Oil wastewater treatment
ClearFox® DAF for the oil wastewater treatment from a coal power plant
Power generation
Project Details
| Size | 3,300 m³/day |
| Location | Bosnia |
| Completed | 2016 |
Project Delivery
| Features | Almost complete reduction of oil from the wastewater |
| Reliable cleaning performance | |
| Treatment Modules | Sand filtration |
| Coalescence stage | |
| ClearFox® DAF | |
| Sludge removal |
Project Results
| Before | After | |
| COD | 800 mg/l | 125 mg/l |
| BOD | 140 mg/l | 25 mg/l |
Discussion
Situation
In a coal power plant, the oil wastewater treatment is an important part of the energy-producing process. The wastewater is produced in different areas. On the one hand, it can be cooling water to protect the plant components from overheating, and on the other hand, it can be wastewater from boiler heating, which is produced during the actual energy generation process. Especially during boiler heating, but also during the cleaning of all plant components, oils mix into the wastewater. Therefore, the oil wastewater treatment in a coal power plant is an important step to protect the environment.
Problem
When cleaning the system, high wastewater pressure is necessary to efficiently clean all surfaces and components. In the process, the oil droplets split into fine oil particles that do not float to the water surface but remain suspended in the wastewater. Conventional oil wastewater treatment by an oil separator is therefore only partially effective. Like many coal power plants, the customer from Bosnia discharges its wastewater into a public body of water. With 3,300 m³ of wastewater daily, it also produces a very high wastewater load. Therefore, reliable oil wastewater treatment is particularly important.
Solution
To cope with the high flow rate, the customer provides a concrete catch basin on the company premises. From there, the wastewater enters a sand filtration system, which removes all coarser contaminants from the wastewater. To remove a first part of the oil from the wastewater, the ClearFox® team used a coalescence stage for the oil wastewater treatment. The floating oil separates from the water via a mechanical system and thus does not reach the next treatment step.
The coalescence stage is followed by a ClearFox® DAF to remove the dissolved and suspended substances from the wastewater. To achieve precipitation and flocculation, the plant adds flocculation aids to the wastewater to convert the dissolved substances into separable substances. In this way, it also binds the oil particles in the wastewater and thus increases their surface area. An aeration system carries all solids to the top, where they collect as sludge, which the plant can discharge at regular intervals. The company collects the sludge safely in a container to be transported away at regular intervals. After oil wastewater treatment by the ClearFox® treatment plant, the oil content in the wastewater is less than 0.05 mg/l.
For this project, the ClearFox® team took over the complete planning of the project. They designed the plant and helped build the catch basin. After delivery, they installed the plant on site and instructed all employees in its operation to ensure a smooth and reliable process.
