Project Details

Project Delivery

Project Results

Discussion

Situation

A large company from Germany mainly produces egg salad, potato salad and fish salads for the entire German-speaking region. During production, around 50 cubic meters of wastewater are produced per hour. Since this has a very high COD, it may only be discharged to the municipal wastewater treatment plant with pretreatment.

The company already had a dissolved air flotation system, but it was getting on in years. Production capacities had grown steadily in recent years, which is why significantly more wastewater is produced today. Therefore, the capacity of the existing plant was no longer sufficient.

Problem

The first challenge in this project was the high COD content of 10,700 mg/l. The reason for this is the high oil content in the wastewater, as the company uses oil-based mayonnaise and sauces. Employees clean the equipment daily, which causes the residues to enter the wastewater.

The second challenge was the short-term implementation of the project. The company had only a few months to find a solution for the existing plant, which was too small.

Solution

PPU Umwelttechnik GmbH has an in-house laboratory in which the wastewater samples were examined by means of jar tests. The aim was to precipitate and flocculate the contaminants in the wastewater in the best possible way. The results showed that in this case polyaluminum chloride is the best flocculant. It achieved a COD reduction of 86%.

The customer chose a ClearFox® leasing DAF because PPU Umwelttechnik GmbH could provide it quickly and because it had references in similar areas. The leasing period is initially one year. Thus, the customer can convince himself of the performance of the dissolved air flotation. After one year, the customer has a takeover option.

The entire leasing DAF consists of two 20′ HC sea containers. One container contains two flotation reactors in rectangular design – the second container contains the technical equipment as well as the control elements.

The ClearFox® leasing DAF has been in operation since July 2023. For this project, PPU Umwelttechnik GmbH took over the planning, production, delivery, commissioning and instruction of the employees on site.