Eliminating aqueous effluents with low-cost bioadsorbents: adsorbent characterization and mechanistic removal studies

Abstract

This study focused on the synthesis and preparation of cationic and anionic biomaterials. These materials were used as adsorbents in waters polluted by various adsorbates likely to be present in the environment. Using a batch adsorption approach, this work interprets biomass Pumpkin Seed Shells (PS) as an inexpensive, environmentally benign, and promising adsorbent for 4-nitrophenol (4NP) adsorption from aqueous solution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer Emmett Teller (BET) spectroscopy were among the methods used to characterize the produced biosorbent. Batch experiments were conducted based on various process factors, such as temperature, pH, concentration, contact time, and material dose. Very excellent results were obtained with a pH of 6.5, a biosorbent dosage of 0.030 g, an initial 4-nitrophenol concentration of 30 mg/L, and a temperature of 25°C.and 298 K, which were ideal for removing 4NP. 97.95% sorption was the maximum. Adsorption data better fit the Freundlich, Temkin, Liu, and Langmuir isotherms. It was demonstrated that the biosorption process is spontaneous and exothermic and that the rate of sorption obeys the Elovich and pseudo-second-order kinetics.This article explains how to create inexpensive, environmentally friendly adsorbents and looks at how well they can remove 4-nitrophenol from wastewater. The unaltered biochar-based pumpkin seed shells were characterized using basic analysis, FTIR, SEM, and BET.