Development of reusable and long-term storable bacteria attached nanofiber mats for highly efficient removal of Cr(VI) and reactive dye from wastewater

Abstract

Developing reusable, sustainable and long term storable bioremoval technologies is essential for removal of heavy metals and reactive dyes in industrial wastewater. <i>Clavibacter michiganensis</i> (<i>C. michiganensis</i>) having bioremediation property was selected for attachment, and polysulfone (PSU) was selected as the polymer matrices for the electrospinning of nanofibrous webs. For this approach, polysulfone nanofiber mats (PSU-NFMs) were produced by electrospinning, followed by attachment of bacteria onto nanofiber mats and a subsequent used in the removal of Cr(VI) and reactive dye. The efficient Cr(VI) removal with 100% yield was achieved within 24 hours (10 ppm) with bacteria attached nanofiber mats. Also, nano bio-composite mats decolorized 100% of Reactive Blue (RB, 20 ppm) within 13 h. Furthermore, the prepared bacteria attached to PSU-NFMs showed storage stability at 23 ± 2℃ and 4℃ for 30 days with efficient removal yields and PSU-NFMs found as potentially storable for keeping attached bacterial cells alive. Finally, the reusability of bacteria attached to PSU-NFMs were determined after five cycles for both pollutant and 70.3% and 51.8% of the Cr(VI) and dye removal capacities were obtained. It was expected that the bacteria attached to PSU-NFMs could be a potential application in wastewater treatment.