Efficient use of agricultural wastes as Biosorbent in the removal of Fuchsin basic dye from aqueous solutions

Abstract

Batch mode adsorption studies of Fuchsin basic (FB) on different agricultural waste materials were carried out using parameters including initial FB concentration, adsorbent dosage, agitation time, particle size of adsorbent and temperature. The best fitting isotherm model is elucidated using linear regression coefficient (R2). Both Langmuir (R2?0.998) and Freundlich (R2 = 0.968 to 0.986) isotherms were found to be best fitting model for the adsorption studies. The monolayer (maximum) adsorption capacities were found to be between 142.857 to 250 mg/g of given adsorbents. Lagergren pseudo -second order model best fits the kinetics of adsorption as qe(the) values are in consistent with qe(exp) with whole range of agitation time. Adsorption process was found to be directly proportional to temperature but inversely proportional to particle size of adsorbent. Thermodynamic analysis showed that adsorption was favourable, spontaneous, increased disorder and randomness at the solid- solution interface of FB with adsorbents. Mangrove plant leaf powder was found to have greater adsorption capacity towards FB amongst the adsorbents under study.