Removal of Pb(II) from Aqueous Solution and Adsorption Kinetics of Corn Stalk Biochar

Abstract

In this work, the Pb adsorption and removal ability of biochar from simulated Pb(II)-contaminated wastewater, adsorption isotherms, kinetics, and thermodynamics were studied. Adsorption characteristics of biochar on Pb(II) were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope with energy dispersive spectrometer (SEM-EDS). The influence of the pH of the solution, the contact time, and the biochar dose on the removal of Pb(II) were investigated by single-factor design and response surface analysis. With the increase in biochar dose from 2 g/L to 4 g/L in wastewater, the Pb(II) amount adsorbed on biochar reduced from 21.3 mg/g to 17.5 mg/g. A weakly acidic environment was more conducive to the ligand exchange between Pb(II) ions and biochar. Pb(II) adsorption kinetics of biochar showed that the Pseudo-first-order model was more suitable than other employed models to describe the adsorption process. During the isothermal adsorption process, Langmuir and Freundlich’s isotherms fitted the adsorption data very well (R2 > 96%). The Pb (II) adsorption onto biochar was spontaneous in the specified temperature range (298–318 K) and the process was exothermic. Simultaneously, the optimal conditions were a pH of 5, a contact time of 255 min, and a biochar dose of 3 g/L, under which the maximum predicted Pb(II) removal efficiency was 91.52%.

A Sustainable Banana Peel Activated Carbon for Removing Pharmaceutical Pollutants from Different Waters: Production, Characterization, and Application

“…It is also noticed that the content of S has increased after the adsorption process, which is indicative that a chemical reaction has occurred. The appearance and disappearance of elements or increase and decrease in their count on the EDS spectrum after adsorption is a common observation in inorganic [ 47 , 48 ] and organic [ 49 ] adsorption studies. It indicates their involvement in the interaction between adsorbate and adsorbents.…”

Biosynthesis of a Functional Silica-Based Biohybrid Material with High Pb(II) Capture Ability

“…Phenolic hydroxyl groups dominate Pb­(II) adsorption as they contain electron-rich aromatic rings that can form stable complexes with Pb­(II) through coordination bonds . The abundance and distribution of these groups provide numerous binding sites for Pb­(II) ions, enhancing adsorption efficiency.…”

“…This is because of the finite adsorption capacity of poly-tannic acid, which represents the maximum amount of Pb­(II) ions that can interact with it. Once all available sites were occupied, additional Pb­(II) ions in the solution could not be removed, leading to a plateau in removal efficiency. , …”

“…Phenolic hydroxyl groups dominate Pb(II) adsorption as they contain electron-rich aromatic rings that can form stable complexes with Pb(II) through coordination bonds. 65 The abundance and distribution of these groups provide numerous binding sites for Pb(II) ions, enhancing adsorption efficiency. Synergistic interactions between functional groups further augment tannic acid's performance as a promising adsorbent for Pb(II) removal.…”

“…Once all available sites were occupied, additional Pb(II) ions in the solution could not be removed, leading to a plateau in removal efficiency. 65,66 The comparison of the maximum adsorption capacity (Q m ) of this biohybrid material with other alternative adsorbents relevant for the removal of Pb(II) ions in water samples at the same conditions is listed in Table 1.…”