In this review article, the use of various low-cost adsorbents for the removal of pesticides from water and wastewater has been reviewed. Pesticides may appear as pollutants in water sources, having undesirable impacts to human health because of their toxicity, carcinogenicity, and mutagenicity or causing aesthetic problems such as taste and odors. These pesticides pollute the water stream and it can be removed very effectively using different low-cost adsorbents. It is evident from a literature survey of about 191 recently published papers that low-cost adsorbents have demonstrated outstanding removal capabilities for pesticides.

Commercial activated carbon has been a preferred adsorbent for the removal of various pollutants, and its widespread use is restricted due to its relatively high costs, which led to the researches on the possible alternative nonconventional and low-cost adsorbents. The use of agricultural products and by-products for instance has been widely investigated as a replacement for the current costly methods of removing various pollutants. In this critical review, an extensive list of the production of activated carbon from oil palm biomass is presented. The effects of various process parameters on the pyrolysis stage, characteristics, and influences of physical and chemical activating conditions on the production of activated carbons from oil palm biomass are discussed. A comparison in characteristics and applications of activated carbons from oil palm biomass with commercial activated carbons is made. It is evident from a literature survey of about 200 recently published articles that activated carbons from oil palm biomass exhibit outstanding capabilities for removal of various pollutants.