Transforming agricultural and industrial waste into biochar through a process of thermal decomposition without the presence of oxygen stands out as one of the most efficient strategies for mitigating the impact of urbanization on the global climate. Biochar has a wide range of potential applications, including soil enhancement and carbon storage, and it has recently gained popularity as a valuable material for remediating soils contaminated with heavy metals. This study focuses on the utilization of moringa biochar for remediating soil contaminated with zinc, with a particular emphasis on assessing the geoenvironmental characteristics, such as soil pH, leaching potential, and compressive strength. The study examines the impact of different levels of biochar content (ranging from 0 to 10%) and curing periods (ranging from 0 to 28 days) on silty soil that has been artificially contaminated with 10,000 mg/kg of zinc. The results of the strength tests indicate that, when compared to untreated soils, the soil amended with 5% biochar exhibited a notable increase in strength of approximately 2.30 units after a curing period of 7 days. Furthermore, the introduction of highly alkaline biochar into the soil resulted in a significant rise in soil pH, creating favorable conditions for the encapsulation of zinc within the soil. The efficiency of immobilizing zinc reached approximately 84.5% in the soil treated with 10% biochar content.