Bacterial cellulose/polyaniline nanocomposite aerogels as novel bioadsorbents for removal of hexavalent chromium: Experimental and simulation study

Abstract

In most countries, rapid industrialization poses a threat to the environment upon discharging the wastewater streams containing heavy metals, especially hexavalent chromium (Cr(VI)), into the environment. In this work, sustainable and biodegradable bacterial cellulose (BC)/polyaniline (PANI) nanocomposite aerogels with different morphology were fabricated in the presence of sodium dodecylbenzene-sulfonate (SDBS) and sodium dodecyl sulfate (SDS). The fabricated BC/PANI in the existence of SDBS and SDS showed thistle like and a cluster of grapes, respectively. The Cr(VI) removal was performed at a neutral pH condition. The highest adsorption capacity of 189 mg/g was determined at pH 7 for BC/PANI/SDBS (BPDB) compared with 151 mg/g for BC/PANI/SDS (BPDS) after 24 h. After five cycles, re-adsorption efficiency was reached to 68% for BPDB and 59% for BPDS. Simulation results showed that the effect of surface diffusion was prevailing compared with the pore volume diffusion (nearly 90% after 1 h). BPDB showed a faster adsorption rate than BPDS. Predicted concentration decay curves had good agreement with experimental data.