抄録
The operation of wastewater treatment on the rotating biological contactor was simulated by a mathematical model. According to this model, effects of daily-fluctuation of the influent load on the effluent quality of water were quantitatively analysed through illustrative calculations and their comparisons with the experimental data, previously reported.
Under a constant influent load, the hydraulic retention time in the contactor θ does not affect on the effluent BOD.
When there exists daily-fluctuation in the influent load, the weighted average effluent BOD is usually higher than its value given under the condition of the averaged constant load. The increase in θ results in relaxation of the effect of daily-fluctuation on the effluent BOD as well as decrease in its weighted average value in some extent.
Use of an equalization tank in advance to the contactor will be more efficient to accomplish the same purposes. Under a constant liquid flow condition, the weighted average effluent BOD takes a constant value, independent of the concentration fluctuation of influent and the value of θ.
