Flocculation of Kaolinite Suspensions in Water by Coconut Cream Casein

Abstract

The flocculation of kaolinite colloidal particles was carried out at pH = 6 in suspension of initial turbidity varying between 24 NTU and 102 NTU by a casein extracted from Cocos nuciferacream. During Jar-test essays, 90% to 99% of colloids were eliminated in the sediments. The optimal doses of casein used depend on the initial colloids concentrations of the suspension and were found to be 60 mg/L and 100 mg/L respect- tively for suspensions having turbidity of 24 NTU and 102 NTU. The corresponding residual turbidity are respectively 2.80 NTU and 10.22 NTU for clarified water.The structural analysis of the freeze-dried sedi- ments by FTIR shows sharp adsorption bands at 1558 cm –1 and 1653 cm –1 , indicating the presence of casein in the sediment. The flocculation process between the particles of kaolinite and the coconut casein is adsorp- tion and bridging.