The obtained results can be explained taking into account specificities of the studied objects, and probable impact of radiochemical reactions of the irradiated water products with radicals formed in substances of foodstuff at irradiation.