A kinetic model of steady state phosphorus fixation in a batch reactor—II. Effect of pH

Measurements of phosphorus fixation at the soil/solution ratio of 250 mg 500 −1 ml at pH = 2, 3, 5, 7 and 8 in a batch reactor with steady input of phosphate were carried out. All results reached a steady state and followed a Michaelis-Menten type equation as predicted for the catalytic process. Maximum rate of reaction showed a decrease with increase of pH due to the competitive effect between OH − and H 2PO − 4. The maximum value of 1/ K at pH = 5 showed H 2PO − 4 may be required in phosphorus adsorption for some specific-bonding mechanism with soil.