Water purification using a novel reactor with the photoactive refill

The aim of the presented work was the removal of organic dye, Acid Red 18, from water using a novel reactor with the photoactive refill. Titanium dioxide was immobilized on the base material as a thin layer from the alcoholic suspension followed by thermal stabilization. The prepared coating exhibits high stability in repeated cycles of water treatment. The complete removal of colour was achieved in a relatively short time of 14 hours. The proposed reactor with the photoactive refill solves the problem of the necessity of the replacement of the reactor or parts of the reactor when the photocatalysts activity decreases. In the case of activity drop of the photocatalyst, only the photoactivve refill can be easily replaced

Removal of organic dye in the hybrid photocatalysis/membrane processes system

The removal of azo dye Acid Red 18 in hybrid photocatalysis/membrane processes systems was investigated. The photocatalytic reactions were conducted in the reactor with photocatalyst suspended in the solution. The reaction solution was recirculated through the ultrafiltration system. A commercially available titanium dioxide (AeroxideŽ P25, Degussa, Germany) was used as a photocatalyst. The solution after the photocatalytic/UF reaction was applied as the feed for the membrane distillation process. The changes of various parameters, including the concentration of the dye, pH and the conductivity of the solution, TOC and TDS content were analyzed during the process. It was found that azo dye Acid Red 18 could be successfully decolourised in the hybrid photocatalysis/UF system. The catalyst particles were retained in the feed solution by means of the ultrafiltration membrane so the obtained permeate was free of TiO2. The application of ultrafiltration together with the photocatalytic process results in the separation of photocatalyst from the treated solution but does not give the complete removal of organic matter from the reaction mixture. Membrane distillation applied with the permeate after the photocatalysis/UF process as a feed gives a complete separation of TOC from the treated solution and the obtained product is practically pure water

Water purification using a novel reactor with the photoactive refill

The aim of the presented work was the removal of organic dye, Acid Red 18, from water using a novel reactor with the photoactive refill. Titanium dioxide was immobilized on the base material as a thin layer from the alcoholic suspension followed by thermal stabilization. The prepared coating exhibits high stability in repeated cycles of water treatment. The complete removal of colour was achieved in a relatively short time of 14 hours. The proposed reactor with the photoactive refill solves the problem of the necessity of the replacement of the reactor or parts of the reactor when the photocatalysts activity decreases. In the case of activity drop of the photocatalyst, only the photoactivve refill can be easily replaced

Stability of selenium diet supplement

Selenium is one of the trace elements playing a crucial role in a proper function of living organisms. Selenium intake varies, largely based on the selenium content of food. The daily Se intake recommended for adults amounts to 55 μg per day. The mean level of selenium in the population varies considerably between countries. Recent studies on the selenium dietary intakes in Poland showed that it is not sufficient to meet the daily requirement for this microelement so it is strongly recommended to employ selenium supplementation. The commercial product SEL-BRCA1®  being a selenium diet supplement was subjected to chemical and microbial analysis to determine its stability in storage time and conditions. Basing on the obtained results it can be stated that the stability of studied supplement, stored in the closed bottles, can be confirmed for the period of time up to 45 months after the production date and it is not recommended to store opened bottles for the period of time longer than 12 months. The studied supplement showed a very high microbial stability what underscores its usefulness as human medicines

TiO Supported on Quartz Wool for Photocatalytic Oxidation of Hydrogen Sulphide

A spacial system consisting of TiO 2 on a fibrous support was prepared by hydrolysis of titanium isopropoxide in the presence of quartz wool, followed by calcination. The material was characterized by X-ray diffraction, nitrogen adsorption–desorption at 77 K, X-ray photoelectron spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The TiO 2 /support system was examined as a photocatalyst for UV-assisted oxidation of H 2 S in air. The results obtained confirmed a superior performance of the TiO 2 /support system over TiO 2 powder. H 2 S underwent oxidation to elemental sulphur and/or S 6+ . The relative amounts of these species were influenced by humidity

Membrane Surface Modification and Functionalization

Surface functionalization of membranes is one of the efficient techniques that can bestow these membranes with novel properties and transform them into valuable finished products. It has been widely applied to polymeric membranes in many fields and has progressed rapidly in recent years. The modified membranes have been widely used in various applications, such as in separation processes for liquid and gaseous mixtures (gas separation, reverse osmosis, pervaporation, nanofiltration, ultrafiltration, microfiltration), biomaterials, catalysis (including fuel cell systems), and “smart” membranes. In this chapter, various approaches to the surface modification and functionalization of polymeric membranes are highlighted and reviewed. Also, the applications of the modified membranes will be discussed from the aspect of environmental stimuli-responsive gating membranes, antifouling membranes, adsorption membranes, pervaporation and reverse osmosis membranes, membranes for energy conversion, gas separation membranes, and biomedical membranes. A detailed overview of the usage of polyzwitterions and oxidative stability of surface modifiers to alter membrane surface charge will be outlined. Finally, recent advances and developments in surface modification techniques such as layer-by-layer assembly and chemical vapor deposition will be discussed

Advances in heterogeneous photocatalytic degradation of phenols and dyes in wastewater : a review

Rasul, M ORCiD: 0000-0001-8159-1321The heterogeneous photocatalytic water purification process has gained wide attention due to its effectiveness in degrading and mineralizing the recalcitrant organic compounds as well as the possibility of utilizing the solar UV and visible light spectrum. This paper aims to review and summarize the recently published works in the field of photocatalytic oxidation of toxic organic compounds such as phenols and dyes, predominant in wastewater effluent. In this review, the effects of various operating parameters on the photocatalytic degradation of phenols and dyes are presented. Recent findings suggested that different parameters, such as type of photocatalyst and composition, light intensity, initial substrate concentration, amount of catalyst, pH of the reaction medium, ionic components in water, solvent types, oxidizing agents/electron acceptors, mode of catalyst application, and calcinations temperature can play an important role on the photocatalytic degradation of organic compounds in water environment. Extensive research has focused on the enhancement of photocatalysis by modification of TiO2 employing metal, non-metal, and ion doping. Recent advances in TiO2 photocatalysis for the degradation of various phenols and dyes are also highlighted in this review