Removal of TCOD and phosphate from slaughterhouse wastewater using Fenton as a post-treatment of an UASB reactor

A pilot was designed to study the removal efficiencies of total chemical oxygen demand (TCOD) and phosphate by a combined biological and chemical method. Two stages of Up-flow anaerobic sludge blanket (UASB) reactor and advanced oxidation processes was operated in batch mode. The UASB reactor was operated with hydraulic retention time of 26 h. UASB removal efficiency of TCOD and phosphate were 62.2 and 36.5%, respectively. Fenton process was used as a post-treatment so as to remove organic matter and nutrients. At this stage, the removal efficiencies of TCOD and phosphate were investigated considering the effect of parameters such as pH, hydrogen peroxide and Fe (II) dose based on Taguchi experimental design. Accordingly, under optimum conditions, pH = 3, 1000 mg/l of H2O2 and 400 mg/l of Fe (II) the removal efficiencies of TCOD and phosphate reached 95.41 and 85.29%, respectively. The combined method removed TCOD and phosphate up to 98.6 and 90.5%, respectively.