Changes in Sediment Properties Caused by a Covering of Oyster Shells Pyrolyzed at a Low Temperature

Influence of Oyster Shell Pyrolysis Temperature on Sediment Permeability and Remediation

“…Comparatively more Ca 2+ was found in the POS600: 53.9 µg/g after 6 h and 54.1 µg/g after 24 h. Results indicate that the concentration of Ca 2+ increased along with an increased temperature of pyrolysis. This result is due to the fact that pyrolysis of oyster shells below 350 • C does not generate CaO [9], whereas, above 500 • C, CaCO 3 is converted to CaO [19], which is the source of Ca 2+ [18].…”

“…The leachate of POS350 has a higher concentration of PO 4 -P than POS600 because of the lower amount of Ca 2+ ions. It is reported that when the pyrolysis temperature of oyster shells is below 350 • C, CaCO 3 does not transform to CaO [9].…”

“…This careless disposal of oyster shells causes socio-economic problems, such as the growth of insects and bad smells, as well as the production of toxic gases such as ammonia (NH 3 ) and hydrogen sulfide (H 2 S) as a result of long-term microbial decomposition [2]. According to recent studies, oyster shells are a useful material for remediating organically enriched marine sediments by removing hydrogen sulfide (H 2 S) from pore water or sediments via adsorption [3,4]; reducing the concentration of dissolved inorganic nitrogen (DIN), phosphate (PO 4 -P), and acid volatile sulfides [5][6][7][8][9]; and increasing the oxidation-reduction potential (ORP), dissolved oxygen, pore water pH, and the shear strength of the sediment [8][9][10][11][12].…”

“…Oyster shells that have pyrolyzed at different temperatures have been shown to have an effect on both their chemical properties and sediment remediation [9][10][11][19][20][21]. However, its effect on permeability performance still has relevance, and further research is required for a better understanding of this phenomenon.…”