Desorption and regeneration of dye colours from low-cost materials

Experimental methods and results are reported in this paper on the desorption and regeneration of eight dye colours individually from six low-cost sorbent materials. Desorption and regeneration values give an idea about the type of interaction between the sorbate and the sorbent, and the possibility of regeneration of the sorbent. Bentonite clay, amongst the six low-cost materials studied in the present investigation, could sorb all the dyes used in investigation with the exception of the acid dyes. No regeneration of clay is possible in the sorption of dyes, since strong chemical bonding occurs between it and the sorbed dyes. Rice husk, bark, cotton waste and hair could sorb only the red and blue basic dyes and a combination of ion-exchange and chemical bonding occurs in the sorption process.