Numerical evaluation of the use of granulated coal ash to reduce an oxygen-deficient water mass

• Published in: Marine pollution bulletin 2016-06, Vol.107 (1), p.188-205
• Main Authors: Yamamoto, Hironori, Yamamoto, Tamiji, Mito, Yugo, Asaoka, Satoshi
• Format: Article
• Language: English
• Subjects: Adsorption; Coal; Coal Ash; Coastal marine sediments; coastal water; Ecosystem; ecosystems; electric power; Environmental Restoration and Remediation - methods; Eutrophication; Geologic Sediments; Granulated coal ash (GCA); hydrogen sulfide; Hydrogen Sulfide - analysis; Japan; Marine; marine sediments; New GCA-based environmental restoration technique; Oxygen - chemistry; Oxygen-deficient water mass; Pelagic–benthic coupled ecosystem model; Pelagic–benthic coupled ecosystem model; Phosphates; society; summer; Water; water pollution
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2016.04.001

Granulated coal ash (GCA), which is a by-product of coal thermal electric power stations, effectively decreases phosphate and hydrogen sulfide (H2S) concentrations in the pore water of coastal marine sediments. In this study, we developed a pelagic–benthic coupled ecosystem model to evaluate the effectiveness of GCA for diminishing the oxygen-deficient water mass formed in coastal bottom water of Hiroshima Bay in Japan. Numerical experiments revealed the application of GCA was effective for reducing the oxygen-deficient water masses, showing alleviation of the DO depletion in summer increased by 0.4–3mgl−1. The effect of H2S adsorption onto the GCA lasted for 5.25years in the case in which GCA was mixed with the sediment in a volume ratio of 1:1. The application of this new GCA-based environmental restoration technique could also make a substantial contribution to form a recycling-oriented society. •A pelagic–benthic coupled ecosystem model was constructed.•Increase of DO concentration in summer by the application of granulated coal ash (GCA) was reproduced by the numerical model.•It was estimated that the effect of H2S adsorption onto the GCA would continue for 5.25years.•The GCA-based environmental restoration technique could also contribute to form a recycling-oriented society.