Arsenic is one of the most toxic elements occurring naturally in the environment. Studies of Argentinian aquifers in cattle ranching areas show arsenic levels that represent a risk to human health as arsenic can enter the food chain via milk or meat. There is a clear need for effective, affordable and sustainable treatment methodologies to provide potable water to cattle. Cows consume around 70 litres of water a day and a medium-sized farm has around 100-120 cattle. This means an onsite water treatment system must be able to treat at least 7 000-8 400 litres of water per day. Financial constraints, operational requirements and water quality issues can make it difficult for small and rural systems to implement many of the different technologies available for removing arsenic. For these reasons, the use of a simple treatment process based on adsorption and ion exchange media is usually recommended. However, disposal of single-use adsorption media and ion exchange regeneration solutions and the hazardous waste they generate present major obstacles to the widespread application of these technologies. Advanced nanostructured materials The EU-funded NANOREMOVAS project addressed these challenges through a network of academia and industry partners from Europe and Argentina. Undertaken with the support of the Marie Curie programme, “the consortium developed and implemented a pilot plant for the remote treatment of arsenic-polluted waters, applying a multidisciplinary approach to solve complex technical, environmental, social, economic, and health and environmental issues,” says project coordinator Dr Manuel Valiente. Project partners gathered new knowledge about arsenic adsorption mechanisms over different advanced adsorption materials including thermodynamics, kinetics and selectivity through state-of-the-art techniques. This information supported the design and application of state-of-the-art advanced multifunctional nanostructured materials for inorganic pollutants by exploring new synthetic processes and surface modification, previously tested at the laboratory level. A new approach Consortium members developed a new method for arsenic desorption and sorbent regeneration with no reagents added by taking advantage of the thermodynamic properties of the adsorption system. “Through the fine tuning of such properties it has been possible to apply to the material and the system the required selectivity and regeneration. This reagentless approach allows recovery of the adsorbent, reducing the consumption of chemical reagents and contributing to a cost-efficient process,” explains Dr Valiente. Researchers integrated these solutions into a pilot plant and validated their performance under real working conditions for on-site remote arsenic-polluted water treatment. “The demonstrator follows the principles of sustainable water management and treatment technologies to ensure energy neutrality, minimal chemical consumption, and responsible management,” concludes Dr Valiente. NANOREMOVAS will benefit cattle farmers in Argentina and consumers in the EU and around the world. In addition, the nanostructured materials developed under the auspices of the project will be evaluated for their application to the mining and metallurgical sector as well as the pharmaceutical and chemical industry sectors.
NANOREMOVAS, water, arsenic, cattle, adsorption, nanostructured, regeneration, ion exchange