Influence of Seasonal Changes of the Effluent Treatment Plant at the Tanning Industry

To evaluate the influence of seasonal changes of the effluent treatment plant at the Tanning Industry, monthly samples were collected for a period of thirteen months (Jan. 2008 to Jan. 2009) from Inlet and outlet of two units namely Aeration Tank-I and Aeration II. The samples were analyzed for the water quality parameters such as pH, temperature, Chemical oxygen demand (COD) and biochemical oxygen demand (BOD5). Secondary treatment system consist of aeration tank 1 and 2, clarifiers 1 and 2. The aeration tank system brings out decomposition of organic matter by microorganisms with help of Dissolved Oxygen. In the aeration tank-I, the COD and BOD values were greatly reduced from 1421.53 ± 75.28 to 665 ± 117 mg/L and from 545 ± 54 to 222 ± 23 mg/L respectively. In the aeration tank-II the COD and BOD values were greatly reduced from 665± 117 to 175± 27 and from 222 ± 25 to 39±7 mg/L respectively. The influence of seasonal changes on the efficiency of bacteriological decomposition in secondary treatment was observed that a maximum efficiency was recorded during the peak summer month of May 2008 (30°C) and decline to the minimum during September 2008 (27°C). From this study it was concluded that the biological treatment process is limited by ambient temperature and its seasonal changes.