Engineering company Colsen International and Voith Paper Environmental Solutions are in the process of establishing an expertise center in order to gather knowledge about water technologies which can tackle the problem of inert COD and in particularly humic substances.

Anaerobic processes are often prescribed as the first waste water treatment step for pulp and paper mill with high COD concentration (chemical oxygen demand) , in order to meet effluent requirements. The inert COD fraction in the waste water makes aerobic degradation often .

More stringent regulation
Industries are increasingly subjected to stringent discharge limits, for instance 50 mg COD L-1 in China. These limits are difficult to obtain with conventional anaerobic and aerobic waste water treatment technologies.

Humic substances
A relatively large fraction of inert COD remains in the effluent mainly as humic substances. This is especially the case with paper mill effluents which are often highly colored due to the humic substances and therefore need treatment.

Best available technology
Colsen conducted a feasibility study in order to list the available technologies and to be able to select for a specific case the best available technology not entailing excessive costs.

In the next phase, Colsen will develop and test new techniques which will be evaluated against the current technologies in order to improve the economic implications and environmental friendliness of removing inert COD from waste water.

This news item was originally published on the website of Colsen International.

More information
Colsen International
Hulst, the Netherlands
+31 114 31 15 48

Voith Paper Environmental Solutions
Ravensburg, Germany
+49 751 83 01