Sawdust as biosorbent for removal of dyes from wastewaters ; Kinetic and thermodynamic study [articol]

Abstract

A new waste material, characterized by low cost, availability and ligno cellulose composition, was tested for its ability to remove reactive dyes from aqueous systems or environments. This paper continues our studies concerning utilisation of sawdust as low-cost sorbent for decolourization of different textile effluents which contain synthetic textile dyes with a high molecular weight. In this context, kinetic and thermodynamic studies were carried out in order to establish all favourable conditions to uptake of Orange 16 reactive dye from aqueous solution of pH =1 by using batch technique. The kinetics of adsorption of Orange 16 reactive dye are following a pseudo-second order model. The values of thermodynamic parameters, ∆G and ∆H, were calculated using Langmuir constant (KL) and showed a spontaneous and exothermic sorption process. The results indicate that waste of wood (like sawdust) is an attractive sorbent for removing reactive dyes from the wastewater.