Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Heavy metals

Heavy Metals Accumulation in Two Types of Tree Leaves from Baghdad Urban Areas

Maha A. Mahmood; Athmar A.M. AL-Mashhady; Ali N. Ali

Engineering and Technology Journal, 2019, Volume 37, Issue 3C, Pages 350-355
DOI: 10.30684/etj.37.3C.8

It is well known that environmental pollution by many heavy
metals is a serious problem to the natural ecosystem due to their toxic
effects. Most heavy metals such as Cu, Mn, Fe, and Zn are needed by
various organisms but at certain concentrations is very necessary for
both plants and animals. However, it has been suggested that ever green
plant trees can assist in controlling such pollution via various methods
where one method is the ability of these plant trees to absorb heavy
metals from contaminated soils. The current work was designed to assess
Cd, Mn and Pb plant content in two tree species (Eucalyptus sp. and
Albizia sp.) collected from Tourist Baghdad Island (TBI) situated in AlFh’hama region. It seems very obvious that these examined trees can be
regarded as certain heavy metals eliminator where eucalyptus tree has
shown considerable ability in removing all examined heavy metals which
were significantly higher than that of Albizia trees.

Cement Based Solidification/Stabilization Leaching Performances of Selected Heavy Metal Ions under Different pH Extractions

Basim A. Hussain A. Hussain; Shahlaa E. Ebrahim; Abbas H. Sulaymon

Engineering and Technology Journal, 2019, Volume 37, Issue 2C, Pages 268-274
DOI: 10.30684/etj.37.2C.11

Liquid to solid partitioning as a function of pH leaching Procedure LSP EPA method 1313 was carried out to test the effectiveness , performance and efficiency of the cement-based solidification / stabilization (S/S) of heavy metals contaminated sand samples using Ordinary Portland Cement OPC type A . Two cement based mix designs ( 7 and 25 % ) have been applied to (S/S) sand contaminated samples with different heavy metal ions ( Pb , Cu , Cr , and Cd ) having the following concentrations ( 500 , 1500 and 3000 mg / kg ). Fixed water to cement ratio of 0.45 was maintained for all the experiments. Effective retention levels for the heavy metal ions was achieved using a 25 % OPC mix ratio to (S/S) the contaminated samples even when the extraction solutions were of pH levels as low as 2. Leaching experiments showed that as the pH level of the extraction solution is reduces and as the OPC content in the (S/S) samples is reduced the more heavy metal ions that can leach out. Up to 80 % of chromium, cadmium, lead, and copper ions leachability can be prevented when higher cement content is introduced to the solidification / stabilization process under the same pH extraction. Acidic extraction effects and solubilized the Calcium – Silica – Hydrate (C-S-H) gel that is created by the OPC binder, which holds, and contain the heavy metal ions and thus results in more release of those ions into the extraction solutions. The alkaline environments provided by the cement binder are believed to have participated in the precipitation of several metal ions such as cadmium and lead io, leading to their less detection in the leaching extracts. Alkaline extraction experiments (pH 8-13) showed that the mobility of the metal ions under the same experimental conditions followed the order of pb> Cr > Cu > Cd in samples of various cement contents.

Influence of Operating Conditions on Adsorption of Lead (II) Ions From Contaminated Water Using Different Adsorbents

Areej Dalf Abbas

Engineering and Technology Journal, 2012, Volume 30, Issue 6, Pages 991-1000

Removal of heavy metals from water and wastewater has received a great deal of attention. Adsorption is one of the most technologies being used for treatment of polluted water. This study records lab scale experiments to test efficiency of activated carbon as an adsorbent and comparing it with low-cost naturally occurring materials (sand & egg shells) in removing lead ions from wastewater. The adsorption of lead ions from solutions containing different initial lead concentrations (100, 150 and 200 ppm pb as lead nitrate) using different particle
size (140, 300 and 500 ìm) and different doses of activated carbon, sand and egg shells at different pH (4, 7 and 10) was examined. Also the metal concentration retained in the adsorbent phase (mg/g) was calculated. This method of heavy metals removal proved highly effective as removal efficiency increased with increasing adsorbent dose while it decreased with increasing metals concentration. The results revealed that of the studied adsorbents, the activated carbon showed
the highest adsorption capacity and the maximum adsorption can be obtained by using particle size of 140 ìm in neutral media (pH 7). This technique might be successfully used for the removal of lead ions from liquid industrial wastes and wastewater.