Preparation, adsorption performance and mechanism of MgO-loaded biochar in wastewater treatment: A review

Biochar is a low cost, porous and solid material with an extremely high carbon content, various types of functional groups, a large specific surface area and many other desirable characteristics. Thus, it is often used as an adsorbent or a loading matrix. Nano-magnesium oxide is a crystalline material with small particles and strong ion exchangeability. However, due to the high surface chemical energy, it easily forms agglomerates of particles. Therefore, to combine the advantages of biochar and magnesium, metal magnesium nanoparticles can be loaded onto the surface of biochar with different modification techniques, resulting in biochars with low cost and high adsorption performance to be used as an adsorption matrix (collectively referred to as Mg@BC). This review presents the effects of different Mg@BC preparation methods and synthesis conditions and summarizes the removal capabilities and adsorption mechanisms of Mg@BC for different types of pollutants in water. In addition, the review proposes the prospects for the development of Mg@BC to solve various problems in the future.