Novel crosslinked and zeolite-filled polyvinyl alcohol membrane adsorbents for dye removal

Enhanced selective adsorption of cation organic dyes on polyvinyl alcohol/agar/maltodextrin water‐resistance biomembrane

“…One of the crucial parameters in adsorption studies is the solution pH, which is related to the surface charge of adsorbents and the degree of ionization of MB molecules . Before evaluating the effect of solution pH on the adsorption capacity of PVA/agar/maltodextrin membranes, the pH pzc value was measured at 5.8 implied that pH value below 5.8 indicated positively charged membrane surface and by contrast, pH value >5.8 illustrated negatively charged surface.…”

“…For instance, the amount of adsorbed MB significantly increased from 4 mg g −1 to 21 mg g −1 by increasing initial MB concentration 10–100 mg/L. This outcome may be explained due to the higher mass transfer driving force when the initial MB concentration surged inducing higher adsorption capacity . However, the removal efficiency slightly decreased with increasing initial dye concentration above 250 mg/L, which is due to the saturation of adsorption points.…”

“…also demonstrated that the fabrication of the PVA/PDAMAC/ZSM‐5 zeolite hybrid membranes was documented in the high efficacy for methyl orange removal up to 71.9 mg g −1 . Although the combination of zeolite may bring significant efficiency, the utilization of these zeolites still has some drawbacks, such as the consumption of chemicals, expense, and time for the adsorbent preparation . Much research effort to seek efficient bio‐adsorbents with sufficient properties and high removal efficiency for organic dyes still requires further investigation.…”

Polyacrylonitrile/α‐Fe2O3 Hybrid Photocatalytic Composite Adsorbents for Enhanced Dye Removal

“…Furthermore, by adding more nanocatalyst to the PAN solution and reaching 10 wt% of the polymer, the equilibrium concentration of MB decreases. This phenomenon can be related to aggregation of photocatalyst nanoparticles and reduction of their effective active sites . Thus, the optimum amount of 8 wt % of α ‐Fe 2 O 3 in the polymer was chosen for further experiments.…”

“…After 200 min, the MB concentration is fixed over time which means reaching to the equilibrium point [29]. It is worth mentioning that the number of available active sites on the PAN/a-Fe 2 O 3 hybrid adsorptive composite drops by approaching to the equilibrium point as a consequence of MB coverage on the adsorbent surface [16,28].…”