COD Lab Report full DOCX

Title	COD Lab Report full
Author	Ra Ba
Pages	8
File Size	261.7 KB
File Type	DOCX
Total Downloads	558
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1.0 OBJECTIVES To determine the organic oxidize able matters content of water samples. 2.0 LEARNING OUTCOMES At the end of the study, the students will be able: a) To understand the oxidation of oxidize able matter with a known amount of potassium Chromate, the titration of excess chromate, and the calculation of oxygen used. b) To identify the organic oxidize able matter pollutant content in water samples. c) To evaluate the water quality status at the location of water or wastewater sampling point. d) To choose the appropriate analytical methodology for measuring COD parameter. 3.0 THEORY The chemical oxygen demand (COD) is the amount of oxygen consumed to completely chemically oxidize the organic water constituents to inorganic end products. COD is an important, rapidly measured variable for the approximate determination of the organic matter content of water samples. Some water samples may contain substances that are difficult to oxidize. In these cases, because of incomplete oxidation under the given test methods, COD values may be a poor measure of the theoretical oxygen demand. It should also be noted that the significance of the COD value depends on the composition of the water studied. COD is used as a measurement of pollutants in natural and waste waters to assess the strength of discharged waste such as sewage and industrial effluent waters. It is normally measured in both municipal and industrial wastewater treatment plants and gives an indication of the efficiency of the treatment process. The dichromate reflux method is preferred over procedures using other oxidants because of superior oxidizing ability, applicability to a wide variety of samples, and ease of manipulation. Oxidation of most organic compounds is 95-100% the theoretical value. 4.0 EQUIPMENT I. COD Reflux System – consisting Erlenmeyer flask (250 mL or 500 mL) with ground- glass 24/40 neck and 300-mm jacket Liebig West, or equivalent condenser with 24/40 ground-glass joint, and a hot plate having sufficient power to produce at least 1.4 W/cm2 of heating surface. II. Burette III. Pipette IV. COD vial...