Utilization of Response Surface Methodology to Optimize Ammoniacal Nitrogen Adsorption Efficiency from Palm Oil Mill Secondary Effluent Using Palm Empty Fruit Bunch as Adsorbent . Mal. J. Fund. Appl. Sci. [Internet]. 2025 Nov. 2 [cited 2026 Sep. 16];21(5):2538-56. Available from: https://mjfas.utm.my/index.php/mjfas/article/view/4326