Dye adsorption from tannery wastewater on Tamarindus indica seed adsorbent

Abstract

The wastewater expelled during leather dyeing harms aquatic life. This study is focused on the dye removal efficiency from the leather dyeing wastewater using ground Tamarindus indica seed adsorbent. The prepared adsorbent was characterized based on the Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM), and isoelectric point (IEP). In the batch experiment, the dye removal efficiency was monitored by various parameters. FTIR depicted the adsorbed functional groups from the dyeing wastewater, SEM micrograph depicted a confirmation of adsorption through the surface morphology, while IEP indicated the adsorbent surface charge. Results suggest that at optimized conditions, the dye removal efficiency was found to be 95.3% at an adsorbent dose of 0.6 g/50 mL wastewater, pH 6.0, stirring time 30 min, settling time 10 h, and temperature 30 °C, which reduced the Biochemical Oxygen Demand (23.9%), Chemical Oxygen Demand (50.0%), and turbidity (93.1%) from the dye wastewater. The adsorption mechanism illustrated the interaction between the positive adsorbent surface and dye molecule with strong evidence from FTIR and SEM. Hence, this new approach of using Tamarindus indica seed biomass revealed a viable way of dye removal from the leather dyeing wastewater.