Cellulose- supported sulfated-magnetic biocomposite produced from hemp biomass: Effective removal of cationic dyes from aqueous solution.

In present study, eco-friendly sulfated cellulose-magnetic biocomposite was successfully synthesized with a simple method from hemp biomass. ATR-FTIR was used to determine chemical changes, while FE-SEM-EDS, STEM, XRD, TG/DTA, and BET techniques were employed to identify changes in morphology, elemental composition, crystal structure, and thermal degradation. Moreover, the saturation magnetization and pHpzc values of the MSHB were also determined. The effectiveness of magnetic sulfated hemp biomass (MSHB) was tested in the removal of cationic dyes from wastewater, including methylene blue (MB), crystal violet (CV), and malachite green oxalate (MGO). The adsorption all three dyes to MSHB, the pseudo-second-order kinetic model and the Langmuir model were determined to be more appropriate, and was endothermic and spontaneous from thermodynamic parameters, too. The maximum MSHB adsorption capacities were found to be 457.6, 509.3, and 1300 mg/g for MB, CV, and MGO at 298 K. With increasing temperature, it also drastically increased in capacity. The outstanding property of the MSHB is that it shows high removal performance wide pH range, even after ten cycles its high removal efficiency is still over 96 % for all three dyes and almost unaffected from dense matrix medium. These results demonstrate that MSHB is remarkable adsorbent for removing cationic dyes.

Cellulose-supported bioadsorbent from natural hemp fiber for removal of anionic dyes from aqueous solution.

The aim of this study is to prepare an eco-friendly bioadsorbent by graft copolymerization and modification from hemp fiber including bio-macromolecules such as cellulose, hemicellulose and lignin for anionic dyes adsorption from aqueous solutions, and to investigate adsorptive properties. The prepared cellulose-supported bioadsorbent (TEPA-(GMA-g-HF)) was characterized in detail using SEM-EDX, STEM, FTIR, XRD, TGA and BET techniques and calculating the point of zero charge. It was used as an adsorbent to remove three different anionic dyes, Remazol Brilliant Blue R (RBBR), Reactive Red 120 (RR120) and Reactive yellow 160 (RY160) from the aqueous medium. The effects of adsorbent amount, pH, initial dye concentration, time and temperature on the adsorption were investigated. From the results, it was determined that the adsorption of all three dyes to the developed fibrous bioadsorbent was more compatible with the pseudo-second-order kinetic and the Langmuir isotherm model. It was found that the adsorption capacity increased with increasing temperature, and the adsorption capacity at 298 K was 91.70 mg/g for RBBR, 83.33 for RY160 and 76.34 mg/g for RR120, respectively. Dye removal efficiencies were provided as approximately 100 % at acidic pHs. This high removal efficiency has also achieved in the dense matrix medium, and even after five consecutive reused.