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Dr Peter Randerson  -  PhD

Current research interests:- pollutant removal and nutrient recovery from effluents and waste water (biofiltration), using constructed wetland eco-technology.


Photo of Dr Peter Randerson testing a novel recirculation system.

Testing a novel recirculation system with willows, planted in a tidal flow tank (mesocosm) to remove pollutants from landfill leachate effluent

Biofiltration of effluents in constructed wetland systems.
Constructed wetlands (CW) planted with reed and willow and acting as biofilters, provide a cost-effective method of pollutant removal and nutrient recovery from waste water and other effluents such as landfill leachate, avoiding the risk of local pollution of water-courses. Field studies using the novel technique of membrane-inlet mass spectrometry (MIMS – developed at Cardiff School of Biosciences by Prof D. Lloyd) demonstrated the role of willow roots in oxygenating the sub-surface environment of a tidal-flow willow bed. MIMS enables in situ measurements of in dissolved gases (e.g. O2, CO2, NH3, CH4) in the undisturbed sub-surface environment. These gases act as indicators of spatial and temporal variation of microbial activity. This technique is now being applied to mesocom tanks planted with reed and willow to monitor N removal capability in low-oxygen, low-redox, inundated environments. Micro-electrode measurements of oxygenation by the roots of individual willow and reed plants in laboratory systems demonstrate the capacity of these plants to modify the rhizosphere environment, and highlight their essential role in the process of N removal by the microbial community in biofiltration systems.

Collaborators: Dr A Bialowiec (Univ. of Wroclaw, Poland); Dr A Albuquerque (Univ. of Beira Interior, Covilha, Portugal); Dr L Avery (James Hutton Institute, Aberdeen); Prof D Lloyd (Cardiff School of Biosciences)

Dissolved oxygen depth profile in a tidal flow willow bed

Dissolved oxygen depth profile in a tidal flow willow bed showing elevated oxygen in rhizosphere zones; measured by membrane inlet mass spectrometry and a mini-rhizotron camera

Previous research activities:

Biomass production with short rotation coppice and energy grasses.

Willow coppice for biomass.

Willow coppice for biomass.

High production willow and biomass grasses are feasible as alternative crops in marginal farmland areas, such as the uplands of Wales. Research over 20 years into planting and management regimes for biomass crops and into habitat enrichment in plantations was based at the University's Field Centre in Powys, mid-Wales. As alternatives to fossil fuels for heat energy and potentially biofuel feedstock, such crops offer additional income for farmers and diversity in the landscape. Visit: Papers produced by Llysdinam Field Centre

Collaborators: Dr F Slater (Cardiff School of Biosciences); Prof P Kowalik (Technical University of Gdansk, Poland)

Enzymic extraction of ethanol from plant biomass and cellulosic waste materials.
Degradation of cellulose to simple sugars enables the production of ethanolic biofuel from biomass grass crops or plant waste residues. Research into the practical and economic feasibility of utilising low cost feed-stocks was aimed at developing novel enzyme systems to optimise ethanol yield.
Collaborator: the late Dr B Dancer (Cardiff School of Biosciences).

Computer simulations for teaching in biosciences.
Computer simulation models can provide valuable insight into the functioning of biological systems both as experimental tools and as teaching aids. Following earlier simulations in genetics, we developed a simulation model of the trophic dynamics of an aquatic ecosystem for ecology teaching (program available on request).

Collaborators: Dr D Bowker (; Dr M Day (Cardiff School of Biosciences)

Research Funds – Awarding Bodies:
EU/Welsh Assembly Government; Dept. Trade & Industry; HEA Centre for Bioscience; Cardiff University; Univ. of Wales; British Petroleum Intl; ESD ltd; Gwent Wildlife Trust; National Trust; Cardiff China Centre; Shropshire District Council.