Application of natural coagulants for sustainable treatment of semi-aerobic landfill leachate

Semi-aerobic landfills become the preferred solution worldwide and expected to remain as future routes of exponentially increasing solid waste disposal. But Landfills emitted leachate, which is liquid residue with extreme pH, BOD, COD, NH3−N, refractory compounds, and toxicity could be an impending source of contamination through percolation to subsoil is a typical dilemma of this method due to its severe pessimistic impact over human health and environment. Hence to establish a green approach of leachate treatment is the paramount necessity to preserve the environmental elements and sustainability. Owing to the extensive variety in composition to explore the appropriate technology of leachate treatment is challenging. However, the application of natural coagulants (hibiscus rosa-sinensis, chitosan, natural starch) through coagulation-flocculation has been proven quite efficient method for stabilized leachate treatment according to research outcome. Comprising with discharge standard due to satisfactory performance regarding pollutant removal and environment-friendly characteristics nowadays these natural coagulants are being privileged over conventional synthetic inorganic coagulants. This study aims to summarize the technological innovations and recent applications of natural coagulants for the treatment of semi-aerobic landfill leachate with high COD, colour and humic substances as well as to focus the prospects of potential natural polymeric material for sustainable leachate treatment.