Application of natural reaeration kinetics to artificial aeration

Abstract EN

The recalibrated Thackston and Krenkel (TK) equation, which was originally derived for natural reaeration of streams and rivers, is used here for the evaluation of artificial reaeration of water.

As many as 180 experiments were conducted in order to provide the data needed for this study.

A laboratory–scale open channel was used for the experimental part of this study.

Artificial roughness was provided by attaching crushed stones to the channel bed.

Each of the three sets of experiments involved was performed using different size of bed stone, namely; 12.70 mm, 22.75 mm and 34, 60 mm.

The bed slopes used at each set of experiments were (0.005, 0.004, 0.003, 0.002, 0.001 and 0.0005), respectively.

An average calibration constant (C) of (218 × 10– 6) was obtained for TK equation for artificial reaeration.

In terms of Froude number (F), the calibration constant (C) was found to have a value of (249 × 10–6 F0.22).

The analysis of the data obtained reveals that the reaeration coefficient (k2) is a function of channel bed slope.

The higher values of the ratio (u* / h) were obtained at the lower values of shear velocities (u*) and flow depth (h).

At each slope in each set of experiments the relationship between (k2) and (u* / h) was found to be of power function.