The Experimental Studies on the prediction model for the decline in DO density of fish culture aria in a semi-closed bay

在封闭海湾的养鱼区，有机沉积物从剩余的鱼饵和鱼粪中积累。有机沉积物对海水水质有重要影响。特别是关于海洋DO密度，底泥氧化是通过有机氧化发生的。本研究阐明了底泥氧化和DO密度恶化的发生机理，在过去11年对底泥颗粒和氧化试验的基础上，得出了以下结果：1)减少底泥的总氧化需要量由底泥颗粒，p11，和水温2)可以通过在7 mg/i DO条件下校正总氧化数据的方法将DOD值和第一级COD值从底泥的总氧化值中分离出来，也可以通过底泥OR值来校准每个值。3)在养鱼区底泥的氧化深度约为9 mm，在累积条件下，底泥的氧化比约为总氧化量的0.30。4)可以通过ORB值来换算累积条件下底泥的氧化需要值。根据这些结果，我们开发了DO浓度变化的计算程序(ORP-MODEL)，该模型的计算值与闭合循环水航道的水力实验值基本一致。

In the fish culture area of a closed bay, organic sediment accumulates from left-over fish bait and fish droppings. The organic sediment has an important influence on the sea water quality. In particular, regarding the sea DO density, bottom sediment deterioration occurs through organic oxidation.This study clarifies the mechanism by which bottom sediment oxidation and deterioration of DO density occurs, This study, based on experiment we haveconducted over the past 11 years on the sediment ORB and oxidation, have yielded the following results.1) The total oxidation demand value of reduced bottom sediment is calculated by sediment ORB, p11, and water temperature.2) It is possible to separate the DOD value and first stage COD values from the total oxidation value of sediment by a method that corrects total oxidation data under 7mg/I DO condition and it is also possible to calibrate each value through sediment ORB.3) The oxidation depth of bottom sediment is about 9 mm in a fish culture area, and the sediment oxidation ratio is about 0.30 to total oxidation under accumulated conditions.4) It is possible to transform the oxidation demand value of bottom sediment under accumulated conditions through the ORB value.As we have demonstrated by these results the calculation program(ORP-model) for DO density variation was developed and the calculation value of the model was almost equal to the hydraulic experimental value of the closed circulating water way.