Project Details
| Size | 120 m³/day |
| Location | Germany |
| Completed | 2023 |
Project Delivery
| Features | Leasing bridging until completion of the new system |
| Treatment for direct discharge | |
| Treatment Modules | ClearFox® FBBR |
| ClearFox® Clarifier | |
| ClearFox® Buffer and sludge storage tank |
Project Results
| Before | After | |
| COD | 900 mg/l | 80 mg/l |
| TOC | 530 mg/l | 25 mg/l |
| P | 5,2 mg/l | 1,3 mg/l |
| Ntot | 66,2 mg/l | 20 mg/l |
Discussion
Situation
A refinery in Germany approached PPU Umwelttechnik GmbH for a solution to an additional wastewater flow. The company already had a biological treatment plant, but the additional flow of around 8 m³/h over approximately nine months required temporary expansion. The objective was to discharge wastewater directly into the nearby River.
The additional flow originated from a gas scrubber for exhaust gas neutralization. The pollutants dissolved in the wastewater amounted to a COD of around 900 mg/l and an ammonium content of around 50 mg/l.
Problem
Until the new plant was completed, the existing wastewater treatment plant was overloaded. To ensure that the limits for discharge into the river can still be met without any problems, the refinery is looking for a bridging solution.
Solution
The solution PPU provided for this project is a leased containerized wastewater treatment plant. This consists of one 40-foot and two 20-foot HC ISO Sea Containers. The first 20-foot container initially serves as a buffer tank with a dosing pump for phosphorus precipitation. Connected to this is the 40-foot container with fixed bed technology. The second 20-foot container contains a lamella settler and the control system.
The buffer tank balances inflow fluctuations and evenly directs the wastewater into the fixed bed reactor. This reactor comprises three different cascades. The fixed bed material in the cascades has a specific surface area that increases from cascade to cascade.
- Cascade 1: 100 m²/m³
- Cascade 2: 150 m²/m³
- Cascade 3: 200 m²/m³
Microorganisms settle on the fixed bed material, metabolizing pollutants in the wastewater into secondary sludge. Since the growth surface area in the first cascade is still very small, only preliminary COD reduction occurs there. The degradation rate increases from cascade to cascade. After biological treatment, the secondary sludge enters a lamella settler to separate it from the clarified water.
The system is in operation since February 2024 and has been working without any faults since then.
