ENVIRONMENTAL POLLUTION CONTROL BY TREATMENT OF HEAVY METAL EFFLUENTS

Industrial and municipal wastewaters frequently contain heavy metal ions. These metal ions, when present in large quantity, can be harmful to aquatic life and human health, if discharged without adequate treatment. Flotation process is a selective separation of solid particles, liquid droplets, chemicals or ions, or biological entities from a bulk liquid, based on their surface properties. Ion flotation is widely used to extract metal ions from aqueous solutions. In this paper the removal of copper ions from simulated wastewater was investigated using a batch flotation processes. A flotation column, 0.15 m diameter and 1.2 m height was design to study the rate of removal of copper ions from waste water by flotation process. Effect of the following parameters: pH, copper ion concentration, air flow rates, and Sodium dodecylsulfate concentration (SDS) as anionic surfactant, have been investigated experimentally. Also the effect of frothers (Ethanol) and ionic strength (NaCI and Na2S04) were also studied and the suitable conditions were selected. Based on the obtained results, the removal efficiency was enhanced by addition of SDS and increasing the pH. An increase in magnitude of ionic strength from 0.0004 to 0.4 moles/lit significantly decreased Cu(II) removal .It is conclude that about 97- 98 % of copper ions of initial concentration 100 mg/l could be removed by flotation process in the presence of 150 ppm SDS at pH = 11 and air flow rate 150 L/min.