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AERZEN - International service and solution provider for water treatment

Water treatment and wastewater treatment in focus

As every wastewater treatment plant is different, the selection of the right components is crucial. We use our many years of expertise in the area of water treatment in sewage treatment plants to support customers with the planning or modernisation of their plants. We prevent energy losses and increase the efficiency of your plant by using the appropriate machine arrangement. We support you with planning aids, individual maintenance contracts and perfected service.

As market leader in the field of water treatment, AERZEN has developed trend-setting concepts that support plant constructors, engineers and operators of wastewater treatment plants in areas such as the selection of technology, increasing efficiency, process safety, data analysis, digitisation, conserving resources, increasing productivity and much more. Summarised under the term AERwater, we offer a holistic solution approach with finely tuned service module via a tight linkage of hardware, software and comprehensive services.


Machine and technology design tailored to individual load profiles for maximum efficiency

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Global control system for the distribution of air volumes among technologies – with efficiency values that come close to the theoretical optimum

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Measuring volume flows to determine actual load profiles

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Machine room optimisation

Support with the planning and implementation of room ventilation and sound concepts

Heat recovery

Concepts and technologies for the recovery of thermal energy

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Support with and for the application of state subsidies of up to 90%

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Delivery of custom-fit machines and components as well as support during commissioning

Rental machines

International rental service with a large pool of immediately available rental machines of various performance levels

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Modern process monitoring and individual service offers with excellent logistics and reliable spare parts supply

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AERZEN offers not only excellent compressors, but also intelligent control systems that regulate the operation of the machines centrally and always within range of the actual air demand. With AERwater, AERZEN is pushing the concept of Water 4.0 and setting the trend for resource-saving digital water management.

Do you want to improve the service life and performance of your plant? No problem for AERZEN. AERZEN’s comprehensive after-sales service includes maintenance, on-site consulting, the supply of original spare parts and the delivery of rental machines that can be used in the event of short-term failures.

With its worldwide service network, the company ensures short distances to the customer and guarantees fast and reliable on-site support.

Over 150 years of experience, state-of-the-art technologies, innovative concepts and perfect service: with this combination, our customers are on the safe side.

For more than 150 years, the family business AERZEN has been manufacturing machines for gas and air compression. In doing so, the machine manufacturer has constantly optimised and refined its products. Today’s positive displacement blower, turbo blowers and screw compressors are best-in-class products: innovative, efficient and low-maintenance. In order to maintain these properties, you need finely tuned service that meets your needs. AERZEN Services extend the lifetime and availability of machines and thus contribute to the added value of every biological sewage treatment plant. AERZEN Services are individual: with tailor-made service offers for water treatment plants, AERZEN provides the right service package to cover all customer requirements.

Water treatment industry experience and know-how 

The compression and conveyance of air and gases are technological components used for a wide variety of applications in many industrial sectors. These include chemical and process engineering, pneumatic conveying of bulk materials, the process gas and refrigeration industry, biogas or biomethane plants, or the offshore sector. Water treatment, however, is one of the most important industries for AERZEN products: AERZEN is a specialist for aeration systems in wastewater treatment plants and supplies its systems all over the world, where they are installed, operated and maintained under the most diverse environmental conditions. Many reference projects and success stories testify to the innovativeness of AERZEN solutions.

Support for planners and plant constructors

AERZEN not only supplies high-quality products for water treatment, but also maintains, services and repair them worldwide.

With its expertise in water treatment plant construction, AERZEN also supports the planning of new plants or the analysis of weak points in existing plants. AERZEN customers always benefit from the expertise of the innovative machine manufacturer: engineering offices, plant constructors and operators can find specific planning materials in an extensive document – Planning Folder Wastewater – which AERZEN makes available to its customers online or as a printout.

It contains a wide range of information for water treatment in sewage treatment plants: basic information on wastewater technology, information on calculating operating data (such as the pressure and standard state of a gas), standards for performance measurement, information on engine room design, concepts for heat recovery, the best pipeline routing and much more. 

An AERZEN whitepaper “How to select the most effective blower technology for wastewater” helps answer this complex question for many customers. The document presents the respective strengths of the different blower technologies and explains the most efficient use in each case on the basis of concrete application examples. 

The room ventilation calculator developed by AERZEN is also a valuable tool for planning and optimising sewage treatment plants. In the online tool, engineers and plant constructors can enter existing values such as engine power, ambient temperature, intake volume flow, flow velocity and installation altitude as well as other relevant data – the room ventilation calculator then automatically calculates the necessary room ventilation. If required, the data can be forwarded to AERZEN support and an individual consultation based on the data is possible. 

Another very important factor of our after-sales service is our service staff: our application specialists are at your disposal worldwide for advice and cooperation.

Original OEM spare parts (original equipment manufacturer)

AERZEN has a comprehensive 1500 m2 service centre with optimised spare parts logistics and stock keeping with short throughput times; approx. 2,500 standard parts are always available here. This means that spare parts, service kits, AERZEN oil, replacement and exchange stages, relubrication equipment and control technology are quickly available with WebView. We clean and paint original parts in our own plant and test them in our own test department. This ensures that wearing parts can be replaced with original OEM parts at any time. Due to the good availability of OEMs, shortening of the service life through the use of non-original spare parts can be ruled out.

Customised service contracts and service packages

AERZEN has more than 50 subsidiaries and a well-developed service network with numerous service points all over the world. More than 200 service technicians across all continents of the world are on-call for our customers. AERZEN Services is always nearby thanks to its decentralised support bases, meaning commissioning, inspections, maintenance and repairs can be carried out quickly on site.

Customised service contracts and service packages

The advantages of regular maintenance are obvious:

  • There are fewer machine breakdowns
  • Service calls can be planned proactively
  • The availability of machines is optimised

How do AERZEN customers find a tailor-made service solution for their plant? Not all water treatment plants are the same. A diversity of offers also makes the difference in this regard. AERZEN offers different partial maintenance contracts with six months warranty each, maintenance contracts with general inspection, contract for work and warranty over the contract period as well as full maintenance contracts with a 24/7 service hotline and two service calls per year. We use OEM spare parts in all packages.

AERZEN has developed various checklists for positive displacement blowers and screw compressors to check whether servicing is necessary, both for standardised maintenance or for those who wish to carry out maintenance work themselves.

International rental service (AERZEN International Rental (AIR) (p 14)

Breakdown or repair may result in unforeseen requirements in system manufacturing. Hence AERZEN International Rental (AIR), an international rental service for assemblies and accessories, is also part of the comprehensive service offering. Not only for water treatment in wastewater treatment plants, but also for almost every other industrial segment – AERZEN provides rental machines and accessories quickly and easily through its depots across Europe and a 24/7 hotline guaranteeing fast delivery.

Machine diagnosis and acoustic evaluation

Consulting for sustainable water treatment is in demand because there is a worldwide need for water treatment plants. In the Western world, too, it is increasingly important to act responsibly with regard to the resource water. A prerequisite for good consulting is precise knowledge of the requirements that a plant must meet. AERZEN offers a very helpful analysis for water treatment plant construction in the form of its acoustic evaluation, which allows the data and conditions of an existing plant to be recorded at the installation site and disturbance variables to be determined. 

The specially developed AERZEN detector for vibration, temperature and speed recording helps with the analysis. It records the vibration data and determines disturbance variables which can be eliminated in the following stage. 

During the project development and planning phase of a system, radiating noise according to VDI 3733 or the expected noise level can be determined with the aid of the acoustic evaluation. This makes it possible to recommend measures to achieve the guaranteed room and emission values. 

Positive displacement blowers, turbo blowers and screw compressors from AERZEN always meet the customer’s requirements. Excessive vibrations can shorten the running time of the machines and be an indicator of rolling bearing damage, imbalance or gear faults. In addition, regular vibration measurements can ensure compliance with the legally prescribed noise prevention limits. 

CFD simulation is another tool for calculating flow dynamics. From this, recommendations for action can be derived for the optimisation of components and volume flows. 

Permanently installed analysis systems are ideal for continuous monitoring. Networking with control systems, such as AERsmart or AERtronic and WebView, not only makes real-time machine monitoring possible, the digitised data can also be stored and forwarded to the central process control room. This means that the plant operator receives information for the next maintenance as well as information about critical machines, necessary renewals or the most efficient use.


Especially for water treatment plants, AERZEN provides its customers with approaches and concepts for optimisation: The AERaudit enables an individual inventory to be taken in every wastewater treatment plant. AERZEN’s service staff collect the relevant data on site, for example the amount of air a plant needs. AERZEN then develops individual solutions.

Serious cost savings are possible through the use of precisely tailored machine technologies. In addition, the data collection in the AERaudit identifies the weak points in a plant. In close cooperation with the operator or the responsible engineering office, possibilities for improvements and increases in efficiency can be developed.

The Performance³ concept

A challenge in water treatment in sewage treatment plants is the varying degree of capacity utilisation, which is subject to daily and seasonal fluctuations. More air is consumed during the day than at night – and the air requirement is higher in summer than in winter. This means, for example, that more process air has to be generated for the aeration tanks during the day. In order for a system to not operate above or below demand, there must be machines that are switched on or off as required. AERZEN meets this challenge with its “Performance3” concept, which allows load changes to be operated flexibly: The individual technologies of positive displacement blowers, screw compressors or turbo blowers are each optimised for specific volume flow ranges. An intelligent control system switches the machine or machine combination on that most efficiently meets the current demand.


The concept: AERwater is an integrated solution for efficient water treatment. A characteristic feature here is the close linking of hardware, software and comprehensive service provision. Significant energy savings can be achieved using optimised machine utilisation, centralised control and targeted activation of the most efficient machine. The basis for this is the digital networking of the individual technologies and demand-driven operation, which are adapted to the respective power requirements.

The use of higher-level control systems is decisive for the AERwater concept. Centralised control systems enable flexible machine use. This enables targeted machine operation according to the current volume flow requirement. The AERZEN controller AERsmart can be networked with the process control system. This allows all data to be tracked, creating transparency over the machine’s life cycle. It also ensures constant monitoring. With the AERZEN WebView control technology, all data can be retrieved from anywhere in the world via the internet. 

With AERwater, AERZEN is setting standards for “Water 4.0” ­– digitised and resource-saving water management.

Success stories

Aachen Soers reference project

This is also illustrated by a joint reference project carried out by Aerzener Maschinenfabrik GmbH and the German Water Partnership (GWP). The GWP is a network of companies, professional associations and research institutions in the water industry. The network is committed to progressive, resource-saving and sustainable water management.

The project’s aim was the energetic optimisation of the Aachen Soers wastewater treatment plant. By optimising the “biology of the plant” (i.e. the aeration of the seven aeration tanks), energy savings of 55% were realised. In concrete terms, this meant a conversion of the individual components to alternating or intermittent operation. The optimisation was based on a CFD simulation (computational fluid dynamics – a mathematical computation of hydrodynamics).

Ichenhausen wastewater treatment plant

AERZEN’s application expertise in the water industry is also illustrated by another success story: The Ichenhausen wastewater treatment plant, originally designed for 45,000 inhabitants, only had to serve approx. 20,000 inhabitants. At the same time, more industrial waste water was to be added. The challenge was to adapt the plant to the oxygen demand, which fluctuated depending on the time of day, day of the week, amount of precipitation and dirt loading. A Performance3 solution was used to optimise the system: The combination of air-bearing AERZEN Turbo and Delta Blowers as well as a demand-driven control system now flexibly cover the fluctuating loads in an energy efficient manner and ensure energy-efficient process air generation.

The turbo blowers in the sewage treatment plant require almost no maintenance despite the approx. 24,000 hours of operation. Minor maintenance, such as filter changes, can be carried out by trained plant personnel.