Modeling and optimization of independent factors influencing lead(II) biosorption from aqueous systems: A statistical approach

Abstract

Lead, [Pb(II)] is a major hazardous contaminant that exists in the soil, surface, and groundwater as a result of human activities. It is carcinogenic in nature and causes damage to the liver, kidney, and bones as well as the digestive, respiratory, and immune systems. As a result, the main purpose of this study was to prepare and employ modified powdered peanut shells as a biosorbent in the decontamination of lead(II) ions from aqueous solutions. The removal of lead(II) onto the biosorbent was modeled and optimized using the response surface methodology and the effects of three biosorption variables on two response variables were investigated using the central composite design of the response surface methodology. The optimization of lead(II) removal by the biosorbent shows that contact time, pH, and initial concentration had a significant influence on the removal efficiency and biosorption capacity of lead(II). This was shown by the response surface methodology where the interaction among the independent variables studied improved the biosorption of lead(II). Applying the central composite design, the optimized contact time (60.00 min), pH (6.00), and initial concentration (25.00 mg/L) gave a removal of 87.27% and biosorption capacity of 2.87 mg/g of lead(II) with the desirability of 1.00. The study revealed that the modified powdered peanut shells, a low-cost biosorbent was efficient in decontaminating lead(II) ions in the aqueous solutions. However, the biosorption process optimization was dependent on contact time, pH, and initial lead(II) concentration. The study recommends that the untreated form of the peanut shells should be used and the results compared with the present study.