REMOVAL OF SOME ORGANIC-DYES BY HEXANE-EXTRACTED SPENT BLEACHING EARTH

The removal of some organic dyes from aqueous solution by hexane-extra cted spent bleaching earth, a waste material from the palm oil industr y, was investigated. It was noted that the material had better affinit y for basic than acid dyes. Various parameters affecting the removal p rocess were studied, These were pH, initial dye concentration, sorbent dosage, temperature and agitation rate in the batch process. Experime ntal data show that both the boundary layer and intraparticle diffusio n effect play important roles in the rate of dye removal. Maximum sorp tion capacities for some basic and acid dyes studied compare favourabl y with those reported using other low-cost sorbents.