NaOH-Activated Oil Palm Empty Fruit Bunch Biochar Adsorption for Integrated Anaerobic–Aerobic Treatment of Palm Oil Mill Effluent

Abstract

Palm Oil Mill Effluent (POME) contains high concentrations of oil and grease (O&G) and organic matter that require effective treatment. This study evaluated NaOH-activated oil palm empty fruit bunch (OPEFB) biochar integrated with an Upflow Anaerobic Sludge Blanket (UASB) reactor and Rotating Biological Contactor (RBC), and developed a simplified first-order adsorption–Anaerobic Digestion Model No. 1 (ADM1) framework to predict soluble chemical oxygen demand (sCOD) removal. Biochar activated with 1 M NaOH achieved the highest O&G removal efficiency (75.93%). The integrated system removed over 97% of O&G, while the highest sCOD removal efficiency (80.91 ± 9.58%) was obtained at a hydraulic retention time of 3 days. The model yielded calibration and validation R² values of 0.9463, 0.8773, and 0.5663. Overall, the integrated adsorption–UASB RBC system effectively enhanced POME treatment and provided a practical framework for predicting sCOD removal.

Limbah cair pabrik kelapa sawit (POME) mengandung minyak dan lemak (O&G) serta bahan organik yang tinggi sehingga memerlukan pengolahan. Penelitian ini mengevaluasi biochar tandan kosong kelapa sawit (TKKS) teraktivasi NaOH yang diintegrasikan dengan reaktor Upflow Anaerobic Sludge Blanket (UASB) dan Rotating Biological Contactor (RBC), serta mengembangkan model adsorpsi orde satu–Anaerobic Digestion Model No. 1 (ADM1) sederhana untuk memprediksi penyisihan soluble chemical oxygen demand (sCOD). Biochar teraktivasi NaOH 1 M menghasilkan penyisihan O&G tertinggi sebesar 75,93%. Sistem terintegrasi menyisihkan O&G lebih dari 97%, sedangkan penyisihan sCOD tertinggi mencapai 80,91 ± 9,58% pada HRT 3 hari. Model menghasilkan nilai R² kalibrasi dan validasi berturut-turut sebesar 0,9463; 0,8773; dan 0,5663. Integrasi adsorpsi biochar–UASB–RBC efektif meningkatkan pengolahan POME sekaligus menyediakan kerangka pemodelan untuk memprediksi penyisihan sCOD.