Waste water isn't only good for flushing, it could be used as a plant nutrient, writes Lorna Siggins, Marine Correspondent
Growing willows that have been fed on contaminants stripped from waste water in order to produce biofuel would certainly meet all the best Gaia principles for an interdependent planet. Small wonder that NUI Galway (NUIG) researchers have recently been awarded a three-year research grant to develop, commission and assess such technologies for treating waste water.
Such by-products generated by small towns and large villages are the main focus of the project, involving a 20-strong team of NUIG engineers and scientists from Ireland, China, Denmark, Spain and Poland, and led by Dr Michael Rodgers. The team, drawn from the university's civil engineering department and its Environmental Change Institute, is currently negotiating access to a local authority site in the western region where it can design, develop and test its ideas.
Pollution of Irish rivers, lakes and groundwater supplies is still a significant problem, according to the most recent Environmental Protection Agency (EPA) report. The Water Quality in Ireland 2005 report found that 30 per cent of lakes and 22 per cent of estuaries and coastal waters require remedial measures, while 30 per cent of groundwater supplies - an important source of drinking water - showed bacteriological contamination.
The finger is often pointed at large scale agricultural and industrial causes, but Dr Rodgers's civil engineering department has done a considerable amount of work on small-scale sources which are often underrated. Some six years ago, his team assessed the impact of septic tanks attached to single dwellings and systems treating waste water from populations of 500 and under. The work was part of a commission to draw up national guidelines, co-ordinated by the EPA.
His department has also been looking into alternatives to septic tanks, filter systems, and nitrate removal from domestic, industrial and agricultural waste water. It has been involved in an EU study on biofilms treating waste water, as one of a series of environmental research projects currently worth over €2.2 million.
The new sustainable waste-water treatment initiative is co-funded by the EPA, under the EU Environmental Technologies Action Plan, and the National Council for Forest Research and Development (Coford) under the National Development Plan.
A pumped flow biofilm reactor will be installed at a local authority waste-water treatment site, and it will draw waste water from the main tank into a series of tanks where solids will be allowed to settle out and to be consumed by micro-organisms.
"The technology should remove a range of contaminants, including organic carbon, nitrogen, phosphorus, odours and solids," Rodgers says. These removed solids can be used as nutrient additives for willow groves. A dairy farmer in Limerick has agreed to try the waste on his trees, and the scientists will monitor optimum levels to ensure there is no groundwater contamination.
The beauty of this is that the willows may be harvested for woodchip boilers, which are now subject to State grant-aid under the renewable energy initiative.
It is expected that two engineers will be employed on the project on a full-time basis. The performance of the technologies will be monitored by online analysers and sensors, controlled from NUIG's campus.
Rodgers says that the long-term plan is to develop a centre for research into water and waste, embracing research, innovation, standard accreditation, education and policy planning.
New commercial environmental products will be developed from this and other higher education and industry projects, part-financed through agencies like the EPA, Coford and Enterprise Ireland, he notes.
The project will also allow NUIG to command a significant stake in a growing environmental technology industry - said to be one of the fastest growing sectors in the EU and supplying a substantial €183 billion worth of goods and services a year.