Nutrients in a circular economy: Role of urine separation and treatment

The top priorities for urban water sustainability include the provision of safe drinking water, wastewater handling for public health, and protection against flooding. However, rapidly aging infrastructure, population growth, and increasing urbanization call into question current urban water management strategies, especially in the fast-growing urban areas in Asia and Africa. We review innovative approaches in urban water management with the potential to provide locally adapted, resource-efficient alternative solutions. Promising examples include new concepts for stormwater drainage, increased water productivity, distributed or on-site treatment of wastewater, source separation of human waste, and institutional and organizational reforms. We conclude that there is an urgent need for major transdisciplinary efforts in research, policy, and practice to develop alternatives with implications for cities and aquatic ecosystems alike. Show more

The prospect of sustainable production of food ingredients from photoautotrophic microalgae was reviewed. Clearly, there is scope for microalgal oils to replace functions of major vegetable oils, and in addition to deliver health benefits to food products. Furthermore, with a limited production surface, a substantial portion of the European Union market could be supplied with edible oils and proteins from microalgae. Yet, before microalgal ingredients can become genuinely sustainable and cost effective alternatives for current food commodities, major breakthroughs in production technology and in biorefinery approaches are required. Moreover, before market introduction, evidence on safety of novel microalgal ingredients, is needed. In general, we conclude that microalgae have a great potential as a sustainable feedstock for food commodities. Copyright © 2012 Elsevier Ltd. All rights reserved. Show more