Micro pollutants in waste water: next generation rapid detection and advanced treatment technologies

Micro pollutants enter into aquatic environments via waste water treatment effluent discharges all over the world. These compounds may have negative effects on plants, animals and humans because often they are persistent and biologically active. The EU recently adopted a ‘watch list’ of potential priority substances, including pesticides, pharmaceuticals and personal care products that need to be monitored to determine their environmental risk. Besides form the known compounds and their suspected metabolites or transformation products, concerns may rise from unknown and unidentified compounds. This session addresses next generation detection methods and materials for fast identification, as well as for effective removal via adsorption/separation and oxidation.


Jeroen Kool, Vrije Universiteit Amsterdam:

Multiple contaminants are found in the aquatic environment including genotoxic and hormone disruptive toxicants. We present a screening platform that integrates liquid chromatography, mass spectrometry, high-frequency fraction collection (3-6 sec fractions) using the FractioMate, and bioassay testing for rapid and sensitive identification of toxicants. Because small time frame fractions are collected, the chromatographic separation is maintained and a single or two fractionation cycles is enough for toxic compound identification. The VU-Spark-Holland FractioMate technology can be used for rapid identification of emerging contaminants that are missed with target analysis.

Gas chromatography’s (GC) high separation power makes it is a popular analytical technique for environmental analysis, but it cannot give information on the toxicity of unknowns eluting from GC. For this, we developed a patented approach with the ability to collect each peak for post column toxicity analysis and for NMR. Simultaneous detection via a mass spectrometer allows correlation of the content of fractions to peaks in the chromatogram. We have used the platform in combination with endocrine disruption, dioxin-like toxicity and pesticide toxicity profiling. Our platform, the Da Vinci DVLS Fractionator, opens up a new world for bioassay testing and compound purification after GC.

Feng Yan / Petra Rudolf, University of Groningen:
Chloridazon has been a widely used especially in sugarbeet cultivation during the past decades since it was considered to be a relatively non-harmful herbicide. UV-induced degradation leads to the formation of the relevant desphenyl-counterparts i.e. desphenyl-chloridazon and methyl-desphenyl-chloridazon. Even if accumulation of these residues in natural water is far from alarming, a low-cost effective and environmental friendly detergent, capable of binding chloridazon and its degradation products as to reduce their concentration in water even further below set limitations is desirable. Here we show that pillared clay, prepared by cation exchange of sodium with copper complexed, cage-shaped polyhedral oligomeric silsesquioxane (Cu2+_POSS) could be a promising candidate for this purpose. X-ray diffration and HRTEM evidenced a homogeneous layered structure with interlayer spacing enlarged by ~4.6 A with respect to the pristine clay, which corresponds to the diameter of POSS. Exposure of this pillared smectite clay to chloridazon and its metabolites in water, the results showed that POSS intercalation significantly improved the adsorption capacity.

Nimmy Kovoor George, Wetsus:
Persistent and new organic micro-pollutants (OMPs) are increasingly found in sources of drinking water and in wastewater. Advanced oxidation processes (AOPs) is one approach to degrade these OMPs eventually making them less harmful. Commonly applied AOPs at full scale in the field of water treatment uses O3, H2O2, chlorine and UV in different combinations. However, a number of alternative AOPs, proven on lab scale, are promising especially in the field of tertiary treatment of wastewater and small-community drinking water applications. One example of such alternative AOPs is vacuum UV185nm (VUV185nm) based AOP (alone and in combination with UV254nm and H2O2). The VUV185 nm and the UV254nm radiation generate hydroxyl radicals (.OH) by photo-chemically splitting water itself and external oxidants such as H2O2 respectively. The generated .OH radicals undergo (photo) chemical reactions with the OMPs to degrade them.

The aim of this project is to investigate the photochemistry and scalability this process using advanced reactor design via computational fluid dynamics (CFD) to provide considerable benefits in terms of minimization of chemical and energy consumption.




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