Abstract The etching of iron materials in sulphuric acid solutions allows the dissolution of the iron oxides with formation of iron sulphates. The relatively low solubility of the formed sulphates imposes their separation for avoiding the contamination of the etching bath, as well as for preventing the environmental pollution through the wastewater. Within the flow sheet of the processing of the hot or cold rolled steel, a stage of separation by crystallization of iron sulphate is foreseen. T...
Autori: Liliana Lazar, Ion Balasanian, Florin Bandrabur
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25415

Abstract The use of fly ash (FA) in wastewater treatment received a lot of attention for the immobilization of heavy metal cations, mainly Cd2+, Pb2+, Ni2+, Zn2+, Cu2+. For an up-scalable wastewater treatment process, the substrate must have good adsorption efficiency and relatively constant behaviour. Modifying the fly ash surface can be a solution for reaching both goals. The use of FA for heavy metals removal, from wastewaters resulted in the dye finishing industry, faces a supplementary p...
Autori: Maria Visa, Anca Duta
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25471

Abstract A crucial stage which makes the other directions of development of membrane processes is getting new membrane materials, to meet increasingly stringent of selectivity and productivity. Polyetheretherketone shows high stability against chemical and physical agents but is poorly soluble in most common solvents. Present studies on obtaining the support of the polyetheretherketone membranes were limited by: solubility of polyetheretherketone in concentrated sulfuric acid and fast speed a...
Autori: Mihaela Emanuela Craciun, Aurelia Cristina Nechifor, Florin Aldea, Gheorghe Nechifor
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25475

Abstract Commercial pure titanium (Cp-Ti) and titanium alloys are used on large scale in restorative dentistry due to their advantages as compared with other similar materials: chemical inertia, low density, high strength, high corrosion resistance in biological media and increased biocompatibility.The effect of fluoride and pH on the corrosion behaviour of Cp-Ti and a new Ti50Ta alloy were examined by open circuit potential (EOC) measurement, linear polarization, potentiodynamic polarization...
Autori: Daniel Mareci, Daniel Sutiman, Georgiana Ciurescu, Igor Creţescu, Romeo Chelariu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25591

The corrosion products of high strength low-alloyed steel and of cast iron, maintained a prolonged period in natural seawater, were analyzed. A part of the corrosion products are soluble compounds of divalent and trivalent iron, the iron dissolution being accelerated when divalent ions are formed and in the case of the aerated seawater. The solid corrosion product formed during corrosion in seawater is principally oxy-hydroxide (FeOOH), but were identified small quantities of Fe2O3, Fe3O4 and so...
Autori: Daniel Mareci, Maria Lungu, Nicanor Cimpoeşu, Nicolae Aelenei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25832

Biomass is a very interesting natural source to obtain renewable energy as well as chemical products based on a renewable feedstock. Fuel produced from renewable resources is widely regarded as an option to substitute traditional fossil fuels and thus to answer to the adjunct climate debate. For the production of chemical substances from renewable substrates many process options are in investigation worldwide at the moment. However the ecological benefits of these technological options have to b...
Autori: Anton Friedl
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25856

AbstractGroundwater hydrochemical evolution has influences on the rational use and conservation of water resources. This paper whichtakes MapGIS as the platform is aimed at demonstrating the evolution of shallow groundwater hydrochemistry in Guanzhongbasin (China) by adopting mathematical statistics, ratios of ion pair equivalents, geochemical simulation. The direction ofevolution is dependent on the geological, geomorphological, and hydrogeological conditions of the study area. The spatialdistr...
Autori: Hua Tian, Lei Duan, Wenke Wang, Xiaoting Yang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25956

AbstractPrinted circuit boards-PCBs are particularly rich in copper and precious metals. Recoveries of metals in our work started withtests for electrodeposition of Au, Ag and Cu from synthetic solutions on graphite and copper electrodes. Processes were studiedusing cyclic voltammetry in ranges: (-1200)-500 mV and (-800)-(-200) mV and (-400)-1400 mV. Different supportingelectrolytes like: H2SO4 0.5M, HCl 0.1M and HNO3 0.1M were used. Electrodeposition of studied metals from real solutions wasfol...
Autori: Adina Căta, Cristian Tănasie, Daniel Boc, Firuţa Fiţigau, Mariana Nela Stefănuţ, Paula Sfîrloagă, Raluca Pop, Zoltan Űrmösi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26036

The book edited by Haibo Xie and NicholasGathergood focuses on one of the most importantscientific issues of the 21 century which is thereplacing fossil fuel with sustainable alternatives suchas biomass. Fossil fuels are conventional rawmaterials for many industrial sectors includingchemical and energy production. Usage of fossil fuelis limited by their availability, price and carbonfootprint. Biomass is a renewable resource globallyavailable, cheaper and carbon sequestering. Step bystep shiftin...
Autori: Adrian Catalin Puitel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26101

Abstract Cadmium leaching experiments from hazardous waste containing 16.5 wt% CdO were conducted using H2SO4. Dominant experimental and process parameters were determined by factorial design. Six controlling factors were considered, i.e. solidliquid ratio, acid concentration, reaction time, particle size, stirring speed and temperature. Analysis of variance (ANOVA) was used to identify main effects and their interactions. An empirical model, based upon experimental results, was developed to...
Autori: Mahdi Gharabaghi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26590

Abstract This study is focused on the dissolution kinetics of zinc oxide in ammonium acetate solutions to recover the zinc from alkaline and zinc-carbon spent battery powders. This study represents a first step for further studies in which actual waste powder is to be used. Therefore, the experiments were performed by using pure zinc oxide powder to evaluate the dissolution behavior of zinc. The effects of ammonium acetate concentration, reaction temperature, stirring speed and solid to liqu...
Autori: Nizamettin Demirkıran
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26618

Abstract The purpose of this study was to investigate the influence of hydroxypropyl-β-cyclodextrin on diosmin, substance from the flavones category with important pharmacological properties. We carried out solubility studies, calculating the solubility constant of the complex formed between diosmin and hydroxypropyl-cyclodextrin at various temperatures (20, 25 and 37 0C) and in the presence of increasing cyclodextrin concentrations. AL type curves were obtained which suggest the format...
Autori: Constantin Ciobanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26643

Abstract The aim of the present study was to determine the most feasible experimental conditions for the dissolution of base metals (Cu, Ni, Zn, Pb, etc.) from waste printed circuit boards (WPCBs) obtained from WMP. The leaching of WPCB samples was performed with FeCl3 in HCl solution which allowed the separation of a precious metal rich solid residue and a high base metal concentration solution adequate for base metal recovery. The most favorable conditions for the leaching process were ide...
Autori: Szabolcs Fogarasi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26877

Abstract To assess the pollutants input of acid mine drainage (AMD) and domestic activities in Aries River, the water was monitored monthly, during one year, in 15 sampling points along the River. The dissolved metals (Ca, Mg, Na, K, Fe, Cu, Zn, Mn), anions (SO42-, NO3- and Cl-), pH and electrical conductivity were analyzed. The obtained data were assessed against the water quality standards, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis. The results revealed the water...
Autori: Erika Andrea Levei
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26881

Waste recycling in steel industry by turning grain-size and powdery waste into pellets is a must now more than ever for economical motivation, in order to save raw materials and also for ecological reasons, as it leads to a cut down in the quantity of dumped waste. Industrial practice offers processors various technologies of waste recycling (agglomeration, briquetting, pelleting, mechanical mixture). The optimal variant should be chosen according to waste type, its content of useful elements...
Autori: Ana Virgina Socalici
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26968

Evaluation of spatial/ temporal water quality data at reservoirs has shown differences after the dam construction as well as long-term changes of water chemistry. One of the most recent reservoirs created in Europe is Ilarion Reservoir in Western Macedonia – Greece (2012). In this work, the water physicochemical characteristics of this young reservoir and the spatiotemporal water quality variation of the feeding river and its main tributaries have been studied, and statistically interprete...
Autori: Elisavet Amanatidou
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27737

In this work, the examination of separation of gypsum from wastewater generated during the machining of casts and the method of waste gypsum management have been presented. This waste gypsum is produced in Ortolab Poland facilities. Gypsum casts are cut and ground in water-cooled circular saws. Wastewater, with over-normative content of suspension, 10000 mg L-1 and sulphates, 1600 mg L-1 is produced in the process. The analysis of water and wastewater management in Ortolab Poland facilities l...
Autori: Ewa Liwarska-Bizukojc
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27910

Leather processing is one of the highly polluting industries, due to generation of significant quantities of tanned and untanned wastes. Untanned wastes are less contaminated with chemicals and a better source of high value products such as collagen rather than tanned or finished leather wastes. In the present study, collagen dissolution substances (CDS) were prepared from bovine limed split wastes as value added products, by treating leather wastes with sodium hydroxide and fermented dairy b...
Autori: Gökhan Zengin
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28095