Biosorption of Pb, Ni, and Cr ions from Industrial Wastewater Using Melon Seed Peels (Cucumeropsis Mannii)

Increased industrialization, among other human activities, is of significant concern as it is a source of heavy metals and other environmental pollutants. These heavy metals tend to bioaccumulate in human and aquatic life, causing serious health issues. On the other hand, the underutilization of agricultural waste such as Melon seed peels has resulted in environmental pollution due to improper disposal. In this study, melon seed peels (Cucumeropsis Mannii) were carbonized, activated, and used to adsorb heavy metals from wastewater. The physicochemical characteristics of the melon seed peel adsorbent were determined using Fourier Transform infrared (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy (SEM). The efficiency of the adsorbent was tested on a simulated Lead, nickel, and chromium solution using batch adsorption at varied Time, pH, Concentration, and adsorbent dosage. The adsorbent was also tested on a paint effluent to see its industrial applicability. The data's adsorption kinetics were also described using a pseudo-first-order model, pseudo-second-order models, and an intra-particle diffusion model. The results show strong correspondence to a pseudo-second-order kinetics model with the correlation coefficient (R2 = 0.99, 0.87, and 0.97 for Pb, Ni, and Cr, respectively. This study’s findings provide insight into the effective utilization of the abundant melon seed peels as adsorbent to remove heavy metals from wastewater to consequently reduce environmental pollution.