what is chemical oxygen demand
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COD or Chemical Oxygen Demand definition COD or Chemical Oxygen Demand definition. Chemical oxygen demand (COD) is a measure of the capacity of water to consume oxygen during the decomposition of organic matter and the oxidation of inorganic chemicals such as Ammonia and nitrite.
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Chalcogen The Chemistry of Oxygen and Sulfur. The Chemistry of Oxygen. Oxygen is the most abundant element on this planet. The earth's crust is 46.6% oxygen by weight, the oceans are 86% oxygen by weight, and the atmosphere is 21% oxygen by volume.
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Oxygen Oxygen is the most abundant chemical element by mass in the Earth's biosphere, air, sea and land. Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. About 0.9% of the Sun 's mass is oxygen. Oxygen constitutes 49.2% of the Earth's crust by mass and is the major component of the world's oceans (88.8% by mass). Oxygen gas is the second most common component of the Earth's atmosphere, taking up 20.8% of its volume and 23.1% of its mass (some 10 15 tonnes).
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Oxygen Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. About 0.9% of the Sun 's mass is oxygen. Oxygen constitutes 49.2% of the Earth's crust by mass and is the major component of the world's oceans (88.8% by mass).xygen is toxic to obligately anaerobic organisms, which were the dominant form of early life on Earth until O 2 began to accumulate in the atmosphere about 2.5 billion years ago during the Great Oxygenation Event, about a billion years after the first appearance of these organisms.
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What is biological oxygen demand and how does it affect water quality? 1 | 2. Biochemical oxygen demand is a measure of the quantity of oxygen used by microorganisms (e.g., aerobic bacteria) in the oxidation of organic matter. Natural sources of organic matter include plant decay and leaf fall. | 2. Biochemical oxygen demand is a measure of the quantity of oxygen used by microorganisms (e.g., aerobic bacteria) in the oxidation of organic matter. Natural sources of organic matter include plant decay and leaf fall.
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Chemical Oxygen Demand Chemical oxygen demand is measured as a standardized laboratory assay in which a closed water sample is incubated with a strong chemical oxidant under specific conditions of temperature and for a particular period of time.
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- Medical Definition of BIOCHEMICAL OXYGEN DEMAND. : the oxygen used in meeting the metabolic needs of aerobic microorganisms in water rich in organic matter (as water polluted with sewage)—called also biological oxygen demand, oxygen demand. Britannica.com: Encyclopedia article about biochemical oxygen demand.noun biochemical oxygen de·mand \-di-ˌmand\. : the oxygen used in meeting the metabolic needs of aerobic microorganisms in water rich in organic matter (as water polluted with sewage)—called also biological oxygen demand, oxygen demand.efinition of BIOCHEMICAL OXYGEN DEMAND. : the oxygen used in meeting the metabolic needs of aerobic microorganisms in water rich in organic matter (as water polluted with sewage). ADVERTISEMENT. noun biochemical oxygen de·mand \-di-ˌmand\.
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- Endogenous Respiration. Endogenous respiration, also referred to as endogenous metabolism, is defined here as “a situation where living organisms oxidize some of their own cellular mass instead of new organic matter they ad sorb or ab sorb from their environment” (California State University, Sacramento, Volume II).hen the OUR value is 9 (mg O 2 /L)/hr the oxygen requirement in the aeration tank is 9,143 lb O 2 /day, 6,857 below what the aerators are capable of producing. That is, as we approach the endogenous respiration rate we begin to have excess oxygen which increases the DO concentration in the reactor.
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Oxygen family In the form of LOX, oxygen is used widely as the oxidizing agent in many kinds of rockets and missiles. For example, the huge external fuel tank required to lift the space shuttle into space holds 550,000 liters (145,000 gallons) of liquid oxygen and 1,500,000 liters (390,000 gallons) of liquid hydrogen.
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Oxygen Toxicity Oxygen Consumption. Oxygen consumption, abbreviated VO 2, is the total amount of oxygen used by the body and is determined by oxygen demand, oxygen availability, and the body’s ability to extract oxygen from hemoglobin and plasma.
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OXYGEN It is a colourless, odourless gas; pale blue liquid. Oxygen is extremely reactive and forms oxides with nearly all other elements except noble gases. It is the most abundant element in the earth's crust and makes up almost 21% of the atmosphere. Oxygen is obtained primarily from liquid air by fractional distillation. Small amounts are made in the laboratory by electrolysis of water. Oxygen is used in steel making, welding and supporting life.
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Oxygen When oxygen is cooled below -297° F (-183° C), it becomes a pale blue liquid that is used as a rocket fuel. Oxygen is one of the most abundant chemical elements on Earth. About one-half of the earth's crust is made up of chemical compounds containing oxygen, and a fifth of our atmosphere is oxygen gas.hen oxygen is cooled below -297° F (-183° C), it becomes a pale blue liquid that is used as a rocket fuel. Oxygen is one of the most abundant chemical elements on Earth. About one-half of the earth's crust is made up of chemical compounds containing oxygen, and a fifth of our atmosphere is oxygen gas.
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Key Words Chemical Properties. Oxygen is a highly reactive element, highly paramagnetic, and is easily capable of combining with other elements. One of oxygen's most important chemical properties is that it supports combustion (see picture to the right).Oxygen also combines with elements at room temperature, for example, the formation of rust.Decaying is an example of oxygen reacting with compounds.Carbon dioxide and water are the main products of decay.ne of oxygen's most important chemical properties is that it supports combustion (see picture to the right). Oxygen also combines with elements at room temperature, for example, the formation of rust.
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Dissolved Oxygen In limnology (the study of lakes), dissolved oxygen is an essential factor second only to water itself ¹. A dissolved oxygen level that is too high or too low can harm aquatic life and affect water quality. Non-compound oxygen, or free oxygen (O2), is oxygen that is not bonded to any other element. Dissolved oxygen is the presence of these free O2 molecules within water.The bonded oxygen molecule in water (H2O) is in a compound and does not count toward dissolved oxygen levels.
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- Reduced myocardial oxygen demand (MVO2) secondary to decrease ventricular volume & wall tension) Recall that wall tension and contractility are the primary determinants of myocardial oxygen demand. Ventricular wall tension is directly proportional to: Intracavitary pressure & ventricular radius.
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Liquid oxygen In commerce, liquid oxygen is classified as an industrial gas and is widely used for industrial and medical purposes. Liquid oxygen is obtained from the oxygen found naturally in air by fractional distillation in a cryogenic air separation plant.
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Oxygen Oxygen is one of the basic chemical elements. In its most common form, oxygen is a colorless gas found in air. It is one of the life-sustaining elements on Earth and is needed by all animals. Oxygen is also used in many industrial, commercial, medical, and scientific applications.
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- Oxygen is an element with the chemical symbol O and atomic number 8. Oxygen is a very reactive element that easily forms compounds such as oxides. Under standard temperature and pressure conditions two oxygen atoms join to form dioxygen (O 2), a colorless, tasteless and odorless gas. Oxygen is essential to human life, it is found in the air we breathe and the water we drink (H 2 0).
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- The Chemistry of Oxygen and Sulfur. The Chemistry of Oxygen. Oxygen is the most abundant element on this planet. The earth's crust is 46.6% oxygen by weight, the oceans are 86% oxygen by weight, and the atmosphere is 21% oxygen by volume. The name oxygen comes from the Greek stems oxys, acid, and gennan, to form or generate..
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Oxygen Oxygen is one of the basic chemical elements. In its most common form, oxygen is a colorless gas found in air. It is one of the life-sustaining elements on Earth and is needed by all animals. Oxygen is also used in many industrial, commercial, medical, and scientific applications.he hydrogen could be used as a fuel, and the oxygen could be used to provide life support for lunar colonies. Another plan involves extracting oxygen from chemical compounds in the lunar soil using a solar-powered furnace for heat.
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Peripheral Muscle Wasting in Chronic Obstructive Pulmonary Disease References. 1  Bernard S, LeBlanc P, Whittom F, Carrier G, Jobin J, Belleau R, Maltais F: Peripheral muscle weakness in patients with chronic obstructive pulmonary disease. 2  Hamilton AL, Killian KJ, Summers E, Jones NL: Muscle strength, symptom intensity, and exercise capacity in patients with car-diorespiratory disorders.
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Biochemical oxygen demand Biochemical oxygen demand is the amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period. The BOD value is most commonly expressed in milligrams of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and is often used as a surrogate of the degree of organic pollution of water. BOD can be used as a gauge of the effectiveness of wastewater treatment ...
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Chemical Oxygen Demand (COD) A chemical oxygen demand test works on the basis that nearly all organic compounds can be oxidized to carbon with a strong oxidizing agent in the presence of acid. Many governments around the world regulate the maximum chemical oxygen demand allowed in wastewater.
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BOD in Water - YSI knows BOD Biochemical Oxygen Demand-BOD. Biochemical oxygen demand or B.O.D. is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.
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An overview of oxygen scavenging packaging and applications More specifically, oxygen scavengers refers to a category within active packaging. Oxygen scavengers are packaging films or devices that chemically react with oxygen to remove it from the packaging environment. This, in turn, protects the product from degradative oxidation reactions.
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Oxygen - O Chemical properties of oxygen - Health effects of oxygen - Environmental effects of oxygen. Oxygen. Gaseous chemical element, symbol: O, atomic number: 8 and atomic weight 15,9994. It’s of great interest because it’s the essential element in the respiratory processes of most of the living cells and in combustion processes. It’s the most abundant element in The Earth’s crust. Nearly one fifth (in volume) of the air is oxygen.