Chiara Belloni, Mohanakrishnan Logan, Stefano Papirio, Piet N. L. Lens
{"title":"Simultaneous removal of critical rare earth elements and chalcogen oxyanions by anaerobic granular sludge","authors":"Chiara Belloni, Mohanakrishnan Logan, Stefano Papirio, Piet N. L. Lens","doi":"10.1007/s12598-024-02726-5","DOIUrl":null,"url":null,"abstract":"<p>Conventional mining of economically and strategically important critical rare earth elements (REEs) (such as neodymium, lanthanum and dysprosium), and chalcogens (such as selenium and tellurium) are associated with a huge economic and environmental cost. Therefore, the need to recover REEs as well as chalcogens from different waste streams including wastewaters is becoming urgent. Batch assays on synthetic chalcogen/REE-laden wastewater showed that the presence of REEs significantly improved the tellurite removal rate (> 80%) and enhanced selenate removal by 66% ± 10%. Three 3.9 L continuous upflow anaerobic granular sludge bed (UASB) reactors were operated at a hydraulic retention time of 24 h and 30 °C. Selenate reduction was achieved with a removal efficiency of ~ 98% with an influent pH of 4.0 for more than 28 days. The effect of REEs on tellurite removal in the UASB bioreactor could not be clearly established since a soluble tellurium removal efficiency of more than 98% was observed already before the addition of REEs at elevated tellurite concentrations. The complete REE removal in both batch assays and UASB reactors at higher pH (7.0 ± 0.5) was attributed to precipitation, whereas chalcogen oxyanions removal was due to microbial reduction. However, at acidic pH, biosorption was responsible for REE’s removal, and the Se-enriched sludge exhibited a superior REE’s removal efficiency than the non-enriched and Te-enriched sludge.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\n","PeriodicalId":749,"journal":{"name":"Rare Metals","volume":null,"pages":null},"PeriodicalIF":9.6000,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Rare Metals","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1007/s12598-024-02726-5","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Conventional mining of economically and strategically important critical rare earth elements (REEs) (such as neodymium, lanthanum and dysprosium), and chalcogens (such as selenium and tellurium) are associated with a huge economic and environmental cost. Therefore, the need to recover REEs as well as chalcogens from different waste streams including wastewaters is becoming urgent. Batch assays on synthetic chalcogen/REE-laden wastewater showed that the presence of REEs significantly improved the tellurite removal rate (> 80%) and enhanced selenate removal by 66% ± 10%. Three 3.9 L continuous upflow anaerobic granular sludge bed (UASB) reactors were operated at a hydraulic retention time of 24 h and 30 °C. Selenate reduction was achieved with a removal efficiency of ~ 98% with an influent pH of 4.0 for more than 28 days. The effect of REEs on tellurite removal in the UASB bioreactor could not be clearly established since a soluble tellurium removal efficiency of more than 98% was observed already before the addition of REEs at elevated tellurite concentrations. The complete REE removal in both batch assays and UASB reactors at higher pH (7.0 ± 0.5) was attributed to precipitation, whereas chalcogen oxyanions removal was due to microbial reduction. However, at acidic pH, biosorption was responsible for REE’s removal, and the Se-enriched sludge exhibited a superior REE’s removal efficiency than the non-enriched and Te-enriched sludge.
期刊介绍:
Rare Metals is a monthly peer-reviewed journal published by the Nonferrous Metals Society of China. It serves as a platform for engineers and scientists to communicate and disseminate original research articles in the field of rare metals. The journal focuses on a wide range of topics including metallurgy, processing, and determination of rare metals. Additionally, it showcases the application of rare metals in advanced materials such as superconductors, semiconductors, composites, and ceramics.