Filtration Test Fe3+ by Duck Feather -Na2S2O5 - High Dencity Polyethylene (HPDE) CompositeUmi Baroroh Lili Utami and Dahlena AriyaniE3S Web Conf., 448 (2023) 03077DOI: https://doi.org/10.1051/e3sconf/202344803077