What is Dissolved Oxygen What is the solubility of oxygen

The molecular oxygen dissolved in water is called dissolved oxygen.

It is usually written as do. It is expressed in milligrams of oxygen per liter of water. The amount of dissolved oxygen is affected by water temperature, air pressure, and solutes (e.g., salt), which decreases as water temperature increases, and is related to the partial pressure of oxygen in the atmosphere.

Proportional increase. Although dissolved oxygen in water is not a pollutant, it is an indicator of the self-purification ability of the water body. The dissolved oxygen value is a basis for studying the self-purification ability of water.

In a flowing river, water samples from different sections are taken to determine dissolved oxygen. It can help to understand the self-cleaning effect of the water body in different locations. It is generally stipulated that the dissolved oxygen in the water body is at least 4mg l or more.

Dissolved oxygen is also an important control indicator in the biochemical treatment of wastewater.

The first thing to understand is the mode of oxygen transport in the human body, which is usually divided into bound oxygen and dissolved oxygen. Bound oxygen is generally combined with hemoglobin in the blood, and dissolved oxygen is dissolved in the blood. However, there is no way to supplement or improve the normal oxygen absorption of dissolved oxygen, and it can only be improved by the O2ARK hyperbaric oxygen chamber, which is an environment that passes through atmospheric pressure.

It can be expedited.

Dissolved oxygen: Molecular oxygen dissolved in water and air.

At 0, the maximum volume of dissolved oxygen can be dissolved in 1 volume of water, and at 20 1 atm, the solubility of oxygen is volume. Chemically speaking, oxygen is insoluble in water, which is less than a volume of micro-solubility that supports the survival of countless marine organisms.

Oxygen is the most widely distributed in nature, covering the mass of the crust, and is the most abundant element. Oxygen is needed for the oxidation of hydrocarbons, the treatment of wastewater, rocket propellants, and the respiration of animals and humans in aviation, aerospace and diving.

Oxygen is a kind of elemental formed by oxygen, the chemical formula O2, its chemical properties are relatively active, and most elements can react with oxygen. It is not very active at room temperature, and it is not easy to interact with many substances. However, it is very active at high temperatures and can be directly combined with a variety of elements, which is related to the electronegativity of oxygen atoms second only to fluorine.

Oxygen is a colorless and odorless gas and is the most common elemental form of oxygen. Melting point, boiling point -183 . Not easily soluble in water, about 30ml of oxygen is dissolved in 1L of water. In the air, oxygen accounts for about 21%. Liquid oxygen is sky blue. Oxygenation is a blue crystal.

1. Dissolved oxygen refers to the amount of oxygen dissolved in water. Also known as the implicit oxygen saturation value, it refers to the concentration of dissolved oxygen in the water body when the oxygen exchange between the water body and the atmosphere is in equilibrium. Under normal atmospheric pressure conditions, the saturated dissolved oxygen (OS) only varies with the water temperature t, and the saturated dissolved oxygen also varies with the atmospheric pressure, and the lower the atmospheric pressure, the smaller the OS value.

Saturated dissolved oxygen also varies with the salinity in the water, with the salinity increasing and the OS value decreasing.

2. Its content is related to the partial pressure of oxygen in the air and the temperature of the water. The partial pressure of oxygen changes very little, so water temperature is the main influencing factor, and the lower the water temperature, the higher the dissolved oxygen in the water. The dissolved oxygen content of clean surface water is close to saturation.

When a large number of algae plants grow in the water, the oxygen released by their photosynthesis can make the dissolved Dachang oxygen in the water supersaturated.

3. When there is organic matter polluting the water body or a large number of algae dies, the dissolved oxygen is continuously consumed and decreased, and even the water body is in an anaerobic state. Therefore, dissolved oxygen in water can be used as an indirect indicator of organic pollution and its self-purification.

Dissolved oxygen. dissolved

oxygen) refers to oxygen dissolved in the molecular state of water, i.e., O2 in water, denoted by DO. Dissolved oxygen is an indispensable condition for the survival of aquatic organisms. One of the ** of dissolved oxygen is that when the dissolved oxygen in the water is not saturated, the oxygen in the atmosphere seeps into the water body; The other ** is the photosynthesis of plants in water.

Oxygen released. Dissolved oxygen varies with temperature, air pressure, and salinity, generally speaking, the higher the temperature, the greater the dissolved salt, and the lower the dissolved oxygen in the water; The higher the air pressure, the higher the dissolved oxygen in the water. Dissolved oxygen is usually used in water in addition to sulfides, nitrites, ferrous ions.

In addition to being consumed by reducing substances, it is also respirated by microorganisms in the water.

and the consumption of organic matter in the water by the oxidative decomposition of aerobic microorganisms. Therefore, dissolved oxygen is the capital of the water body and the expression of the self-purification ability of the water body. Dissolved oxygen in natural water is close to saturation value (9ppm) for algae.

When reproduction is vigorous, the dissolved oxygen content decreases. Water pollution by organic matter and reducing substances can reduce dissolved oxygen, for the aquaculture industry, dissolved oxygen in water has a vital impact on the survival of aquatic organisms such as fish, when dissolved oxygen is less than 4mg L, it will cause fish suffocation and death, for humans, the dissolved oxygen content in healthy drinking water shall not be less than 6mg L. When the rate of dissolved oxygen (DO) consumption is greater than the rate of oxygen dissolution into the water body, the content of dissolved oxygen can approach 0, and anaerobic bacteria are at this time.

It can reproduce and deteriorate the water body, so the dissolved oxygen size can reflect the pollution of the water body, especially the degree of organic pollution, it is an important indicator of the degree of water pollution, and it is also a comprehensive indicator to measure water quality. Therefore, the measurement of dissolved oxygen content in water is of great significance for environmental monitoring and the development of aquaculture.

The dissolved oxygen standard value is the minimum amount of oxygen in the water, which under ideal conditions is typically 5 milligrams of liters (mg L). But in fact, the standard value of dissolved oxygen in various water bodies will vary according to different factors such as temperature, water depth, water flow, pollution degree, etc.

Dissolved oxygen. The molecular oxygen in the air dissolved in water is called dissolved oxygen, and the content of dissolved oxygen in water is closely related to the partial pressure of oxygen in the air and the temperature of the water. Under natural conditions, the oxygen content in the air does not change much, so the water temperature is the main factor, and the lower the water temperature, the higher the dissolved oxygen content in the water.

The molecular oxygen dissolved in water is called dissolved oxygen and is usually denoted as do, expressed in milligrams of oxygen per liter of water. The amount of dissolved oxygen in the water is an indicator of the self-purification ability of the water body.

Dissolved oxygen is closely related to the partial pressure, atmospheric pressure, water temperature and water quality of oxygen in the air, and at kPa, the dissolved oxygen in pure water is about 9mg L. Some organic compounds are biodegraded by aerophilic bacteria, which consumes dissolved oxygen in the water. If the organic matter is calculated as carbon, according to C+O2=CO2, it can be seen that 32g of oxygen is consumed for every 12g of carbon.

When the dissolved oxygen level in the water drops to 5 mg l, some fish have difficulty breathing.

There are usually two dissolved oxygens: one is when the dissolved oxygen in the spring water is not saturated, the oxygen in the atmosphere infiltrates into the water body; The other** is the oxygen released by plants in the water through photosynthesis. As a result, the dissolved oxygen in the water is constantly replenished by the dissolution of oxygen into the air and the photosynthesis of green aquatic plants.

However, when the water body is polluted by organic matter, the oxygen consumption is serious, and the dissolved oxygen is not replenished in time, the anaerobic bacteria in the water body will multiply quickly, and the organic matter will make the water body black and smelly due to corruption.

The dissolved oxygen value is a basis for studying the self-purification ability of water. The dissolved oxygen in the water is consumed, and it takes a short time to return to the initial state, indicating that the water body has a strong self-purification ability, or that the water body is not seriously polluted. Otherwise, it means that the water body is seriously polluted, the self-cleaning ability is weak, and even the self-purification ability is lost.