Toilet paper used twice?

Wastewater Treatment, Nutrient Factory

The primary sludge from the pre-settling tanks contains a lot of cellulose (toilet paper). At Harnaschpolder wwtp the cellulose is to a large extend from the primary sludge removed by a STRAINPRESS®. Currently the strainpress material is transport to a paid third party for processing. Research will be conducted on this material to see if this cellulose can be of used in the existing wwtp. This cellulose can likely be charged (cat- or anion) by an chemical/catalytic reaction. If this works, this product can likely be used as flocculant to improve the removal of organic suspended material in the pre-settling tanks. Likely the yield of biogas can increase because of the increase of primary sludge and maybe also a decrease of energy consumption for the aerobic biological process is achieved. Several tests are conducted and a feasibility study is done to obtain insight in sustainable and financial aspects.

- Han van de Griek
- Paul Hankinson (final internship Aquatic Ecotechnology)



Start of Research
January 2017

End of Research
June 2017


- Evides Industrial water BV
- Delfluent Services BV
- Delfland Water Authority
- HZ University of Applied Sciences


Han van de Griek
[email protected]