Dewatering of Industrial Sludge - Case Study
At Ten Cate Protect, town of Nijverdal, The Netherlands, 2006
During the wastewater treatment process at Ten Cate Protect large quantities of sewage sludge are liberated. A couple of days per week this sludge is transported in tanker trucks to a waste disposal plant.
On June 14th 2005 a Geotube MDS unit was put in operation at Ten Cate Protect to separate and condense the sludge of the aerobic sewage works; and with good success!
This is the story …
It is not allowed to discharge directly to the surface water the contaminated wastewater that is liberated during the production process of Ten Cate Protect. For purification of this water Ten Cate Protect operates an anaerobic/aerobic water-treatment plant During the aerobic step a lot of sewage sludge is liberated. By the conventional method the sludge was removed in tanker trucks to a special site, where it was processed at considerable expense. Ever increasing transport charges and the costly special sludge processing gave cause for an inquiry to develop a more effective and economic method. It goes without saying that Ten Cate preferred an eco-friendly solution.
At that moment the sister company len Late Nicolon made its appearance, since they have developed a new dewatering and containment technology with Gcotube', specially designed for similar applications. Geotube is a high-strength permeable filter fabric that is fabricated into an oval 'tube'. For the complete wastewater treatment process some additional operations are required. In a pumping-, mixing- and dosage system polymers are added to the wastewater. These polymers form a compound with the waste particles and almost clean water is left.
Together both Ten Cate companies, in cooperation with Ashland, the suppliers of polymers and Q-Flow, the producer of the pumping-, mixing- and dosage system, found the effective overall solution of the problem: the Geotube Mobile Dewatering System.
After having been pumped through the mixing- and dosage system and when the waste particles have started to 'flake', the wastewater is put into Geotube. Geotube* has been placed in an iron container, allowing the liberated clean water to be displaced effectively. Clean water drains from Geotube through the small pores of the filter fabric and the grain solids of the sludge are retained in the 'tube'. The decanted water is of such a good quality that it simply can be drained via the sewer. When the maximum capacity of the solid waste fraction in Geotube has been reached, the whole is removed by container.
The final result is a drastic volume reduction of the sewage sludge to be transported for further processing: the former number of approximately 12 transports per month has been reduced by the factor 10. And there is an additional advantage: the new method is very eco-friendly!