The oxidn. of total org. content (TOC) present in the two selected Bangalore city lake (Medahalli and Ulsoor lakes) water samples at two different seasons of the year 2010 using photocatalyst TiO2 as been studied. The different forms of TiO2 such as anatase, rutile and mixed form (Degussa P25) are used for the study. The mixed form (mixt. of anatase and rutile) has given better results in photooxidn. than the individual TiO2 forms. The oxidn. of these pollutants present in the wastewater will be oxidized by photo/ photocatalysis and the extent of contamination and oxidn. are measured by COD and BOD tests. The photooxidn. studies were made under natural sun light illumination. The efficiency and the rate consts. for the oxidn. of TOC are calcd. and presented. The TOC oxidn. reactions are found to follow first order kinetics. The rate consts. for photocatalytic oxidn. of TOC of the Medahalli lake samples of June and Dec. months are 0.333 and 0.49 (× 10-4 s-1) and for Ulsoor lake samples are 0.52 and 0.666 (× 10-4 s-1) resp
