Up until 2011, the aquafer from the Princess Juliana water production plant (WPJ) at Andijk ended up for instance in noise barriers or as construction material. This was a pity, since the sludge contains enough iron to be used as a sulphur binding agent in the biogas sector. And given the plant’s location, right on the IJsselmeer lakeshore, the sludge could be easily transported away by ship. In other words, high time to go and speak to ‘Germany’.
That same year, 2011, Mr Gert Peek of the Münsterländische Reststoffenverwertung visited WPJ. And, indeed, he saw that there were sufficient opportunities of selling the dewatered aquafer in North-West Germany. However, the process at the time did not yet ensure product purity or continuity: the aquafer contained stones, too much ‘fresh’ plant material and sand, and its dry-matter content was not always consistent.
PWN staff got down to work and successfully solved these concerns – in 2012 the first ship set sail for Germany. The sludge had no foreign bodies (Fremdkörper) like sand and stones. The plant material was dead and, for the most part, had disappeared and then rotted away in the stirred sludge. The end-clients – biodigesters – were very happy with the quality and continued ordering the material. Now, three to four ships transport dewatered aquafer from Andijk to Germany every year.
Five years on, the people at WPJ who continue ensuring the sludge is of the right quality wanted to witness directly what happens with the material once it gets to Germany. They paid a visit to two digestors, where Gert Peek showed them why the specific quality requirements are so important. It’s great to see the end result of your work with your own eyes. It was also good to meet our German colleagues. A successful day in every way!