Quantitative Study of Photocatalyst Degradation of Propanil Herbicide in Water Using different Analytical Methods

S.A. Dhahir

Chemistry Department, College of Science for Women, University of Baghdad, Al-Jadria, Baghdad, Iraq

B.R.J. Muhyedeen

Chemistry Department, College of Science for Women, University of Baghdad, Al-Jadria, Baghdad, Iraq

N.S. Nassory

Chemistry Department, College of Science for Women, University of Baghdad, Al-Jadria, Baghdad, Iraq

S.A. Numan

Chemistry Department, College of Science for Women, University of Baghdad, Al-Jadria, Baghdad, Iraq

ABSTRACT:

In this study the photocatalytical degradation of propanil that used frequently in Iraq was investigated in different sources of water (distilled, tap and river waters) by using zinc oxide as a photocatalyst and mercury lamp as a source of light with intensity 2.66 x 10-4 Ein.l^-1 sec.^-1 . The rate of photo oxidation process is followed-up under optimum conditions at natural pH of solution, 10-4 M initial concentration of propanil, 0.4 g/lZnO loading and 20 ml/min oxygen flow rate. The photodegradation rate measurements were based on chloride ions liberation and the change in conductivity and pH. Kinetic study of photodegradation was found that the reaction is of the first order reaction and found equal to 0.0046, 0.0079 and 0.0086 min-1 for distilled, tap and river waters, respectively. Also the activation energy and quantum yields were calculated. UV-Visible spectrophotometric and PHLC were utilized to identify final species of the reaction products.