Water-purification method promises radical improvement

Delft University of Technology research has discovered a method that could drastically change the way we purify water within a few years. Delft, in partnership with DHV engineering bureau, has developed a compact and environmentally-friendly purification method, in which aerobic bacteria form granules that sink quickly.

With the aerobic granular sludge technology, aerobic bacterial granules are formed in the water that is to be purified. The advantage of these granules is that they sink quickly and that all the required biological purifying processes occur within these granules.

The technology offers advantages when compared to conventional water purification processes. For example, all the processes can occur in one reactor. Moreover, there is no need to use large re-sinking tanks, such as those used for conventional purification. Such large tanks are needed for this because the bacteria clusters that are formed take much longer to sink than the aerobic granule sludge.

According to Delft PhD researcher Merle de Kreuk, the purification installation needs only a quarter of the space required by conventional installations. Moreover, it uses 30% less energy than the normal purification process. This purification process is suitable for both domestic and industrial waste water.

The aerobic granular sludge technology has been nominated for the Dutch Process Innovation Award 2006. The technology is now in the commercialisation phase. DHV is currently negotiating with water purification companies to test this purification method on a larger scale. The first installations are already in use in the industrial sector.