Chitosan, starch, polyaniline and polypyrrole biocomposite with sugarcane bagasse for the efficient removal of Acid Black dye

Polymeric biocomposites (Polyaniline/sugarcane bagasse (Pan/SB), polypyrrole (PPy/SB), polyaniline/chitosan (PAn/Ch), polyaniline/starch (PAn/St) and polypyrrole/starch (PPy/St)) were prepared and applied for Acid Black-234 (AB-234) dye removal as a function of pH, reaction time, adsorbent dose, initial dye concentration and temperature. The optimum pH for the efficient adsorption for SB, PPy/SB, PAn/SB, PPy/Ch, PAn/Ch, PPy/St and PAn/St were 2, 3, 4, 4, 5, 3 and 3, respectively using adsorbent dose of 0.05 g for the reaction time of 60 min. The pseudo-first-order-kinetic model better explained the biosorption processes of SB, PAn/SB, PAn/Ch, PPy/St and PAn/St, while pseudo-second-order kinetic model better fitted to the kinetic data of PPy/SB and PPy/Ch. It was observed that the biosorption process of dye showed the satisfactory fitness for Langmuir isotherm for the biosorbents with maximum adsorption capacities 52.6, 100, 90.91, 90.0, 71.4, 66.6 and 62.5 for SB, PPy/SB, PAn/SB, PPy/Ch, PAn/Ch, PPy/St and PAn/St, respectively. The thermodynamic study revealed the exothermic nature of adsorption of dye on to biocomposites. Results revealed that polymeric biocomposites are efficient adsorbent and could possibly be used for the adsorption of dyes from textile wastewater.