Studies have shown that the use of herbicides to control organisms can trigger environmental problems, such as surface and ground water contamination, and in humans, can cause problems in reproductive and developmental systems. Atrazine (ATZ) is one of the most widely used herbicides in the world. Recently, it was included in the priority substances list of the United States Environmental Protection Agency and European Comission. Considering the toxic potential of this herbicide, suitable treatment methods need to be developed to remove it from contaminated water. Adsorption is one of the most used methods to treat water and many studies have been conducted in order to obtain low cost adsorbents, like agricultural sources biomass, biological, and industrial by-products. The plant Moringa oleifera Lam (MO) belongs to Moringaceae family, and is a tropical tree that grows naturally in India, South-Saharan region and South America. The parts of its fruit, especially the seeds have been employed as coagulating agents for water treatment and as biosorbents, being the MO seed husks a by-product of its uses. Also, an adsorbent material that not only possessed a good adsorption capacity, but show favourable regeneration properties, would contribute to a significant reduction of the overall cost of the process. Therefore, successful regeneration of the adsorbent can be considered as a key process for determining the applicability of an adsorbent in a water-purification application. This study evaluated the biosorption potential of ATZ by MO seed husks in fixed-bed column, and its regeneration capacity. The experiments were performed in a glass column, packed with 3 g of biosorbent (13.5 cm bed depth) and fed in upward mode with an ATZ solution of 5 mg/L and pH 7, at a constant flow rate (1 mL/min). Five cycles of biosorption–desorption were performed at the same flow rate (1 mL/min), using ultra-pure water as eluent. The breakthrough curves obtained presented no differences in behaviour, maintaining the same trend throughout all five cycles. However, there was a slight decline in the saturation time, and in the amount of ATZ biosorbed per gram of MO. On the other hand, as the removal efficiency is obtained from the relation between the amount of ATZ transported to the bed and the time required to reach saturation, this parameter remained almost constant. Hence, it was possible to achieve five cycles of biosorption–desorption without loss of biosorption capacity. This study shows that Moringa oleifera Lam seed husks can be used as an effective biosorbent in the removal of ATZ from aqueous solutions using a fixed-bed column. Moreover, the biosorbent could be regenerated using a simple and cheap process, highlighting it as a distinctive material in relation to other biosorbent materials presented in the literature. It is important to point out that the alternative forms of water treatment, including biosorption using biomass of agricultural sources as biosorbents, are of great importance, since it would be a viable alternative for water treatment in developing countries, poorest regions and in places where obtaining water drinking is still a challenge.