DOI: https://doi.org/10.55373/mjchem.v28i2.319

Keywords: Iron-based additive, biohydrogen, hydrothermal, dark fermentation

Abstract

Current renewable energy research focuses on developing environmentally friendly alternatives to fossil fuels, such as solar, wind, geothermal power, and biomass, to reduce greenhouse gas emissions and pollution. Biohydrogen production involves the use of biological processes to generate a clean and efficient energy carrier in the form of hydrogen gas. In this study, an iron-based additive (SC1) was synthesized, and its performance in biohydrogen production was evaluated. The additive was prepared using the hydrothermal method and subsequently tested in a dark fermentation reaction. Raw palm oil mill effluent (POME) was used as the inoculum, with glucose as the substrate. The morphology and elemental composition were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The structural properties were characterized by X-ray diffraction (XRD). The results revealed that the additive consisted primarily of iron(III) oxyhydroxide and hydrated iron(III) oxide. SEM analysis revealed a porous surface morphology, while EDX confirmed the elemental composition of the material. XRD analysis demonstrated that the additive comprised nanoparticles (NPs) with an average crystallite size of 23.02 nm. The additive performance results showed that under optimized reaction conditions (300 mg/L additive, pH 6, and 37 °C), the biohydrogen yield increased by 7.39% compared to the control experiment. This improvement was likely attributed to enhanced electron transfer and hydrogen-producing bacteria (HPB) enrichment, which increased hydrogenase activity. The study provides evidence that iron-based NPs additives can serve as effective and practical additives in biohydrogen production.