Selected Information - Proposed Research

Advanced oxidation processes potentially offer attractive alternatives to ozone and activated carbon to degrade organic micropllutants, particularly pesticides, algal toxins, and taste and odour compounds. This study will complement an UKWIR project, where WRc is assessing advanced oxidation to remove specific pesticides (particularly metaldehyde), by examining a much broader range of organic micropollutants, and obtaining more detailed site specific considerations for process design and operation.

The main focus of the project will be the use of high dose UV, with or without dosing of hydrogen peroxide (UV/peroxide) to:

• Identify the capabilities of UV/peroxide for water treatment and the costs and technical implications for its implementation.
• Compare UV/peroxide performance and cost against current ozonation and GAC practice and identify where UV/peroxide could provide a cost-effective alternative.

Benefits to Clients

• Reduced risk from being a technology leader by having access to robust information, independent of process plant suppliers, on the use of emerging technologies.
• Cost savings and/or improved compliance through adoption of UV/peroxide where it offers more cost-effective treatment.

Work Programme

1. Identify the capabilities of UV/peroxide through published data and contacts with equipment suppliers. This will include collation of performance data for removal of organics, costs/energy use (including carbon emissions), and examples of full scale plants worldwide.
2. Identify benefits and limitations in the context of, for example:
   • Pre-treatment needed, and the extent to which conventional treatment might be reduced or replaced through the installation of UV/peroxide e.g. for removal of natural organics.
   • Disinfection benefits, within the current regulatory framework.
   • The need for post-treatment, for example to remove excess hydrogen peroxide, and any implication for water quality e.g. biological benefits and potential microbiological problems.
   • By-product concerns.

3. Develop site specific guidance for process selection, conceptual design and operation, based on a comparison of UV/peroxide and ozone/GAC based treatment.

Project Output

• Detailed review of UV/peroxide technology, with guidance on implementation for defined site conditions.
• Implementation workshop.

Related WRc Work

• Treatment for new and emerging pesticides including a review and pilot plant trials of AOPs for pesticide removal, UKWIR, DW14, 2010-11.
• Various projects evaluating ozone and activated carbon for removal of a wide range of organic micropollutants, 2005-10.
• Optimising GAC regeneration frequency, CP393, 2009-10.
• Implementing UV disinfection, CP377, 2009-10.
• Energy use for ozonation, including a review of energy use for full scale plants, client confidential, 2009-10.