A new warehouse was constructed on the outskirts of Plovdiv to support the growing logistics operations of a commercial company. Its location next to one of Bulgaria’s major transport corridors provides excellent access for freight traffic and ensures efficient day-to-day operations. However, the site also presented a significant challenge. Situated outside the urban area, it had no connection to the municipal sewer network.
The warehouse does not generate any process wastewater. Its sole purpose is storage and logistics. All wastewater originates from the sanitary facilities used by employees throughout the working day. Staff members use the toilets, wash their hands and produce exclusively domestic wastewater.
This wastewater has a distinctive flow pattern. It is generated almost entirely during normal business hours, resulting in clearly defined peak loads throughout the day. At the same time, the wastewater contains very little dilution water because no industrial processes, showers or other significant water consumers contribute to the overall flow. As a result, the wastewater contains a higher concentration of organic pollutants than typical domestic wastewater.
The client therefore required a reliable decentralised wastewater treatment solution that matched the specific operating conditions of the site. Cost-efficient operation, low maintenance requirements and long-term reliability ranked among the project’s key objectives. Through PPU Umwelttechnik GmbH’s local partner, Hidro Group 7, the client found a solution specifically engineered to meet the site’s technical and environmental requirements.
The local authorities imposed clear requirements regarding wastewater treatment. A simple septic tank or holding tank did not comply with the applicable discharge regulations. Primary treatment alone failed to achieve the required effluent quality. The treated wastewater had to meet significantly higher environmental standards before discharge.
The wastewater characteristics also placed specific demands on the treatment process. Very little wastewater enters the system during nights and weekends. As each working shift begins, the hydraulic and organic load increases rapidly within a short period of time. The treatment plant therefore needs to respond automatically to fluctuating inflows while maintaining consistently high treatment performance.
In addition, the wastewater exhibits a relatively high organic concentration. Since it originates primarily from toilet flushing and handwashing facilities, it contains a higher pollutant load than conventional domestic wastewater that is diluted by showers or other water uses. Stable biological treatment therefore plays a crucial role in achieving reliable treatment results.
Operational costs also influenced the client’s decision. Collecting and transporting all wastewater to an external treatment facility would have created permanently high operating expenses. Every tanker journey would also increase fuel consumption and carbon emissions. The client therefore chose to treat the wastewater directly on site while keeping maintenance requirements and operating costs to a minimum.
For applications like this, PPU Umwelttechnik GmbH has been developing decentralised wastewater treatment systems under the ClearFox® brand for many years. Manufactured at the company’s headquarters in Bayreuth, Germany, these systems operate successfully in projects around the world. Depending on local discharge regulations and project requirements, PPU supplies biological as well as physico-chemical treatment technologies. For municipal and domestic wastewater applications, the SBR process delivers an outstanding balance between treatment performance, operational reliability and cost efficiency. Its compact design makes it particularly suitable for locations without access to a central sewer network.
For this project, PPU Umwelttechnik GmbH supplied a ClearFox® QuickOne+, a fully pre-assembled SBR wastewater treatment plant designed for the reliable treatment of both greywater and blackwater. The system achieves the effluent quality required for direct discharge in accordance with treatment class N. Its compact footprint enables fast installation and rapid commissioning with minimal on-site work.
The ClearFox® QuickOne+ operates as a fully biological treatment system without the use of chemicals. During the filling phase, wastewater enters the reactor tank, where an integrated pressure sensor continuously monitors incoming flow and detects changes in hydraulic loading. Based on this data, the control system automatically adjusts every treatment cycle to match the actual wastewater volume.
During the aeration and biological treatment phase, fine bubble diffusers supply oxygen to the wastewater. Naturally occurring microorganisms break down organic pollutants and nitrogen compounds under aerobic conditions. The control system continuously adapts the aeration time to the incoming wastewater load, ensuring highly efficient treatment while maintaining consistently high purification performance, even under fluctuating operating conditions.
Following biological treatment, the settling phase allows activated sludge to separate naturally from the treated water. Before the clear water discharge begins, compressed air flushes the airlift pump pipework to remove any accumulated suspended solids. This cleaning cycle ensures reliable long-term operation while maintaining very low suspended solids concentrations in the treated effluent. Finally, the clog-free airlift pump transfers the purified water from the upper water layer for discharge.
Aerobic sludge stabilisation significantly reduces the amount of excess sludge produced during treatment. This extends desludging intervals to well over one year while substantially reducing maintenance requirements and long-term operating costs.
Every ClearFox® QuickOne+ is manufactured at PPU Umwelttechnik GmbH’s production facility in Bayreuth, Germany. The system complies with EN 12566-3 and fulfils all relevant European standards for small wastewater treatment plants. Today, ClearFox® systems operate successfully in more than 50 countries under a wide range of climatic and operational conditions.
By installing the ClearFox® QuickOne+, the warehouse operator invested in a cost-effective, sustainable and future-proof wastewater treatment solution. The system reliably manages the fluctuating wastewater loads typical of commercial facilities, operates fully automatically and requires only minimal maintenance. At the same time, it consistently achieves the required discharge standards, allowing the client to combine dependable environmental compliance with efficient day-to-day operation and responsible water management.
Yes. The ClearFox® QuickOne+ is suitable for any project where wastewater originates primarily from sanitary facilities. Typical applications include warehouses, logistics centres, workshops, office buildings, retail facilities and other commercial sites that do not generate industrial process wastewater. Each system is individually sized according to the number of users and the expected wastewater volume.
No. The ClearFox® QuickOne+ has been specifically designed for locations without access to a municipal sewer system. It treats wastewater directly on site, providing a cost-effective and sustainable solution for remote locations or newly developed properties.
The system automatically adapts its operation to the actual wastewater inflow. An integrated pressure sensor continuously monitors the incoming flow and adjusts the aeration time accordingly. This enables reliable biological treatment during both low-load periods and peak hydraulic conditions.
Maintenance requirements remain low. The system operates fully automatically and produces only small amounts of excess sludge thanks to aerobic sludge stabilisation. As a result, desludging intervals exceed one year, helping to minimise both maintenance efforts and operating costs.
The SBR process combines high treatment efficiency with a compact system design. It operates entirely as a biological treatment process without the need for chemicals and automatically adapts each treatment cycle to the actual wastewater volume. This makes it an ideal solution for municipal and commercial domestic wastewater applications.
Yes. The ClearFox® QuickOne+ complies with EN 12566-3 and achieves the effluent quality required for direct discharge, depending on the project and local regulations. Before each project begins, PPU Umwelttechnik GmbH evaluates the applicable discharge requirements and selects the most suitable treatment solution accordingly.
Yes. PPU Umwelttechnik GmbH supports customers throughout the entire project lifecycle, from the initial wastewater assessment and process selection to engineering, manufacturing and commissioning. Every solution is tailored to the specific technical requirements and local regulatory framework of the project.
