AbstractThe crystallization of ferrierite/ZSM-35 zeolite at 180 Âą 50C in the presence of ethylenediamine as a structure-directing agent from reaction mixtures containing various active NaOH/SiO2 ratios has been studied. X-ray diffraction, scanning electron microscopy, TG/DTG/DSC analysis, nitrogen sorption measurements and temperature-programmed ammonia desorption were used to characterize the ferrierite/ZSM-35 solids. The XRD data reveal that the samples synthesized in optimized conditions are...
Autori: Ioana Droahna, Iuliean Asaftei, Nicolae Bilba
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25251

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

It is a promising way for CO2 capture and sequestration by hydrates crystallization. In this study, the characteristics of CO2 hydrate formation are investigated in a small scale dynamic reactor under pressure conditions from 2.0-3.5 MPa and temperature varied between 0.5-4.0Â?C. The effects of supercooling degree and pressure on hydrates formation were discussed. Hydrates formation can be completely finished within 150 min and the final pressure-temperature points of system are just located on ...
Autori: Ni Liu, Xiaobo Xuan, Daoping Liu, Yingming Xiehttp://www.ecozone.ro/reviste.php?RID=25689

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

Fly ash and fly ash based zeolites are inorganics used for improving soil quality. In the current paper, the hydrothermal modification of fly ash was studied. Three methods have been employed for this purpose. The first method involved the use of an autoclave, where synthesis has been performed at a temperature of 120 0C and a treatment time of 4 to 8 hours. Within the second method, the modification of the ash at a temperature of 600 0C by fusion was carried-out. In this method, a mixture of as...
Autori: Corneliu Munteanu, Daniel Bucur, Lacramioara Rusu, Maria Harja, Marinela Barbuta, Ramona Carla Ciocinta
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25885

This work describes the variations in nitrogen (N) and phosphorus (P) removal performances and bacterial population dynamics in response to different influent C/N and C/P ratios in a novel BNR-IC process combining biological nutrients removal (BNR) with induced crystallization (IC). A good nutrients removal performance was achieved at 7.8 of C/N ratio and 23.3 of C/P ratio, where P and TN removal efficiencies were 94.0±2.4% and 90.5±4.3%, respectively. Moreover, significant changes...
Autori: Haiming Zou
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27523

This study was carried out to determine the feasibility of applying a freeze-concentration technique to purify wastewater polluted with dye, such as methylene blue (MB) using a stationary wastewater vessel. In this study, we investigated the impact of freezing temperature, initial MB wastewater concentration and vessel depth upon the removal ratio of MB. Results showed that when the freezing temperature was decreased (from –5 °C to –15 °C), the freezing rate increased. The...
Autori: Yingjie Dai
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27878

The valorization of a metallurgical waste (i.e., an iron-rich slag) as raw material for the fabrication of high hardness glass-ceramics using differential thermal analysis, X-ray diffraction, X-ray fluorescence and scanning electron microscopy was investigated. The melting of the slag was aided by the addition of waste glass cullet (WGC) and the vitrification field of this system was investigated. The non-isothermal crystallization kinetics of the parent glass with the highest slag content was s...
Autori: Erika Iveth Cedillo-GonzĂĄlez
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28168