Fats, oil, and grease in wastewater (often referred to as "FOG") pose special problems for the environment and H2O treatment plants. |
Origins of FOG
FOG originate from animal and vegetable fats and petroleum products. In a residential setting, oil and grease in wastewater primarily come from household cooking oils that are either directly poured down the sink or are residue from cleaning dishes, floors, and kitchen appliances and equipment. In non-residential settings, industrial food plants typically generate a significant amount of FOG in their discharge water. Motor, lubricating, and hydraulic fluids are also typical contaminants.
Without proper cleaning, oil and grease in wastewater build up in sewerage pipes, ultimately restricting the flow of water and causing clogs. Sewage clogs cause backups, overflows, and spills in homes, neighborhoods, and businesses. This creates significant health hazards that are costly to clean up.
Grease effluent also creates difficulties for treatment plants, causing the cost of treatment to rise. These increased costs are passed on to consumers, whether residential, commercial, or industrial. Oil and grease in wastewater not only impact humans, but also the environment. These non-soluble materials contaminate beaches, lakes, and streams, harming aquatic plant and animal life. In addition to directly impacting aquatic life, the residue also decreases the available oxygen, damaging the waterbody.
How is FOG Treated?
Because it is not suitable for human consumption or use, contaminated effluents must be cleaned or disposed of. How waste is treated depends on the nature and degree of the contamination and consists of physical, chemical, or biological treatments. Thorough cleaning sometimes requires all three. First, mechanical methods are employed. Viscous residues are skimmed from the surface of the discharge. If skimming does not produce sufficiently clean water, then further treatment is required. As an additional line of treatment, a blower is employed to remove solid residue that could not be skimmed. Soluble or emulsified oils are removed in a specialized separator. Filtration is yet another method used to clean oils from discharge. Clay and carbon filters are well suited to removing oil. Finally, chemical and biological agents are applied to remove the final traces of oil and grease in wastewater.
How Can Industries Cut Down on FOG?
Industries can reduce their impact by employing a comprehensive removal process. Monitoring the amount of FOG in industrial discharge is an important first step. Not only does this help various industries avoid fines and potential prosecution down the road, it also helps to reduce removal costs and negative environmental impacts. When it comes to effective monitoring, there are many options for equipment, such as using traps in the discharge pipes or employing other methods of mechanical removal. For example, factories can use an interceptor, a large-capacity exterior vault that has two chambers. One chamber retains any grease residue, and the other chamber provides a place for the industrial discharge to cool, which allows leftover residue to rise to the surface where they can be easily removed. These methods help to remove some FOG before discharge even gets to the public sewer system and treatment plants.
When you need solutions for monitoring oil and grease in wastewater, contact the experts at http://wilksir.com/applications/oil-in-water-soil-testing/fog-in-wastewater.html.
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