(DETERMINATION OF CHEMICAL OXYGEN DEMAND (COD) IN WASTE WATERS BY FLOW INJECTION ANALYSIS (FIA) METHOD)

• Main Author: Hartanto S W, Alfonsus
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34677
• Institution: Institut Teknologi Bandung

Chemical Oxygen Demand (COD) can be defined as the amount of oxygen (mg O2) needed to oxidize the organic compounds in water. Water with high COD value is not suitable for daily use because of the low oxygen content. Waste water is an example of water sample with high COD value because it has been polluted. In this research, COD value of waste water will be determined using Flow Injection Analysis (FIA) by visible spectrofotometer method as detector. This method is used to analyze chemical content automation. In this procedure, KMnO4 has been used to act as an oxidator and H2SO4 has been used to stabilize MnO -, while Na C O is used as standard. In this research, concentration of KMnO and H2SO4 used are 0.2 mM and 1 M, respectively. By using UV-vis spectrofotometer as detector, maximum absorbance achieved at wavelength 525 nm. The reaction between KMnO4 and organic compounds occured in a slow rate at room temperature. Hence, the reaction has been optimized at elevated temperature, ranging from 60 to 70ºC. Under optimum condition, this procedure gained reproducibility value (%CV, n=11) 1.32% at 10 mg L-1. Standard solution linierity within concentration range 10 until 42.5 mg L-1 is R2 = 0.9868 and Limit of Detection is 9.31 mg L-1 Waste water samples measurement, gave COD value 12.20 mg L-1 with value of % recovery 107.73. These data indicate that the FIA method used to analyze the COD in waste waters is quite effective.