Evaluation of methods for the synthesis of biodegradable sponges for oil spills from residues of the poultry industry

ORJUELA PALACIO, JULIANA MARCELA; ZARITZKY, NOEMÍ ELISABET

Buenos Aires

Congreso; World Congresses of Chemical Engineering (WCCEs); 2023

World Chemical Engineering Council (WCEC)

Chicken feathers are an attractive biomass due to their composition of keratin (Ke), a protein with a high content of disulfide bonds, making it a valuable resource for generating sorbent sponges for controlling crude oil spills that can cause environmental damage. Current methods for transforming biomass into Ke-biomaterials dependent on the use of toxic, expensive, and non-recyclable reducing agents, as well as dialysis and drying steps. This study aimed to compare sponge synthesis methods using less toxic reagents and avoiding the dialysis step. Three methods were tested: S1 sulphytolisis involved Sodium sulfite/Urea/Sodium dodecyl sulfate at pH= 9; S2 involved Sodium sulfite/Urea at pH= 6.5; S3 involved L-cysteine/Urea at pH= 10.5. Solutions obtained were filtered, dialyzed, and precipitated (pI=4.2), while solution S3 was precipitated (pI= 4.2), washed and centrifuged, without dialysis. All suspensions were lyophilized to achieve a self-assembly sponge. Ke-sponges had a low solubility in aqueous media and thermal stability at high temperatures (DSC). The characteristic bands of Ke were observed during structural characterization (FTIR-ATR). Analysis of Amide-I indicated the conformation of β-pleated sheet/α-helix/β-turn change depending on the applied method. Sorption isotherms at 20°C were modeled using the GAB equation. The sorption capacity (CSC, g crude/g Ke) and retention (%CRC) of crude were determined, with values of 5.9 (S1), 21.2 (S2), and 16.9 (S3) g crude/g Ke, and 47%, 78%, and 80% CRC, respectively. S3 allowed the formation of sponges with good characteristics by applying L-cysteine/Urea without including a dialysis stage, representing an economic alternative and environmentally sustainable