Selecting wastewater treatment filters using local raw materials Uchqun Umarov, Quvonchbek Quvondiqov, Axror Obidjonov, Askar Babaev and Otabek Ochildiyev E3S Web of Conf., 401 (2023) 03019 Published online: 11 July 2023 DOI: 10.1051/e3sconf/202340103019