SIEMENS

No one really knows how dangerous they are. They flow with waste water out of plastics factories, or pass into sewage pipes when toilets are flushed. The intractable chemicals in question even survive bacteria in sewage treatment plants. They are called “endocrine disruptors,” and these long-lived compounds are suspected of having an effect on the hormonal systems of humans. They include plant pesticides, active agents in birth control pills, and chemicals from the synthetic resins industry. Some of them can cause cancer, while others are believed to cause male fish to turn into female fish.

Because they cannot be destroyed with conventional biological sewage treatment technology, they accumulate in the environment. To get rid of them, heavier weaponry is needed: hydrogen peroxide or ozone, for example, which form aggressive radicals and thereby decompose the contaminant molecules into harmless constituents. There are currently only a few reference systems on the market that are designed to attack endocrine disruptors with oxygen.

The technology that decomposes these molecules is called “Advanced Oxidation Process” (AOP). It uses ultraviolet lamps for radical formation. Although contaminants are effectively decomposed, the process uses a great deal of power. In addition, elaborate posttreatment steps with activated carbon are required to remove extra chemicals and byproducts.

Experts from Siemens Water Technologies in Günzburg, Germany, are now developing a much more efficient and economical system. To achieve their goals, they are working with specialists at the Technical University of Denmark (DTU) in Copenhagen. Chemist Henrik Rasmus Andersen’s team has been researching AOP units for years and has developed first-rate analytical procedures for detecting mere micrograms of endocrine disruptors or antibiotics in water. The team is now working with Siemens on a new reaction chamber that will be more efficient than comparable systems. Because radicals are extremely short-lived, the flows in the system - the fluid dynamics - have a considerable influence on the cleansing effect of the chamber. The geometry of the chamber must therefore be designed accordingly. Ultimately, the objective is to optimize the system as a whole, so that the best result can be achieved while using only small amounts of chemicals and energy.

Reliable Partners. It is no coincidence that the Germans and the Danes have chosen to work together on this project. The DTU is one of eight outstanding international universities with which Siemens maintains close research partnerships. Several years ago, Siemens set up a CKI program (Center of Knowledge Interchange) to foster such relationships, which are based on a common framework agreement with the universities in question (see article "Tapping New Worlds of Ideas"). The DTU, which has been a leader in the development of environmental technology for many years, has been a CKI university since 2006.

“With the CKI program, we try to achieve loyal, long-term cooperation giving rise to many individual joint research projects,” says Dr. Dieter Wegener, chief technology officer of Siemens Industry Solutions. For a long time, companies in the industrial sector were cautious when it came to working with external partners; they were worried about the effects of transferring knowledge to outsiders. Siemens has liberated itself from this fear. “If you want to make big advances in development and you’re aiming for radical innovations, you have to rely on the expertise of universities,” says Wegener. In addition to technical expertise, another key to success is personal rapport. This can be cultivated in the CKIs, which are designed to last many years.

“First, we met with experts at Siemens to discuss which fields of technology we can best cooperate in,” says Henrik Søndergaard from the DTU, who oversees the cooperative projects at the university as CKI manager. “That resulted in projects like AOP systems technology, and the EDISON project, which is studying how electric cars can interact with the power grid” (see article "All Charged Up"). In another example, experts from Industry Solutions and Siemens Corporate Technology have worked with the DTU and Berlin’s Technical University to develop the “Eco Care Matrix” - a new assessment methodology that identifies the economic and ecological value of green products and solutions.

For water technology experts at Siemens, the CKI partnerships have many benefits. “We can fall back on experts that we don’t have inside the company,” says Klaus Andre, a research director in Günzburg. “We also meet young scientists who could work for Siemens after their studies.” With regard to AOP development, one shouldn’t forget that DTU has expensive analytical equipment, such as mass spectrometers. “Endocrine disruptors have been the subject of detailed study for about ten years - particularly since the technology became available to detect these substances relatively quickly and easily,” says Andre’s colleague Cosima Sichel, a process engineer.

The U.S. - especially California - Germany and the EU are promising markets for AOP technology, because awareness of the issue is already widespread. “Hormones and antibiotics are mostly expelled by human beings and end up in the water,” says Sichel. In the case of antibiotics, it is thought that they can lead to the development of resistant infectious germs. And hormonally-active substances are consumed by human beings in drinking water. At present, ecotoxicologists do not yet know exactly what effects that may have. Prudence would therefore dictate that endocrine disruptors should be removed from drinking water.

The AOP system that is currently being developed with the DTU for market launch within three years is expected to solve this dilemma. It is suitable for drinking water purification at water works. In the chemical and pharmaceutical industry, it can process contaminated effluents before they are discharged into the primary waste water stream. And in the microelectronics industry, it can produce ultra-pure water to clean sensitive components.

Systems of different sizes will be used, depending on the application. A simple system for drinking water purification will supply about 200 cubic meters of water per hour. It is still difficult to estimate the size of the future market, says Andre. “The AOP systems will be used on a large scale as soon as they are mandated by law.” There are few such regulations in effect now, Andre adds. But the potential is huge. In Germany alone, there are around 10,000 sewage treatment plants and over 6,000 water supply companies.