Review on COD and ammoniacal nitrogen removal from landfill leachate using low-cost adsorbent

The rapid generation rate of solid waste is due to the increasing population and industrialization. Nowadays, solid waste has been a major concerning problem in handling and disposal thus adsorption treatment process has been introduced which is an effective and low-cost method in removing organic and inorganic compounds from leachates such as chemical oxygen demand (COD) and ammoniacal nitrogen (NH₃-N). A most commonly adsorbent used for the removal of organic and inorganic compounds is activated carbon (AC), yet the main disadvantage is being too expensive in cost. Many researchers tried to use low-cost adsorbent waste materials, such as peat soil, limestone etc. This review article reveals a list of low-cost adsorbent and their capacity of adsorption for the removal of COD and NH₃-N. Furthermore, the preparation of these low-cost adsorbents as well as their removal efficiencies, relative cost, and limitation are discussed. The most efficient, cost-effective, and environment-friendly adsorbent can be used for the removal of COD and NH₃-N thus can be provided for commercial usage or water treatment plant.Implications: The concentration of organic constituents (COD) and ammonia nitrogen in stabilized landfill leachate has significant strong influences of human health and environmental. This review article shows the list of low-cost adsorbent (i.e., Activated carbon, Peat soil, Zeolite, Limestone, and cockle shell and their capacity of adsorption for the removal of COD and ammonia nitrogen. This would be greatly applicable in future research era as well as conventionally minimizing high-cost materials use and thereby lowering the operating cost of leachate wastewater treatment.