The removal of arsenic from （ground）-water by adsorbent loaded in polymeric microspheres

Arsenic is a natural tasteless and odourless element,existing in the earth’s crust at average levels of between two and five thousands micrograms per liter (parts per million) . Arsenic is highly toxic to humans, who are exposed to it primarily from air,food and water. The occurrence of arsenic in groundwater is due to geological composition of soil. High concentrations of arsenic in water are the result of dissolution or desorption of ferric oxides and the oxidation of mineral arsenopyrites. Arsenic in drinking water has an important impact on the human health,especially in the less developed countries. Different methods exist to remove arsenic from aquatic media,and one of them is by adsorption. In this work,the adsorption of both As(III) and As(V) by means of novel microspheres has been investigated. In particular,TiO2 has been embedded into polymeric microspheres PES (PolyEtherSulphone) and PEEK-WC (PolyEtherEther-Ketone) . The main advantages of this encapsulation adsorption material are: no loss of adsorbents into the water stream,easy to be used and scaled-up.     

Mechanochemical Synthesis and Electrochemical Characterization of Nano Crystalline Calcium Ferrite

Abstract  

The studies on the mechanochemical synthesis and electrochemical characterization of orthorhombic calcium ferrite (CaFe₂O₄) are reported in this paper. Stoichiometric mixtures of α-Fe₂O₃ and granulated Ca metal were used as the starting materials for the synthesis process. The synthesized calcium ferrite was characterized by room-temperature M?ssbauer spectra, XRD and TEM. The electrochemical characterisation was carried out using cyclic voltammetry studies. M?ssbauer spectra provide the yield of the reaction, information on the charge status, the local symmetry and the magnetic state of the iron ions in the mechanosynthesized ferrite material. XRD analysis of the CaFe₂O₄ compound reveals the orthorhombic crystal structure with an average crystalline size of about 28 nm. TEM micrographs reveal the nanoparticles with irregular crystal morphology ranging from 8 to 30 nm. The electrochemical studies clearly show that the calcium ferrite compound can act as an electrocatalyst for Oxygen Evolution Reaction (OER).