{"title":"Potential of CO2 sequestration by olivine addition in offshore waters: A ship-based deck incubation experiment","authors":"","doi":"10.1016/j.marenvres.2024.106708","DOIUrl":null,"url":null,"abstract":"<div><p>Ocean alkalinity enhancement is considered as an effective atmospheric CO<sub>2</sub> removal approach, but currently, little is known about the carbon sequestration potential of implementing olivine addition in offshore waters. We investigated the effect of olivine addition on the seawater carbonate system by carrying out a deck incubation experiment in the Northern Yellow Sea; the dissolution rate of olivine was calculated based on the increase in seawater alkalinity (TA), and the CO<sub>2</sub> sequestration potential was evaluated. The results showed that the dissolution of olivine increased seawater TA and decreased partial pressure of CO<sub>2</sub>, resulting in oceanic CO<sub>2</sub> uptake from the atmosphere through sea-air exchange; it also increased seawater pH and mitigated ocean acidification to a certain extent. The addition of 1 ‰ olivine had a more significant effect on the seawater carbonate system than 0.5 ‰ olivine addition. The average dissolution rate constant of olivine was 1.44 ± 0.15 μmol m<sup>−2</sup> d<sup>−1</sup>. Assuming that olivine settles completely on the seabed due to gravity, the theoretically maximum amount of CO<sub>2</sub> removed by applying 1 tonne of olivine per square meter area in the Northern Yellow Sea is only 2.0 × 10<sup>−4</sup> t/m<sup>2</sup>. Therefore, when olivine addition is implemented in the offshore waters, it is necessary to consider reducing the olivine size, prolonging the settling time of olivine in the water column; and spreading olivine in well-mixed waters to prolong the residence time through repeated resuspension, thus increasing its potential in carbon sequestration.</p></div>","PeriodicalId":18204,"journal":{"name":"Marine environmental research","volume":null,"pages":null},"PeriodicalIF":3.0000,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Marine environmental research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0141113624003696","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Ocean alkalinity enhancement is considered as an effective atmospheric CO2 removal approach, but currently, little is known about the carbon sequestration potential of implementing olivine addition in offshore waters. We investigated the effect of olivine addition on the seawater carbonate system by carrying out a deck incubation experiment in the Northern Yellow Sea; the dissolution rate of olivine was calculated based on the increase in seawater alkalinity (TA), and the CO2 sequestration potential was evaluated. The results showed that the dissolution of olivine increased seawater TA and decreased partial pressure of CO2, resulting in oceanic CO2 uptake from the atmosphere through sea-air exchange; it also increased seawater pH and mitigated ocean acidification to a certain extent. The addition of 1 ‰ olivine had a more significant effect on the seawater carbonate system than 0.5 ‰ olivine addition. The average dissolution rate constant of olivine was 1.44 ± 0.15 μmol m−2 d−1. Assuming that olivine settles completely on the seabed due to gravity, the theoretically maximum amount of CO2 removed by applying 1 tonne of olivine per square meter area in the Northern Yellow Sea is only 2.0 × 10−4 t/m2. Therefore, when olivine addition is implemented in the offshore waters, it is necessary to consider reducing the olivine size, prolonging the settling time of olivine in the water column; and spreading olivine in well-mixed waters to prolong the residence time through repeated resuspension, thus increasing its potential in carbon sequestration.
期刊介绍:
Marine Environmental Research publishes original research papers on chemical, physical, and biological interactions in the oceans and coastal waters. The journal serves as a forum for new information on biology, chemistry, and toxicology and syntheses that advance understanding of marine environmental processes.
Submission of multidisciplinary studies is encouraged. Studies that utilize experimental approaches to clarify the roles of anthropogenic and natural causes of changes in marine ecosystems are especially welcome, as are those studies that represent new developments of a theoretical or conceptual aspect of marine science. All papers published in this journal are reviewed by qualified peers prior to acceptance and publication. Examples of topics considered to be appropriate for the journal include, but are not limited to, the following:
– The extent, persistence, and consequences of change and the recovery from such change in natural marine systems
– The biochemical, physiological, and ecological consequences of contaminants to marine organisms and ecosystems
– The biogeochemistry of naturally occurring and anthropogenic substances
– Models that describe and predict the above processes
– Monitoring studies, to the extent that their results provide new information on functional processes
– Methodological papers describing improved quantitative techniques for the marine sciences.