How do you determine wastewater COD?
How do you determine wastewater COD?
To establish the COD:BOD ratio for your wastewater, simply have both COD and BOD run on several wastewater samples. Divide the COD concentration by the BOD concentration for each sample and average the results.
What is COD method?
1.1 The Chemical Oxygen Demand (COD) method determines the quantity of oxygen required to oxidize the organic matter in a waste sample, under specific conditions of oxidizing agent, temperature, and time. For lower concentrations of carbon such as in surface water samples, the Low Level Modification should be used.
How does a spectrophotometer measure COD?
The COD can be easily determined using a spectroscopy method based on the oxidation of the organic matter by potassium dichromate (K 2 Cr 2 O 7 ), which is converted to potassium chromate (K 2 CrO 4 ) in the presence of mercury sulfate (HgSO 4 ) and silver sulfate (AgSO 4 ).
How do you express COD of waste water sample?
COD. The chemical oxygen demand (COD) test is commonly used to indirectly measure the amount of organic compounds in liquid waste. It is expressed in milligrams/grams per liter, which indicates the mass of oxygen consumed per liter of solution. Older references may express the units as parts per million (ppm).
How COD is calculated?
Chemical oxygen demand, or COD, is a test that measures the amount of organic compounds in water. Consider the formula for COD calculation: (a – b) X C X 8,000 / the volume of the sample in mL. Let “a” represent the titrant used for your sample expressed in mL.
How do you calculate COD?
There is a formula for calculating COD. Consider the formula for COD calculation: (a – b) X C X 8,000 / the volume of the sample in mL. Let “a” represent the titrant used for your sample expressed in mL. Let “b” represent the titrant used for your blank sample in mL.
How is COD theoretically calculated?
The COD can also be estimated from the concentration of oxidizable compound in the sample, based on its stoichiometric reaction with oxygen to yield CO2 (assume all C goes to CO2), H2O (assume all H goes to H2O), and NH3 (assume all N goes to NH3), using the following formula: COD = (C/FW)·(RMO)·32.
What happens if COD is high?
Higher COD levels mean a greater amount of oxidizable organic material in the sample, which will reduce dissolved oxygen (DO) levels. A reduction in DO can lead to anaerobic conditions, which is deleterious to higher aquatic life forms.
Is the APHA standard method examination water wastewater?
Analysts, researchers, and regulatory officials have relied on this comprehensive reference tool as a trusted source of accurate, proven methodology for analysis of natural water, water supplies and wastewater. Hundreds of methods have been approved and are referred to by the Environmental Protection Agency.
How to calculate chemical oxygen demand using APHA manual?
Add 25.00 mL 0.04167M K2Cr2O7 solution and mix. Attach flask to condenser and turn on cooling water.
Which is standard method for examination of water and wastewater?
Standard Methods for the Examination of Water and Wastewater © Copyright 1999 by American Public Health Association, American Water Works Association, Water Environment Federation COD is a defined test; the extent of sample oxidation can be affected by digestion time, reagent strength, and sample COD concentration.
How many people trust standard water analysis methods?
Over 50,000 water professionals worldwide trust Standard Methods for water and wastewater analysis techniques. Analysts, researchers, and regulators have relied on this peer-reviewed content since 1905.