Utilizing a granulated coal bottom ash and oyster shells for nutrient removal in eutrophic sediments.

Various in-situ capping materials have been studied to remediate contaminated sediments for sustaining a healthy ecosystem in a coastal area. We developed Granulated coal bottom ash and oyster shells (GBO) with different mixing ratios of OS. Pyrolyzed and grounded coal bottom ash and oyster shells were used to produce GBO, which the main chemical elements were analogous to cement. The nutrient-removal abilities of GBO were evaluated through long-term mesocosm experiments. It was found that GBO was an effective in-situ capping material for remediation of eutrophic coastal sediments, decreasing PO4-P and SiO2-Si concentrations in pore water by 88.4% and 56.5%, respectively. The most efficient mixing ratio of coal bottom ash and oyster shells was at a weight ratio of 1:1 for PO4-P and SiO2-Si removal.