Comparative Performance of NaOH and KOH-Activated Rice Husk Carbon for Heavy Metal Removal from Agricultural Runoff

Adika Helmi Ruzaimi; Nor Hafizah Che Ismail

doi:10.56532/mjsat.v6iS1.794

Authors

Adika Helmi Ruzaimi Faculty of Applied Sciences, Universiti Teknologi MARA, 02600 Perlis, Malaysia https://orcid.org/0009-0005-2035-8012
Nor Hafizah Che Ismail Faculty of Applied Sciences, Universiti Teknologi MARA, 02600 Perlis, Malaysia https://orcid.org/0000-0002-9844-2450

DOI:

https://doi.org/10.56532/mjsat.v6iS1.794

Keywords:

Adsorption, Rice Husk, Activated Carbon, Heavy Metal, Water Treatment

Abstract

Removal of heavy metal from agricultural runoff by adsorption of activated carbon (AC) derived from rice husk (RH) were investigated. In this work, rice husk-derived activated carbon (RHAC) was chemically impregnated with sodium hydroxide (NaOH) and potassium hydroxide (KOH) separately and its difference in absorption efficiency and physicochemical properties were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES). The removal efficiencies of heavy metal were strongly dependent on types of activation agent used. Adsorption performance analysis from KOH-activated RHAC revealed a significant removal of lead (Pb) at 65.7% and cadmium (Cd) at 85.0% respectively, attributed to the presence of stronger carbonyl and hydroxyl functional groups. Conversely, NaOH-activated RHAC performed better in achieving 60.0% for copper (Cu) and 15.8% for chromium (Cr), likely due to possible desorption or competitive adsorption. The results highlight the critical role of activation agents in influencing the adsorption behavior of heavy metals in real agricultural runoff. Overall, rice husk was successfully valorized into low-cost adsorbent thus, highlighting its potential in agricultural wastewater treatment.

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