Palm Oil Mill Effluent (POME) Characteristic in High Crop Season and the Applicability of High-Rate Anaerobic Bioreactors for the Treatment of POME

Palm oil mill effluent (POME) is a wastewater generated from palm oil milling activities which requires effective treatment before discharge into watercourses due to its highly polluting properties. The characterization of wastewater is the essential step in the design of any wastewater treatment plant (WWTP) in the industry as conducting pilot-scale tests to obtain design and operating parameters is time-consuming and expensive. Characterization of POME had been conducted in various studies which only involve parameters that were listed as discharge standards by local environmental authorities and those that were significant to the results of the chosen treatment methods. Other important parameters that were seldom considered in the characterization of POME are as follows: total phosphorus (TP), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), total volatile solids (TVS), volatile suspended solids (VSS), lignin and sulfate concentrations, and toxicity. These parameters are very important in determining the suitable treatment method for industrial-scale WWTP designs besides detecting the operational problems of the selected treatment system due to the characteristics of POME. This would also ensure a proper process design and equipment sizing for POME treatment systems. Therefore a comprehensive POME characteristic study was conducted in the present research with two main objectives: (i) to obtain a complete, up to date, and representative characteristic of POME which is important for treatment method selection, process design, and equipment sizing for industrial-scale WWTP and (ii) to evaluate the suitability of POME to be treated anaerobically on the basis of the characteristic study. POME characteristics sampled from Golconda palm oil mill at high crop season was found to have deviated at approximately ±20−50% from the values recorded during low crop season. An overall characteristic of POME obtained from this study indicated that the biochemical oxygen demand (BOD) concentration in POME was 49000 mg/L; chemical oxygen demand (COD) was 79000 mg/; total volatile solids (TVS) concentration was 42600 mg/L; and COD:N:P ratio of POME was 250:2.9:3.2. The POME characteristic obtained in this study indicated that POME treatment using anaerobic systems was a viable option due to the high biodegradability of the POME and the versatility of high-rate anaerobic bioreactors to cope the variation and fluctuation of POME characteristics. Furthermore, the introduction of the clean development mechanism (CDM) encourages the utilization of high-rate anaerobic bioreactors for POME treatment and methane capture to earn certified emission reduction (CER) credits as a source of revenue.