Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Kinetics


Removal of Ni (Ii) and Cd (Ii) Ions From Aqueous Solutions by Adsorption on to Synthetic Zeolite

Alhassan H. Ismail; Zainab Ali Abd-aljaleel; Ali S. Jaffer

Engineering and Technology Journal, 2013, Volume 31, Issue 8, Pages 1497-1507

In this study, the removal of Ni (II) and Cd (II) ions from aqueous solutions using the adsorption process onto synthetic Zeolite has been investigated as a function of initial metal concentration, contact time, pH and temperature. In order to find out the effect of temperature on adsorption, the experiments were conducted at 20, 30, 40, 50 °C and 15, 30, 50 °C for Ni (II) and Cd (II) respectively. Kinetics data show that at higher temperatures, the rate of adsorption on the synthetic Zeolite is much higher compared to that on the lower temperatures. The optimum pH for Ni (II) and Cd (II) removal is found out to be 5.5 and 6 respectively. The batch method has been employed using initial metal concentrations in solution ranging from 25 to 100 mg/l for Ni (II) and from 10 to 25 for Cd (II) at optimum pH. An Atomic Absorption Spectrophotometer was used for measuring the heavy metal concentrations before and after adsorption. Langmuir, Freundlich, models were applied to adsorption equilibrium data to find the best amongst these models. This study has demonstrated that Zeolite was capable to remove 90% of nickel and cadmium from solution of different concentrations. This implies that Zeolite is an important in the removal process. These capabilities of Zeolite could lead to development of a viable and cost effective technology for removal of these pollutants from wastewater for countries like Iraq.

Effect of Transformation Temperature on Microstructure andMechanical Properties of Bainite

Hala Salman Hasan

Engineering and Technology Journal, 2012, Volume 30, Issue 13, Pages 2165-2174

Fully bainitic microstructure can be obtained by isothermal transformation at
temperatures within the range of bainite transformation. Both transformation temperature
and time determine the phase fraction, the scale of the resultant microstructure and the
carbone content of the retained austenite, which in turn determine the mechanical
properties.
In this study, the thermomechanical simulator was used to obtained the fully bainitic
microstructure for the high carbon alloy steel (0.78%C) at a different bainite
transformation temperatures (200 to 350°C) in order to study the effect of the isothermal
transformation temperature on the resultant mechanical properties.
It has been concluded from the detailed analysis of the microstructure, the dilatometric
data and the mechanical properties (hardness and tensile properties) that finer bainite and
less retained austenite phase fraction can be obtained by transformation at lower
temperatures, and that leads to exceptional mechanical properties (Hardness ≈ 660 HV,
and Tensile strength ≈ 2 Gpa).