Bio removal of heavy metals by algae with determination of their molecular responses using the COMT assay

Abstract

The present study included testing the ability of three types of algae, which include Oscillatoria sp., Westiellopsis prolifica, and Stigonema sp.  to reduce the values ​​of some heavy elements. Wastewater from the final sedimentation tanks of the Al-Ma'mara wastewater treatment plant was used as culture media for growing algae.

      The results showed the efficiency of algae in reducing sodium values and the highest reduction rates recorded by Oscillatoria sp. and Stigonema sp. were 43.4% and 35.9% respectively, while W. prolifica recorded a reduction rate of 27.3% . Algae also recorded efficiency in reducing potassium, as Oscillatoria sp. recorded a higher reduction efficiency of 71.2%, while W. prolifica and Stigonema sp. recorded the highest reduction rate of 43.1% and 32.1% respectively. Algae recorded iron reduction rates throughout the treatment period, and reduction rates reached 98.3% for both Oscillatoria sp. and Stigonema sp. while W. prolifica recorded higher reduction rates of 100%. Algae also recorded a reduction of copper of 61.8% and 53.03% for Oscillatoria sp. and W. prolifica respectively, while Stigonema sp. recorded lower reduction rates of 38.3%. Stigonema sp. recorded a higher efficiency in reducing zinc values ​​of 86.8%, while Oscillatoria sp. and W. prolifica recorded a reduction rate of 69.2% and 72.74% respectively..As for cadmium, Oscillatoria sp. recorded the highest reduction rate of 72.7%, while W. prolifica and Stigonema sp. recorded reduction rates of 66.4% and 53.3% respectively. As for the role of algae in treating lead, the results indicate that the highest rates recorded when treating with Oscillatoria sp., W. prolifica and Stigonema sp. reached 99.6%.