Multicomponent Adsorption of Pollutants from Wastewater Using Low-Cost Eco-Friendly Iron-Modified Rice Husk Biochar in the Era of Green Chemistry

Abstract

As pollution escalates, water purification is becoming crucial, with adsorption emerging as an efficient technique. This study aimed to evaluate the effectiveness of iron-modified rice husk biochar as an adsorbent for water pollutants. The biochar was produced at a pyrolysis temperature of 500 °C and modified by FeSO4·7H2O. Diverse adsorbent dosages were introduced to simulated wastewater containing aldrin, mercury (Hg2+), lead (Pb2+), and cadmium (Cd2+). The solution was agitated for 60 min, then filtered, and the samples were sent for analysis. The results were promising; aldrin had a removal efficiency of 100%. The removal efficiency for Hg2+ ranged from 99.80% to 99.96%, for Pb2+ from 88.90% to 99.56%, and for Cd2+ from 78.90% to 99.98%. The Freundlich adsorption isotherm best described the mono- and quaternary component systems, while the Langmuir isotherm was the best fit for the binary system. Therefore, iron-modified rice husk biochar shows potential as a sustainable and efficient adsorbent for wastewater treatment.

Water Purification Using Active Charcoal with Microbes and Chelated Iron Soaked into Its Micropores

“…The water treatment industry has shown great interest in using iron powder, especially zero-valent iron, for sewage treatment [14]. Zero-valent iron is a cost-effective and efficient treatment agent because its standard oxidation electrode has low potential, enabling it to reduce various contaminants, including nitrate.…”

“…Studies have demonstrated that nZVI eventually oxidizes to a complex of iron oxide and fibrous iron ore, especially when in an acidic environment [17]. Several mechanisms, including activated charcoal, nano-iron powder, and microbes, have been described for water purification [8,14,17]. However, there are certain disadvantages to using zero-valent iron powder for reducing nitrate in water.…”

“…Despite these drawbacks, the iron reduction method remains a popular choice as it does not have any specific environ-mental requirements other than pH regulation. Currently, there are several improvement measures that have been proposed, suggesting that using zero-valent iron with auxiliary methods to remove nitrate from water is an emerging research area [14][15][16].…”