Integrated DAF System for Oily Wastewater from Mayonnaise Production
Background
Our client, a long-standing customer in the UAE, is developing a wastewater treatment project for a food processing unit whose main product is mayonnaise. The wastewater therefore contains significant amounts of oil and grease, and a dissolved air flotation (DAF) unit is required.
The required specifications are as follows:
- Quantity: 1 set (including coagulation and flocculation units)
- Medium: Industrial wastewater
- Treatment capacity: 25.0 m³/h
Recommended Solution
We recommended our 25 t/h integrated high-efficiency DAF unit, which includes:
1 DAF tank — with 2 reaction compartments
2 High-efficiency dissolved air system
3 Dissolved air water piping system — large filtration area, allowing maintenance without shutdown
4 Micro-bubble generator
5 Compressed air system — can be replaced by the site compressed air supply
6 Scum removal system
7 Reaction mixers
8 Electrical control system — local manual/automatic control, non-PLC, Schneider
9 Ladder and operating platform
Technical Q&A with the Client
The client raised several technical questions. We share our answers below so that you can better understand the equipment.
Q1: We plan to install an oil-water separator before the DAF. Please confirm how these two units should be installed in series. We need to know whether an intermediate storage tank is required for the oil stream collected by the oil-water separator, or whether the oil stream can flow directly by gravity through piping into the DAF.
A: The oil-water separator must be installed and operated in a tank ahead of the DAF. The separated oil cannot enter the DAF; it needs to be stored in a tank or treated separately.
Q2: Please confirm whether your oil-water separator is suitable for emulsified vegetable oil.
A: Oil that floats to the surface can be separated. This equipment is designed to treat oil floating on the surface.
Q3: Please confirm whether the PAC and anionic polymer dosing systems are included. If not, please provide attachments and state the recommended dosage and consumption of each chemical.
A: The dosing systems are included. The dosing reaction section is divided into two compartments: one for rapid mixing with PAC, and one for slow mixing with PAM. The dosage needs to be determined through on-site testing. Alternatively, you can contact chemical suppliers now and ask them to run tests for you — it is advisable to approach several suppliers, as the suitability and quality of the chemicals both affect the results.
Discussion: Oil-Water Separator vs. DAF Only
The client wanted to install an oil-water separator ahead of the DAF. However, given the client's limited budget and the relatively high cost of an oil-water separator, we suggest first consulting chemical suppliers. If their chemicals can enable the oil-water separation to meet the effluent standard of 10 mg/L, then a single DAF unit will be sufficient.
Delivered Equipment
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Closing
The client provided detailed data for our analysis. If you have a similar application or are interested in this equipment, please contact us. We will analyze the data you provide or supply the technical parameters of the equipment.