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Evoqua – WateReuse Project of 2017

Evoqua Water Technologies and Air Products, a Los Angeles based hydrogen production facility, installed a brine recovery reverse osmosis technology to reduce water and wastewater impact by up to 75 million gallons a year.

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ADI-BVF® reactor helps Ohio cheesemaker reduce sludge, energy and operational requirements

Location: Middlefield OH, USA • Sector: Food & Beverage

The Client:

Since 1956, Rothenbühler Cheesemakers has been producing delicious cheese using all natural ingredients and 100 percent Grade A milk. Formerly known as Middlefield Cheese, the family-owned company is one of the largest Swiss cheese manufacturers in the United States. Its plant in Middlefield, Ohio, USA, produces five Swiss cheese varieties, as well as high-quality whey ingredient products.

The Client’s Needs:

Rothenbühler Cheesemakers prides itself on adhering to strict environmental practices, blending the cheese making artistry of the past with modern day innovation. The company’s USDA-approved, SQF (Safe Quality Foods) certified facility was already using ecofriendly “green” initiatives to recycle on-site resources. The company wanted an on-site solution to anaerobically pre-treat raw wastewater, thereby remaining environmentally-responsible and reducing its carbon footprint.

The Solution:

ADI Systems was selected to design, install, and commission an anaerobic wastewater treatment system for Rothenbühler Cheesemakers’ plant in Middlefield. The system consists of a 230,000 gallon equalization (EQ) tank, which pumps wastewater into an in-ground 6.8 MG ADI-BVF® reactor. Anaerobic effluent is discharged by gravity to the existing downstream membrane bioreactor (MBR) system for aerobic polishing. The project also included construction of a control/electrical equipment building.

The large volume of the BVF® reactor provides a robust and diverse anaerobic microorganism community, making the system resilient to variations in influent characteristics such as organic load, influent solids concentrations, pH, temperature, and alkalinity. As wastewater passes upward through the sludge blanket, microorganisms digest the majority of the organic load, reducing chemical oxygen demand (COD), total suspended solids (TSS), and fats, oils, grease (FOG). The low-rate system is designed to treat 600,000 gpd of wastewater. The anaerobic digestion process continuously produces biogas, which is collected beneath the reactor cover and delivered to a standard biogas flare and/or utilization system.

The Results:

The wastewater treatment system that ADI Systems engineered for Rothenbühler Cheesemakers has simplified and improved process efficiency. The BVF® reactor can directly digest raw wastewater (no DAF or other FOG or TSS removal is required), and requires very little electrical horsepower, helping lower operational costs. Aeration energy and chemical requirements for the existing aerobic system have also been reduced.

We are thrilled to be able to process our wastewater responsibly. The BVF® reactor supports our vision of a well-ordered, efficient, and technically advanced system,” says Gary Schoenwald, CAO, Rothenbühler Cheesemakers. “The wastewater treatment system reduces our electrical consumption, provides biogas to supplement our existing plant heating, reduces bio-solids production, and ultimately reduces our carbon footprint.

The BVF® reactor at Rothenbühler Cheesemakers is designed to remove approximately 90 percent of the influent COD. The reactor’s long solids retention time (SRT) and hydraulic retention time (HRT) ensure complete biodegradation of the raw organic compounds, thus higher biogas production can be achieved. At design conditions, approximately 320,000 ft3 (9,000 m3) of biogas is captured per day. This biogas is utilized at a new dual-fuel boiler in the production plant, further minimizing costs for the cheesemaker.

This project was a success due to the attention to detail that we experienced from ADI Systems’ staff—everything from the concept drawings through to installation and startup,” says Schoenwald. “We have seen significant savings in our electrical consumption and expect exceptional savings as well from the use of the biogas.

Vortisand® Cooling Tower Filtration

High Efficiency Media Filtration and Ultraviolet (UV) Disinfection is becoming a crucial component for today’s cooling tower needs
Taking the heat out of cooling: Data Center Example

An increasing number of technology industries are turning to cooling towers to remove excess heat from buildings or processes. Server farms or server clusters are typically located between the system switches and routers, the removal of heat from these facilities is critical to their optimal performance. The advances in cluster computing, scientific simulation (such as Computational Fluid Dynamics), the rendering of detailed 3D images for health care, and the complex transactions required by web enterprises are all processed at server farms. The buildings cooling capabilities, rather than its processing speed, limit performance of the servers. In many cases for every 100 watts used to power the server, 50 watts is required to cool it. The critical design parameter for these large and complex continuous systems is performance per watt. As a result, maintaining effective and continuous cooling is critical to server performance.

Facebook has established a server cluster in Lulea, Northern Sweden (within 62 miles of the Arctic Circle), to benefit from the availability of cold air. High-speed fiber optic cables link the USA to cooler climates, such as Iceland. Google operates 12 data centers globally, with 6 in the USA, and uses 260 million watts of power, or 0.01% of global power consumption. Amazon operates 450,000 servers across 9 locations globally, with a 10th under construction in Ningxia, China. These complex, large scale operations require a great deal of cooling, and for some time now the trend has been to move away from the use of chemicals and towards non-chemical, more water efficient and critically robust disinfection processes. UV disinfection of the cooling water plays a central role in these process critical applications; preventing harmful microbial growth that can pose a danger to employees, while effecting the performance of the cooling system.

Click here to open and download the PDF version of this article.

How does cooling take place
Evaporative Cooling

Evaporative cooling occurs when water evaporates, changing state from liquid to vapor and requires an input of heat energy – the latent heat of evaporation. The input of heat is drawn as a waste product directly from the server facility. Modern heat rejection requirements employ cooling towers or evaporative condensers as the most efficient and cost effective method, maximizing the contact between air and the water to be cooled.

Legionella Bacteria

Cooling towers used in evaporative cooling water systems and domestic hot and cold water systems are a common source of Legionella. The disease is transmitted via the inhalation of mist droplets containing the bacteria. The use of UV water treatment ensures that microbial contaminants are effectively inactivated, including slime formers that impair cooling tower performance. Unlike chemical disinfection systems, organisms do not demonstrate a tolerance or resistance to UV light. Typically, cooling towers require nearly 66% less power to reject a given amount of heat than alternative “dry methods”. In addition, they occupy a smaller footprint and are significantly quieter. Some server farms use reclaimed water for cooling, although all need optimal performance from their cooling loops.

Dissolved Solids

Cooling towers evaporate pure water, leaving any suspended or dissolved solids, such as minerals etc., behind in the retained water. This resultant build-up of solids or concentration factor would leave the water unusable, reducing operating efficiencies and potentially damaging the recirculating system. In an effort to reduce build up, it is necessary to blowdown or bleed a proportion of the system water. In the US, the total dissolved solids (TDS) of the supply water requires that the concentration factor within an evaporative cooling system is maintained at 3 to 3.5 times, requiring an amount of water equivalent to up to 50% of the evaporation losses being bled to waste. For a typical MW (1,000Kw) of heat rejected, this equates to 150 to 200 gallons per hour that is drained to waste. Several novel approaches are being utilized for cooling water systems, including the use of reclaimed or wastewater for cooling in an attempt to reduce the use of potable water. The selection of filtration products that minimize backwash water loss is critical; as a result high efficiency media filters such as the Vortisand® Systems with Cross-Flow Microsand Filtration are specified for the most demanding applications.

Airborne Contaminants

Cooling towers are effective air scrubbers. As a consequence of the cooling method, they flush airborne contaminants into the system where they deposit on and foul the heat exchange surfaces. Suspended matter in the cooling water also supplies waterborne microorganisms with a supply of nutrients. Modern UV systems use automatic wipers to keep the optical path free from contamination. Many of these airborne contaminants, as well as iron in solution in the water, will foul the quartz sleeves and prevent optimal disinfection of the cooling water.

Particulates under 5 micron in size contribute to reduced cooling efficiencies by fouling the surfaces of heat exchangers.

Microbial and fouling concerns in cooling systems

Fouling, Biofilm & Slime

The dynamics of flora and fauna in cooling water systems are beginning to be better understood. In systems where a single microbial group or species dominates, fouling problems can often occur. In a balanced population mix, often little or no fouling is evident. It is probable that when mixed populations co-exist, they compete for the available oxygen and nutrients, and so control each other’s growth. When one group successfully displaces the others, its growth can proceed without competition, leading to the quick formation of biofilm and slime.

Colonizing Bacteria

A wide variety of bacteria, including Klebsiella Pneumoniae and Bacillus Emegaterium, can colonize cooling systems. Spherical, rod-shaped, spiral, and filamentous forms are common. Some are spore producing to survive adverse environmental conditions, such as dry periods or high temperatures. Both aerobic bacteria (needing oxygen to survive) and anaerobic bacteria (such as Desulfovibrio Desulfurcans – SRB that can survive in the absence of oxygen) are found in cooling systems. The SRB species are directly linked to Microbial Induced Corrosion (MIC), as they metabolize Sulfur and form Hydrogen Sulfide as a waste product. This then leads to hydrochloric acid formation, causing corrosion of pipes and structures.


Several forms of fungi are encountered in cooling systems, including Candida Krusei and Trichoderma Viride. Filamentous molds will lead to rot of any exposed wood and as with yeasts; they are prolific slime formers that will impair cooling performance.


Algae, including Chlorella Pyrenoidosa and Scenedesmus Obliquus, are commonly found in cooling systems. Green and blue-green algae are very common in cooling systems. Several species of algae will produce the growths that foul screens and block distribution decks. Without disinfection, algae fouling will lead to unbalanced water flow and dramatically reduced cooling tower efficiency.

Combination of high media filtration and ultraviolet (UV) systems
​Ultraviolet (UV) Systems

A high efficiency media filtration system and UV combination can remove contaminants before they have a chance of increasing the cost of operation, cause infection, and/or cause a shutdown situation. Earlier applications of UV, for cooling water loops, was to disinfect a side-stream flow. Modern, high capacity UV systems, when used with the correct separation processes, can deliver a high dose of UV to the cooling loop and turn over the entire reservoir frequently. A key benefit of UV disinfection is that the water cannot be overdosed.

High Efficiency Media Filtration Systems

Typically a cooling system will turn over the entire volume of water several times each hour. A typical reservoir might contain 7,000-15,000 gallons, with a filtration rate of 500 to 1,000 gallons per minute. A 100-ton cooling tower would recirculate the cooling water at 300-500 gallons per minute. Side-stream technologies are a lower cost, but a less effective method to disinfect the cooling system. Process critical applications such as server farms need to have full flow automated disinfection, operating 24 hours a day, 365 days a year.

Vortisand® filtration systems with high efficiency cross-flow technology is a replacement to the older, more traditional sand filters. The Vortisand system is a high capacity media filter that combines cross-flow dynamics with microsand media to achieve submicron filtration performance. This technology allows the unit to operate at filtration rates of up to 5 times greater than those of traditional media filters, while filtering 10-50 times finer. Water from cooling towers attracts and absorbs airborne contaminants on a continuous basis. Typically, 85% of suspended solids in chilled water and hot water loops are smaller than 5 microns. Studies have shown these small particles (5 microns and less) are the adherent contaminants fouling cooling tower and heat exchangers, reducing the performance of the cooling system. Bacteria, such as Legionella, also contribute to this phenomenon.

The Vortisand system typically requires 3-5% of the cooling tower flow, or a turnover rate of 7-12 depending on the tower location. Standard sand filters and centrifugal separators will require typically 10-30% of the cooling tower flow. Due to its particulate removal capabilities, the Vortisand system is an excellent pre-treatment filter for UV applications.

High efficiency media filtration system and UV combination can remove contaminants before they have a chance of increasing the cost of operation.


​Modern high efficiency media filtration and UV disinfection systems are capable of filtering the full flow of modern cooling loops, and disinfecting the entire water system many times each hour. Server farms are just one of many applications in which high efficiency filtration is critical to attaining optimal ROIs. Having an efficiently operating and clean cooling tower can lead to multiple benefits. Such benefits include a cleaner HVAC system, reduced maintenance costs and higher operating efficiencies. Industrial applications can also benefit; having a clean source of cooling tower water to pull from will help meet improved levels of production and quality.

Contact our team of water experts to learn how the Vortisand® and ETS-UV™ systems can help you meet your water objectives!

Click here to open and download the PDF version of this article.


1. U.S. Department of Energy (2011). Cooling Towers: Understanding Key Components of Cooling Towers and How to Improve Water Efficiency. DOES/PNNL-SA75820
2. Amir Samimi (2013). Micro-Organisms of Cooling Tower Problems and How to Manage Them. International Journal of Basic and Applied Science, 01 (04), 705-715.
3. http://www.zdnet.com/pictures/facebooks-data-centers-worldwide-by-the-numbers-and-in-pictures/
4. https://www.google.com/about/datacenters/inside/locations/index.html

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EcomuseumZoo: High Efficiency Filtration Reduces Turbidity & Maintenance Costs
The Project

​The Ecomuseum Zoo is home to the most impressive ambassadors of Quebec’s wildlife. All residents of the Ecomuseum Zoo are there for a special reason: orphaned, injured or born under professional human care, each of them could not return to the wild. Hence, they have found a forever home at the zoo.

The $1.4 million 6,000 square foot river otter habitat, first of its kind in Canada, is made up of vast land, river banks and a 250,000 litre (66,000 gallon) water basin; includes two port holes, an underwater tunnel and a 15 meter (50 foot) viewing window. In order to improve water clarity, a high efficiency submicron performance filtration system was required to fit in a 3 meter by 4 meter (10 foot by 14 foot) mechanical room.

With the need to filter contaminants and fine particles, engineering consultants had specified Vortisand® cross-flow filtration technology as the go to side stream filtration system.

Download PDF version of the case study here.

Montreal Ecomuseum Zoo Otter Water Basin

​The footprint of the mechanical room presented itself as one of the first challenges the Ecomuseum Zoo was faced with. With only a portion of the mechanical room space being dedicated to the water filtration system, the Vortisand team of application engineers were mandated to design a customized configuration. The natural outdoor environment of the habitat posed a second challenge for the Ecomuseum Zoo and engineering consultants. Over time the water basin acts as an air scrubber, absorbing airborne contaminants and debris as they brush along the surface of the water. These contaminants can buildup and create a film on various types of hard surfaces, potentially covering the viewing window and other surfaces found within the otter habitat. The airborne contaminants and debris also increase the risk of experiencing higher levels of water turbidity. Such high levels of turbidity will result in reduced water clarity, further limiting the learning experience for Ecomuseum Zoo visitors. Routine water basin cleaning would be costly, and the use of harmful chemicals are prohibited; ultimately requiring the removal of the fine particles before they have the chance of creating a concern. The Vortisand system was required to handle various types of contaminants and fine particulates, while yielding minimal maintenance and operational related costs.

The Solution

​Thanks to its compact design, the Vortisand H2F® system was installed within the current parameters of the maintenance room. Its submicron filtration performance and high efficiency capabilities helped remove the fine particles that would otherwise make it impossible for visitors to see the otters through the viewing glass, portholes and underwater tunnel. Most importantly, the Vortisand® system made it possible for the otters to go about their daily activities comfortably. With minimal maintenance and manual intervention required, the Ecomuseum Zoo employees were able to focus on nurturing and growing their family.

Upon start up a particle analysis test was conducted, showing that particles of 5 micron and less in size made up the vast majority of the particles within the otter water basin. The Vortisand system delivered 94% removal of particles less than 5 micron in size.

“Every effort is made to provide an exceptional level of care. Here at the Ecomuseum Zoo, we make animal welfare our number one priority, and this habitat is a faithful reflection of that choice. Nothing has been neglected to ensure that the River Otters in our care have a safe, soothing and stimulating environment. We are deeply satisfied with the work achieved by Vortisand systems. Being able to work with such a high level product means a lot for our team’s efficiency and our animals’ well-being, two of our main concerns.”

David Rodrigue, Executive Director of the Ecomuseum Zoo