Investigating the Efficiency of Dissolved Air Flotation Process for Aniline Removal from aquatic Environments

Aniline is an almost undegradable compound found in many industrial effluents. It was the objective of this lab-scale applied-experimental study to determine the efficiency of the dissolved air flotation process in the removal of aniline from aquatic environments. Initially, the optimal conditions of pH and dosage of poly-aluminum chloride were determined using the jar test. The parameters involved in the dissolved air flotation process including coagulant concentration (10, 20, 30, 40, and 60 mg.l‒1), coagulation time (5, 10 , 15, and 20 min), flotation time (5, 10, 15, and 20 s), saturation pressure (3.5 / 3, 4, and 5.4 atmospheres), and turbidity (10, 20, 30, 40, and 60 NTU) on the reduction of COD and aniline were then calculated. Results showed that the dissolved air flotation process was capable of reducing COD and aniline by 86.6% and 95%, respectively (at pH = 6, an initial aniline concentration of 200 mg/ L, a coagulation time of 10 min, a flotation time of 20 s, a saturation pressure of 4 atmospheres, and a concentration of 20 mg/L PAC). It was also shown that removal efficiency declines with increasing turbidity. It may, therefore, be claimed that the dissolved air flotation process is an effective method of removing aniline from aquatic environments.