INTEGRATED PRODUCTION OF ALGAL BIOMASS

Applied research is increasingly defined within a context of sustainability and ecological modernisation. Within this remit, recent developments in algal biotechnology are considered to hold particular promise in integrating aspects of bioremediation and bioproduction. However, there are still a number of engineering and biological bottlenecks related to large scale production of algae; including requirements to reduce both capital expenditure (CAPEX) and operational expenditure (OPEX). One potential avenue to reduce these costs is via feedstock substitution and resource sharing; often described as industrial symbiosis. Such an approach has the benefit of providing both environmental and economic benefits as part of an ‘eco-biorefinery’. This thesis set out to investigate and address how best to approach some of the cost related bottlenecks within the algal industry, through a process of industrial integration and novel system design. The doctorate focussed on applications within a Northern European context and was split into four research topics. The first and second parts identified a suitable algal strain and were followed by the characterisation of its growth on wastewater; with the findings showing Chlorella sorokiniana (UTEX1230) capable of robust growth and rapid inorganic nutrient removal. The third part detailed the design, construction and validation of a lower cost and fully scalable modular airlift (ALR) photobioreactor, suitable amongst other applications for use within wastewater treatment. This work concluded with a pilot scale deployment of a 50 L ALR system. The fourth research section detailed the costs of ALR construction and operation at a wastewater treatment works, with a particular focus on the benefits that can be derived by industrial symbiosis. The thesis concludes with an appraisal of the ALR design and considers the potential for the technology, particularly within a wastewater treatment role. A final consideration is given to the practicalities of developing the algal industry within the UK in the short to medium term.