Huge quantities of waste are produced in the oil palm mill. The process of oil extraction leads to the generation of liquid waste commonly referred as palm oil mill effluent . Palm oil mill effluent is generated mainly from oil extraction, washing and cleaning processes in the mill and these contains cellulosic material, fat, oil and grease etc.Palm oil mill effluent also contains significant amounts of solids, both suspended solids and total dissolved solids in the range of 18,000 mg L 1 and 40,000 mg L 1 respectively ( Table 2). These solids are commonly known
as palm oil mill sludges (POMS). The solid waste that are produced in the process of extraction are the leaves,trunk, decanter cake, empty fruit bunches, seed shells and fibre from the mesocarp.
Palm Oil Mill Effluent:
Characteristics of palm oil mill effluent depend on the quality of the raw material and palm oil production processes in palm oil mills.The extraction of crude palm oil from FFB requires enormous amounts of water. It has been estimated that 5-7.5 tonnes of water is required for the production of 1 tonne crude palm oil and more than 50% of the water ends up as palm oil mill effluent . Sethupathi has categorized three major processing operations responsible for producing the POME. Sterilization of FFB, clarification of the extracted CPO, hydrocyclone separation of cracked mixture of kernel and shell. Hydrocyclone contributes about 36, 60 and 4% of respectively in the mills. Based on palm oil production in 2005 (14.8 million tonnes), Lorestani estimated that in Malaysia about 53 million m3 POME is being produced every year. Yacob et al. estimated that about 0.5- 0.75 tonnes of will be discharged from mill for every tonne of fresh fruit bunch.
Wastewater composition depends mainly on the season, raw matter quality and the particular operations being conducted at any given time. Generally palm oil mill wastewater is low in pH because of the organic acids produced in the fermentation process, ranging about 4 – 5. It also contains large amounts of total solids (40,500 mg l 1), oil and grease (4000 mg l 1) [31]. Wastewater includes dissolved constituents such as high concentration of protein, carbohydrate, nitrogenous compounds, lipids and minerals, which may be converted into useful materials using microbial processes. The effluents from palm oil mill may lead to considerable environmental problems, if discharged untreated Therefore, the challenge of converting POME into an environmental friendly waste requires an efficient treatment and effective disposal technique.
Regulatory Standards for Palm Oil Mill Effluent:
Malaysian experiences in effluent control in the palm oil industry reveal that a set of well designed environmental policies can be very effective in controlling industrial pollution in a developing country. The Environmental Quality (prescribed Premises) (Crude Palm Oil) Regulations 1977, promulgated under the enabling powers of Section 51 of the EQA, are the governing regulations and contain the effluent discharge standards. Other regulatory requirements are to be imposed on individual palm oil mills through conditions of license according to Environmental Quality Act 1974 . The effluent discharge standards usually applicable to crude palm oil mills are presented in Table 3.Malaysia is identified as the country that produces the largest pollution load in the river . Due to this fact,the palm oil industry faces the challenge of balancing the environmental protection, its economical viability and sustainable development. There is an urgent necessity to find an approach to preserve the environment while.
Palm Oil Mill Sludge (POMS) Management:
The oil palm mills generate many by-products and wastes besides the liquid wastes that may have a significant impact on environment if they are not properly dealt with. Among these by-products palm oil mill sludges (POMS) as result of POME treatment plays crucial impact on the environment, which makes it necessary to find a proper technology for mitigating these wastes. According to Chooi [64], palm oil mill sludge (POMS) can be dried and used as a fertilizer as it contains high nutrient value.Drying is mostly done in open ponds, but during the rainy seasons this process becomes difficult due to slow rate of drying and over flow problem. Composting as well as vermicomposting technology can be used in POMS management.