*1.1.3 Environmental and aquatic pollutions caused by palm oil mill effluent (POME)*

POME is the wastewater produced by processing oil palm which has a higher biochemical oxygen demanded (BOD) and chemical oxygen demand (COD) and contains higher concentration of organic nitrogen, phosphorus and different supplement substance [27]. Oil palm trunks, oil palm fronds, empty fruit bunches, palm pressed fibers and palm kernel shells, less fibrous materials such as palm kernel cake and liquid discharge are waste products generated during oil processing [28]. The boom in the oil palm industry has resulted in the setting up of many oil mills for processing of the fleshy mesocarp and kernel. In Malaysia, mills increased from 10 in 1960 to 410 in 2008. For every ton of FFB produced, 600–700 kg of

POME is generated. POME has contributed to environmental pollution due to the production of large quantities of by-products during the process of oil extraction.

POME is generated mainly from oil extraction, washing and cleaning processes in the mill and these contain cellulosic material, oil and grease [29]. The oily waste which forms part of the POME are hazardous pollutants to aquatic environments because they are highly toxic to aquatic organisms when discharged in large quantities into watercourses e.g. river, streams. These goes a long way to contribute to human health hazards and environmental pollution. In Africa, many people depend on rivers as source of water. Sequestering POME into these watercourses creates a great danger for those that depend solely on these water bodies as a source of drinking water and other domestic and irrigation purposes. POME contains high amount of oil and grease (4000 mg/L), COD (5000 mg/L), BOD (25000 mg/L) and total solids (40, 500 mg/L) [29]. In Malaysia, about 44 million tons of POME are produced and are increasing every year [30].

Efficient POME treatment is very necessary to avoid continuous contribution to human health hazards and environmental pollution and also ensure the sustainability of the oil palm industry. Although treatment methods such as waste stabilization ponds, activated sludge systems, closed anaerobic digester and hand application harvester have been employed in the treatment of POME, the use of microalgae has received much attention in current times due to its ability to remove pollutants and also breakdown the organic compounds present in it [31, 32]. Micro algae has the potential of treating waste water such as removal of CO2 and NOx and high capacity of nutrients absorption [33]. Undoubtedly, microalgae can use the nitrogen and phosphorus compounds in water waste to produce micro algae biomass for various kinds of lipid generation, which can serves as substrate for biofuel production [31].
