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

Abstract The feasibility of catholyte-conditioning to enhance the electrokinetic (EK) remediation of cobalt and lead polluted soil has been investigated in this study. Electrokinetic experiments were conducted using an EK cell 10 cm in width, 10 cm in height, and 50 cm in length. Plate type electrode of graphite was used as electrode material. Two experiments were conducted under constant voltage condition (2 V/cm). The pH values of the soil significantly affect the removal of Co and Pb ions...
Autori: Mahdi Bahemmat
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26623

Abstract Biochar derived from agricultural biomass waste is increasingly recognized as multifunctional material for various applications according its characteristics. It is therefore essential to investigate biochar properties before large-scale application. In this study, rice straw-derived biochars produced at different temperature (550, 650, 750 oC). The resulting biochars were subjected to liquidphase oxidation by different agents including KOH, HNO3, H2SO4, H2O2 and KMnO4 to obtain bio...
Autori: Sobhy M. Yakout
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26661

Abstract The aim of this study was to determine the content of the main essential trace (Co, Cr, Cu, Mn, Se and Zn) and toxic (As, Cd, Hg and Pb) elements in milk by inductively coupled plasma-mass spectrometry (ICP-MS) and cold vapor atomic fluorescence spectrometer (CV-AFS) following priory microwave-assisted digestion with HNO3-H2O2. The milk samples were collected from local small-scale producers of different parts of Rodnei Mountains, Eastern Carpathians, Romania. Mean concentrations in...
Autori: Oana Cadar
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26876

An experimental design methodology was applied to study the copper removal from aqueous solutions by immobilized nanoscale Lentinus edodes. The effect of the various variables (biomass loading, initial metal ions concentration, PH, contact time, agitation speed and temperature) were studied in the batch experiment. The results showed that pH, contact time and agitation speed were the most significant variables on biosorption of copper ions determined by Minimum Run Equireplicated Res V Design...
Autori: Rong Chen
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27487

Among the organic pollutants, the chlorinated phenols represent an important class of compounds having a stable world market of ca. 100 kt per year. Due to their aryl structure and presence of the chlorine atom, chlorinated phenols are exceptionally recalcitrant toward chemical reactions aimed at their reduction. Adsorption from liquid phase has received special interest due to its flexibility and simplicity in operation. Especially adsorption using activated carbon (AC) has been recognized by t...
Autori: Marius Sebastian Secula
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27552

The Silicon wafer plays an important role in modern electronic products. During the production of Silicon wafer, a large amount of scrap Silicon wafer is generated. The necessity for it to be recycled and recovered is of vast importance since the metal Silicon (Si) is the major by product. Besides Silicon, the wafers also contain a small quantity of Copper (Cu) and Aluminum (Al), that are considered as minor elements during the recovery process of the Silicon wafer production. Therefore, in o...
Autori: Ching-Hwa Lee
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27660

Huge amount of red mud has been disposed for the past several decades and it is still generating all over the world. Red mud is a waste of the bauxite processing industry obtained during the alkaline extraction of alumina from bauxite ore. The red mud is a potential raw material containing several valuable components including iron, titanium and rare earth metals. The aim of the research was to develop an appropriate acid digestion technique for the red mud in order to determine the amount of...
Autori: Tatjána Juzsakova1
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27780

The corrosion inhibition of mild steel in acidic media at 303 – 333K in 0.1 - 0.5M acids (hydrochloric acid - HCl and trioxonitrate (v) acid - HNO3) and 0.01-0.03g/L Aloe Vera extract (AVE) were investigated by standard weight loss method. The corrosion rate was calculated in the absence and presence of the inhibitors. The inhibition efficiencies of AVE in both acid media increased with increase in concentration and decreased with increase in temperature and period of immersion. Results sh...
Autori: Maureen Ndibe
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27870