Inteauclean: Integrated treatment of wastewater from tank cleaning industry

Problem:

The tank cleaning sector cleans tanks and containers used for transport of chemicals, paints, food products and soaps. Some of these products contain non-ionic surfactants that leave a sticky layer behind in the tanks after discharge, which are very difficult to remove. So when those tanks are being cleaned, parts of the sticky surfactants that stayed behind end up in the wastewater treatment plant of the companies that clean the tanks. Those companies often have their own wastewater treatment plant, but still there was evidence of the sticky residu in the ecosystems afterwards because of an insufficient removal. Though the biodegradable compounds can be easily removed, some persistent organic pollutants can often not be sufficiently degraded during this wastewater treatment and can, as a result, imitate natural hormones when exposed to the environment. This can cause disruption of the endocrine functions of animals and humans.

Goal:

Together with KU Leuven PETLab, KU Leuven LFA, UAntwerpen BioGEM and other industrial partners we launched the project INTEAUCLEAN.

The goal of this project was to develop an efficient method to improve degradation of these persistent organic pollutants in the wastewater treatments. Ozonation as an advanced oxidation process (AOP) was evaluated because of its big potential. Ozonation in combination with a biological treatment was investigated, and the optimal order of both was determined.

Solution:

The wastewater of several tank cleaning companies was tested. The concentration of persistent organic pollutants in the effluent of the wastewaters of all these companies did not comply with the legal discharge limits set by the European regulations. The result of the research within the INTEAUCLEAN project showed that ozonation was best applied after the biological treatment. The biological treatment could after all degrade most of the biodegradable organics and ozone could react directly with the persistent organic pollutants. Afterwards the concentration of these pollutants did comply with the discharge limits.

This solution is now being tested on pilot scale. The ozonation is applied through a pilot installation of PETLab KULeuven and a second and mobile pilot installation for the ozonation step is built by InOpSys and will know its first use in the week of 1 July 2019!

Please contact us if you wish to have more information.

More info: Mélanie Mignot (KUL) wrote a publication on the methods of analysis within this project, called "Fast liquid chromatography-tandem mass spectrometry methodology for the analysis of alkylphenols and their ethoxylates in wastewater samples from the tank truck cleaning industry".