Ammonium nitrogen in water and earth

The biogenic element, which is most actively involved in the processes of biohydrocenosis, is ammonium nitrogen.

Ecological situation

In reservoirs, a change in the content of this element can be observed: in the spring it becomes less, but in the summer, in connection with a favorable temperature regime, its concentration increases, because organic substances are massively decomposed.

And this fundamentally affects the health of water bodies, which makes it necessary to strengthen control over the viability of the ecosystem. The maximum permissible concentration in the water bodies where the fish are caught is the one where the ammonium nitrogen does not exceed 0.39 milligrams per liter.

In water

The accumulation of protein nitrogen is subject to ammonification, and this process decomposes proteins to an ammonium state. Wastewater is purified using this nitrogen source if there is a source of carbon nutrition for the cells. Intensive use occurs during the periods of their growth phase, and when oxidation begins, ammonium nitrogen is released in the form of ammonia. Further, it is oxidized to the state of nitrites and then nitrates, or re-participates in a new synthesis.

In order to remove the ammonium nitrogen from the reservoir, clinoptilolite is used, then the water recovers its qualities. There are cooling towers in the warm season, and in the winter they are replaced by ion-exchange facilities, thanks to which harmful substances are removed from the sewage. Constantly, samples are taken for ammonium nitrogen in water, which is distilled from the sample taken, and then its quantity is determined in the distillate obtained.

How to clean a reservoir

There is an ion exchange material in nature, which is called clinoptilolite (class of zeolites). It is with his help that it is advisable to restore the purity of water. Nitrogen ammonium in water is not dissolved completely, so first you need to release it from all suspended solids, and then apply water to clinoptilolite filters. This is a pretty expensive cleaning, but the most effective is reaching ninety-seven percent.

Regeneration will require a solution of sodium chloride - five or ten percent. After this, the load must be washed with water. Ammonia will be released from the solution, which can be absorbed by sulfuric acid to form ammonium sulfate, which is very good as a fertilizer. Ammonium nitrate in wastewater, as well as nitrogen-containing organic compounds, is removed by various types of distillation, extraction, adsorption.

Methods of obtaining fertilizers

This method is good if it is necessary to determine ammonium nitrogen. Other forms that occur in the same fertilizers, amide, nitrate, can not be determined by this method. First you need to extract ammonia nitrogen, in wastewater, for example, it is abundant. This method is written above. Next, the sample of the future fertilizer should be placed in a flask and spilled with a solution of hydrochloric acid (the concentration should be a molar - 0.05 mol per dm ³ ). The flask must be shaken with a special apparatus for at least half an hour, after which it can be insisted for up to fifteen hours.

Then shake the solution again and filter through a folded dry filter. With the same solution of hydrochloric acid, rinse the contents of the filter at least three times, then the volume of the filtrate must be brought to the original again with an acid solution. Thus, first, the determination of ammonium nitrogen in water took place, and secondly, the determination of its quantity in the fertilizer obtained. The latter ranges from forty to one hundred and fifty milligrams per liter, and caprolactam in the same solution is contained from eight to eighty milligrams per liter. If the content of ammonium nitrogen is less than twenty milligrams, then experience will not succeed, and this method is not applied.

Sources of pollution

The most characteristic features of industrial wastewater are the unstable chemical composition, the necessary adaptation period for the development of microflora, the excess of compounds of organic and mineral origin of nitrogen. Before the biological treatment at the sewage treatment plant, the wastewater is mixed with household and household wastes and thus averaged. Ammonium nitrate (formula NH ₄₊ ) is an obligatory component of waste water.

Sources of pollution can be wastewater of various industries - from food and medical to metallurgical, coke chemical, microbiological, chemical and petrochemical. Here you can include all domestic sewage, manure, agricultural - from the fields. As a result, protein substances and urea decompose, and nitrites and nitrates are reduced anaerobically.

Influence on the body

On the human body, such compounds are extremely negative. Ammonia denatures proteins, reacting with them. Then the cells and, accordingly, the tissues of the body stop breathing, the central nervous system, liver, respiratory organs are damaged, the work of the vessels is disrupted. If you regularly use water with a high content of ammonium, the acid-base balance suffers, acidosis begins.

Therefore, it is not allowed to use above the norm of organic and mineral fertilizers in land use, it is necessary to constantly struggle with excessive content of harmful substances: for example, ammonium nitrogen in the soil has a high solubility, therefore both food and water are literally poisoned, its concentrations often reach toxic levels. Children are especially affected by this. Methemoglobinemia develops, the oxygen regime in the body quickly collapses, the gastrointestinal tract begins to suffer first.

Limit doses

Single cases of methemoglobinemia begin when the content of nitrates in water is up to fifty milligrams per liter, and when their concentration reaches ninety-five milligrams per liter, the disease takes on a mass character. In the USA, France, the Netherlands, the FRG, detailed surveys have been carried out, which showed that more than fifty milligrams of nitrates per liter can be found in fifty percent of cases. Soil and well waters carry tens of times the concentration limit of nitrates - up to 1,500 milligrams per liter, while the World Health Organization has set a limit of forty-five milligrams. And this is the water people drink!

And waste water is purified in many ways - by biological filtration, and by oxidation with ozone, and hypochlorites of alkaline earth metals, and by aeration and sorption, in which sodium-form zeolites are used, and ion-exchange resins, and treated with strong alkalis and flotation, and ammonium is reduced by metallic Magnesium, and add solutions of magnesium chloride with trisodium phosphate. However, cleaning technologies are always far behind the pollution technologies.

Nutrients

In natural waters, gas (NH ₃ ) ammonia dissolves, when biochemical decomposition of organic compounds, including ammonium nitrogen, takes place. Then other compounds are formed and accumulate-ammonium-ion and ammonium-nitrogen. Dissolved ammonia enters the reservoirs with underground or surface runoff, with sewage, with atmospheric precipitation. If the concentration of ammonium ion (NH ₄₊ ) exceeds the background value, this will mean the emergence of a new and near source of pollution. It can be either livestock farms or manure accumulations, and orphaned nitrogen fertilizers, like industrial settlers, and sewage treatment facilities.

And compounds of nitrogen, carbon, phosphorus, which are contained in sewage, getting into the reservoirs, cause significant damage to the ecology of virtually all regions of Russia. Wastewater treatment day by day is becoming more relevant, since the concentration of harmful substances, including nitrogen compounds, is often simply off scale. This affects not only drinking water. Nitrates are rapidly accumulating almost all vegetables and fruits, they are contained in grass and grain, which are eaten by cattle.

The content of NH3 and NH4

Reservoirs always contain nitrogen in several transitional forms: ammonium salts and ammonia, albuminoid nitrogen (organic), nitrites (salts of nitrous acid) and nitrates (salts of nitric acid). All this is formed together with the process of mineralization of nitrogen, but more comes with wastewater. Now the reservoirs must be cleaned. The nitrogen compounds come to the treatment plants in the form of nitrogen nitrates, nitrogen nitrites, ammonium nitrogen and nitrogen bound by organic compounds. Wastewater from the household plan has a small concentration of such substances, most of it is sent to industry by water.

In the purification process, the ratio of the mass concentrations of all forms of nitrogen compounds is constantly changing. The composition of the waste water becomes different already during transportation, because urea, which is contained in domestic and household wastewater, interacting with bacteria, decomposes and forms an ammonium ion. The longer the sewage network, the further this process will go. Sometimes the content of the ammonium ion at the entrance to the purification is up to fifty milligrams per cubic decimeter, which is very, very much.

Organic nitrogen

This is nitrogen, which is found in organic substances - proteins and proteins, polypeptides (high molecular compounds), amino acids, carbamides (low molecular compounds), amines, amides. All organic matter, including nitrogenous, falls into the waste water, after which the nitrogen compounds are subjected to ammoniation. Organic nitrogen in waste water is many, sometimes up to seventy percent of all nitrogen compounds. But as a result of ammoniation on the sewage route, no more than fifteen percent of organic nitrogen comes to the treatment facilities.

Further, there is already a man-made biological treatment. The first stage is nitrification, that is, the alteration of nitrogen compounds due to certain types of microorganisms that ammonia nitrogen oxidizes into nitrate ion and nitrite ion. Nitrifying bacteria can not be feared - they are very susceptible to external conditions and are easily displaced. But nitrates, if they get into the reservoir, lead to its death, because they are an excellent nutrient medium for a variety of microflora. This is why it is necessary to derive nitrates from the ecosystem.

Nitrites and nitrates

If the wastewater penetrates the soil, then the ammonium nitrogen under the influence of some bacteria turns first into nitrites, then into nitrates. The predominance and content of various forms depends on those conditions that are added at the time of the connection with the presence of nitrogen in the soil, and then into the reservoir.

During the flood, the concentration of organic forms is significantly increased, since organic residues are washed from the surface of the soil, and in the summer they decrease as much, because they serve as "food" for various aquatic organisms. Nitrite is an intermediate form of oxidation of ammonium nitrogen, which tends to become nitrates. In natural waters of nitrates there is usually not much, if there has not been a flush of fertilizers from the fields.