{"title":"Economic feasibility and direct greenhouse gas emissions from different phosphorus recovery methods in Swedish wastewater treatment plants","authors":"","doi":"10.1016/j.spc.2024.07.007","DOIUrl":null,"url":null,"abstract":"<div><p>Phosphorus (P) is a finite, non-renewable resource that is a critical component of fertilizers; therefore, recovering P from municipal wastewater can provide an alternative sustainable source of this nutrient. This work analyses economic impacts and greenhouse gas emissions of P recovery in Swedish municipal wastewater treatment plants. The study examines different scenarios, including P recovery technologies in individual plants and hubs, and considers various P-rich streams (supernatant, sludge, and ash) in plants, different plant sizes, and multiple sludge management strategies such as land application, incineration, and hydrochar production, under current market conditions. The goal is to identify and offer solutions tailored to local conditions, addressing both technical opportunities and strategies to reduce costs.</p><p>The results show varying recovery rates: 5 % from supernatant, 36–65 % from sludge, and 17 % from sludge ash relative to total P in wastewater. Despite technical feasibility, P recovery costs are not covered at current market prices of P, indicating a lack of financial incentive, especially for smaller treatment plants. The least expensive recovery method costs about 7 k€/t P for ash, compared to 30–187 k€/t P for supernatant, however with the latter coming with the co-benefit of mitigated greenhouse gas emissions. The emissions from studied plants range from 84 to 123 kt CO<sub>2</sub> eq (CO<sub>2</sub> equivalent) for supernatant, 94–141 kt CO<sub>2</sub> eq for sludge, and 75–102 kt CO<sub>2</sub> eq for ash among different P recovery methods. Comparatively, P recovery methods from supernatant showed the lowest emissions, while the lower emissions range for ash is due to the consideration of fewer plants. Developing hub networks and converting sludge into products like hydrochar are crucial for attracting investments, enhancing P recovery, and leveraging economies of scale. Results highlight the urgency for localized strategies and proactive policy interventions to reconcile economic and environmental objectives in P recycling. Furthermore, P recovery from wastewater treatment plants, although more resource-intensive than mineral fertilizer, promotes circularity in the food chain and mitigates the risk of eutrophication.</p></div>","PeriodicalId":48619,"journal":{"name":"Sustainable Production and Consumption","volume":null,"pages":null},"PeriodicalIF":10.9000,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2352550924001994/pdfft?md5=8b5200f331972c6b48541624a1d6c1fb&pid=1-s2.0-S2352550924001994-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sustainable Production and Consumption","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352550924001994","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL STUDIES","Score":null,"Total":0}
引用次数: 0
Abstract
Phosphorus (P) is a finite, non-renewable resource that is a critical component of fertilizers; therefore, recovering P from municipal wastewater can provide an alternative sustainable source of this nutrient. This work analyses economic impacts and greenhouse gas emissions of P recovery in Swedish municipal wastewater treatment plants. The study examines different scenarios, including P recovery technologies in individual plants and hubs, and considers various P-rich streams (supernatant, sludge, and ash) in plants, different plant sizes, and multiple sludge management strategies such as land application, incineration, and hydrochar production, under current market conditions. The goal is to identify and offer solutions tailored to local conditions, addressing both technical opportunities and strategies to reduce costs.
The results show varying recovery rates: 5 % from supernatant, 36–65 % from sludge, and 17 % from sludge ash relative to total P in wastewater. Despite technical feasibility, P recovery costs are not covered at current market prices of P, indicating a lack of financial incentive, especially for smaller treatment plants. The least expensive recovery method costs about 7 k€/t P for ash, compared to 30–187 k€/t P for supernatant, however with the latter coming with the co-benefit of mitigated greenhouse gas emissions. The emissions from studied plants range from 84 to 123 kt CO2 eq (CO2 equivalent) for supernatant, 94–141 kt CO2 eq for sludge, and 75–102 kt CO2 eq for ash among different P recovery methods. Comparatively, P recovery methods from supernatant showed the lowest emissions, while the lower emissions range for ash is due to the consideration of fewer plants. Developing hub networks and converting sludge into products like hydrochar are crucial for attracting investments, enhancing P recovery, and leveraging economies of scale. Results highlight the urgency for localized strategies and proactive policy interventions to reconcile economic and environmental objectives in P recycling. Furthermore, P recovery from wastewater treatment plants, although more resource-intensive than mineral fertilizer, promotes circularity in the food chain and mitigates the risk of eutrophication.
期刊介绍:
Sustainable production and consumption refers to the production and utilization of goods and services in a way that benefits society, is economically viable, and has minimal environmental impact throughout its entire lifespan. Our journal is dedicated to publishing top-notch interdisciplinary research and practical studies in this emerging field. We take a distinctive approach by examining the interplay between technology, consumption patterns, and policy to identify sustainable solutions for both production and consumption systems.