Project Details

Project Delivery

Project Results

Discussion

Situation

Municipal wastewater comes from two sources: On the one hand, households feed the municipal wastewater treatment plant, and on the other hand, companies produce wastewater that is not allowed to flow into the environment without treatment. Households mainly produce hygienic wastewater. The dissolved substances are mostly organic and can be easily degraded. Wastewater from companies can contain different substances, depending on the core business. For it to be allowed to flow into the sewage treatment plant as municipal wastewater, a wastewater analysis is indispensable in advance.

A total of nine districts supply municipal wastewater to the customer’s wastewater treatment plant. This treats about 500 m³/day. The responsible wastewater association was not satisfied with the treatment performance on the one hand and the energy efficiency on the other hand. Therefore, it commissioned the ClearFox® team to refurbish the plant. The focus was to be on biological wastewater treatment.

Problem

The ClearFox® team faced three challenges with this project: The first challenge was timely implementation. Since municipal wastewater flows into a public body of water after treatment, environmental protection was a crucial factor. Second, the region of Upper Franconia is strongly characterised by agriculture. Therefore, municipal wastewater is also heavily polluted with nitrate. The third challenge was the already existing tanks in which the ClearFox® engineers had to install the treatment system.

Solution

The customer opted for an SBR system with a two-line aeration system. Over a certain interval – specially designed for municipal wastewater – the system supplies the microorganisms in the wastewater with oxygen. This allows them to grow and treat the wastewater. The treated wastewater contains a COD of 200 mg/l, a BOD of 40 mg/l and a nitrogen content of 10 mg/l. This makes the wastewater suitable for direct discharge into the environment.

The ClearFox® team first visited the municipal wastewater treatment plant on site. The employees took over the complete planning of the project, the installation in the tanks, the commissioning as well as the instruction of the responsible persons.