Zeolite Utilization as a Catalyst and Nutrient Adsorbent of an Organic Fertilizer Process From Palm Oil Mill Effluent as Raw Material. j Trop. Soils [Internet]. 2014 Sep. 12 [cited 2025 Nov. 14];18(3):177-84. Available from: https://journal.unila.ac.id/index.php/tropicalsoil/article/view/185