Fajar, M., R. Angreni Limbong, and R. Utami. “TUDY N HE FFECTIVENESS F CTIVATED ARBON OR EDUCING ARDNESS ND RON (FE) ONTENT N ELL ATER”. ingkar: ournal of nvironmental ngineering, vol. 5, no. 1, June 2023, pp. 1-9, https://journal.ar-raniry.ac.id/lingkar/article/view/6006.