High-tech from Baden-Württemberg for tomorrow’s environment


aqua plus GmbH from Böbingen is one of the guarantors for the ecological and economical handling of the resource water in the manufacturing industry worldwide.

Water is probably one of the most important raw materials on earth. It is essential for all living beings. But water is also a very important means of production for industry, from cooling or heating in mechanical production to the main component of environmentally friendly cleaning of systems or vehicles to a wide variety of metal-containing solutions in almost every type of chemical production. In industry, water must be treated both before it is used and, more importantly, after it is used to make products.

Water treatment

Water from natural springs, lakes or rivers contains numerous substances, from dissolved metals to chlorine, sulfur or nitrogen compounds to organic compounds. The most well-known substances include calcium carbonate, the precursor of calcium deposits, or sodium chloride as a crucial component of salt water, which leads to increased corrosion in metals. For numerous uses of this so-called raw water, the ingredients have to be removed in order to avoid damage to or impairment of systems or process methods. The processing of used water after its use for the manufacture of products plays an equally important role.

Above all in metalworking – for example pickling iron and steel, galvanic coating with zinc for corrosion protection, precious metal for decorative purposes or copper in the field of electrical engineering – more or less large amounts of metal-containing waste water are produced. Intensive wastewater treatment has been state of the art in these areas for more than 50 years.

For some years now, in addition to pure wastewater treatment, the focus has increasingly been on reducing the amount of water used and the amount of wastewater generated for reasons of environmental protection. The aqua plus brand from Böbingen has been a constant in this industrial sector for around 25 years. Especially in the surface treatment and coating of and with metals, aqua plus devices and systems are part of production facilities worldwide. Different technologies are used for this, depending on the water treatment requirements.

Process for water treatment and purification

Membrane technology is a long-established process for removing disruptive components from raw water. Defined porous plastic membranes are used for this. Depending on the pore size, ingredients with certain particle sizes (or the size of ions or dissolved molecules) can pass through these membranes; this process is known in chemistry as diffusion. The diffusion process is intensified by the provision of differently concentrated aqueous solutions on the left and right of the membrane, possibly supplemented by the application of electrical voltage between the two sides of the membrane.

The end result is that defined components can be removed from the raw water. Another important process technology for water treatment is ion exchange. In this case, plastic granulates are used that can bind certain substances. Depending on the acidity of the aqueous solution and the type of ingredients to be removed, different types of ion exchangers are commercially available.

Almost all dissolved metals are bound by ion exchange resins as soon as they come into contact with the metals dissolved in water. In addition, sulfate, nitrate or phosphate, for example, can also be bound and removed from an aqueous solution; these constituents, known as anions, always appear in aqueous solutions as partners of dissolved metals. Ion exchangers have the great advantage that the bound substances are specifically released again in a supplementary operation, the so-called regeneration.

In this way, the bound substances can be specifically removed from a water cycle and passed on for further use (especially the metals) or disposal. The ion exchange resins are then fully functional again for the renewed metal removal process. The classic methods of work-up include the precipitation reactions.

Here dissolved substances are converted into insoluble compounds (e.g. in hydroxides) and converted into a more or less solid state as sludge. Sludge with a high water content can also be converted into a solid mass by filtering with the help of special presses and by drying. In the case of metal-containing sludge, these are often smelted in order to then participate in the material cycle again.

Systems in different dimensions

On the basis of these various basic technologies, aqua plus GmbH develops the system that is optimally designed for every application. This applies to the composition of the various types of raw water and wastewater as well as to the amount of water and wastewater to be treated. The dimensions of such systems range from the smallest ion exchange systems with a floor area of ​​barely 1 m2 for the treatment of water to hall-sized wastewater treatment plants with floor areas of a few 100 m2 and more and tanks with a volume of several thousand liters. With these systems, however, the focus must always be on low water and energy consumption while at the same time achieving ideal water quality and extensive automation of the processes. This applies both to industrial water used in the various processes and to wastewater, which is usually fed to the local sewage treatment plant.

A complete system for water treatment and wastewater treatment was recently completed for a world-famous manufacturer of sanitary articles, from which today’s common industrial requirements can be seen. The system has the task of supplying rinsing water in different qualities for the galvanic plastic metallization and treating the waste water produced.

For the galvanic coating around 10,000 liters of clean water of the highest purity (deionized water) are required per hour. For example, the dissolved copper in the resulting wastewater is first concentrated using ion exchange technology. It is then extracted from these generated solutions by electrolysis and is then available in metallic form for return to the industrial cycle – around 60 kg per day. This efficient technology avoids around 100 tons of heavy metal sludge per year. Other dissolved metals that arise in the process are converted to low-water sludge and then also go back into the industrial cycle of metal processing. The various methods of wastewater treatment, as designed and created by aqua plus, make it possible to reduce the total amount of wastewater from up to 40,000 liters per hour to a volume of around 8,000 liters.

The water, cleaned of metal and other pollutants, goes into the public sewer. So that such enormous amounts of water and wastewater can be safely processed or available on all working days over 24 hours of operation, collecting tanks with a diameter of approx. 3 m and a height of up to 6 m are available. All containers with the necessary treatment systems are connected by pipelines – also manufactured by aqua plus – and are operated fully automatically. They guarantee the highest level of reliability in terms of environmental protection as well as maximum economy.

From the Ostalbkreis to the whole world

The origins of aqua plus lie – as with many innovative and motivated start-ups – in your own four walls. Today’s owner Walter Baur in Durlangen, with three employees, started manufacturing systems under his own roof. After a short period in Spraitbach, the company was able to settle in the industrial park in Böbingen an der Rems. All preliminary tests for the treatment of raw water and wastewater in the most varied of states are carried out in the operating rooms. This results in the planning and the system concepts for discussion with the customers. The systems, insofar as they are smaller versions, are then manufactured, tested and delivered to customers all over the world.

For example, a system was delivered to Sydney in the autumn of last year; the customer was one of the world market leaders in microphone and studio technology. Large-scale systems are prefabricated in individual parts in Böbingen and installed by customers. The setup at the customer is always connected with a detailed instruction for correct operation. Likewise, customers in the metal processing, ceramic and optical industries or semiconductor manufacturing expect a long-term readiness for maintenance and support, if necessary also a modernization of the systems for water and wastewater treatment. In this way, aqua plus GmbH makes an important contribution to environmental protection and to saving the indispensable resource water!