Palm oil: Minimizing water use
Efficient irrigationIn nurseries for palm oil seedlings, drip or perforated tube irrigation systems are preferable to sprinklers.
Harvesting freshwaterPalm oil processing mills should divert rainwater from the factory effluent stream to minimize water treatment requirements and the dilution of nutrient-laden wastewater that requires treatment. Ponds and water catchment areas can be constructed to collect rainwater and reduce the amount of water taken from natural bodies.
Re-using mill effluentsFor every metric tonne of palm oil produced, 2.5 metric tonnes of effluent are generated, with an average biochemical oxygen demand (BOD) of 25,000 parts per million. In Malaysia, the BOD level must be below 100 parts per million before effluent can be legally discharged into streams.
This effluent should be concentrated and reused as fertilizer. Indeed, Golden Hope Plantations Berhad in Malaysia has found that returning the palm oil mill effluent to the plantations saves them in costs for fertilizers (nitrogen, phosphorous, and potassium) while avoiding pollution and pollution taxes.
The sludge cake produced when the effluent is allowed to settle can also be used to make biogas or livestock feed.
Source: Adapted from "World Agriculture & Environment" Clay (2004)