Valorisation of sewage sludge through phosphate-based geopolymer production (FES-PhD-2425-06)

Are you interested in contributing to net zero by creating environmentally friendly cementitious systems from unconventional materials? If yes, then why not consider this project?

Sewage sludge is rich in valuable nutrients/minerals such as phosphorus and aluminosilicates. However, its management represents some 20 – 60% of operational costs and thus require effective solutions. Hence, this project aims to leverage on its chemical composition to produce geopolymers. Geopolymers are new-generation environmentally friendly binders in contrast to Portland cement that can be synthesized from aluminosilicate sources through alkali or acid activation. However, very few studies have considered acid activation for geopolymer production using sewage sludge as aluminosilicate source. Thus, this work will employ sewage sludge as aluminosilicate source and phosphoric acid as acid source to produce acid-activated geopolymer mixtures, which can be used as construction materials and even slow-release fertilisers. It will attempt to generate phosphoric acid from sewage sludge through thermal and chemical treatments including use of sulphuric acid and sodium aluminate. Additionally, triple super phosphate (TSP) would be ground to powder form and used as acid source for geopolymer activation. The project’s objectives are: 

(1) Investigation of the potential of different mixture formulations of the thermally treated sludge cakes, ground TSP and the additives to produce geopolymeric cementitious composites that immobilises any toxic components of the sludge within their alumino-silicate structures. 

(2) Assessment of the mechanical, durability, microstructural and environmental performance of the geopolymeric composites produced using conventional tests for concrete and pH-dependent granular leaching tests.

(3) Evaluation of the potential of utilising the geopolymeric composites produced for 3D concrete printing by optimising the mixture formulations using suitable additives.

The PhD student working on the project will gain significant exposure on a range of techniques in wet chemistry, materials characterisation and environmental testing, and writing papers for publication in leading journals.

Making an application:

Please read this information before making an application. Information on the application process is available at: https://www.gre.ac.uk/research/study/apply/application-process. Applications need to be made online via this link. No other form of application will be considered.

All applications must include the following information. Applications not containing these documents will not be considered.

•       Scholarship Reference Number (FES-PhD-2425-06) – included in the personal statement section together with your personal statement as to why you are applying

•       a CV including details of 2 referees *

•       academic qualification certificates/transcripts and IELTs/English Language certificate if you are an international applicant or if English is not your first language or you are from a country where English is not the majority spoken language as defined by the UK Border Agency *

*upload to the qualification section of the application form. Attachments must be a PDF format.

Before submitting your application, you are encouraged to liaise with the Lead Supervisor on the details above.