Electrochemical Ocean Iron Fertilization and Alkalinity Enhancement Approach Toward CO Sequestration

Overview

Journal NPJ Ocean Sustain

Date 2024 Dec 16

PMID 39677975

Authors

Amir Taqieddin

Stephanie Sarrouf

Muhammad Fahad Ehsan

Ken Buesseler

Akram N Alshawabkeh

Affiliations

Soon will be listed here.

Abstract

Achieving net-zero emissions by 2050 requires the development of effective negative emission techniques, including ocean-based approaches for CO sequestration. However, the implementation and testing of marine CO removal (mCDR) techniques such as ocean iron fertilization (OIF) or ocean alkalinity enhancement (OAE) face significant challenges. Herein, a novel self-operating electrochemical technology is presented that not only combines OIF and OAE, but also recovers hydrogen gas (H) from seawater, hence offering a promising solution for achieving quantifiable and transparent large-scale mCDR. Experimental results show that the electrochemical OIF (EOIF) can not only increase the concentration of ferrous iron (Fe) by 0-0.5 mg/L, but also significantly increases the seawater pH by 8% (., a 25% decrease in the hydrogen ions concentration). The release of iron (Fe/Fe) can be regulated by adjusting the magnitude of the electric current and its form (e.g., pulsed current and polarity reversal), as well as by optimizing the electrode material and geometry. In certain ocean regions, enhanced iron concentrations stimulate the naturally occurring biological carbon pump (BCP), leading to increased phytoplankton growth, CO uptake, and subsequent export of carbon to the deep ocean. Simultaneously, the system increases seawater alkalinity and the buffer capacity, enhancing CO solubility and storage in the shallow ocean through the solubility pump. The obtained measurements demonstrate the scalability of EOIF and its ability to operate using solar energy at a lower cost. Overall, the proposed EOIF technology offers a practical, effective, and sustainable solution for addressing climate change on a large scale.

References

Lakshmanan D, Clifford D, Samanta G . Ferrous and ferric ion generation during iron electrocoagulation. Environ Sci Technol. 2009; 43(10):3853-9. DOI: 10.1021/es8036669. View

Buesseler K, Doney S, Karl D, Boyd P, Caldeira K, Chai F . Environment. Ocean iron fertilization--moving forward in a sea of uncertainty. Science. 2008; 319(5860):162. DOI: 10.1126/science.1154305. View

Watson A, Schuster U, Shutler J, Holding T, Ashton I, Landschutzer P . Revised estimates of ocean-atmosphere CO flux are consistent with ocean carbon inventory. Nat Commun. 2020; 11(1):4422. PMC: 7474059. DOI: 10.1038/s41467-020-18203-3. View

Jansson J, Hofmockel K . Soil microbiomes and climate change. Nat Rev Microbiol. 2019; 18(1):35-46. DOI: 10.1038/s41579-019-0265-7. View

Compton P, Dehkordi N, Sarrouf S, Ehsan M, Alshawabkeh A . Electrochemical Synthesis of HO for -nitrophenol Degradation Utilizing a Flow-through Three-dimensional Activated Carbon Cathode with Regeneration Capabilities. Electrochim Acta. 2023; 441. PMC: 9983606. DOI: 10.1016/j.electacta.2022.141798. View

Zhao Y, Hojabri S, Sarrouf S, Alshawabkeh A . Electrogeneration of HO by graphite felt double coated with polytetrafluoroethylene and polydimethylsiloxane. J Environ Chem Eng. 2023; 10(4). PMC: 10035042. DOI: 10.1016/j.jece.2022.108024. View

Zhou W, Rajic L, Meng X, Nazari R, Zhao Y, Wang Y . Efficient HO electrogeneration at graphite felt modified via electrode polarity reversal: Utilization for organic pollutants degradation. Chem Eng J. 2020; 364:428-439. PMC: 7314056. DOI: 10.1016/j.cej.2019.01.175. View

Blain S, Queguiner B, Armand L, Belviso S, Bombled B, Bopp L . Effect of natural iron fertilization on carbon sequestration in the Southern Ocean. Nature. 2007; 446(7139):1070-4. DOI: 10.1038/nature05700. View

Tong M, Yuan S, Zhang P, Liao P, Alshawabkeh A, Xie X . Electrochemically induced oxidative precipitation of Fe(II) for As(III) oxidation and removal in synthetic groundwater. Environ Sci Technol. 2014; 48(9):5145-53. PMC: 6321744. DOI: 10.1021/es500409m. View

10.

Pollard R, Salter I, Sanders R, Lucas M, Moore C, Mills R . Southern Ocean deep-water carbon export enhanced by natural iron fertilization. Nature. 2009; 457(7229):577-80. DOI: 10.1038/nature07716. View

11.

Mazzotta M, McIlvin M, Saito M . Characterization of the Fe metalloproteome of a ubiquitous marine heterotroph, Pseudoalteromonas (BB2-AT2): multiple bacterioferritin copies enable significant Fe storage. Metallomics. 2020; 12(5):654-667. PMC: 8161647. DOI: 10.1039/d0mt00034e. View

12.

Tian Y, Zeng G, Rutt A, Shi T, Kim H, Wang J . Promises and Challenges of Next-Generation "Beyond Li-ion" Batteries for Electric Vehicles and Grid Decarbonization. Chem Rev. 2020; 121(3):1623-1669. DOI: 10.1021/acs.chemrev.0c00767. View

13.

Boyd P, Watson A, Law C, Abraham E, Trull T, Murdoch R . A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization. Nature. 2000; 407(6805):695-702. DOI: 10.1038/35037500. View

14.

Mao X, Baek K, Alshawabkeh A . IRON ELECTROCOAGULATION WITH ENHANCED CATHODIC REDUCTION FOR THE REMOVAL OF AQUEOUS CONTAMINANT MIXTURES. Environ Eng Manag J. 2019; 14(12):2905-2911. PMC: 6703562. View

15.

Breyer C . Low-cost solar power enables a sustainable energy industry system. Proc Natl Acad Sci U S A. 2021; 118(49). PMC: 8670524. DOI: 10.1073/pnas.2116940118. View

16.

Amelung W, Bossio D, de Vries W, Kogel-Knabner I, Lehmann J, Amundson R . Towards a global-scale soil climate mitigation strategy. Nat Commun. 2020; 11(1):5427. PMC: 7591914. DOI: 10.1038/s41467-020-18887-7. View

17.

Kuang Y, Kenney M, Meng Y, Hung W, Liu Y, Huang J . Solar-driven, highly sustained splitting of seawater into hydrogen and oxygen fuels. Proc Natl Acad Sci U S A. 2019; 116(14):6624-6629. PMC: 6452679. DOI: 10.1073/pnas.1900556116. View

18.

Baek K, Ciblak A, Mao X, Kim E, Alshawabkeh A . Iron anode mediated transformation of selenate in sand columns. Water Res. 2013; 47(17):6538-45. PMC: 6886739. DOI: 10.1016/j.watres.2013.08.018. View

19.

Shaked Y, Lis H . Disassembling iron availability to phytoplankton. Front Microbiol. 2012; 3:123. PMC: 3328120. DOI: 10.3389/fmicb.2012.00123. View

20.

Wilberforce T, Baroutaji A, Soudan B, Al-Alami A, Olabi A . Outlook of carbon capture technology and challenges. Sci Total Environ. 2018; 657:56-72. DOI: 10.1016/j.scitotenv.2018.11.424. View