Arno Rosemarin

Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options

Human intervention in the global phosphorus cycle has mobilised nearly half a billion tonnes of the element from phosphate rock into the hydrosphere over the past half century. The resultant water pollution concerns have been the main driver for sustainable phosphorus use (including phosphorus recovery). However the emerging global challenge of phosphorus scarcity with serious implications for future food security, means phosphorus will also need to be recovered for productive reuse as a fertilizer in food production to replace increasingly scarce and more expensive phosphate rock. Through an integrated and systems framework, this paper examines the full spectrum of sustainable phosphorus recovery and reuse options (from small-scale low-cost to large-scale high-tech), facilitates integrated decision-making and identifies future opportunities and challenges for achieving global phosphorus security. Case studies are provided rather than focusing on a specific technology or process. There is no single solution to achieving a phosphorus-secure future: in addition to increasing phosphorus use efficiency, phosphorus will need to be recovered and reused from all current waste streams throughout the food production and consumption system (from human and animal excreta to food and crop wastes). There is a need for new sustainable policies, partnerships and strategic frameworks to develop renewable phosphorus fertilizer systems for farmers. Further research is also required to determine the most sustainable means in a given context for recovering phosphorus from waste streams and converting the final products into effective fertilizers, accounting for life cycle costs, resource and energy consumption, availability, farmer accessibility and pollution.

Liming and reacidification reactions of a forest lake ecosystem, lake Lysevatten, in SW Sweden

Long-term monitoring, 1973 to 1987, of reactions to liming and reacidification of a forest lake ecosystem near the Swedish west coast is reported in this study. Treatment of Lake Lysevatten with a slag product of limestone in 1974 resulted in neutralization and a positive alkalinity. Prolonged dissolution proceeded for about 7 yr whereby 86% dissolved. During 1984–86 Lake Lysevatten approached maximum reacidification with high Al concentrations and an affected biota. Asellus aquaticus L. decreased and dominance within chironomid groups approached preliming conditions. However, the most obvious biological change was the development of the filamentous algal genus Mougeotia and increased growth of Sphagnum. Populations of both plants increased notably when pH declined to about 5. Our study suggests that extensive reacidification (pH < 6.0) of limed lakes should be avoided by successive treatments to prevent development of destabilized lake ecosystems.

Pathways for Sustainable Sanitation: Achieving the Millennium Development Goals

The report is a product arising from the work of the Sustainable Sanitation Alliance which was initiated prior to the International Year of Sanitation in 2008 in an attempt to inject sustainable development ideas into the sanitation sector. It functions as a vision document for those policymakers, researchers and practitioners that are striving towards fundamental reform and improvements within the sanitation sector in both rural and urban populations in all countries of the world. It reviews the global progress being made towards achieving the Millennium Development Goal (MDG) target on sanitation. A literature review is presented on sanitation provision including human health impacts and the estimated costs and benefits of achieving the MDG target. The report also provides a critique in that the UN has not yet introduced the concept of sustainability into the MDG programme in general and in particular into the sanitation sector which is highly dysfunctional and suffering from limited political leadership at both the local and global levels. It introduces the various sustainable sanitation options available and what approaches can be taken to improve sanitation systems – not just toilets which are only a small part of the overall system of food, nutrients and water cycles. The study estimates the numbers of urban and rural households, including slum populations that are being targeted in all world regions. It also evaluates the historic trends in morbidity and mortality linked to diarrhoea arising from lack of functioning sanitation services comparing these to the UN data on sanitation coverage. The report estimates the potential fertiliser replacement capacity that reuse of human excreta can have for all world regions. Finally it provides a vision for future development within the sector where more sustainable options like source separation and reuse are promoted giving positive environmental or “green” impacts but also catalysing greater involvement and understanding on the part of individuals in society.

Evaluating the Sustainability of an Innovative Dry Sanitation (Ecosan) System in China as Compared to a Conventional Waterborne Sanitation System

The use of sustainability indicators for evaluating sanitation systems is applied to the Erdos EcoTown Project (EETP) in China for illustration. The EETP is the largest urban settlement in the world employing ecological sanitation, which incorporates separation of waste streams, dry toilets, and resource recovery. The EETP’s dry sanitation system is compared against the Dongsheng District’s conventional sewer and centralised STP. The two systems are compared based on technological, environmental, economic, and societal indicators. Overall, the two systems perform reasonably well from a technological perspective. The conventional system performs significantly better than the dry system with regards to land and energy requirements, and global warming potential; it also performs better based on freshwater aquatic and terrestrial ecotoxicity potentials, but by a smaller margin. The dry system has superior environmental performance based on water consumption, eutrophication potential, and nutrient and organic matter recovery. The dry system is a more costly system as it requires greater infrastructure and higher operational costs, and does not benefit from economies of scale. The waterborne system performs better based on the societal indicators largely because it is a well-established system.

The governance gap surrounding phosphorus

There are gaps in the governance of phosphorus (P) across the value chain components (from “mine to fork”), within the monitoring and regulation of these components, and surrounding the role of stakeholders in the process. As a result the intrinsic objectives of a governance system for P are not well formulated and yet to be implemented. Phosphorus is a mineral and is produced and marketed much like other minerals. But since P is also an essential element in our food systems, critical for all forms of life and very dispersed in different products, it requires special attention concerning data collaboration especially regarding rock phosphate (RP) commercial reserves and potential resources. Policy leadership in this area is lacking and the world has no independent source of data or a governance system set up to provide independent monitoring of the knowledge and resource base. The science of P governance benefits from a review of how other minerals have been governed but also by taking a multi-level governance perspective to unpack the complexities. This study reviews key interacting factors affecting the need for governance including common perceptions surrounding P and fertilizers among producers and consumers, the highly skewed distribution of the global resource, the absence of the UN system in monitoring availability and consumption of RP resulting in uncertainty about the size of the commercial reserves, and the inefficiencies in various steps in the phosphate value chain from “mine to fork”. The paper provides an overview of governance opportunities including the realms of mining, agriculture and waste management, the respective parameters worth monitoring and regulating, the stakeholders involved and the associated objectives of the resulting improved governance. It provides some suggestions for policy priorities and a staged process of steps to achieve progress.