In a recent study preprinted on Research Square, Wan Noni Afida Ab Manan and Ahmad Zamani Ab Halim investigated the development and optimization of activated nanomagnetic biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More (ANB) derived from oil palm trunk (OPT) biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More, named ANBO, for the efficient removal of malachite green (MG) dye from water. Organic dye pollution, especially from industries like textiles and paper, poses a severe environmental threat due to its toxicity and associated health risks. While activated carbonActivated carbon is a form of carbon that has been processed to create a vast network of tiny pores, increasing its surface area significantly. This extensive surface area makes activated carbon exceptionally effective at trapping and holding impurities, like a molecular sponge. It is commonly More (AC) is a common adsorbent, its limitations in separation and regeneration drive the need for more effective and sustainable alternatives.

The researchers utilized residual oil palm trunk biomass, a waste product from wood manufacturing, as the raw material. This biomass was ground and chemically activated with phosphoric acid to create activated biochar (AB). Subsequently, ANBO was synthesized by incorporating Fe₃O₄ nanoparticles onto the AB surface using a coprecipitation method, enhancing its magnetic properties for easier separation from treated water.

Characterization techniques confirmed the successful synthesis and beneficial properties of ANBO. Scanning Electron Microscopy (SEM) images revealed that ANBO possessed a rougher surface with a higher number of granular bulges and increased porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More compared to the raw OPT and activated biochar. This indicates the successful loading of Fe₃O₄, which improved the material’s surface area and functional groups for adsorption. Fourier Transform Infrared (FTIR) spectroscopy identified various functional groups, including hydroxyl and carbonyl groups, and stretching vibrations of Fe-O bonds, all crucial for dye adsorption. Brunauer-Emmett-Teller (BET) analysis showed a significant increase in surface area from 34.28 m²/g for AB to 76.07 m²/g for ANBO, with a corresponding increase in pore volume, attributed to the uniform distribution of iron nanoparticles and expansion of micropores. X-ray Diffraction (XRD) confirmed the crystalline nature of the magnetic particles within the amorphous biochar structure. The study employed Response Surface Methodology (RSM) with a Box-Behnken design (BBD) to optimize the MG removal process by investigating the impact of three key variables: adsorbent dosage, contact time, and pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More.

The optimization process identified the ideal conditions for maximum MG removal. At an adsorbent dosage of 0.08 g, a contact time of 1 hour (60 minutes), and a pH of 8, the model predicted a 95% MG removal efficiency. A verification experiment conducted under these optimized conditions achieved an actual 91% MG removal, with a minimal error of ±4.21% from the predicted value. This strong agreement validates the reliability of the RSM optimization method and the practical value of the determined optimal conditions.

The pH at which the total surface charge of ANBO is zero (pHzpc) was determined to be 6.3. This is significant because at pH values above 6.3, the negatively charged surface of ANBO facilitates the adsorption of the positively charged MG dye through ionic or electrostatic interactions. The study successfully demonstrated that ANBO, synthesized from readily available oil palm trunk biomass, is a promising and economical adsorbent. Its enhanced physical characteristics and the optimized adsorption conditions provide an effective solution for removing malachite green dye from aqueous solutions. This research aligns with Sustainable Development Goals (SDGs) 6 (Clean Water and Sanitation) and 3.9, which aim to reduce health risks from hazardous chemicals and pollution.

Source: Manan, W. N. A. A., & Halim, A. Z. A. (2025). Modeling and Optimization of Activated Nanomagnetic Biochar Derived from Oil Palm Trunk Biomass via Response Surface Methodology for the Removal of Malachite Green Dye. Research Square.