Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Magnesium Oxide

Removal of Heavy Metals Using Chemicals Precipitation

Balasim A. AbiD; Mahmood M. BrbootI; Najah M. Al-ShuwaikI

Engineering and Technology Journal, 2011, Volume 29, Issue 3, Pages 595-612

The single component and multi-component hydroxide precipitation and
adsorption were studied for different heavy metals namely Iron (III), Chromium
(III), Copper (II), Lead (II), Nickel (II), and Cadmium (II) from aqueous solutions.
By using the jar tester Magnesia (MgO) was used as a precipitator at different
doses and compared with other chemicals like lime (CaO) and caustic soda
(NaOH). The treatment involves the addition of either magnesia or lime-water
suspensions (combined with cationic polyelectrolyte, CPE) in various doses, 1.0 –
5.0 g/l for the metal samples to study the effect of varying doses on the treatment
efficiency. The results show that the percent removal of metal ions increases to
about 99 % with increasing the MgO dose to some limits. The optimum values of
MgO doses were found to be 1.5-3.0 g/l. The pH value ranges are 9.5 to 10 with
MgO precipitant and pH of 11.5 to 12 with CaO precipitant. In the jar experiment
the rotation speed, N, 180-200 rpm, (G of 460-480 s-1) of mixing for two minutes
was the most favorable speed of rapid mixing and the slow mixing speed of 15-30
rpm, G of (14-35 s-1), for twenty minutes gave the best results.At the best operating
conditions of the pilot plant, the removal efficiency of metal ions was more than
97% at doses of MgO (1.0-4.0 g/l).

Transparent Oxide MgO Thin Films Prepanred By Reactive Pused Laser Deposition

Evan T. Salem; Farhan A.Mohamed

Engineering and Technology Journal, 2010, Volume 28, Issue 4, Pages 723-729

Transparent dielectric thin films of MgO have been deposited on glass
substrates at different oxygen pressure between (50-300) mbar using a pulsed laser
deposition technique to ablation of Mg target in the presence of oxygen as reactive
atmosphere. Structural, and optical, properties of these films have been
investigated. The films crystallize in a cubic structure and X-ray diffraction
measurements have shown that the polycrystalline MgO films prepared at oxygen
pressure (200) mbar and substrate temperature (150°C) with (111) and (002)
orientations. The films deposited at oxygen pressure between (150-300) mbar and
substrate temperature (150°C) exhibited highest optical transmittivity (>80%) and
the direct band gap energy was found to be 5.01 eV at oxygen pressure (200) mbar.
The measured of the resistivity of the film prepared at oxygen pressure (200) mbar
and substrate temperature (150°C) was 1.45x107Ω cm.