DairyWater research presented at recent Microbiology Society conference

The Irish Division of the Microbiology Society recently hosted a conference entitled “Microbial Resources for Agricultural and Food Security”. The conference took place from the 21st to 23rd June 2017 in Belfast and was attended by a number of DairyWater researchers, Peter Leonard (NUI Galway), Beatriz Gil Pulido (UCC) and Dr. Niall O’Leary (UCC). The conference dealt with a number of concerning issues in both the agricultural and food sectors, which included the difficulties in nutrient removal and phosphorus recycling and recovery.


DairyWater researchers, Peter Leonard (NUI Galway), Dr. Niall O’Leary (UCC) and Beatriz Gil Pulido (UCC), during the poster session in Belfast

A number of emerging technologies to address these problems were central to many presentations. Peter spoke about IASBR technology, a novel system developed at NUI Galway, which offers a more economical and sustainable method of biological water treatment than what is currently employed within the industry. This technology is under investigation by the DairyWater project at both pilot- and laboratory-scale in order to determine its viability for use within the Irish dairy sector. Peter was able to report that the IASBR system has a promising future as initial testing has exhibited that the system has the capacity to remove over 95% of nitrogen, phosphorus and chemical oxygen demand on a wastewater and is capable of high strength dairy processing wastewater.

PhD student, Beatriz, presented a first approach on the microbial ecology of an IASBR system treating synthetic dairy wastewater. Molecular techniques were used to investigate the diversity of the bioreactor, where the results from a laboratory-scale trial, which was performed in 2015, were summarised in a poster presentation. The ecology of an IASBR was presented alongside its performance. Specific groups of bacteria were identified and linked to the optimal performance of the bioreactor (orthophosphate and ammonia removal efficiencies >90%) under one of the three aeration rates investigated during the trial.

DairyWater install pilot-scale IASBR system

As part of DairyWater Task 2, the researchers at NUI Galway have recently installed a pilot-scale IASBR (Intermittently Aerated Sequencing Batch Reactor) system at Aurivo Dairy Ingredients, Ballaghderreen, Co. Roscommon. An IASBR is a biological wastewater treatment system in which wastewater is completely mixed with the microorganisms in the system for the duration of the react phase. During this phase periods of non-aeration and aeration are cycled to maximise the removal capacity of the microbes present in the system. After the react phase, the circulation is stopped and the biomass will settle to the bottom of the unit allowing the treated water to be decanted from the top section of the system. The pilot-scale system, which is pictured below, has a working volume of 3000 litres, is running on a 12 hour cycle with a 4 day hydraulic retention time (i.e. 375 litres treated per cycle) and a 16 day solids retention time. Levels within the system are accurately regulated using a set of float switches and pumps.

Pilot scale IASBR system at Aurivo Dairy Ingredients

In order to monitor the performance of the system, a refrigerated auto-sampler takes a daily sample of the treated effluent. These samples are collected weekly and transported to the environmental laboratory at NUI Galway for physico-chemical analysis. The removal rates for chemical oxygen demand (COD), total suspended solids (TSS), ammonia-nitrogen (NH4-N) and orthophosphate (PO4-P) from the Aurivo’s process wastewater are calculated based on the analysis of these samples. Initial results has exhibited that the system has great potential for the treatment of dairy processing wastewater as it has the capacity to remove up to 96.9% of COD, 99.8% of TSS ,99.6% of NH4-N and 99.9% of PO4-P.

The removal rates initially were quite unstable but this has since stabalised. For the majority of effluent samples analysed, the nutrient content was far below the EPA licence limits for the site. The next stages of the research involves improving the overall efficency of the system by maximising its treatment capacity and improving the effectiveness of the aeration rate.

DairyWater researcher presents as part of the EU Aquaponics Hub COST Action meeting

An EU Aquaponics Hub COST Action meeting entitled “Modelling nutrients, energy and growth in aquaponic systems” took place between the 24th and the 27th April 2017 in UCC’s School of Biological and Earth Science. DairyWater researcher, Beatriz Gil Pulido, was invited to deliver a presentation on her work entitled “Microbial ecology of a bioreactor approach to treat dairy wastewater”.


Beatriz Gil Pulido presenting at the EU Aquaponics Hub COST Action meeting

The presentation included a brief introduction into the DairyWater project in order to give context to the participants as to why the project was initiated and details of the involvement of the different universities, research centres and industry stakeholders across Ireland.

The core of the presentation detailed the intermittently aerated sequencing batch reactor (IASBR) technology and the removal of nutrients by the biological pathway, which indicates the importance of the microbiology. Previously published results were reported, which demonstrated the efficiency of the IASBR technology for N and P removal under cool operational temperature. Results from the first laboratory-scale IASBR trials exploring the microbial ecology in the system when treating dairy waste water where shown as a first approach in the knowledge of the bacterial community structure of an IASBR treating dairy processing waste water. Dominant bacterial structures were linked with optimal nutrient removals in the bioreactor during a good performance operational conditions.

DairyWater researcher holds successful Green Farm workshop

March 28th 2017 saw farmers, technology providers, engineers, regulators and academics come together at the Teagasc Grange Research Centre to discuss the barriers to, and potential of, an on-farm biogas industry in Ireland.

Bio Gas Cropped March 2017
Delegates at the recent Green Farm on-farm biogas workshop, held in Teagasc, Grange, Co. Meath

The event was convened as part of the Green Farm project, a Science Foundation Ireland-funded collaboration between NUI Galway, Teagasc and Waterford Institute of Technology.  The project, led by Prof. Xinmin Zhan of NUI Galway, in collaboration with Dr Peadar Lawlor (Teagasc) and Dr Gillian Gardiner (WIT), is investigating the technical and economic viability of on-farm anaerobic digestion of pig manure and food waste.

The invited speakers included Dr. Denis Dineen of the Sustainable Energy Authority of Ireland, Justin Byrne from the Department of Agriculture, Food and the Marine, John Toner of WIS Group, Conor McEntegart and Dr. James Brown of Gas Networks Ireland.  The topics covered included; an overview of the current “state of play” in Ireland in terms of the contribution that the biogas industry makes to Ireland’s fuel mix, and the potential role it may play in future in meeting targets on renewable heat, transport and electricity; the animal by-product (ABP) regulations which biogas plants in Ireland must abide by, as well as the common pitfalls experienced by developers applying for ABP licences; technology solutions that can be used in biogas plant development; and problems in digester operation due to poor design and specification; the upgrading of farm-generated biogas and injection of this biomethane into the natural gas grid.

Two PhD researchers from the Green Farm project, Conor Dennehy and Yan Jiang, also presented results from their work on economic modelling of on-farm biogas plant viability, and on the development of dry anaerobic digestion technology.

The 80 plus attendees were also led in a tour of the recently constructed 0.15 MW biogas plant located on-site at Grange by JJ. Lenehan of Teagasc. The digester is expected to be in operation later this year and will convert a combination of grass silage and cattle manure into electricity, which will be sold to the grid, and heat which will be utilised by the buildings on the Grange campus.

The workshop concluded with a lively panel discussion which yielded great insights into the impact that the introduction of a renewable heat tariff would have on the industry, the need to look critically at the potential of food waste as a substrate, and the crucial role access to finance has to play in the development of a biogas industry. The success of this “sold out” event highlights the heightened interest there is in developing the biogas industry in Ireland. The conference materials and key takeaways from the panel discussion are freely available from Teagasc. For further information about the Green Farm project, contact Conor Dennehy.