Challenge
In an Amsterdam cellar contaminated with wastewater some 1,000 tonnes of sludge had to be removed. During the fermentation process of the sludge, large amounts of H2S and methane were released, resulting in an explosive mixture in the cellar. For its business partner Reym, HMVT took care of the ventilation of the space and the purification of the vapours released.

Solution
After a great deal of consultation between Reym and the customer concerning the RI&E (risk inventorying and evaluation), QHSE aspects and the purification process – gas washing – the Reym-HMVT combination was able to convince the client that they were the right parties for this specialist task.

In February 2018, nine Reym employees started work using five tilting tankers, which continued from Saturday through to Sunday. Three employees were at hand with independent breathing protection in order to assist with the connecting and disconnecting of pipes and other activities during which H2S and methane could be released.

There was also a gas washer from Reym HMVT available to purify the released H2S gas and to provide good ventilation in the cellar and ensure it was kept below the explosion limit.

When the tankers were discharged at ATM, a Reym member of staff was present with independent breathing protection to assist with the unloading and cleaning of the tankers. By setting the tilting tankers to maximum vacuum and afterwards switching off the vacuum pump, no gases were discharged to the outside air during loading. A total of 250 tonnes were removed from the cellar and transported to ATM.

Results
Thanks to the good collaboration between the various Reym branches and HMVT, the project was carried out safely, efficiently and in an as environmentally friendly way as possible, without any emissions of poisonous vapours.