Incidence of Calcic, Sulfates and Phosphates Salts on the Coagulation-Flocculation of Organic Compounds by Aluminium Sulfate

Abstract

The objective of this work is to evalute the coagulation-flocculation efficiency of the aluminum sulfate for the elimination of aromatic organic molecules (phenylalanine and catechol) in the presence of mineral salts of Ca2+, SO42-and PO43-.Trials were conducted on the one hand on synthetic solutions of aromatic compounds in distilled water enriched by ions of calcium, sulphates and phosphate ions introduced in various forms (CaCl2; CaSO4; MgSO4; Na2SO4; NaH2PO4; KH2PO4), and on the other hand on Algerian drilling waters of different physicochemical characteristics. Results show that the addition of minerals salts seems to improve the yields of elimination of aromatic compounds tested and affects the optimal pH range of coagulation. The application of this process on mineralized waters (water drilling) leads to improve yields compared with those obtained in distilled water. It was also found that the process efficiency depends on the nature and the number of functional groups on the molecules and on their position relative to each other. The main mechanisms would be either a physical adsorption ,an exchange of ligand or a complexation on the floc surface of aluminum hydroxides.