A recent study published in the Journal of Water Process Engineering explores the use of biochar derived from Macadamia nut shells combined with Mg-Al layered double hydroxides (LDH) for efficient phosphate ion removal from water. Phosphate pollution, largely responsible for water eutrophication, poses a significant environmental threat, causing algal blooms and water quality deterioration.

The research developed a composite material (MBC/Mg-Al LDH) that demonstrated high phosphate adsorption capacity, reaching up to 43.05 mg/g, especially at a 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 of 5.7 and temperatures between 25°C and 60°C. The material also showed excellent selectivity for phosphate ions, even in the presence of other competing anions like bicarbonate and sulfate.

The study utilized various adsorption models to evaluate performance, finding that the Langmuir isotherm model best represented the data. Importantly, the composite material retained much of its adsorption capacity over eight regeneration cycles, indicating its potential for long-term use.

This work highlights the potential of utilizing agricultural waste, such as Macadamia nut shells, in sustainable water treatment applications. By combining biochar with Mg-Al LDH, the study provides a cost-effective and environmentally friendly solution for mitigating phosphate pollution, a major cause of eutrophication in aquatic environments. This composite material offers a promising alternative to traditional phosphate removal methods.