Total oil and grease

The terminology for total oil and grease, dispersed oil, and dissolved oil may vary with location and specific test standard used by the authorities having jurisdiction. These terms should be applied with caution and should conform to the regulations and test standards applicable to the specific location. 

Produced water treating equipment performance is commonly described in terms of its oil removal efficiency. This efficiency considers only the removal of dispersed oil and neglects the dissolved oil content. For example, if the equipment removes half of the dispersed oil contained in the influent produced water, it is said to have a 50% oil removal efficiency. For a specific piece of equipment or an overall system, the oil removal efficiency can be calculated using the following equation  

Co = dispersed oil concentration in the water outlet (effluent) stream, ppm (mg/1), 

The performance can be described by determining the inlet and outlet oil concentrations and the associated oil droplet size distributions at the equipment inlet and outlet. This information can then be used to define the oil removal efficiency for any given oil droplet size or range of droplet sizes. This concept is further discussed in Chapter 3. 

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The removal of mineral oils from sea sand was studied in [323] in presence of aqueous solutions of nonionic surfactants (Triton X-100, Triton X-114, Alconox) with and without solid additives, such as granular activated carbon, powder activated carbon. The process was conducted in a scrubber by froth flotation. Contaminants and fine sand particles were transferred, together with sorbents, into the water-froth stream, whereas clean sand remained in the tails . Without addition of sorbent, the content of contaminants (total oil and grease -TOG) was 4000 ppm, while the additives reduced the TOG content to less than 1000 ppm. 

A vendor has quoted that one of its standard plate packs would be capable of reducing the total oil and grease content of the effluent water to less than 200 mg/1. The vendor s standard plate pack has the following geometric specification ... 

Calculate the total oil and grease content in effluent water from the plate pack to check the vendor s quoted performance. 

In order to calculate the total oil and grease in the effluent water, we must first determine the smallest oil droplet size that can be removed in the vendor s standard plate pack at the design conditions given. Equations (3.20a) and (3.20b) were derived for the given plate pack geometric configuration assumed in this example calculation. 

Since the plate pack does not remove any of the dissolved oil, the total oil and grease content in the effluent water from the plate pack is equal to 183.6 + 10 mg/1, or 193.6 mg/1. Therefore, the vendor s quoted... 

Total oil and grease" is defined as the combination of both the dispersed and dissolved liquid hydrocarbons and other organic compounds (i.e., "dissolved oil" plus "dispersed oil") contained in produced water. This term is referenced in certain regulatory standards and is commonly used to evaluate water treating system design. Total oil and grease consists of normal paraffinic, asphaltic, and aromatic... 

Total oil and grease" is defined by the measurement procedure stipulated by the authorities having jurisdiction. Important variations that could give different results for the same sample are ... 

The dissolved oil and grease content is first determined by measuring the total oil and grease content and then subtracting the measured dispersed oil and grease content. The measured dispersed oil is obtained by removal of the dissolved oil and grease from the solvent with silica gel. This can be expressed by the following equation ... 

Refs. 22, 23. BOD = Biological oxygen demand. COD = Chemical oxygen demand. TSS liihle 1. (Continued) Total suspended solids. O and G = oil and grease. ... 

Corrosive Liquid Chemical pH Constituent analysis Oil and grease content Total suspended solids Total dissolved solids... 

Dissolved Solids Boiling Pt/Freezing Point For Liquids/Solid Mixtures Bulk Density Total Solids Content Solids Size Distribution Suspended Solids Content Suspended Solids Settling Rate Dissolved Solids Content Free Water Content Oil and Grease Content Viscosity For Gases Density... 

Applied water rates for the contact systems are typically about 3600 gal/t of cast product discharge rates for the better controlled casters are less than 25 gal/t. The principal pollutants are total suspended solids, oil, and grease, and low levels of particulate metals.15... 

Comparatively, the modified reduction-flotation system will have lower annual total cost (amortized capital cost plus O M cost) and will require less space, because the flotation unit is very shallow in depth and thus can be elevated. It is expected, however, that the treatment efficiency of the modified system will be higher due to the fact that the DAF clarifier can separate not only the suspended solids but also organics such as oil and grease, detergent, and so on.57-58-61 Conventional sedimentation clarifiers can separate only insoluble suspended solids. 

Removal of Total Suspended Solids and Oil and Grease from Coil Coating Wastewater by Emulsion Breaking and Clarification Process... 

Table 7.8 indicates that the major regulated parameters for pretreatment of coil coating industrial wastewater are chromium, cyanide, zinc, total toxic organics (TTO), oil and grease, manganese, fluoride, phosphorus, and copper. The effluent limitations of all coil coating operations represent the following ... 

The contaminants that can be removed by flotation include conventional pollutants such as BOD, COD, total suspended solids (TSS), phosphorus, phenols, oil and grease, as well as toxic pollutants including heavy metals, toxic organics, pathogenic microorganisms, and radioactive radon 22.28,33,54,64,100-102... 

Zinc, manganese, mercury, oil and grease, and total suspended solids (TSS)... 

Method 1664 n-Hexane Extractable Material (HEM) and Silica Gel Treated n-Hexane Extractable Material (SGT-HEM) by Extraction and Gravimetry (Oil and Grease and Total Petroleum Hydrocarbons) Monitoring Trace Metals at Ambient Water Quality Criteria Levels Briefing Book... 

The data obtained by the analysis have become key remediation criteria and it is essential that the environmental analyst (and others who may use the data) be knowledgeable about the various analytical methods. It is also important to know that minor method deviations may be found from region to region. For example, in terms of nomenclature, itself a complex and often ill-defined area of petroleum science (Chapter 1) (Speight, 1999), the analytical methods may refer to total petroleum hydrocarbons as mineral oil, hydrocarbon oil, extractable hydrocarbon, and oil and grease. 

BOD, biochemical oxygen demand COD, chemical oxygen demand TOC, total organic carbon TSS, total suspended solids O G, oil and grease. 

Presently there are no EPA pretreatment standards for the oil and gas extraction (oilfield) point source category. The EPA pretreatment standards for discharge from existing and new petroleum refining facilities to publicly owned treatment works include 100 mg/L each for oil and grease (O G) and ammonia (as N). For new facilities a total chromium concentration of 1 mg/L for the cooling tower discharge part of the refinery effluent is also required (40 CPR Part 419). 

Note pH (within the range of 6.0 to 9.0) BPT incorporates BAT and BCT BPT, best practicable control technology NS, new source performance standards BOD, biochemical oxygen demand TSS, total suspended solids COD, chemical oxygen demand O G, oil and grease BAT, best available technology economically achievable BCT, best conventional pollutant control technology. 

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