Deadline: Applications will be accepted at any time until the position is filled.

Due to its benefits in terms of renewable energy production, organic waste management and resource recovery (nutrients and soil conditioner), anaerobic digestion (AD) has gained widespread policy support and become a thriving industry. Although AD is a mature technology, instability and system failure can happen, often due to biological imbalance caused by incorrect feedstock selection. Without detailed biochemical analysis of digester content it is difficult to assess if a digester is particularly overloaded with, or would benefit from, high carbohydrate, protein, or lipid feedstock. No field-determined evaluation parameters, however, are currently available that would inform operators the concentrations of metabolites of each major biochemical compositions in mixed substrate digesters. The routine field analyses, biogas production rates, CH4/CO2 ratios, and pH, are not sufficient for evaluation of co-digestion feedstock and detailed chemical analysis is costly and done sparingly. New feedstock can be evaluated in batch or semi-continuous tests, but these are time consuming and expensive. Determining “target feedstock” is therefore largely an empirical and trial-and-error task, and its success relies on the experience of AD operators. An instantaneous handheld test that can indicate the stability of digester and the scope for feedstock input adjustment would be a valuable tool for AD operators.

The aim of this project is therefore to establish if markers of metabolites in digesters can be identified in volatile organic compounds in the gas phase. Selected indicators will then be evaluated on their feasibility to provide information on feedstock selection and process stability under different digestion scenarios. As any development of this type of system, this research will take account of the-state-of-the-art of commercially-available portable analysis equipment. This study can also provide important information for the understanding of the metabolic pathways involved in the AD process, as well as data potentially useful for digestate odour management.

If you wish to discuss any details of the project informally, please contact Dr Y Zhang, Water & Environmental Engineering research group, Email: Y.Zhang<στο>soton.ac.uk, Tel: +44 (0) 2380 59 2188.

This integrated PhD project will be funded through the Center for Doctoral Training in Sustainable Infrastructure Systems http://cdt-sis.soton.ac.uk. The studentship comprises support from both EPSRChttp://www.epsrc.ac.uk and an industrial sponsor.