considered to be edible before the removal of various nonglyceride compounds
through an operation known as refining. The vegetable oil refinery uses various
types of physical and chemical processes to offer a premium quality of oil. The
refining processes remove undesirable materials, such as phospholipids,
monoacylglycerols, diacylglycerols, free fatty acids, color and pigments, oxidized
materials, etc., but may also remove valuable minor components, such as antioxidants and vitamins (carotenes and tocopherols). The major steps involved in
chemical refining include degumming, deacidification, deodorization, and neutralization processes. During these processes, a high amount of water is used, and
highly polluted effluents are formed. The treatment of vegetable oil refinery
wastewaters has been a major problem of environmental concern in developing
countries for the last decades due to their complex nature consisting of water and
soluble and insoluble substances that contain fats and oil, carbohydrates, phenolic
compounds, and suspended solids. Therefore, a suitable wastewater treatment prior
to their discharge into the receiving bodies is required. Numerous treatment
technologies have been applied to treat oily wastewaters. Coagulation/flocculation,
electrocoagulation, reverse osmosis, flocculation/membrane filtration, air flotation,
microfiltration, and enzymatic catalysis are the most common ones. However, due
to the complex nature and low biodegradability of the oily wastewater, some of
these technologies may not be efficient in treating such wastewaters, while
others may be of high cost and generally require a pretreatment. As a result, in
this chapter, the processes involved in the vegetable oil refining, the environmental
impacts of those processes, the characterization of the waste produced during the
processes, waste reduction at source, recovery from waste, and treatment technologies are discussed.
Keywords Vegetable oil industry · Vegetable oil · Refining · Industrial wastewater ·
Waste characterization · Reduction · Removability · Treatment technologies
Acronym
BOD Biochemical oxygen demand
COD Chemical oxygen demand
DAF Dissolved air flotation
DGF Dissolved gas flotation
FFA
Free fatty acids
IAF
Induced air flotation
MBR Membrane bioreactors
NO x
Oxides of nitrogen
TSS
Total suspended solids
UF
Ultrafiltration
VOC Volatile organic compounds
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through an operation known as refining. The vegetable oil refinery uses various
types of physical and chemical processes to offer a premium quality of oil. The
refining processes remove undesirable materials, such as phospholipids,
monoacylglycerols, diacylglycerols, free fatty acids, color and pigments, oxidized
materials, etc., but may also remove valuable minor components, such as antioxidants and vitamins (carotenes and tocopherols). The major steps involved in
chemical refining include degumming, deacidification, deodorization, and neutralization processes. During these processes, a high amount of water is used, and
highly polluted effluents are formed. The treatment of vegetable oil refinery
wastewaters has been a major problem of environmental concern in developing
countries for the last decades due to their complex nature consisting of water and
soluble and insoluble substances that contain fats and oil, carbohydrates, phenolic
compounds, and suspended solids. Therefore, a suitable wastewater treatment prior
to their discharge into the receiving bodies is required. Numerous treatment
technologies have been applied to treat oily wastewaters. Coagulation/flocculation,
electrocoagulation, reverse osmosis, flocculation/membrane filtration, air flotation,
microfiltration, and enzymatic catalysis are the most common ones. However, due
to the complex nature and low biodegradability of the oily wastewater, some of
these technologies may not be efficient in treating such wastewaters, while
others may be of high cost and generally require a pretreatment. As a result, in
this chapter, the processes involved in the vegetable oil refining, the environmental
impacts of those processes, the characterization of the waste produced during the
processes, waste reduction at source, recovery from waste, and treatment technologies are discussed.
Keywords Vegetable oil industry · Vegetable oil · Refining · Industrial wastewater ·
Waste characterization · Reduction · Removability · Treatment technologies
Acronym
BOD Biochemical oxygen demand
COD Chemical oxygen demand
DAF Dissolved air flotation
DGF Dissolved gas flotation
FFA
Free fatty acids
IAF
Induced air flotation
MBR Membrane bioreactors
NO x
Oxides of nitrogen
TSS
Total suspended solids
UF
Ultrafiltration
VOC Volatile organic compounds
326
D. Kaya and Y.-T. Hung