Iron and manganese removal from drinking water

The purpose of the present study is to find a suitable method for removal of iron and manganese from ground water, considering both local economical and environmental aspects. Ground water is a highly important source of drinking water in Romania. Ground water is naturally pure from bacteria at a 25 m depth or more. However, solved metals may occur and if the levels are too high, the water is not drinkable. Different processes, such as electrochemical and combined electrochemical-adsorption methods have been applied to determine metals content in accordance to reports of National Water Agency from Romania (ANAR). Every water source contains dissolved or particulate compounds. The concentrations of these compounds can affect health, productivity, compliance requirements, or serviceability and cannot be economically removed by conventional filtration means. In this study, we made a comparison between the electrochemical and adsorption methods (using membranes). Both methods have been used to evaluate the efficiency of iron and manganese removal at various times and temperatures. We used two membrane types: composite and cellulose, respectively. Different approaches, including lowering the initial current density and increasing the initial pH were applied. Reaction kinetics was achieved using mathematical models: Jura and Temkin

Emulsion Membranes Iodine Separation I. Preparation of organic phase membrane emulsion / receiving aqueous solution

One of the major obstacles in membranes achievemen

Research and Science Today No. 1(5)/2013

Research and Science Today Journal is a publication founded in 2011 and it is dedicated to the students of all levels (license, master and doctoral) of faculties in the country and abroad. We want to offer the participants the opportunity to present their scientific works in the following areas: Social Sciences, Economic Sciences, Legal Sciences, Humanities, Education Sciences, Engineering, Medicine and Sport. This journal provides students the opportunity to create and/or to improve their abilities to write scientific papers. So each appearance (two appearances per year at which we can add supplements) contains a number of papers written by students, masters and doctoral from the faculties from the country or/and abroad. The journal promotes original studies contributing to the progress of knowledge and it is motivated by the need to address issues of theory and practice in the areas mentioned above

Research and Science Today No. 1(5)/2013

Research and Science Today Journal is a publication founded in 2011 and it is dedicated to the students of all levels (license, master and doctoral) of faculties in the country and abroad. We want to offer the participants the opportunity to present their scientific works in the following areas: Social Sciences, Economic Sciences, Legal Sciences, Humanities, Education Sciences, Engineering, Medicine and Sport. This journal provides students the opportunity to create and/or to improve their abilities to write scientific papers. So each appearance (two appearances per year at which we can add supplements) contains a number of papers written by students, masters and doctoral from the faculties from the country or/and abroad. The journal promotes original studies contributing to the progress of knowledge and it is motivated by the need to address issues of theory and practice in the areas mentioned above

Research and Science Today No. 1(5)/2013

Research and Science Today Journal is a publication founded in 2011 and it is dedicated to the students of all levels (license, master and doctoral) of faculties in the country and abroad. We want to offer the participants the opportunity to present their scientific works in the following areas: Social Sciences, Economic Sciences, Legal Sciences, Humanities, Education Sciences, Engineering, Medicine and Sport. This journal provides students the opportunity to create and/or to improve their abilities to write scientific papers. So each appearance (two appearances per year at which we can add supplements) contains a number of papers written by students, masters and doctoral from the faculties from the country or/and abroad. The journal promotes original studies contributing to the progress of knowledge and it is motivated by the need to address issues of theory and practice in the areas mentioned above

Removal of Cr 3+ from Waste Solution by a Bulk Liquid Membrane and Ion-Exchange Membrane Nafion 117

In this paper the removal efficiency of chromium trivalent ions by a bulk liquid membrane (BLM

Degradation of Triclosan by TiO 2 -UV Irradiation in Aqueous Solutions

Triclosan (TCS) 5 chloro -2 - Triclosan (TCS) 5 chloro -2 -(2, 4 -dichlorophenoxy) phenol is an antimicrobial agent widely used for personal care products The last decades shown a revaluation of the issue of environmental pollution. Removal of organic compounds of wastewater is a very important subject of research in the field of environmental chemistr y. Available technologies dealing with phenolic compounds include the advanced oxidation processes (AOPs), based on the formation of very active hydroxyl radicals, which react quickly with the organic contaminant. AOPs present the advantage of completely removing organic contaminants from the environment, not only from the aqueous phase, by transforming them into other organic compounds with low toxicity and finally into innocuous inorganic species AOPs type procedures can become very promising technologies for treating wastewater containing nonbiodegradable or hardly biodegradable organic compounds with high toxicity. In this sense, photocatalysis (UV-TiO 2 ) is a handy promising technology, very attractive for wastewater treatment Photochemical processes for the oxidation of organic pollutants, a series of researchers have proposed direct photo-oxidation with ultraviolet light. TiO 2 is the most used semiconductor because of its higher photocatalytic activity. The anatase form of TiO 2 is reported to give the best combination of photoactivity and photostability. The photocatalytic oxidation of organic compounds in water has been widely discussed in the literature. Many studies shown that are possible different methods for treating the effluents The working conditions applied for TCS degradation from synthetic solutions were the following: pH domain = 5.3-8.7; initial pollutant concentration [TCS] 0 = 1 -13.5 mg/L; photocatalyst dose [TiO 2 ] 0 = 100 -500 mg/L; irradiation time t = 30 -180 min; air flow Q air = 50 L/h. Experimental part Materials and methods The following reagents were used: triclosan supplied by Aldrich, TiO 2 (Merck) anatase form, NaOH (Merck) and H 2 SO 4 (Merck) for pH correction, HCl (Merck), Na 2 SO 4 anh. (Chimreactiv), n-hexane (Fluka) for samples preparation. The TCS degradation was carried out in a Heraeus-type laboratory UV reactor equipped with a medium pressure Hg lamp TQ 150. The incident photon flow was I 0 = 1.05 . 10 -6 einstein s -1 determined by ferrioxalat actinometry. Prior to irradiation, TiO 2 powder was added to the samples with TCS content and the suspensions were bubbled with air (50 L/h), in the dark, for 30 min, in order to attain the pollutant adsorption equilibrium. For the analysis of TCS, gas chromatography coupled with ion trap mass spectrometry was used. Up to 400 mL of sample wer

Thorium Removal, Recovery and Recycling: A Membrane Challenge for Urban Mining

Although only a slightly radioactive element, thorium is considered extremely toxic because its various species, which reach the environment, can constitute an important problem for the health of the population. The present paper aims to expand the possibilities of using membrane processes in the removal, recovery and recycling of thorium from industrial residues reaching municipal waste-processing platforms. The paper includes a short introduction on the interest shown in this element, a weak radioactive metal, followed by highlighting some common (domestic) uses. In a distinct but concise section, the bio-medical impact of thorium is presented. The classic technologies for obtaining thorium are concentrated in a single schema, and the speciation of thorium is presented with an emphasis on the formation of hydroxo-complexes and complexes with common organic reagents. The determination of thorium is highlighted on the basis of its radioactivity, but especially through methods that call for extraction followed by an established electrochemical, spectral or chromatographic method. Membrane processes are presented based on the electrochemical potential difference, including barro-membrane processes, electrodialysis, liquid membranes and hybrid processes. A separate sub-chapter is devoted to proposals and recommendations for the use of membranes in order to achieve some progress in urban mining for the valorization of thorium