Controlling water chemistry to improve drinking water quality and minimising disinfection by-products?

Controlling water chemistry to improve drinking water quality and minimising disinfection by-products?
This exciting fully funded PhD, with an enhanced stipend of £19,000 per annum, will deliver insights into the formation of brominated disinfection by-products seeking insights to allow their concentrations to be minimised through chemical engineering at a molecular level. This will allow operational mitigations and investment decisions to be made by water companies to ensure future reductions in risk when producing drinking water. Students will benefit from being part of the EPSRC Centre for Doctoral Training in Water Infrastructure and Resilience (WIRe), a world leading collaboration between three UK universities.
The WIRe programme includes a bespoke training programme in technical and personal skills development, and provides opportunities for overseas travel and access to world leading experimental facilities (PhDs under this scheme are for a duration of four years full time).

Disinfection by-products (DBPs) are formed when organic matter remaining in water after initial treatment reacts with the chlorine when used for disinfection and other processes. Other components in the water can influence the type and concentration of DBPs that form. This includes the presence of bromide, which can promote the formation of a greater proportion of brominated DBP compounds.
In the UK, regulation requires that DBP concentrations must be kept as low as possible without compromising the effectiveness of the disinfection process. The main groups of DBPs formed are trihalomethanes and haloacetic acids. A prescribed concentration of 100 µg L-1 has been set for the sum of the concentrations of the four trihalomethanes (THMs) measured at the consumers tap. Although haloacetic acids (HAAs) are not currently regulated in the UK, they can be monitored as part of the Drinking Water Safety Planning risk assessment process required to be carried out by water companies by the Drinking Water Inspectorate. On 1 February 2018, the European Commission published a proposal for a revision of the Directive on the quality of water intended for human consumption (the Drinking Water Directive). One element of the proposal was a revision of the water quality standards with a proposed value for nine HAAs of 80 µg L-1).

The THMs and HAAs include brominated compounds some of which have been identified by the national toxicological programme in the US as being of concern. The reactions leading to the formation of these brominated DBPs has been well studied, including in previous collaborations between Cranfield and UKWIR. However, it has not previously been determined whether these reactions can be manipulated to alter the DBP formation profile away from the brominated species.

The aims of this project are therefore to 1) to investigate the kinetics of brominated DBP formation to find the tipping points where their formation is enhanced, 2) to investigate the incorporation of bromine into DBPs, and 3) to determine the reaction conditions and develop ways of manipulating both the kinetics and thermodynamics of these chemical reactions to reduce their formation.
The project is an exciting collaboration between Cranfield University and UK Water Industry Research Ltd (UKWIR). UKWIR is a collaborative research platform for the UK and Ireland water sector, funded by the water utility companies operating in these countries. The project will enable water companies to develop strategies for control of brominated DBPs in order for them to meet the requirement for minimisation. By looking at the manipulation of DBP formation using chemistry, this project will require fundamental science to be able to develop strategies for future investment to increase the resilience of our water supplies.

The successful applicant will make use of the Drinking Water Pilot Plant facility at Cranfield University to translate the lab results to full-scale. Additionally, as part of the WIRe doctoral centre, undertake an international placement, and complete a bespoke training programme within a cohort of up to 15 students.

Start date 28 Sep 2020
Duration of award 4 years

Entry requirements
Applicants should have a first or upper second class UK honours degree, or equivalent, in a related discipline, such as chemistry or chemical engineering. The ideal candidate should have some understanding of chemical kinetics and water treatment.

How to apply
For further information:
Name: Dr Emma Goslan
Email: [Email Address Removed]
T: (0) 1234 750111 Ext: 8343