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Influence of Calcium Concentration and Dosage Regime on Calcification Mediated Dissolved Inorganic Carbon Capture Efficiency
Author(s) -
Mahanty Biswanath,
Kim Subin,
Kim Chang Gyun
Publication year - 2015
Publication title -
clean – soil, air, water
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 66
eISSN - 1863-0669
pISSN - 1863-0650
DOI - 10.1002/clen.201400008
Subject(s) - chemistry , calcium , precipitation , kinetics , calcification , saturation (graph theory) , reaction rate constant , dissolved organic carbon , nuclear chemistry , phosphate , mineralogy , inorganic chemistry , analytical chemistry (journal) , chromatography , biochemistry , environmental chemistry , organic chemistry , mathematics , medicine , physics , pathology , quantum mechanics , combinatorics , meteorology
Calcification mediated dissolved inorganic carbon (DIC) sequestration, in the form of insoluble CaCO 3 , is an environmentally important geochemical process. In this study, the influence of calcium concentration and its dosing regime (single vs. partitioned multiple additions) on DIC capture efficiency (mole of DIC loss per mole of soluble calcium consumed, i.e. ∆DIC/∆Ca 2+ ) and calcification kinetics has been investigated. For this purpose, liquid medium containing 80 mM DIC, generated through microbial ureolysis, was dosed with either varying amount of initial Ca 2+ (50–300 mM) or 300 mM Ca 2+ equivalent in three equally partitioned doses with the intermittent removal of the precipitate. The analysis of precipitation kinetics revealed a unique precipitation rate constant (0.0836 mM d −1 ) and a saturation state change rate constant (19.66 ± 1.61 d −1 ) across all batch experiments. The results suggest that the apparent loss of both soluble Ca 2+ and DIC increased along with the initial Ca 2+ concentrations, until reaching a plateau. However, ∆DIC/∆Ca 2+ continued to decrease, signifying an increased loss of Ca 2+ without proportional DIC capture. On the other hand, addition of an equivalent amount of Ca 2+ (300 mM) in multiple partitioned dosages not only improved the cumulative DIC removal (from 50.84 mM to 62.27 mM) but also ensured a better ∆DIC/∆Ca 2+ ratio. The results could be extended to design an efficient engineered calcification system for carbon sequestration.