Gala, D. S., Rahmanpiu, R., & Mulyana, W. O. (2025). Application of Silica Adsorbent Rice Husk Ash-Activated Carbon in Refining Waste Cooking Oil. Hydrogen: Jurnal Kependidikan Kimia, 13(1), 197–208. https://doi.org/10.33394/hjkk.v13i1.14802