Surface functionalization of magnetic graphene oxide@bentonite with α -amylase enzyme as a novel bionanosorbent for effective removal of Rhodamine B and Auramine O dyes

Rhodamine B (Rhd-B) and Auramine O (Aur-O) dyes are frequently used in textile, leather, wood, and paper industries and used as food colouring. Consequently, it is common knowledge that the effluent from these sectors has a disastrous impact on water sources, the environment, and human health. According to that, removing such contaminants from water is essential. MagGO@Bentonite@-amylase is prepared as a novel bionanosorbent, where carboxyl, hydroxyl, and epoxy groups are present on the graphene oxide (GO) backbone, which has been modified with bentonite and iron oxide nanoparticles and functionalized with an alpha-amylase enzyme. The maximum removal was 76.55 and 90.51% under pH 3 and 5 during contact times 90 and 50 min for (Rhd-B) and (Aur-O), respectively. The adsorption kinetics study obeys the pseudo-second-order model for eliminating (RhdB) and (Aur-O). The Linear Freundlich model is the best-described isotherm model for the adsorption of (Rhd-B), whereas the Langmuir model is the best-described adsorption isotherm model for the removal of (Aur-O) using MagGO@Bentonite@-amylase.