Studies on the potential of inorganic carbon removal and carbon sequestration in seawater through Ca2+addition
This study explored the potential of introducing Ca2+into seawater to remove dissolved inorganic carbon and enhance the oceanic carbon sink.Laboratory simulations under various initial conditions were conducted,by altering the initial pH of seawater,Mg/Ca ratio,and introducing seeding nuclei,monitor the changes in seawater pH,DIC,and TA regularly.Results indicated that the introduction of Ca2+effectively reduced the magnesium-to-calcium ratio(5.2)in natural ocean and increased the oversaturation of calcium carbonate,thereby facilitating the removal of inorganic carbon from the marine system.Furthermore,the efficacy of inorganic carbon removal with calcium-containing compounds was positively correlated with the initial pH of seawater.However,solely elevating seawater pH was insufficient to induce calcium carbonate formation;additional Ca2+introduction was necessary to enhance calcium carbonate oversaturation for significant inorganic carbon removal.Additionally,the study revealed that inducing non-homogeneous precipitation through the addition of specific nuclei further promotes calcium carbonate generation,thereby improving inorganic carbon removal from seawater.The research findings indicated that under the conditions of adding 45mmol/L of Ca2+and montmorillonite nuclei,with an initial pH of 8.5,the maximum amount of calcium carbonate generated can reach 959μmol/L.The removal of inorganic carbon from seawater,leading to the short-term absorption of atmospheric CO2and increased oceanic carbon sink,offers a novel perspective and theoretical foundation for exploring ocean carbon enhancement technologies.
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维普
