Utilization of coffee husk ash for soil stabilization: A systematic review

Coffee is currently one of the most prized food commodities. Its production has grown so much in recent times, however, the waste by-products generated are also huge. It is envisioned that with rapid urbanization and construction, the use of these by-products can offset the demand for construction materials such as cement and concrete. It is now generally accepted that the manufacture of cement and concrete reduces the supply of natural aggregates at the same time generates carbon dioxide emissions and deteriorates the environment. In this paper, the sustainable use of coffee husk ash (CHA), produced from coffee production is discussed. The CHA necessitates huge land for storage and is normally then left in site locations where it is first dumped, while others are burned in incinerators, contributing to air pollution, thus creating a significant environmental issue. This article will first focus on general coffee production, consumption, and waste by-products. Its life cycle from plantation to wastes is then discussed followed by the effective usage of CHA for the production of ceramics and use in soil stabili-zation. The article summarizes the use of CHA in soil stabilization and examines development patterns in terms of strength and durability. The findings indicate that adding CHA into soil stabilization benefits both sustainability and zero-waste technologies.