Evaluation of Granulated Coalash Covering Method Utilized to Habitat Basis of Corbicula Japonica in Estuary

Abstract

Recently, sludge purification of organic matter enriched river bottom using granulated coal ash (GCA) have been used in Hiroshima Otagawa delta areas. It has been proved that GCA can absorb the compounds of phosphorus, nitrogen and sulfur. By previous study, the material properties of GCA for biological affinity have been clarified. On the other hands, a characteristic as the inhabiting basis of bivalves is not sufficiently clarified. The purpose of this study is to evaluate GCA covering method utilized to habitat basis of Corbicula japonica. Laboratory experiments and field investigation were carried out to compare GCA (covering material) for habitat basis with control materials (e.g. natural sand, natural stone and organic mud) about a sneaking act by Corbicula japonica. From our findings, it can be concluded that GCA can be used as a covering material to improve biological environment and utilized to habitat basis of Corbicula japonica in organic matter enriched river bottom.