Synthesis of hydrogels from fractionated proteins of Moringa oleifera Lam. seeds for the treatment of water contaminated with black reactive dye 5

Abstract

As has been portrayed in the literature, the main proteins extracted from the seeds of Moringa oleifera Lam. have coagulant and clarifying potential in water treatment. However, when using them as coagulant agents, sludge formation occurs, which is an environmental problem. Thus, it was proposed to synthesize hydrogels from the main Moringa seeds proteins and use them as adsorbents. This work aimed to synthesize albumin hydrogels and globulin hydrogels and evaluate their efficiency as adsorbents to remove the reactive black 5 dye. Through FTIR spectrum it was possible to confirm that the synthesis of hydrogels occurred successfully. The kinetic data fit the pseudo‐second order model for both hydrogels. The equilibrium isotherms showed that adsorption occurs in multilayers, due to Freundlich fitting. The maximum adsorption capacity occurred at 298 K and was 1.19 mg g−1 for the albumin hydrogel and 10.06 mg g−1 for the globulin hydrogel. Through the results it is possible to state that globulin hydrogel was more favourable for adsorption since it has a more porous morphology and requires less mass compared to albumin hydrogel.

Thermally modified nanocrystalline snail shell adsorbent for methylene blue sequestration: equilibrium, kinetic, thermodynamic, artificial intelligence, and DFT studies

“…Meanwhile, when the solution pH is higher than the pH pzc , the net surface charge becomes negative due to the desorption of H + , favoring the adsorption of positively charged moieties. 66 The interfacial characteristics are based on the pH at the point zero charge (pH pzc ), which can be used to determine which ionic species the TMNSS can adsorb at a particular pH. For this test, 50 mL of sodium chloride (NaCl) 0.1 N electrolyte, buffered to pH 2.00–12.00 by adding HCl (0.01 M) and NaOH (0.01 M), were combined with 0.10 g of the adsorbent as the sorbent mass.…”