Development of chitosan/Spirulina bio‐blend films and its biosorption potential for dyes

Abstract

Chitosan/Spirulina bio‐blends (CSBB) in films form were developed to be an alternative/renewable biosorbent, able to remove anionic and cationic dyes from aqueous solutions. CSBB potential as biosorbent was investigated for cationic dye Methylene Blue (MB), and anionic dyes Tartrazine Yellow (TY) and Reactive Black 5 (RB5). Chitosan and Spirulina samples were obtained and characterized, and CSBB films were prepared with different chitosan/Spirulina ratios. The CSBB films characteristics, as, mechanical properties, thermal profile, crystallinity, functional groups, morphology, and biosorption potential were strongly dependent of chitosan/Spirulina ratio. CSBB films preserved its mechanical structures at pH from 4.0 to 8.0. The biosorption capacities were 120, 110, and 100 mg g−1 for RB5, TY, and MB, respectively. The increase of chitosan amount favored the TY and RB5 biosorption; however, the increase of Spirulina amount favored the MB biosorption. Thus, the CSBB in film form is a renewable biosorbent suitable to remove anionic and cationic dyes from aqueous solutions. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44580.

Carboxyl-Functionalized Covalent Organic Frameworks for the Adsorption and Removal of Triphenylmethane Dyes

“…The positive Δ S indicates the augmented randomness during the process. The carboxyl group in TzDBd formed H bonds with water molecules in water, resulting in a higher state of ordering (lower entropy) . When the adsorption process occurred, CV&BG molecules replaced the water molecules because of electrostatic interaction.…”

“…The carboxyl group in TzDBd formed H bonds with water molecules in water, resulting in a higher state of ordering (lower entropy). 50 When the adsorption process occurred, CV&BG molecules replaced the water molecules because of electrostatic interaction. As a result, more water molecules were released and the hydration shell was disrupted, leading to the increase in enthalpy.…”