Yusoff, M. S., Adam, N. H., Watalinggam, K., Abdul Aziz, H., & Alazaiza, M. Y. (2021). Effectiveness of Oil Palm Frond Activated Carbon for Removing COD, Color and Fe from Landfill Leachate. Journal of Engineering and Technological Sciences, 53(1), 210104. https://doi.org/10.5614/j.eng.technol.sci.2021.53.1.4