Removal of Toxic Lead from Wastewater by Lupinus albus Seed Hull

In this work, we address two concerns at once: waste reduction and the development of a lead removal adsorbent. The potential of Lupinus albus seed hull (LSH) powder as an efficient, innovative, and economical adsorbent for Pb-(II) absorption was examined in this study. Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy investigations were used to determine the structural and morphological properties of the LSH adsorbent. The adsorption process was studied in batch mode with multiple process variables (adsorbent dosage of 4.0-20 g/L; solution pH of 1.5-5.5; contact time of 15-70 min). By fitting the equilibrium data to the Langmuir isotherm model, the maximum adsorption capacity of Pb-(II) was 357.14 mg/g at optimized pH (5.5), LSH dose (0.4 g), and interaction time (60 min) with starting Pb-(II) concentration of 50 mg L-1. As for the reaction kinetics, the pseudo-second-order model was shown to be a convenient match. LSH can be reused after four desorption/adsorption cycles and has a high potential for eliminating Pb-(II) from wastewater.