Fajar, Mutiara, Ruth Angreni Limbong, and Resarizki Utami. 2023. “STUDY ON THE EFFECTIVENESS OF ACTIVATED CARBON FOR REDUCING HARDNESS AND IRON (FE) CONTENT IN WELL WATER”. Lingkar: Journal of Environmental Engineering 5 (1):1-9. https://journal.ar-raniry.ac.id/index.php/lingkar/article/view/6006.