As large generators of oily wastewater tighten effluent controls, the U.S. Environmental Protection Agency (EPA) is targeting smaller generators. Some of the firms receiving their attention are smaller manufacturing plants, automotive garages, mobile equipment service shops and truck farms. Many of these firms do not have access to a sanitary sewer system that will accept oily wastewater.

Because disposal in storm sewers also is prohibited, they frequently use injection wells, septic system drain-fields, dry wells and ground pits to dispose of oily wastewater; one EPA concern is that oily wastewater will find its way into an underground aquifer that is a source of drinking water.

Many oily wastes contain organic and inorganic chemicals in concentrations that exceed the primary drinking water standards established by the Safe Drinking Water Act. So, the focus of one EPA program is aimed at preventing contamination of groundwater by controlling oily wastewater recycling at the generator’s site.

Getting Rid of Oily Wastewater

If oily wastewater isn’t recycled, it must be disposed of safely. One option is to have it collected and hauled away by a licensed disposal firm. The annual volume of oily wastewater generated by many shops and plants makes hauling too costly.

Even firms connected to sanitary or industrial wastewater sewer systems have limitations on the oil content in their effluent. When oil concentration exceeds a certain level, usually 100 ppm or less, the generator can get hit with hefty surcharges by the local government providing wastewater treatment.

At some level of oil concentration, the oily water effluent is prohibited from entering the sanitary sewer line.

Wastewater Recycling

With wastewater recycling, the most common methods of oil/water separation include decanting tanks, oil skimming, coalescing, membrane separation and various chemical treatments. Any of these methods can be effective. Selection should be based on economic as well as technical considerations.

Although it is a cost-effective method of reducing contamination, oil skimming often is overlooked as a primary technique. Frequently, this results from the misperception that skimming is only suitable as a pretreatment ahead of other oil/water separation devices.

Certainly, skimming is a retreatment method used to prevent oil overloads in downstream membranes, coalescers and sand bed filters. But it can stand alone as an oil removal method in many applications, reducing oil to only a few parts per million concentrations, depending on conditions. In many locales, this is good enough to allow the water to enter a sanitary sewer system without paying connection surcharges.

More exotic methods of oil removal, such as membrane filtration and chemical treatment, are most often required when tight emulsions and other chemicals must be removed. If an emulsion is the water-in-oil type, a skimmer may do the job.

Types of Oil Skimmers

Oil skimmers usually incur a low initial cost, install easily, offer rugged construction, reliable operation and minimal upkeep. Training personnel for operation, monitoring and routine maintenance is nil.

Still, there are different types of skimmers, and each application requires some analysis to make the best selection. Also, the water collection system must be set up properly in order to get maximum performance from the skimmer.

The six major skimmer configurations for industrial plants and service shops are belt, disk, drum, mop, tube and floating suction types. For all types, the oil or other hydrocarbon liquids must be floating on top of the water. For all but the floating suction type, a moving skimmer medium is pulled through or across the surface to attract the oil.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

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Abanaki offers industrial wastewater skimmers specially designed for steel mills where plant maintenance engineers are looking for the lowest cost, most reliable method of removing greases and heavy oils from the steel-mill scale pit. Abanaki oil skimmers use the difference in specific gravity and surface tension between grease and water, allowing the belt to attract grease and oil as the belt passes through the surface of the water. The simple belt-and-motor approach is proven to operate unattended and reliably for decades with little maintenance.

Grease Grabber Oil Skimmer

To avoid fines from government and municipal sewer districts, steel mills must limit the amount of grease in wastewater discharged into the environment. The Grease Grabber® oil and grease skimmer provides a continuously operating belt and wiper that can remove up to 160 gallons per hour of heavy greases and oils. Depending on the characteristics of the liquid, the oil/grease skimmer is capable of reducing grease content to fewer than five parts-per-million in water. Reclaimed grease and oil can be re-used or used as furnace fuel, avoiding sucker truck disposal costs.

How Grease Skimmer Works?

Using a double drive roller and tail pulley system, the grease skimmer belt runs through wastewater to pick up grease and heavy oil from the surface. The belt travels over the head pulley and then passes through tandem wiper blades, from which oil is scraped off both sides and discharged. A heated hopper keeps grease flowing in cold outdoor temperatures.

The tail pulley features flanges that allow the pulley to roll freely on the inside of the belt without becoming dislodged in turbulent applications. No bearings are needed; the unit does not need to be fastened to the tank. An optional tether and cage assembly is offered to prevent the tail pulley from being dislodged. The Grease Grabber oil skimmer can be used in pits with depths as shallow as one foot or as deep as 100 feet.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Abanaki Model 8 Belt Skimmer in Operation

Refineries are capable of producing gasoline, jet fuel, or even asphalt and, like most large-scale high-capacity plants, require process optimization and advanced process controls.

Oil Skimming Solution

Oil skimming is a popular method for capturing and removing oil from wastewater in plant treatment systems. This process is mandatory to avoid fines and to produce fuel as economically and environmentally friendly as possible. Oil skimmers work by making use of the differences in specific gravity and surface tension between oil and water. These physical characteristics allow the belts to attract oil and other hydrocarbon liquids from the surface of the fluid.

By implementing an oil skimming solution, the goal to recapture 100% of all hydrocarbons before they go down the drain, can be achieved. The oil skimmer collects the bulk of the hydrocarbons and sends them back to a crude tank. Any residual oils can be removed through filtration or chemical treatment. The oil skimmer is operated 24 hours a day 7 days a week. A refinery oil skimmer requires very little oversight, no maintenance, and the time saved more than offsets the electrical costs.

Abanaki Oil Skimmers

The Model 8 oil skimmer is the most widely used Abanaki oil skimmer. Its size and removal capacity make it suitable for most applications. From a mere shimmer on top of water to a heavy oil slick, the Model 8 oil skimmer performs efficiently, removing up to 40 gallons of oil per hour.

The Abanaki Model MB oil skimmer is a dependable and effective means of removing oil from water and water-base solutions. Often, oil skimming by itself will reduce oil to an acceptable level of water purity. Depending on the characteristics of the liquid, it is possible for the Model MB alone to reduce oil content to less than five parts per million in water. The unit can be used as a pretreatment before filtration, and in conjunction with a coalescing system.

The Model 4 oil skimmer utilizes a continuous belt and wiper to remove up to 20 gallons of oil per hour from the fluid surface. Depending on the characteristics of the liquid, it is possible for the Model 4 alone to reduce oil content to less than five parts per million in water.

 The Abanaki Oil Viper tube skimmer is a surface oil skimmer that effectively removes floating surface oils by means of an oleophilic (oil attracting) 3/4 inch diameter continuous looped tube. The tube extends out over the surface of the tank or pit and collects the free-floating oils. The Oil Viper has a specially designed method for removing the oil from the tube. It has a unique wiper combination attached to the tube itself in addition to the ceramic wiper on the skimmer.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Oil Skimmers Get the Dirty Jobs Done

Small leaks of hydraulic oil from turbines at hydroelectric plants are common and can end up in the facility’s sump or in its water resource. Oil skimming cost-effectively removes the oil before the water is discharged into the environment.

Typically, the utility is charged with environmental stewardship of the adjacent reservoir or river that is vital to hydro power generation. Often the reservoir or river also provides a public recreation, and it may be a source for drinking water and irrigation. Hydraulic oil leaks cannot be tolerated.

Utilities may employ absorbents and other manual methods of oil skimming. These methods are messy and inefficient, and take maintenance personnel away from more important work. In contrast, Abanaki oil skimmers are proven in thousands of applications to be the lowest maintenance and most reliable means of oil removal.

Oil Grabber® Model 8 Oil Skimmer

The Oil Grabber® Model 8 oil skimmer is a dependable and cost-effective tool for removing oil from sumps in hydroelectric plants. With its rugged construction it is made to last many years with little or no maintenance. The Model 8 oil skimmer utilizes continuous belt and wipers to remove oil from existing sumps. With its specially designed belts, it can collect virtually all oils present in sumps, and with the optional oil concentrator it can virtually eliminate any residual water that may be picked up.

Oil skimming makes use of the differences in specific gravity and surface tension between oil and water. These physical characteristics allow the belt skimmer to attract oil and other hydrocarbon liquids from the surface of the fluid. The Model 8 can be used in tanks with depths as shallow as one foot, or as deep as 100 feet.

The Model 8 Oil Skimmer may be part of an emergency oil spill system, in which wastewater flows through a coalescer tank, is skimmed, and then passes though filters. These systems satisfy the requirements of government standards intended to prevent oil spills from entering the environment. Abanaki has experience in designing and installing complete emergency oil spill systems for the power generation industry.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Abanaki Model 8 Belt Skimmer in Operation