Bioregeneration of sulfate-laden anion exchange resin
|Author:||Virpiranta, Hanna1; Leiviskä, Tiina1; Taskila, Sanna1;|
1University of Oulu, Chemical Process Engineering, PO Box 4300, 90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 4 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2022092159723
|Publish Date:|| 2022-09-21
Ion exchange technology removes ionic compounds from waters effectively but treatment of the spent regenerant is expensive. The bioregeneration of sulfate-laden strong base anion exchange resin was successfully tested using both pure and mixed sulfate-reducing bacterial cultures. The resin was first used for removal of sulfate from neutral (pH 6.7 ± 0.5) synthetic sodium sulfate solutions, after which the spent resin was regenerated by incubating with a viable sulfate-reducing bacterial culture in batch and column modes. In the batch bioregeneration tests, the achieved bioregeneration was 36–95% of the original capacity of the fresh resin (112 mg SO₄ 2−/g) and it increased with regeneration time (1–14 days). The capacity achieved in the column tests during 24 hours of bioregeneration was 107 mg SO₄ 2−/g after the first regeneration cycle. During the bioregeneration, sulfate was mainly reduced by the sulfate-reducing bacteria (approx. 60%), but part of it was only detached from the resins (approx. 30%). The resin-attached sulfate was most likely replaced with ions present in the liquid sulfate-reducing bacterial culture (e.g., HCO₃−, HS−, and Cl−). During the subsequent exhaustion cycles with the bioregenerated resin, the pH of the treated sodium sulfate solution increased from the original 6.7 ± 0.5 to around 9. The study showed that biological sulfate reduction could be used for sulfate removal in combination with ion exchange, and that the exhausted ion exchange resins could be regenerated using a liquid sulfate-reducing bacterial culture without producing any brine.
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
This research was funded by the Finnish Cultural Foundation (Grant ID 00221104) and the KAUTE Foundation (Grant ID 20220052). The study was also part of the Supporting Environmental, Economic and Social Impacts of Mining Activity (KO1030 SEESIMA) research project and received financial support from the Kolarctic CBC (Cross-Border Collaboration), the European Union, Russia, Norway, Finland, and Sweden. Its contents are the sole responsibility of the authors at the University of Oulu, and do not necessarily reflect the views of the European Union or the participating countries. Part of the work was carried out with the support of Biocenter Oulu, University of Oulu, Finland and the Centre for Material Analysis, University of Oulu, Finland.
© 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).