University of Bath

Drinking water & wastewater ozonation: Fate of ozonation products and gas transfer through membranes

This project aims to study the removal of organic trace contaminants during ozonation, as well as investigate membrane ozonation for water treatment.

Lab-scale system for continuous and long term (over several months) ozonation – biofiltration studies.
The laboratory setup developed for this study significantly simplifies advanced studies on biodegradability and adsorption of ozonation products.

The project goal is (1) to obtain a deeper understanding on removal of organic trace contaminants during ozonation, including fate of ozonation products at subsequent treatment steps and (2) to investigate the efficiency ozone delivery through membranes. Ozone is among the most promising technologies to remove a wide range of water contaminants that occur at traces in both waste water effluent and in drinking water resources. Traditionally ozone is injected into water by bubble-based methods, using membranes for water treatment applications is a relatively recent approach.

Therefore, the research has two directions: a) Ozonation with biofiltration post-treatment, with a focus on the fate of ozonation products. b) To investigate membrane ozonation for water treatment.

Project outline

For part a) A lab-based system was developed to combines continuous ozonation with post-treatment options such sand filtration or activated carbon filtration. The setup for this system has been previously unavailable and has been newly designed and tested. The developed setup significantly simplifies advanced studies on biodegradability and adsorption of ozonation products. In the initial study pharmaceuticals in wastewater and drinking water matrices served as example, while ongoing experiments look at relevant pesticides in the water cycle.

For part b) Membrane ozonation rigs are developed to investigate bubble-less ozone transfer into water with different membrane materials for both single hollow fibres and whole modules. The results are combined with computational simulations to obtain reliable ozone mass transfer predictions.

Science

For part a) Lab scale setups to combine continuous long-term ozonation with biofiltration were previously unavailable. The development of this system, which was in collaboration with the DVGW-Technologiezentrum Wasser (TZW) in Karlsruhe, Germany, will lead to (a joint manuscript on the results is submitted). Recently, this research has also been presented at the ACS annual meeting in New Orleans.

For part b) The initial modelling results are published in Water 2017, 9(7), 452; https://doi.org/10.3390/w9070452

A manuscript on the experimental results is currently in preparation.

Impact

The awareness of the impact of trace contaminants in the water cycle has been increasing and is now being taken into account in water quality regulations. There is need for advanced water treatment technologies to be widely adopted. Ozonation is one of the most promising technologies, and needs to be optimised to ensure that its large-scale application is sustainable.

This is the PhD project of Garyfalia Zompouli from the Department of Chemical Engineering. Email address: G.Zoumpouli@bath.ac.uk