Separation sludge

In addition, oily sludge from a wastewater treatment facility that results from treating sour wastewaters may be a hazardous waste (unless recycled in the refining process). These include API separator sludge, primary treatment sludge, sludge from various gravitational separation units, and float from dissolved air flotation units. 

As an example of the problems such mixing can cause, consider the case with API separator sludge that is a listed hazardous waste (K051). The wastewater from a properly operating API separator is not hazardous unless it exhibits one of the characteristics of a hazardous waste. That is, the derived-from rule does not apply to the wastewater. However, if the API separator is not functioning... 

This wastewater is often cleaned further by other treatment systems (filters, impoundments, etc.). The solids separating in these systems continue to be API separator sludge, a listed hazardous waste. Therefore, all downstream wastewater treatment systems are receiving and treating a hazardous waste and are considered hazardous waste mauagement units subject to regulation. 

Metals removal may require pretreatment. Other applications may require equalization tank, oil/water separator, sludge dewatering, postcarbon adsorption or filter. Certain applications may require off-gas control system. It may also be unsuitable for groundwater with a chemical oxygen demand less than 40 mg/liter. 

Alternatively, plain sedimentation basins with mechanical equipment for continuous collection of the fresh sludge may be used. The fresh sludge, so collected, is discharged into separate sludge digestion tanks which operate on the principle of the lower story of the Imhoff tank except that by means of higher and better temperature control the digestion cycle is much more rapid and efficient than for the Imhoff tank. 

The sterilizer condensate and separator sludge are segregated into separate oil pits for residual oil recovery before they are mixed again for treatment. The hydrocyclone waste contains very little residual oil and is discharged directly into the treatment plant. The final mixed wastewaters are commonly known as palm oil mill effluent. 

Parameter Sterilizer Condensate Separator Sludge Hydrocyclone Water POME... 

In the interelectrode space, the dissolved metals, in most cases (Ni, Fe, Al, Ti), convert into insoluble hydroxides. To separate sludge from the liquid phase, several methods are used. The simplest method... 

Refinery Primary and Secondary Oil/Water/Solids Separation Sludges (F037,... 

EPA. 1981a. Hazardous wastes from non-specific sources Petroleum refinery primary and secondary oil/water/solids separation sludges (F037, F038). U.S. Environmental Protection Agency. Code of Federal Regulations. 40 CFR 261.31. 

A 10 gal/day (l.OMGD) wastewater from a treatment plant contains 0.2mg suspended solids (SS) per cubic meter of wastewater. The separated sludge from the plant consists of the SS. If 10% by weight of lime is required to stabilize the sludge treatment and 80% of the solids are captured, calculate the daily and annual lime requirements. 

Huesemann MH. Moore KO. Johnson RN. 1993. The fate of BDAT polynuclear aromatic compounds during biotreatment of refinery API oil separator sludge. Environ Progress 12(1) 30-38. 

Of the phosphorus recovered as elemental phosphorus, about 5% is in the form of sludge, even after a series of settling steps to separate sludge from clean phosphorus. This sludge phosphorus may be recovered by burning it separately to produce impure phosphoric acid, by distillation, or by dewatering and returning it to the furnace. 

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