Valorization of boiler ash for the production of coagulants for treatment of water and wastewater: a bibliographic and systematic review

Proper treatment of domestic and industrial water and effluents is of utmost importance. The use of coagulation methods in wastewater treatment is one of the most common methods applied in the physicochemical treatment of water and effluents. The use of synthetic coagulants, including those obtained from boiler ash, is essential for the correct treatment of water and for reducing the amount of waste sent to industrial landfills, thus contributing to the reduction of environmental impacts both in its manufacture and in its application. This review aims to present the different methods of producing ash-based coagulants for water and wastewater treatment, highlighting the types of ash that can be applied, how the coagulant is obtained, and its efficiency during the coagulation step. A literature review and systematic review was carried out to investigate the use of boiler ash in the production of coagulants and to analyze the data obtained from the Scopus database, resulting in a final bibliometric portfolio of 50 publications. The use of various types of ashes as primary coagulants or auxiliaries offers an efficient and sustainable alternative to replacing synthetic coagulants, such as salts, aluminum, and iron, in the treatment of water and effluents.

Valorization of boiler ash for the production of coagulants for treatment of water and wastewater:a bibliographic and systematic review