Eco-Fer (Ecotru Fixed Bed Reactor) : Application of Ecotru on Fixed Bed Reactor for Eliminating Ammonium in Waste WaterSyakira Hana, Novelendah Lidiya, Pertiwi Kartika, Syahidah Rusyda, Purwono and Istirokhatun TitikE3S Web Conf., 73 (2018) 05005DOI: https://doi.org/10.1051/e3sconf/20187305005