investigated for the removal of organics and nutrients by varying chemical oxygen demand
(COD) to NH 4-N ratio (C/N ratio: 3.5, 6.75, and 10), hydraulic retention time (HRT: 6 h, 15 h,
and 24 h), and recirculation ratio (R: 1, 2, and 3). The use of activated carbon coated carriers
prepared from waste polyethylene material and polyurethane sponges attached to a
cylindrical frame in the integrated A/O MBBR increased the attached growth biomass …