Diharyo (2020) “EFFECTIVENESS TEST OF ABSORPTION CAPACITY OF ACTIVATED CHARCOAL BY IMMERSING H3PO4 AND GRAIN SIZE PALM OIL SHELLS ON INSTALLATION OF PEAT WATER TREATMENT”, International Journal of Research -GRANTHAALAYAH, 8(5), pp. 383–389. doi: 10.29121/granthaalayah.v8.i5.2020.228.