Background Overall waste generation is stable in the EU. However, generation of sewage sludge is still increasing, partly as a result of the progressive implementation of the Urban Waste Water Treatment Directive (91/271/EEC). Between 1992 and 2005, production of dry sewage sludge in the EU increased from around 5.5 million tonnes to nearly 9 million tonnes. Current trends suggest that EU27 production will reach 13 million tonnes by 2020. However, by 2020, all waste should be managed as a resource and landfilling of organic material should be virtually eliminated. However, to achieve this for sewage sludge – and avoid landfilling or incineration – new technologies are necessary. These technologies need to take account of the fact that sludge tends to concentrate heavy metals and poorly biodegradable trace organic compounds, as well as potentially pathogenic organisms. Current environmental issues related to the recycling of sewage sludge on land include the risk of nutrient leaching, impacts on soil biodiversity and greenhouse gas emissions. As well as the presence of heavy metals and other inorganic elements, there is also concern over the presence of endocrine disrupting chemicals, including natural and synthetic hormones, and less potent industrial agents such as phthalates. Wastewater treatments need a multidisciplinary approach to addressing water quality, sewage sludge management, pollution - organics, nitrates and phosphorous - derived from sludge application, and the overall water-energy nexus. Objectives The Lo2x project aims to demonstrate the environmental and socio-economic benefits of using WWTPs as a means of resource recovery, not only from sludge but also from other waste streams with similar or worse effects on water quality. It specifically aims to demonstrate a synergic co-treatment of sewage sludge and other wastes - including raw/digested manure, high-load food processing wastes, pesticides and leachates – based on supercritical water oxidation technology, with energy and phosphorous recovery. The project will design and construct a prototype for the oxidation in supercritical water of mixtures of sludge and other wastes. The mix should provide enhanced performance through synergies. The sludge will provide embedded energy from the organic content, manure should provide for phosphorous recovery and ammonia elimination, and food wastes should provide extra carbon. This should enable the complete destruction of organic toxic substances - pesticides and leachates. The beneficiary will work to define optimum operating conditions and mix ratios for best process yield – including optimum recovery of phosphorous - and energy balance. It thus aims to reduce the final amount and environmental impact of waste generated by a WWTP. It also expects to show economic benefits from: reductions in the cost of sludge management – treatment and disposal; exploitation of recovered phosphorous; and improved energy balance. The process thus expects to demonstrate feasible improvements that can contribute to the achievement of European objectives related to: reducing landfill of organic wastes; energy efficiency; water quality; and the European Resource Efficiency Roadmap. Expected results: The successful demonstration of a treatment process for mixed sludge and other wastes based on supercritical water oxidation technology, and achieving: 100% elimination of pesticides; 100% elimination of ammonia; climate neutrality of wastewater systems / positive energy balance; 100% recovery of phosphorous; 90% reduction of sewage sludge leaving the WWTP; complete mineralisation of the final waste (compared to around 55-60% volatile fraction in current dehydrated sludge that has undergone anaerobic digestion); at least a 10% reduction in sludge treatment costs, including investment and running costs.