A meta-analysis of LCAs for environmental assessment of a conceptual system: Phosphorus recovery from dairy wastewater (original) (raw)
Related papers
2022
Recovering phosphorus from wastewater in more concentrated forms has potential to sustainably recirculate phosphorus from cities to agriculture. The environmental sustainability of wastewater-based phosphorus recovery processes or wastewater-derived phosphorus products can be evaluated using life cycle assessment (LCA). Many LCA studies used a process perspective to account for the impacts of integrating phosphorus recovery processes at wastewater treatment plants, while some used a product perspective to assess the impacts of producing wastewaterderived phosphorus products. We demonstrated the application of an end-user perspective by assessing life cycle environmental impacts of substituting half of the conventional phosphorus rock-based fertilizers used in three crop production systems with wastewaterderived phosphorus products from six recovery pathways (RPs). The consequential LCA results show that the substitution reduces global warming potential, eutrophication potential, ecotoxicity potential, and acidification potential of the assessed crop production systems in most RPs and scenarios. The end-user perspective introduced in this study can (i) complement with the process perspective and the product perspective to give a more holistic picture of environmental impacts along the "circular economy value chains" of wastewater-based resource recovery, (ii) enable systemwide assessment of wide uptake of wastewater-derived products, and (iii) draw attention to understanding the long-term environmental impacts of using wastewater-derived products.
Water Environment Research, 2011
Phosphorus can be removed from wastewater biologically, chemically, or through a combination of the two. In this study, we applied environmental life-cycle assessment to develop a metric with which decision-makers can compare processes. Two phosphorus-removal scenarios were contrasted-one based on a desktop-level design and one based on full-scale operational data. To achieve 0.5 mg/L effluent phosphorus (desktop design), a biological-only process would incur 5.2% less effect on global warming potential, as contrasted with a chemical-only process. At an effluent quality of 0.1 mg/L (full-scale facilities), where a biological process augmented with chemicals was contrasted with a chemical-only process, the relative gap increases to 13.2%. As chemical usage increased, the adverse environmental effect of chemical treatment only increased. The results of this study suggest that best practices would center phosphorus removal first on the biological process, with chemical processes added only as necessary. Water Environ. Res., 83, 750 (2011).
Energy demand for phosphorus recovery from municipal wastewater
Energy Procedia, 2019
Phosphorus (P) is one of the essential nutrients for production of food. In modern agriculture, a large part of P comes from finite sources. There are several suggested processes for reuse of P from wastewater. In this paper, the energy use of direct reuse of sludge in agriculture is compared to the energy demand connected to use of mineral P and to reuse of P after thermal processing of sludge. The study is based on literature data from life cycle analysis (LCA). In the case of direct sludge reuse the sludge stabilization processes applied and the system boundaries of the LCA has a large impact on the calculated energy demand. The results though indicate that direct reuse of sludge in agriculture is the reuse scenario that potentially has the lowest energy demand (3-71 kWh/kg P), compared to incineration and extraction of P from sludge ashes (45-70 kWh/kg P) or pyrolysis of sludge (46-235 kWh/kg P). The competitiveness compared to mineral P (-4-22 kWh/kg P) depends on the mineral P source and production. For thermal processing, the energy demand derives mainly from energy needed to dry sludge and supplement fuel used during sludge incineration together with chemicals required to extract P. Local conditions, such as available waste heat for drying, can make one of these scenarios preferable.
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.
Enhanced Biological Phosphorus Removal for Liquid Dairy Manure
2008 Providence, Rhode Island, June 29 - July 2, 2008, 2008
Enhanced biological phosphorus removal (EBPR) has been widely used in municipal wastewater treatment, but no previous studies have examined the application of EBPR to treat dairy manure. This study was conducted to evaluate the (i) performance of pilot-scale EBPR systems treating liquid dairy manure, to balance the ratio of nitrogen to phosphorus in manure to meet crop nutrient requirements, (ii) effects of dissolved oxygen and solids retention time on the efficiency of EBPR, and (iii) I would like to express my appreciation to my advisor, Dr. Jactone Arogo, for his time and guidance throughout this research. I would also like to thank my committee members, Dr. Katharine F. Knowlton and Dr. Amy J. Pruden, for their invaluable comments and assistance in my study. I am very grateful to Dr. Clifford W. Randall and Dr. Chao Shang for their time and patience to answer my questions. I am very appreciative of Hope White, Jody Smiley and Julie Jordan for being so supportive and helpful, when I was using IC, GC and other facilities in their labs. I want to thank Karen Hall for her hard work and continuous support for my sample analysis. Also, I want to thank Monika Corbett and Jo DeBusk for kindly teaching me many laboratory skills. Many thanks go to Lifeng Li for his tremendous support, help and encouragement during my graduate studies. Finally, I would like to extend thanks to Sonja Galley,
Phosphorus recovery from domestic wastewater: A review of the institutional framework
Journal of Environmental Management, 2024
Phosphorus (P) is an essential element for life that must be managed sustainably. The institutional framework for P recovery from wastewater includes policies, regulations, plans, and actions that promote the recovery, recycling, and safe use of this element, aimed at moving toward more sustainable nutrient management and environmental protection. This review analyzes the status of the institutional framework for P recovery from wastewater in different countries around the world. Europe is the continent where the most progress has been made in terms of legislation. Countries such as Germany, the Netherlands, Austria, and Denmark have already implemented policies and regulations that promote environmental protection, as well as P recovery and reuse. In other parts of the world, such as the United States, China, and Japan, there have also been significant advances in promoting the closure of the P cycle, with the implementation of advanced recovery technologies in wastewater treatment plants and regional/national action plans. By contrast, in Latin America there has been little progress in P treatment and recovery, with a weak regulatory framework, unclear goals, and insufficient allocation of techno-economic resources. In this context, it is necessary to reinforce the comprehensive institutional framework, which covers technological aspects, economic incentives, political agreements, and regulations, to promote the sustainable management of this valuable resource.
Water Science and Technology, 2017
To provide input to sewage sludge management strategies that address expected new regulations in terms of hygienisation and phosphorus recovery in Sweden, an environmental life cycle assessment (LCA) was made. The LCA identified environmental hot spots for methods that may permit sludge or phosphorus from sludge to be applied on agricultural land. In particular, thermophilic digestion, pasteurisation, thermal hydrolysis, urea treatment and mono-incineration with phosphorus recovery were compared. In addition, a sludge management system involving drying of sludge before use in forestry was investigated. The results showed that some major impacts are related to large uncertainties, such as those related to emissions from sludge storage. It also showed that large gains can be achieved when products from the systems replace other products, in particular when biogas is used to replace natural gas in vehicles, but also when sludge is used in agriculture and forestry. In general, there are...
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...
Journal of Dairy Science, 2008
A major source of environmental pollution has been overfeeding P to dairy cows, caused by the "safety margins" added to diets in order not to compromise the health and production of animals. An extant whole-animal model was evaluated using an experiment conducted in Ontario to assess its applicability for predicting P excretion. The objective of the study was to use the model to estimate P excretion levels and the economic and environmental implications of implementing mitigating options by following recommendations from studies that have reported sufficient levels of P inclusion in the diet. Mean square prediction error and concordance coefficient analysis showed that the overall predictions were close to the mean and that there was only a slight underprediction of fecal P output by the model. The majority of the error was random, with only 8.9% coming from error caused by deviation from the regression line, and the model did not show a systematic trend of overor underprediction. The model was then used to predict P excretion in Ontario by using diets commonly fed to dairy cows on Ontario farms. It is estimated that Ontario dairy farms produce 7 kt of P annually at current levels of P inclusion in the diet. Reducing P levels from the current 0.41% P of dry matter to 0.35% is estimated to save producers CAN $20/cow per year and the environment 1.3 kt/yr without impairing cow health or productivity. Additionally, the reductions might be from inorganic P sources added to the feed, which are more polluting than organic sources because of their water-soluble nature and liability to leaching and runoff.
The Nutrient-Energy-Water Technology (N-E-W Tech TM) system is an emerging and innovative process with the primary objective of addressing the food-energy-water nexus. The system utilizes novel biochar-catalytic oxidation-reactive filtration as means of recovering nitrogen, phosphorus, and clean water from wastewater resources. The ongoing research surrounding this system is looking both towards new ways to molecularly bind phosphorus and nitrogen to a functionalized biochar and disinfect water resources in order to produce reusable water and a nutrient rich soil amendment for agricultural applications. Nutrient enriched biochar used as a soil amendment will sequester carbon from the atmosphere while offsetting the demand for fertilizers produced through mining and industrial processing. The intention of this project is to conduct a life cycle analysis surrounding the N-E-W Tech system. Life cycle analysis is a cradle-to-grave analysis and establishes benchmark of the energy required to operate the system, energy efficiency optimization opportunities, and an analysis of potential reductions in the harvesting of natural resources. Additionally, due to the potential offsets in the demand for natural resource extraction, a reduction in greenhouse gas emissions released into the atmosphere via the mining, processing, and production of agricultural fertilizers. Currently, the N-E-W Tech system can achieve full operations utilizing approximately 5.7 kW of electricity and is capable of processing 1000 gallons (12 gpm) of waste water for approximately 0.60 dollars. Furthermore, the system has state-of-the-art removal of total phosphorus to 0.006 mg/L when treating secondary municipal waste water. Analysis regarding the global warming potential (GWP) showed that the combined net GWP of the inputs and outputs of the system was approximately 6.07216 pounds CO2 equivalent.