ESTIMATION OF SOIL'S SORPTION CAPACITY TO HEAVY METALS IN ALGERIAN MEGACITIES: CASE OF ALGIERS AND ANNABA.

Soils contamination with heavy metals is a major concern and common problem in Algerian megacities. The case of Algiers and Annaba which have known in last years a rapid urbanization and increasing of industrialization. These activities were synonymous with economic and social progress. Moreover, they led to many ecological problems, due to different urban pollution: waste disposal, noise pollution, atmospheric, industrial, soils pollution etc. It is well known that heavy metal contamination is a serious threat to the environment. In fact, large concentrations of heavy metals introduced into the environment may represent a potential toxicity for all living organisms, including humans. The present study was conducted to determine the features of heavy metals adsorption by soils collected in Algiers and Annaba. Wherefore the soil adsorbency to heavy metals was assessed by plotting the isotherms and determining the maximum adsorbency. Whereas results study on sorption isotherms of Algiers soils show that the tested elements can be arranged in the following descending order: Pb> Cu> Zn> Cd. According to study results, the highest value of maximum adsorption capacity of soils taken in four zones of Annaba in relation to lead, zinc, cadmium and copper, were respectively 7; 6; 4.5 and 3 times higher than the minimum. These findings could play a key role to effective assessment of soil pollution with heavy metals in the study area. [ABSTRACT FROM AUTHOR]