Handayani, Syahfitri2022-03-142022-03-142021-08wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10456Fresh Palm oil mill effluent (POME) is a thick brownish colour in the viscous and colloidal suspension, having an unpleasant odour and high value of BOD and COD, thus sensitive to environmental issues. The most widely used ponding systems for POME treatment have to ways such as long hydraulic retention time (HRT), obsolete, and require large area pond. Alternative treatment systems need to be introduced and studied to anticipate incoming problems associated with the limitations of the current system. In this study, the adsorption-degradation process was investigated for the treatment of the POME. The adsorption process was conducted using the adsorbent of palm oil fly-ash activated with HCl solution at a temperature of 105 oC for 24 hours. The composition of activated ash was determined by X-ray fluorescence (XRF) and contains SiO2 (47.778%), CaO (20.646%), K2O (6.041%), P2O5 (12.586%), MgO (6.324%) and Fe2O3 (4.304%). The adsorption process was able to reduce 37.50% of the initial COD value using 0.025 mg/L mg of activated fly ash, POME volume 100 ml for 15 minutes of reaction time. Whereas the degradation of POME following the adsorption process by layer birnessite (δ-MnO2) catalyst, H2O2 concentration of 17,000 mg/L and POME volume 20 mL in 60 minutes further reduced 61.33% of COD value. These tandem processes seem to be promising to tackle the POME issue in near futureencatalystdegradationfly ashArticle