Abstract
Undoubtedly, industrial activities have produced a large amount of waste, which has significantly contributed to the global environmental problem. The palm oil sector, which is considered a water-intensive industry, is one of the industrial sectors that have become a major source of severe water pollution concerns. Normally, 50% of the freshwater used during the extraction of crude palm oil will end up in the production of undesirable liquid waste. Thus, proper regulation and enforcement are required to control the discharge of such waste to ensure the sustainability of water resource management. Based on research databases such as Scopus, ScienceDirect, Web of Science and PubMed the total number of publications focused on palm oil mill effluent (POME) treatment has increased significantly over the past five years. The increase in publications shows the growing concern about the POME issue among the scientific community. This mini review focuses on selected biological treatment techniques for remediation of POME focusing on ponding systems, bioadsorption, activated sludge, microorganism and plant, aerobic biodegradation and integrated/hybrid treatment strategies. The summary of optimum operating conditions, characteristics of the treatment system, properties of materials and performance of each treatment are discussed in detail. To achieve a high level of contaminant removal performance, it is critical to discover the synergistic effect between the treatment procedures, materials employed, operational cost, and circumstances.