Life Cycle Environmental Impacts of Wastewater-Derived Phosphorus Products: An Agricultural End-User Perspective (original) (raw)
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Environmental Impacts and Economic Implications of Phosphorus Recovery
2019
The impact of excessive nutrient loading from phosphorus (P) and nitrogen (N) is one of the most pervasive and challenging environmental issues in the United States. However, with growing concern for the longevity of global phosphate rock stores there is also interest in recovering these nutrients. One potential piece of sustainable nutrient management is the recovery of P and N from wastewater through the precipitation of magnesium ammonium phosphate (NH4MgPO4 ∙ 6H2O), or struvite. However, a potential concern is that the environmental impacts struvite recovery creates through the use of additional chemicals and energy are not offset by its benefits. A well-established method for assessing the environmental impacts of products and processes is life cycle assessment (LCA), which can provide information about impacts in a variety of different environmental categories. In conventional decision making processes these environmental impacts are usually only a small part of the considerat...
Innovations of phosphorus sustainability: implications for the whole chain
Frontiers of Agricultural Science and Engineering, 2019
Phosphorus (P) is a non-renewable resource, therefore ensuring global food and environmental security depends upon sustainable P management. To achieve this goal, sustainable P management in the upstream and downstream sectors of agriculture from mineral extraction to food consumption must be addressed systematically. The innovation and feasibility of P sustainability are highlighted from the perspective of the whole P-based chain, including the mining and processing of P rock, production of P fertilizers, soil and rhizosphere processes involving P, absorption and utilization of P by plants, P in livestock production, as well as flow and management of P at the catchment scale. The paper also emphasizes the importance of recycling P and the current challenges of P recovery. Finally, sustainable solutions of holistic P management are proposed from the perspective of technology improvement with policy support.
Life cycle assessment of phosphorus alternatives for Swedish agriculture
Resources, Conservation and Recycling, 2012
Phosphorus is an important nutrient in plant cultivation. Global reserves of phosphate rock worth mining are limited. Reuse of phosphorus in wastewater is therefore important. This LCA study assessed the environmental impact of four ways to supply Swedish agriculture with phosphorus fertiliser of acceptable quality as regards cadmium content: mineral fertiliser; certified sewage sludge; struvite (MgNH 4 PO 4 ·6H 2 O) precipitated from wastewater; and phosphorus recovered from sludge incineration. These were examined with respect to impacts on global warming, eutrophication, energy demand and cadmium flows to farmland. The functional unit chosen was 11 kg P (25.2 kg P 2 O 5 ) to agricultural land, which was the average phosphorus output (removal with harvest) per hectare from Swedish farmland in 2007. Using sewage sludge directly on farmland was the most efficient option in terms of energy and emissions of greenhouse gases, but also added most cadmium to the soil. Phosphorus recovery from incinerated sludge was the most energy demanding option and gave most emissions of greenhouse gases. Despite great concerns about cadmium in Swedish fertilisers and sludge, it was found that almost no regular analyses for cadmium are made on imported food by the authorities, although food imports are constantly increasing. Total imports of cadmium with food are therefore unknown.
Phosphorus recovery and recycling from waste: An appraisal based on a French case study
Resources, Conservation and Recycling, 2014
Phosphate rocks, used for phosphorus (P) fertilizer production, are a non-renewable resource at the human time scale. Their depletion at the global scale may threaten global food and feed security. To prevent this depletion, improved P resource recycling from food chain waste to agricultural soils and to the food and feed industry is often presented as a serious option. However, waste streams are often complex and their recycling efficiency is poorly characterized. The aim of this paper is to estimate the P recovery and recycling potential from waste, considering France as a case study. We assessed the P flows in food processing waste, household wastewater and municipal waste at the country scale using a substance flow analysis for the year 2006. We also quantified the P recycling efficiency as the fraction of P in waste that ultimately reached agricultural soils or was recycled in the food and feed industry. Efforts were made to limit data uncertainty by cross-checking multiple data sources concerning P content in waste materials. Results showed that, in general, P recovery in waste was high but that the overall P recycling efficiency was only 51% at the country scale. In particular, P recycling efficiency was 75% for industrial waste, 43% for household wastewater and 47% for municipal waste. The remaining P was discharged into water bodies or landfilled, causing P-induced environmental problems as well as losses of nutrient resources. Major P losses were through food waste (which amounted to 39% of P in available food) and treated wastewater, and the findings were confirmed through cross-checking with alternative data sources. Options for improving P resource recycling and, thereby, reducing P fertilizer use were quantified but appeared to be less promising than scenarios based on reduced food waste or redesigned agricultural systems.
Journal of Cleaner Production, 2022
This confluence of events has led to the development of technologies for phosphorus recovery from dairy wastewater. This study aims to inform and guide such development with regard to life cycle environmental impacts prior to their implementation in dairy contexts. With the lack of inventory data at this point and the non-existence of earlier life cycle assessments on the use of phosphorus recovery technologies in a dairy context in literature, we performed a meta-analysis where we extracted and compared published results on life cycle environmental impacts from two fields (1) dairy industries, with a focus on the dairy wastewater treatment and (2) phosphorus recovery technologies in a municipal wastewater treatment context. The results show that despite its intended effect, normal dairy wastewater treatment in many cases still contributes significantly to eutrophication. Most of the phosphorus recovery technologies examined here exhibited a lower global warming potential and cumulative energy demand than those of dairy wastewater treatment processes. It indicates that problem shifting could be avoided when phosphorus recovery is introduced. However, no technologies involving incineration have had the impact of acidification reported which represents a potential knowledge gap since impacts are expected related to incineration emissions. A comparison between the extracted data for phosphorus recovery technologies shows that there are lower impacts related to technologies that recover phosphorus from the liquid phase, than from sludge or ash.
Facilitating Phosphorus Recovery Through Improved Waste Management
2016
Phosphorus (P) is an essential resource for global food security, but global supplies are limited and demand is growing. Demand reductions are critical for achieving P sustainability, but recovery and re-use is also required. Wastewater treatment plants and livestock manures receive considerable attention for P recovery, but municipal organic waste is another important source of P to address. Previous research identified the importance of diverting this waste stream from landfills for recovering P, but little has been done to identify the collection and processing mechanisms required, or address the existing economic barriers. In my research, I conducted a current state assessment of organic waste management by creating case studies in Phoenix, AZ and New Delhi, India, and surveyed biomass energy facilities throughout the US. With participation from waste management professionals I also envisioned an organic waste management system that contributes to sustainable P while improving e...
Sustainability
Phosphorus (P), being one of the building blocks of life, is essential for a multitude of applications, primarily for fertilizer usage. Sustainable management of phosphorus is becoming increasingly important in light of adverse environmental effects, ambiguous reserves, increasing global demand and unilateral dependence. Recovery of phosphorus from the biggest loss stream, communal wastewater, has the potential to tackle each of these problems. The implementation of phosphorus recovery technologies at wastewater treatment plants is not widespread, despite prolonged efforts primarily done by researchers over the past decade. This study aimed to assess the drivers and barriers of a phosphorus recovery transition. Several key stakeholders involved in this transition in The Netherlands were interviewed. The Netherlands was taken as a case study, since it serves as a frontrunner in the implementation of phosphorus recovery technologies. This study shows that the main barriers from the point of view of fertilizer companies are the different and unclear characteristics of the phosphorus recovery product struvite compared to common fertilizers. Moreover, the end-of-waste status of struvite is mentioned as a prominent barrier for a phosphorus transition, since it hinders free market trade. Many water boards indicate that the main barrier is the high investment cost with an uncertain return on investment for onsite struvite recovery processes. The specified main driver for water boards for onsite struvite phosphorus recovery technology is the reduction of maintenance costs, and for phosphorus recovery from sewage sludge ash, the low organic pollutant in the P recovery product.
Second-Generation Phosphorus: Recovery from Wastes towards the Sustainability of Production Chains
Sustainability
Phosphorus (P) is essential for life and has a fundamental role in industry and the world food production system. The present work describes different technologies adopted for what is called the second-generation P recovery framework, that encompass the P obtained from residues and wastes. The second-generation P has a high potential to substitute the first-generation P comprising that originally mined from rock phosphates for agricultural production. Several physical, chemical, and biological processes are available for use in second-generation P recovery. They include both concentrating and recovery technologies: (1) chemical extraction using magnesium and calcium precipitating compounds yielding struvite, newberyite and calcium phosphates; (2) thermal treatments like combustion, hydrothermal carbonization, and pyrolysis; (3) nanofiltration and ion exchange methods; (4) electrochemical processes; and (5) biological processes such as composting, algae uptake, and phosphate accumula...
This article provides a comprehensive and cross-disciplinary overview of the phosphorus cycle through the wastewater and agri-food system. While mineral phosphorus stocks are finite, the use of mined phosphorus is accompanied with many losses, leading to pollution of water bodies. Recovering phosphorus from human ex-creta can contribute to more efficient use of phosphorus to ensure its availability for food production in the future. Phosphorous can be recovered through different recovery technologies and consequently used in agriculture via different recycling routes. Each recycling route has its own particularities in terms of interactions with technologies, actors and the environment to bring the recovered phosphorus back into agriculture. In this literature review, we adopt a socio-ecological-technical approach to map three phosphorus-recycling routes, via municipal sewage sludge, struvite recovered from municipal wastewater and source-separated urine. We firstly show that improvements are still needed in all three routes for achieving high P recovery efficiency, and a combination of these recycling routes are needed to achieve maximum recovery of phosphorus. Second, we identify key issues for each recycling route that currently limit the use of recovered phosphorus in agriculture. We indicate where interaction between disciplines is needed to improve recycling routes and identify gaps in research on how recovered phosphorus accesses agriculture.