Novel corn stalks derived activated carbon for promising adsorption of lead (II) from aqueous solution: Characterization, IoT real-time monitoring, and performance investigation

Abstract

Contamination of water sources by (Pb(II)) presents significant environmental and public health challenges. AC samples were prepared at various temperatures (500 °C, 700 °C, and 900 °C) using 3M KOH activation, where AC prepared at 500 °C achieved the maximum Pb(II) removal efficiency of 98.15 % and an adsorption capacity of 255.6 mg/g without stirring to handle the actual environmental conditions. Here, the application of the Internet of Things (IoT) has been successfully implemented for monitoring Pb(II) removal, and activated carbon (AC) derived from corn stalks has been synthesized as an adsorbent. Real-time IoT monitoring confirmed the adsorbent's efficacy, showing a significant decrease in Pb(II) concentration from 13.02 mg/L to 0.24 mg/L. Optimal adsorption conditions were found at pH 7.2, working temperature 26.3 °C, and contact time 90–180 min. The performance of AC 500 °C is attributed to its favourable structure, such as the broadening of phonon vibrations (Δ(LO − TO)), the corresponding amorphous index (X_a) and high electron loss function (ELF) wave number shift, including porous structure that forms a pipe-like shape with holes in the body. Additionally, BET analysis showed a high specific surface area in each sample (>1000 m²/g). After three consecutive rounds of cyclic remediation, the AC prepared at 500 °C still showed high adsorption efficiency (72.65 %).