石灰系改良剤の溶解と水中pHの上昇予測モデル Simulation Model in Solubilization of lime-based amendment and pH increase as a Results of interactions with Natural Water

Simulation of hydroxyl ion in water after liming was carried out with the model derived from the material balance of hydroxyl ion. Hydroxyl ion balance could be explained by the equation, V.dC/dt=K<SUB>1</SUB>·f·A-Q·C-K<SUB>2</SUB>·C-V in which V, C, K<SUB>1</SUB>, f, A, Q and K<SUB>2</SUB> represent water volume (<I>l</I>), concentration of hydroxyl ion (equ/<I>l</I>), release rate of hydroxyl ion by lime (equ/m<SUP>2</SUP>/day), coverage percentage by lime (%), bottom area (m<SUP>2</SUP>), flow rate (<I>l</I>/day) and uptake rate of hydroxyl ion by Mg<SUP>2+</SUP> (1/day), respectively. Parameters needed for simulation, K<SUB>1</SUB>, K<SUB>2</SUB> and f were measured by flow-through apparatus empirically.<BR>A proposed model was successfully tested with the data obtained from Oota River in Kouchi Prefecture and Kuwabara River in Gifu Prefecture where lime was applied.