Potassium enrichment of treated palm oil mill effluent in a fixed-bed contactor

Abstract

Treated Palm Oil Mill Effluent (POME) is the effluent of POME-based biogas production process. This liquid is potential as a raw material of liquid organic fertilizer, but the potassium content should be upgraded. Ash of empty palm fruit bunches (EPFB-a) which is locally available in huge amount is an attractive source of potassium. Potassium enrichment of treated POME was performed by contacting this liquid with EPFB-a in a fixed bed contactor. This research studied the effects of treated POME flow rate and height of EPFB-a bed on potassium mass transfer coefficient from solid to liquid phase in the contactor. Treated POME and EPFB-a were obtained from a crude palm oil mill in Rantau Sakti Village, Tambusai Utara Sub-district, Rokan Hulu Regency of Riau Province. The treated POME flow rates were set at 3.72; 3.36; and 2.52 L/min. EPFB-a bed height were fixed at 0.03, 0.06, and 0.09 m. The performance of this fixed bed contactor was evaluated based on extracted potassium content.