Continuous Production of Organic Acids from Palm Oil Mill Effluent with Sludge Recycle by the Freezing-Thawing Method

• Main Authors: Yee, Phang Lai, Hassan, Mohd Ali, Shirai, Yoshihito, Wakisaka, Minato, Abdul Karim, Mohamed Ismail
• Format: Article
• Language: English; English
• Published: The Society of Chemical Engineers, Japan 2003
• Online Access: http://psasir.upm.edu.my/id/eprint/7700/1/Continuous%20Production%20of%20Organic%20Acids%20from%20Palm%20Oil%20Mill%20Effluent%20with%20Sludge%20Recycle%20by%20the%20Freezing.pdf; http://psasir.upm.edu.my/id/eprint/7700/; http://dx.doi.org/10.1252/jcej.36.707
• Institution: Universiti Putra Malaysia

The performance of the anaerobic treatment of palm oil mill effluent for organic acids production at a short retention time of less than 5 days was assessed by incorporating a sludge recycle system with no pH control except by adding calcium carbonate. The system could be operated successfully for a 3.5-day retention time at pH 5. The sludge solids in the treated effluent were separated by a freezing-thawing technique and it was partly recycled back to the reactor. The thawed clarified POME solution contained a low SS of 2,200–3,500 mg/L. The organic acids production with a concentration of 10–14 g/L was essentially similar to the treatment for a 5-day retention time without a sludge recycle. Hence by incorporating a sludge recycle system with the freezing-thawing method, the retention time for the treatment could be reduced without affecting the organic acids generation.