Siemens Presents WWT Updates at SIWW

At Singapore International Water Week (SIWW), the company is to give an update on key projects like the energy self-sufficient biological wastewater treatment process, electrochemical desalination, a micro media column for contaminant removal and the membrane bioreactor (MBR) Changi pilot plant.

These wastewater treatment combines two technologies In the form of potential energy indigenous to the organic matter, municipal wastewater contains about ten times the energy that is needed to treat it.

It combines aerobic biosorption and anaerobic treatment to reduce aeration demand and generate enough methane to produce the energy needed to achieve zero net energy. Since June 2010, a pilot facility has been treating about half a cubic metre of wastewater per day and, at the same time, operating in an energy-neutral manner. Unlike conventional wastewater treatment, the bacteria are charged with the organic impurities only for a short time during the aerobic process step. This results in cutting energy consumption for aeration and in producing less sludge. In the next anaerobic step, the bacteria ferment the organic matter into methane that is used for energy generation. To further develop this process on a larger scale, a pilot plant scheduled to begin operating this year in Singapore will be able to treat wastewater for approximately 2,000 residents.

As a result of an R&D initiative that commenced in October 2008, Siemens has been working on an advanced desalination technology that reduces energy consumption by half compared to systems that are currently available. A demonstration plant has been built in Singapore to treat 50m³ of seawater per day to drinking water quality. The results of the pilot facility show that the new process, a combination of Electrodialysis (ED) and Continuous Electrodeionization (CEDI), not only functions in the laboratory but also on a larger scale. Siemens is now ready to set up a full-scale customer pilot in 2013 at the Tuas facility of Singapore’s national water agency PUB to proceed with the commercialisation of the electrochemical desalination technology.

Even closer to market launch is another R&D project that will be presented at the Ultrapure Water Asia conference, co-located at the SIWW. The  (MMC, image) removes selected contaminants including selenium, chromium, mercury and arsenic. It will help municipalities and customers from the power, microelectronics, pharmaceutical and metals and mining industry meet new regulations reducing contaminant levels. As conventional ion exchange media have difficulties in achieving such low levels, Siemens developed the MMC based on a new filter media and flow design. It removes contaminants down to the parts-per-trillion level. Despite its small footprint, the MMC is a high-throughput solution. As the water flows radially through the filter media, channelling is avoided, which leads to life cycle cost savings compared to existing solutions. In field testing early this year, the MMC proved capable in removing mercury and copper. The results will be presented in Singapore before the product launch takes place in August 2011.

Water reuse technologies are also being used in both industries and municipalities to mitigate water stress and ensure a reliable water supply. Low-pressure membrane systems are suitable for treating wastewater for reuse. Siemens improves existing technologies like the membrane bioreactor (MBR). In 2010 the company commissioned a 1.0 million litre/day MBR testing facility at the Changi Water Reclamation Plant in Singapore to validate new design parameters. The testing under real conditions has proven the presumptions of a detailed Computational Fluid Dynamics analysis that preceded the plant’s commissioning. By optimizing the aeration and the resulting macroscopic fluid flow in the membrane operating system, the energy use and the system’s overall performance could be significantly improved.

To further enhance the membrane technology, a new R&D group was established at Siemens Water Technologies’ global research centre in Singapore in March 2011. The team will focus on fibre development and the next generation membrane filtration systems. By the end of 2012 the Singapore R&D team, will increase to 50 research scientists, engineers and technicians. This is another example of Siemens’ investment in research and development. The new team will further enhance the work achieved by the R&D center, established in Singapore in early 2007, with strong support from the Singapore government and PUB.