In environmental chemistry, the chemical oxygen demand (COD) test is commonly used to indirectly measure the amount of organic compounds in water. Most applications of COD determine the amount of organic pollutants found in surface water (e.g. lakes and rivers) or wastewater, making COD a useful measure of water quality. It is expressed in milligrams per liter (mg/L) also referred to as ppm (parts per million), which indicates the mass of oxygen consumed per liter of solution.
Read more about Chemical Oxygen Demand: Overview, History, Using Potassium Dichromate, Preparation Ferroin Indicator Reagent, Inorganic Interference, Government Regulation
Famous quotes containing the words chemical, oxygen and/or demand:
“We do not want actions, but men; not a chemical drop of water, but rain; the spirit that sheds and showers actions, countless, endless actions.”
—Ralph Waldo Emerson (1803–1882)
“All the oxygen of the world was in them.
All the feet of the babies of the world were in them.
All the crotches of the angels of the world were in them.
All the morning kisses of Philadelphia were in them.”
—Anne Sexton (1928–1974)
“...America has enjoyed the doubtful blessing of a single-track mind. We are able to accommodate, at a time, only one national hero; and we demand that that hero shall be uniform and invincible. As a literate people we are preoccupied, neither with the race nor the individual, but with the type. Yesterday, we romanticized the “tough guy;” today, we are romanticizing the underprivileged, tough or tender; tomorrow, we shall begin to romanticize the pure primitive.”
—Ellen Glasgow (1873–1945)