Turning waste into wastewater treatment
Water scarcity in the Mediterranean, South America, Africa... It is a growing global problem, as climate change pressure mounts and inefficiencies in water use and treatment continue, particularly in water-intensive industries. An EU-backed team - working with international partners - has developed an innovative, low-cost inorganic wastewater treatment using agricultural and industrial leftovers.
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Attention is turning to research and innovation for solutions to some of the worlds pressing environmental concerns. Water recycling and treatment ranks high among these major challenges, as confirmed by its inclusion in the 17 United Nations Sustainable Development Goals (#6). The key is to make better use of the fresh water resources we have, and for this, new low-cost technologies are needed to ensure the widest possible take-up.
The EU-funded REMEB project has developed a novel membrane bioreactor (MBR), a device that uses ceramic membranes made from recycled materials to carry out upstream cleaning of wastewater destined for municipal and industrial treatment stations.
The new sustainable membranes are based on residues from agriculture, such as olive oil solid waste, as well as leftovers from the likes of the marble-working and ceramic tile industries. They are cheaper to make than conventional ceramic membranes, which offers significant cost savings for sewage treatment stations, especially those in water-starved countries. And the eco-friendly membranes have proven to work well under heavy-duty wastewater treatment conditions.
How does it all work?
Today, two types of filtration membrane compete on the market; costly but more effective ceramic ones made from materials like alumina, zirconia and titania oxide, and cheaper polymeric membranes which generally have poorer mechanical, chemical and thermal resistance.
REMEBs ceramics fill the gap, providing filtration properties on par with current high-end ceramic models without the costly minerals that go into them: Our inorganic membranes are made with waste, which means they are much cheaper to make, so they are a robust and long-term microfiltration alternative to the polymeric organic class of membranes, says REMEBs project coordinator Elena Zuriaga.
A membrane bioreactor combines a biological process with membrane technology. Flat-sheet membranes are submerged in the MBR and act as a barrier between the permeated water and the biomass. As fluid passes through the tiny pores, the pressure difference between two membrane surfaces keeps microorganisms and contaminants to one side and the now clean water to the other.
The project has now validated the different materials used in the membrane composition. The first membranes have been manufactured on an industrial scale in Spain and replicated at pilot scale using local wastes in Italy and Turkey. The industrial membranes have been tested in a municipal wastewater treatment plant in Aledo, Murcia (Spain), a largely agricultural region which already reuses around 98 % of its treated wastewater. This a leading example for Europe, according to Zuriaga.
While all partners have played a strategic part in REMEBs success, Universitat Jaume Is Instituto de Tecnología Cerámica was instrumental in characterising wastes and raw materials used to manufacture the ceramic membranes at pilot scale, as well as in supporting the ceramic industry during the industrial-scale manufacturing process.
International ties are key
Climate change and water scarcity are global issues, so having partners in non-EU countries around the Mediterranean and in South America, which is experiencing unprecedented drought conditions, adds an important global dimension to the research findings, says Zuriaga who is a research, development and innovation specialist at Sociedad de Fomento Agrícola Castellonense in Spain.
For example, Colombian partners at the Universidad Antonio Nariño (UAN) have analysed the new solution in different industrial sites across the country and in neighbouring countries: The South American market is very important to several of the consortium partners, so the potential of the technology in the industrial sector is quite high, notes UANs Javier Rincón.
Business plans are now being developed by Norwegian partner Biowater for commercialising REMEBs results once it concludes in the summer. The team is also evaluating the environmental impact of the product and the process that goes into the MBR, following life-cycle analysis methods.
Efforts are also well under way to disseminate the projects findings, taking advantage of the entire consortiums networks in participating countries Colombia, Cyprus, Spain, France, Italy, Norway and Turkey but also further afield, and especially in water-scarce countries that need low-cost, sustainable and efficient solutions to their wastewater treatment needs.