Project Report

Aerobic treatment for pulp and paper industry

By General, Press Release, Project Report

Energy-efficient and proven: Mixing and aeration system for aerobic treatment in the paper industry

INVENT uses the example of a large manufacturer of paper and cardboard products for the pulp and paper industry to show why they are the ideal solution for wastewater treatment in this industry.

Some industries are plagued by particularly high energy and water consumption and therefore aim to reduce both sustainably. This is particularly true for the pulp and paper industry. Water treatment plays an essential role here, with INVENT Umwelt- und Verfahrenstechnik AG providing the best suited products.

An excellent example of the practical use of INVENT technology in paper wastewater can be found in the north of Germany, more precisely in Varel in the district of Friesland. The Papier- und Kartonfabrik Varel (paper mill), located on the outskirts of the small town, employs around 600 people on its site. It is not only a major regional employer but also one of the largest production sites in the German pulp and paper industry with a production capacity of around 925,000 tonnes.

The mill has a proud history stretching back 84 years. It mainly produces classic raw materials for the packaging industry and has been progressively modernized and expanded over the decades. As early as 1976, the company was one of the first paper mills in Germany to install a biological wastewater treatment plant. As part of the company’s growth, the plant was expanded to a two-step treatment plant in 1994.

The next expansions – in which INVENT technology came into action for the first time – took place from 2012 through 2014. HYPERCLASSIC®-Mixing and Aeration Systems were installed in stainless steel cages for aerobic wastewater treatment. One advantage of this cage solution is that it can be removed for installation and maintenance and put back in place, even in a filled tank.

The HYPERCLASSIC®-Mixing and Aeration System uniquely combines the characteristics of a mixer with those of an aerator, offering very flexible areas of operation and application. Firstly, it provides sufficient oxygen to the activated sludge during the aerobic process to break down the organic load. Secondly, the aeration tank is mixed homogeneously so that both the heavy activated sludge and small particles are kept in suspension.

Due to the energy-efficient operation, high quality and durability of the components the HYPERCLASSIC®-Mixing and Aeration System has made a name for itself as the industry standard in the aerobic treatment of paper wastewater in recent decades.

When the operators of the Papier-und Kartonfabrik Varel decided to invest 280 million euros in the production site in 2019, this also entailed a significant expansion of the wastewater treatment plant – and thus an order over another 13 of the trusted HYPERCLASSIC®-Mixing and Aeration Systems with a cage from Erlangen, Germany.

HYPERCLASSIC®-Mixing and Aeration System in the Pulp and Paper Industry

Providing clean water in Qatar

By General, Press Release, Project Report

HYPERCLASSIC® systems provide clean water in Qatar

While star athletes are running on the soccer fields of Qatar, things are also running smoothly at the country’s largest wastewater treatment – thanks to the reliable hyperboloid mixing and aeration systems from INVENT.

The desert is alive! Wherever animals and people settle in the driest regions of our planet, water plays a vital role. The fact that some countries experience an economic boom despite the desert climate comes down to other causes, such as natural resources like oil and gas.

The resources that bubble up each day make dreams come true, build ultramodern cities with trading centers and tourism infrastructure, and even create living spaces in the desert for millions of people. Now more than ever, Qatar is in the public eye as the host of the 2022 FIFA World Cup.

The capital of Doha and the neighboring city of Al Rayyān in particular is right now playing host to sports-loving businesspeople, media representatives, and private individuals from all over the world. More than one-third of the 2.8 million inhabitants of the desert state live in the city of Doha. Residents and guests need food and in particular water for drinking and domestic use. This is a challenge in the dry, hot climate of the Persian Gulf, and every drop of freshwater is precious.

The city planners are prepared for this. The vast majority of the freshwater is sourced from seawater desalination plants. This is then pumped into the water circulation system and used for human consumption or agriculture. The water and wastewater treatment plants are indispensable parts of this system in this and other modern cities.

The largest in the country is currently the Doha West wastewater treatment plant. Since it was put into operation in 2009, the plant has been expanded several times and is now able to treat an average of 280,000 cubic meters of water each day. Slightly more than 50 percent of the treated wastewater is used for agriculture and around 40 percent is used to water green spaces in the city. The rest is fed into the ground to raise the groundwater level.

To ensure that the plant works smoothly, the client chose technology from Germany – from INVENT, to be precise. No fewer than 48 HYPERCLASSIC®-Mixing and Aeration Systems and 24 HYPERCLASSIC®-Mixers reliably perform their duties in various tanks at the plant each day.

In this way, INVENT technology is contributing to Doha not only being a modern city, but also a green one in which residents and guests can enjoy spending time outdoors and where thriving agriculture is possible nearby. Once the World Cup is over and the next large event is being planned, the HYPERCLASSIC® systems will continue to turn—the final whistle won’t be blown on them any time soon.

For more information, contact our INVENT office in United Arab Emirates:

INVENT Middle East (FZE)
SAIF Office Z3-06
P.O. Box 121720 Sharjah

Contact INVENT Middle East (FZE) now
HYPERCLASSIC Mixer Aerator Balen

Mixing and Aeration in the pharmaceutical Industry

By Project Report

HYPERCLASSIC®-Mixing and Aeration System at Ajinomoto Omnichem

In recent years, the HYPERCLASSIC®-Mixing and Aeration Systems have been developed into complete solutions for the industrial and municipal wastewater treatment. The characteristics of a mixer and those of an aerator are uniquely combined by the HYPERCLASSIC®-Mixing and Aeration System.

A recent example is the company Ajinomoto Omnichem in Belgium, leader in pharmaceutical ingredients and intermediates. The cooperation between Ajinomoto and INVENT began already in 1998, when two HYPERCLASSIC®-Mixing and Aeration Systems were initially installed in Balen and another ten in Wetteren. After these functioned to complete satisfaction, the plant in Balen was extended by five additional machines. After 20 years of reliable service the first two systems were replaced by two of the latest generation in 2020. The mixing and aeration systems in Balen and Wetteren provide mixing and aeration for COD removal and nitrification. Even with a low oxygen demand, a sedimentation-free operation can be ensured. The oxygen content remains homogeneous throughout the basin due to the generated flow.

The objective of low-maintenance, yet energy-efficient mixing and aeration, could be achieved with INVENT’s HYPERCLASSIC®-Mixing and Aeration Systems in both plants of Ajinomoto Omnichem.


INVENT in the Netherlands

By Project Report
Dordrecht INVENT HYPERCLASSIC municipal

Hyperboloid mixers in Dordrecht

The wastewater treatment plant in Dordrecht, Netherlands, relies on INVENT’s hyperboloid technology. Back in 2005, 22 HYPERCLASSIC®-Mixers were installed at the municipal wastewater treatment plant. After 16 years of successful operation, they were replaced by even more energy-efficient mixers of the 7th generation in 2021. This is not an exception: A large number of wastewater treatment plants that INVENT has equipped since the mid-1990s follow the example of the wwtp Dordrecht and continue to rely on the Hyperboloid-Mixers.

Thanks to their low energy consumption and high reliability, INVENT and the HYPERCLASSIC®-Mixer became well-known among Dutch water association 25 years ago. Since then, more than 700 of the unique hyperboloid mixers have been delivered throughout the Netherlands for the mixing of municipal wastewater. Until today, the HYPERCLASSIC®-Mixer is the most widespread vertical mixer.

Article in Journal NEWEA

By Project Report

Stakeholder collaboration achieves los level nitrogen removal and improved peak wet-weather capacity at Warren, Rhode Island

Abstract: At 50 years, the Clean Water Act (CWA) has directly and indirectly benefited not only our planet but also our citizens and economy. While innumerable people and programs have contributed to the CWA’s success, the collaboration among stakeholders in our industry and communities has solidified it. Each group of stakeholders, including public officials and employees who manage and operate wastewater treatment facility facilities (WWTFs), regulators, funding agencies, contractors, equipment suppliers, researchers, trainers, and consultants, have contributed to maintaining and improving water quality. The evaluation, design, construction, and operation of the Warren, Rhode Island WWTF upgrade exemplifies how stakeholders throughout the wastewater industry can effectively collaborate to improve water quality and serve our communities.

Text by: Jon Himlan, PE, Woodard & Curran and Paul Dombrowski, PE, BCEE, F.WEF, Woodard & Curran

Learn more in the PDF document

Copyright: Journal of the New England Water Environment Association

Stigsnaes INVENT HYPERDIVE Installation

Industrial Park Stigsnæs

By Project Report

Optimal systems for wastewater treatment in Danish Industrial Park: HYPERDIVE® and E-FLEX®

Fluidmechanically optimized INVENT mixing and aeration systems have been providing reliable wastewater treatment in an industrial park on the Danish island of Zealand since 2016.

Ten HYPERDIVE®-Mixing and Aeration Systems and two E-FLEX®-Aeration Systems have been in service in the “Stigsnæs Industripark” reliably and maintenance-free since 2016. The industrial park is located on the west coast of Zealand, Denmark’s largest island. One of Denmark’s most important industrial ports is located in the immediate vicinity. An oil refinery operated here until 1997. The oil port with oil terminal, however, is still in operation, – as are the many large storage tanks. Wastewater treatment and purification are particularly important in this environment. That is why there was no question about building a dedicated wastewater treatment plant at the time the industrial park was being planned. Operators at the time relied on high-quality plant and mechanical engineering technology like the technology offered by INVENT.

The ten HYPERDIVE®-Mixing and Aeration Systems operate in two round sludge basins to keep the content in motion. The HYPERDIVE® is a fluid mechanically optimized mixing and aeration system consisting of a robust hyperboloid mixer- body with cage design, an aeration ring, a foot construction, a submersible drive and a process air hose, specifically designed for heavy-duty use in industrial and municipal wastewater treatment plants. It is a combination of efficient oxygen supply and optimized mixing of the basin content, ensuring that as little sediment as possible is formed on the bottom.

The high-quality systems are designed for long service life

The hyperboloid mixer-body is made of high-quality fiber-reinforced plastic, making it both lightweight and non-corrosive. The cage with its specially molded stainless steel base construction provides the required weight, allowing the construction to be placed on stable footing. The base is also coated with epoxy resin.

Only energy-saving and robust motors, gears with reinforced bearings and seals from reputable manufacturers are used for the moving parts. The supply air hose is connected to a blower station located outside the basin, ensuring the supply of air or oxygen to the HYPERDIVE®-Mixing and Aeration System.

The two rectangular E-FLEX® membrane aeration modules are placed in a smaller, round aeration tank. The maintenance-free systems are made of stainless steel and other wastewater-resistant, environmentally friendly, resource-efficient and recyclable materials, facilitating the supply of fresh air so that the purification bacteria that are „active“ in the wastewater receive sufficient oxygen.

The E-FLEX®-Aeration System is designed to inject large volumes of oxygen into the wastewater with the least amount of energy possible. Air bubbles with optimum bubble sizes are generated on the flexible membranes to achieve this task. This technology incorporates a wealth of fluid mechanical knowledge from INVENT’s research laboratories as well as a great know-how in computational fluid dynamics (CFD) from the THINK Fluid Dynamix® experts

The fact that the systems have performed so reliably and maintenance-free up until now was to be expected, given that even the most heavily stressed components were designed for a service life of at least 100,000 hours.


Project Report New York City

By Project Report

Energy-efficient mixers for the activated sludge process

Approximately 70% of the total energy demand of a water or wastewater treatment plant is consumed specifically for the mixing and aeration systems in the activated sludge process. In view of that it is becoming increasingly important to use systems that deal with resources in a responsible way.

HYPERCLASSIC® -Mixer – the hyperboloid mixing technology

INVENT made significant contributions to the efficiency and effectiveness of such plants with the introducing of hyperboloid mixing technology in the early 1990s. Since this time, the hyperboloid mixing technology has been continuously developed. Many thousands of successfully operating installations world-wide impressively demonstrate that the HYPERCLASSIC®-Mixer has become the industry standard in this field of application.

Example New York City

The tremendous potential for energy savings can be shown using the example of the large wastewater treatment plant Bowery Bay in New York City. At an equal purifying capacity the energy costs of the Hyperboloid-Mixers have shown to be as little as only a third as those of the replaced mixers. The slightly higher initial capital costs were compensated by reduced operational costs. In total, the savings mounted up to 3,500,000 US-Dollar over a period of 10 years. The New York experience demonstrates without doubt, that the selection of mixing equipment has a significant effect on the operating costs of large wastewater treatment plants.

Due to the achieved energy savings and high level of reliability of the INVENT equipment the City of New York also have converted Wards Island, Jamaica Bay, Coney Island, Rockaway Beach and Hunts Point plants to INVENT Mixers.

Product information

The HYPERCLASSIC®-Mixer is the optimum mixer for all suspending and homogenization tasks required for water and wastewater treatment. The rotation of the hyperboloid-shaped mixer-body close to the bottom generates high-speed and turbulence at the bottom of the basin. This reliably prevents the settling of sludge particles. Eight transport ribs generate a three-dimensional main flow with a high circulation rate. This ensures excellent, uniform mixing. Because of the low speeds, the energy input is low in shear force. Sludge flocculation is thus subjected mechanically to minimal stress loads. Low speed at the water surface reliably prevents aerosol formation and oxygen transfer. The efficient design and the use of rugged materials minimize operating and maintenance costs.

Contact INVENT Environmental Technologies, Inc. now
Georgetown INVENT Drinking Water

Clean Drinking Water in Georgetown County

By Project Report
Georgetown Drinking Water Flocculation

HYPERCLASSIC® Flocculation System: Clean Drinking Water in Georgetown County

One of our leading products ensures reliable mixing in the flocculation basins of a drinking water treatment plant in the Southeastern USA.

Drinking water treatment is one of the most important public tasks worldwide. Even where fresh water is available in sufficient quantities, the water must be clarified, filtered, and disinfected to make it safe for human consumption and for supplying to drinking water systems. There is also no shortage of available water in Georgetown County in the U.S. state of South Carolina, which lies directly on the Atlantic Ocean. A number of rivers together form an estuarine delta here, including expansive marshy areas.

The Georgetown County Water and Sewer District Public Water Utility has been operating since 1967. It is responsible for supplying more than 20,000 households and established industrial and commercial enterprises. Among other things, GCWSD operates a drinking water treatment plant, which recently required replacement of aging equipment. These updates included a replacement of their vertical inclined-blade flocculators, which had reached the end of their useful life.

In their search for a high-performance replacement that could solve the problems associated with the accumulation of solids in the flocculation basin, while still maintaining good floc formation, the managers found what they were looking for through our local representative, DXP|Premier Water of Charlotte, NC. They ultimately offered the INVENT HYPERCLASSIC® Flocculation System, the world’s leading technical product for this application.

The HYPERCLASSIC® Flocculation System utilizes a hyperboloid shape to effectively balance the amount of mixing energy required to prevent settling in the floc basins, while simultaneously minimizing floc shear. The hyperboloid shape allows for a gradual acceleration of the floc particles to gently transfer the mixing energy to the particles and prevent breakage.

After the first year of operation the plant staff inspected the new hyperboloid flocculators and found almost no settling or build-up in the flocculation basins, even when using lime for pH adjustment. This was a welcome change for maintenance staff from the previous equipment, which used to cause significant settling and sludge buildup.

INVENT is proud to be a part of improving local water treatment systems. Thank you to Georgetown County WSD, we appreciate their trust in our equipment.

Contact INVENT Environmental Technologies, Inc. now
iDEC Sbr Dekantiersystem INVENT Mexiko Kläranlage SBR

Viva HYPERCLASSIC! Efficient Wastewater Treatment in Mexico

By Project Report

INVENT Press Release

Thanks to the mixing and aeration technology from Erlangen, Germany, a state-of-the-art wastewater treatment plant is now able to transform wastewater from a vacation resort into valuable hydration for an evergreen golf paradise.

There is plenty to discover in San Miguel de Allende, Mexico. Its fortified baroque downtown with featuring a number of striking church buildings has been a UNESCO World Heritage Site since 2008.

In the recent past, sophisticated weekend and vacation home developments have emerged around this gem. In keeping with the upscale construction quality, the builders of one of these resorts implemented an equally high-quality wastewater treatment plant fitted with technical equipment from INVENT.

The plant, which was built in 2017, is designed for a wastewater volume of 1,080 cubic meters per day and operates based on SBR treatment technology. A “Sequencing Batch Reactor” requires the construction of basins for pre-treatment, for the periodically repeated multi-phase sewage sludge treatment (filling, aeration, mixing, emptying) and for the clear water that in the end is the result of the process.

This is where the INVENT technology comes in with three rectangular tanks. In the SBR tank (dimensions length 22 m x width 10 m x depth 5 m), two HYPERCLASSIC®-Mixing and Aeration Systems, each with a diameter of 2.5 m, along with an aeration system, ensure uniform mixing of the content. In a final step, the extracted water is discharged from the SBR basin via an iDEC®-Decanting System with a pipe diameter of 20 cm.

INVENT HYPERCLASSIC®-Mixer featuring a diameter of 2 m is utilized in the 12 m x 5 m x 5 m equalization basin, and an iCBA®-Aeration System with 18 aerators is utilized in the sewage sludge basin of the same size, to prevent, among other things, foul odor emissions.

With the water extracted from the wastewater treatment plant, the operators of a neighboring golf course cover their needs for the green areas and the artificial lake in between.

Now in its fifth year, the INVENT technology is running efficiently and contributing almost silently, yet effectively, to the comfort and recreational value of the residential and recreational complex.

Montage TEX FLEX Belüftungssystem INVENT

TEX-FLEX: First-class aeration for a petroleum refinery

By Project Report

INVENT Press Release

Since 2014, quality INVENT products have provided reliable aeration of highly sensitive waste water in a petroleum refinery south of Oslo.

If our systems could talk, they’d have a lot to say. They’d tell how reliably and uncomplainingly they have performed their duties day in and day out in all seasons of the year.

Just look at Norway! On the western shore of the Oslo fjord — more specifically in Slagentangen, near the town of Tønsberg, energy conglomerate ExxonMobil has operated a large refinery for North Sea petroleum since 1961. About 6 million tons of oil are processed here every year.

Naturally, an operation like this has its own sewage treatment plant. In 2014, the operators had an outstanding idea — for purifying waste water, they ordered a TEX-FLEX®-Aeration System consisting of 15 liftable modules, each with 12 aeration elements.

A liftable TEX-FLEX®-Module consists of a TEX-FLEX® aeration grid, complete with bracket and steel beam. The grid is made of pre-assembled rust-free premium stainless steel tubes, whose openings are equipped with fine-meshed membranes of insensitive textile fibers. Robust hoses feed the air in.

The 15 modules were installed in a ring-shaped waste water tank with an external diameter of 22.5 m and an internal diameter of 12.5 m. The tank’s capacity is about 1,575 cubic meters. The aeration is needed for chemical processes that treat organic compounds in the waste water, which arise from oil processing.

For almost eight years, the operators have been satisfied with their maintenance-free INVENT aeration system, and so are we!