Adsorption of methyl red from aqueous solution using Bali cow bones (Bos javanicus domesticus) hydrochar powder oleh Yantus A.B. Neolaka, Yosep Lawa, Johnson Naat, Arvinda C. Lalang, Bernadeta Ayu Widyaningrum, Gilbertus F. Ngasu, Krisanti A. Niga, Handoko Darmokoesoemo, Munawar Iqbal, Heri Septya Kusuma