Adsorption of methylene blue from aqueous solution by graphene.

Magnetic Fe3O4@poly(m-phenylenediamine) particles (Fe3O4@PmPDs) with well-defined core–shell structure were first designed for high performance Cr(VI) removal by taking advantages of the easy separation property of magnetic nanoparticles (MNPs) and the satisfactory adsorption property of polymers. Through controlling the polymerization on MNPs, directly coating was realized without the complicated premodification procedures. The particle property and adsorption mechanism were analyzed in details. Fe3O4@PmPDs exhibited tunable PmPD shell thickness from 10 to 100 nm, high magnetic (∼150 to ∼73 emu g–1) and facile separation property by magnet. The coating of PmPD significantly enhanced Cr(VI) adsorption capacity from 46.79 (bare MNPs) to 246.09 mg g–1 (71.55% PmPD loading proportion), much higher than many reported composite adsorbents. The high Cr(VI) removal performance was attributed to the adsorption of Cr(VI) on protonated imino groups and the efficient reduction of Cr(VI) to Cr(III) by amine, followed...

Synthesis of Core–Shell Magnetic Fe3O4@poly(m-Phenylenediamine) Particles for Chromium Reduction and Adsorption

Characterization of modified wheat straw, kinetic and equilibrium study about copper ion and methylene blue adsorption in batch mode

Adsorption characteristics of methylene blue by peanut husk in batch and column modes

High performance agar/graphene oxide composite aerogel for methylene blue removal

A natural wheat straw was used as adsorbent for removal of copper and methylene blue (MB) from aqueous solution. A batch system was applied to study the behavior of Cu2+ and MB adsorption in single and binary systems on wheat straw. In the single systems, there was no significant difference in the quantity of MB adsorbed onto wheat straw within a pH range of 4.0 to 10.0. But for Cu2+, the optimal pH is about 5. Kinetic studies indicate that Cu2+ and MB adsorption on the wheat straw follows the Elovich equation. The Cu2+ adsorption isotherm follows the Langmuir and Redlich−Peterson models, while MB adsorption follows the Redlich−Peterson isotherm. The adsorption capacities of Cu2+ and MB at 273 K and pH 5 are (7.05 and 60.66) mg·g−1, respectively. In the binary system, Cu2+ and MB exhibited competitive adsorption. The adsorption of Cu2+ or MB is considerably reduced with an increasing concentration of the other. The quantity of Cu2+ adsorbed is more strongly influenced by MB due to the higher affinity of w...

Adsorption of Copper Ions and Methylene Blue in a Single and Binary System on Wheat Straw

The effect of solution temperature and the determination of the kinetic parameters of methylene blue (MB) adsorption onto cereal chaff were performed to understand the adsorption mechanism. The pseudo-second order kinetic model was fitted to the experimental data and found it was good to predict the adsorption behavior using nonlinear regressive method, suggesting that the mechanism may be a chemisorption process. The activation energy of adsorption (Ea) was 22.4 kJ mol-1. The thermodynamic parameters (&#916;G0, &#916;H0, and &#916;S0) were also determined from the temperature dependence. The results showed that the process of adsorption MB was spontaneous and endothermic process and an increase in temperature favored the adsorption. The diffusion coefficient was also estimated.

Jiangyan Ma

Papers

Adsorption of Copper Ions and Methylene Blue in a Single and Binary System on Wheat Straw

Kinetics and Thermodynamics of Methylene Blue Adsorption by Cereal Chaff