Adsorption of Methylene Blue and Pb2+ by using acid-activated Posidonia oceanica waste

Abstract

Dead leaves of seagrass Posidonia oceanica were activated by using one mol L −1 acetic acid and used as an eco-adsorbent for the removal of methylene blue (MB) and Pb 2+ from aqueous solutions. The seagrass was characterized by chemical and physical measurements that confirmed the acid-activation of seagrass. The favourable conditions for MB and Pb 2+ adsorption onto the activated seagrass (SG a ) were determined to be a pH range of 2–12 and ≥6, an adsorbent dosage of 3.0 and 0.5 g L −1 , respectively, and a shaking time of 30 min, which are suitable for a wide range of wastewaters. The equilibrium data were analysed using the Langmuir, Freundlich and Dubinin-Raduskavich-Kaganer (DRK) adsorption isotherm models. The Freundlich and DRK models best describe the adsorption processes of MB and Pb 2+ , on SG a with capacities of 2681.9 and 631.13 mg g −1 , respectively. The adsorption isotherm fitting and thermodynamic studies suggest that the adsorption mechanism of MB may combine electrostatic and physical multilayer adsorption processes, in which MB may be present as monomers as well as dimers and trimers which were confirmed from UV spectroscopy whereas Pb 2+ is chemically adsorbed onto SG a . The pseudo-2 nd -order kinetic model was utilized to investigate the kinetics of adsorption processes. The removal process was successfully applied for MB-spiked brackish waste water from Manzala Lake, Egypt, with removal efficiencies of 91.5–99.9%.

Green Reduction of Graphene Oxide using Kaffir Lime Peel Extract (Citrus hystrix) and Its Application as Adsorbent for Methylene Blue

“…The photocatalyst Fe 3 O 4 -RGO-TiO 2 , only able to adsorp 1.67 mg MB per gram of particle. However, the use of activated seagrass Posidonia oceanica waste can achieve almost ten times higher than our adsorbent 40 . The high adsorption capacity of RGO (this study) can be explained by its high specific surface area, i.e.…”

Citric acid modified waste cigarette filters for adsorptive removal of methylene blue dye from aqueous solution

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Cellulose citrate: a convenient and reusable bio-adsorbent for effective removal of methylene blue dye from artificially contaminated water

“…[22][23][24][25][26][27] The common methods for the removal of organic dyes include: chemical oxidation or reduction, 28 precipitation, 29 ion exchange, 30 electrolysis, 31 photo-catalytic processes, 32,33 membrane ltration, 34 ozonation, 35 degradation, 36 bio-sorption 37 and adsorption. 38,39 In particular, adsorption is one of the most used techniques because it relies on a simple mechanism, does not produce handling problems, and the process can be reversible. 40,41 Among adsorbents, activated carbon was employed over the years because of its efficacy for the removal of water and air pollutants, but it possesses many limitations as the production costs and the regeneration.…”