Daud, Z., Abubakar, M. H., Rosli, M. A., Ridzuan, M. B., Awang, H., & Aliyu, R. (2018). Application of response surface methodology (RSM) to optimize COD and ammoniacal nitrogen removal from leachate using moringa and zeolite mixtures. International Journal of Integrated Engineering, 10(1). https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/2294