Dechlorinated secondary effluent is placed in a storage basin until needed for reuse. If the initial dissolved oxygen concentration is 1.5 mg/L, estimate the time required for the dissolved oxygen concentration to increase to 8.5 mg/L due to surface reaeration assuming the water in the storage basin is circulated and not stagnant. Assume the KL value for oxygen is equal to 0.03 m/h. The surface area of the storage basin is 400 m² and the depth is 3 m. Assume the temperature is 20 °C and that the saturation value for DO is 9.09.