Characterization of thermic keratin biosorbent for removal of turbidity from tannery wastewater: waste-to-waste treatment approach

Turbidity harms the healthy aquatic environment. This study is focused on the preparation, characterization, and application of the thermally activated keratin adsorbent (TAKA) derived from the goat hair waste of a tannery. In a batch test, TAKA is used to remove turbidity from the generated wastewater during bating and degreasing operations in the beamhouse. The pure TAKA and wastewater-treated TAKA were characterized using SEM, EDS, FTIR, XRD, and pHpzc. The turbidity removal for bating and degreasing wastewater was 85.75% and 75.93%, respectively, at 0.3 g/50 mL wastewater for a 20 min contact time, 300 rpm stirring speed, and 0.5 h settling at 23±2°C. The environmental pollutants, such as COD, BOD, chloride, and oil reduction, were 49.33%, 49.74%, 30%, and 51.76% for bating wastewater and 33.65%, 20%, 50%, and 73.13% for degreasing wastewater, respectively. The pH of the treated wastewater (7.1-7.9) was within the discharge standard (6-9). FTIR spectra provided insight into the characteristics of the adsorbent materials before and after treatment, as evidenced by the presence of functional groups. The morphological and elemental changes of pure TAKA and wastewater-treated TAKA were well pronounced through SEM and EDS assessment. XRD analysis revealed the presence of additional sharp peaks indicating adsorption. The Freundlich and PSO models illustrated acceptance outcomes for proper adsorption. Hence, TAKA is recommended in wastewater treatment, especially for bating and degreasing wastewater before discharging it into aquatic bodies. • Turbidity removal achieved 85.75% and 75.93% in bating and degreasing wastewater • Reduction of COD, BOD, and Cl - were 49.33%, 49.74%, and 30% for bating wastewater • Reduction of COD, BOD, and Cl - were 33.65%, 20%, and 50% for degreasing wastewater