Rewetting of milled peat: laboratory investigation of water movement and storage

Abstract. Air- dried milled peat (0.45 g g^-1 wet weight basis) is used as an electricity generating fuel in Ireland. It is stored on peat bogs in triangular section stockpiles. These stockpiles comprise of milled peat of varying types, classified by poured density, and are subject to rewetting during storage which incurs an economic penalty. A water applicator was constructed to study the nature of rewetting mechanisms in laboratory-scale milled peat stockpiles, and to assess some potential protection strategies. Results indicated that there were few consistent short-term mechanisms linked to milled peat type. Over a longer period, low density milled peat stored most water, high density milled peat generated most runoff from the stockpile surface, and under certain conditions, throughflow was very important in all milled peat types. The industrial implications of the findings conclude that protection strategies should focus on lower density stockpiles.