The interest of researchers has been more and more focused on identifying adsorption materials for pollutant removal with a specific interest in agriculture waste. It is noteworthy that many agricultural wastes are modified in different ways to improve the porosity and surface area of the material. Activation, carbonisation and grafting are only some of the most utilised technologies to produce adsorbents from agricultural waste. Some agriculture waste filters use less adsorbent and achieve the same metal ion adsorption efficiency of commercial filters at a potentially cheaper price. As they are made from renewable material found in abundance, they provide a solution to environmental problems and offer an additional value to the agricultural economy. This paper presents an overview of the recent improvements in the field and represents an evaluation of the different possibilities of using agricultural by-products to produce activated carbon for water purification.