Photocatalytic activity and water purification performance of in situ and ex situ synthesized bacterial cellulose-CuO nanohybrids.

The aim of this research was synthesizing of bacterial cellulose (BC) nanohybrids by incorporation of CuO-NPs and evaluation of their ability in the removing of microbial, heavy metals, and dyes pollutants from water. CuO-BC nanohybrids were synthesized by two in situ (sonochemical and precipitation) methods and compared with ex situ synthesized nanohybrid. FE-SEM images revealed that the growth of CuO-NPs in the sonochemically synthesized in situ substrate is better. The ex situ nanohybrid had the highest loading capacity (27.17 μg/cm2 ) but the migration of CuO-NPs from this substrate was higher than in situ ones. According to antimicrobial tests, 80% and 90% of initial population of E. coli and S. aureus, respectively, were removed after 6 hr contact of substrates with water. The potential of the substrates in the adsorption of lead and arsenic was about 60% after 24 hr. About 75% of methylene blue and methyl orange dyes were adsorbed into substrates after 6 hr. CuO doped substrates had the photocatalytic activity and caused to decrease the oxygen content about 4%-7% during 6 hr. In general, the reusability of ex situ synthesized substrate was lower than in situ nanohybrids. Sonochemically synthesized substrate was suggested as the best nanohybrid for water purification applications in terms of morphological properties and reusability. PRACTITIONER POINTS: CuO-BC nanohybrids were prepared by in-situ and ex-situ methods. Well distribution of NPs and slower release was achieved by in-situ methods. Antimicrobial and photocatalytic activity of ex-situ nanohybrid was higher than in-situ ones. Dyes and heavy metals were removed successfully with nanohybrid substrates. Sonochemical in-situ nanohybrid exhibited the best water purification performance.