The biogenic element, which is most actively involved in the processes of biohydrocenosis, is ammonium nitrogen.
Ecological situation
In reservoirs, one can observe a change in the content of this element: in spring it becomes smaller, but in summer, due to favorable temperature conditions, its concentration increases significantly, since organic matter is massively decomposed.
And this fundamentally affects the sanitary condition of reservoirs, which forces us to tighten control over the viability of the ecosystem. The maximum permissible concentration in water bodies where fish are caught is considered to be where ammonia 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 treated with this nitrogen source if it has a carbon source for cells. Intensive use occurs during periods of their growth phase, and when oxidation begins, ammonia nitrogen is released in the form of ammonia. Then it oxidizes to a state of nitrites and then nitrates, or re-participates in an already new synthesis.
In order to remove ammonia nitrogen from the reservoir, clinoptilolite is used, then the water restores its quality. Cooling towers are installed in the warm season, and in winter they are replaced by ion-exchange plants, due to which harmful substances are removed from wastewater. Analyzes are constantly carried out, samples are taken for ammonium nitrogen in water, which is distilled off from the taken sample, and then its amount is determined in the obtained distillate.
How to clean a pond
There is in nature an ion-exchange material called clinoptilolite (a class of zeolites). It is with its help that it is advisable to restore the purity of water. Ammonia nitrogen does not completely dissolve in water, so first you need to free it from all suspended substances, and then supply water to clinoptilolite filters. This is a fairly expensive cleaning, but the most effective one is up to ninety-seven percent.
Regeneration will require the introduction of a solution of sodium chloride - five or ten percent. After that wash the load with water. Ammonia will be released from the solution, which can be absorbed with sulfuric acid to form ammonium sulfate, which is very good as a fertilizer. Ammonium nitrogen in wastewater, as well as nitrogen-containing organic compounds are removed by various types of distillation, extraction, adsorption.
Fertilizer Production Methods
This method is good if ammonium nitrogen determination is necessary. Its other forms, which are found in the same fertilizers - amide, nitrate - cannot be determined by this method. First you need to extract ammonia nitrogen, in wastewater, for example, it is abundant. This method is described above. Next, a sample of the future fertilizer should be placed in a flask and spilled with a solution of hydrochloric acid (the concentration should be 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 infused for up to fifteen hours.
Shake the solution again and filter through a folded dry filter. Rinse the contents of the filter with the same hydrochloric acid solution at least three times, then the volume of the filtrate must be brought back to the original again with an acid solution. Thus, firstly, the determination of ammonium nitrogen in water took place, and secondly, the determination of its amount in the resulting fertilizer. The latter ranges from forty to one hundred and fifty milligrams per liter, and caprolactam in the same solution contains from eight to eighty milligrams per liter. If the content of ammonia nitrogen is less than twenty milligrams, then the experiment will fail, and this method is not applied.
Sources of pollution
The most characteristic features of industrial wastewater are an unstable chemical composition, the necessary adaptation period for the development of microflora, and an excess of compounds of the organic and mineral origin of nitrogen. Before biological treatment at the wastewater treatment plant, the wastewater is mixed with domestic and domestic and thus averaged. Ammonium nitrogen (formula NH 4+ ) is an essential component of wastewater.
Sources of pollution can be wastewater of various industries - from food and medical to metallurgical, coke, microbiological, chemical and petrochemical. This also includes all household wastewater, manure, agricultural - from the fields. As a result, protein substances and urea decompose, and nitrites and nitrates are anaerobically reduced.
Effect on the body
Such compounds are extremely negative for the human body. Ammonia denatures proteins, reacting with them. Then the cells and, accordingly, the tissues of the body stop breathing, there is a lesion of the central nervous system, liver, respiratory organs, the functioning of the vessels is disturbed. If you regularly use water with a high ammonium content, the acid-base balance suffers, acidosis begins.
Therefore, it is impossible to prevent the use of organic and mineral fertilizers in land use above the norm, it is necessary to constantly combat the excessive content of harmful substances: for example, ammonium nitrogen in the soil has high solubility, therefore both food and water are literally poisoned by it, its concentrations often reach a toxic level. Children are especially affected by this. Methemoglobinemia develops, the oxygen regime in the body is rapidly destroyed, the gastrointestinal tract begins to suffer first.
Dose limits
Isolated cases of methemoglobinemia disease begin when the nitrate content in the water is up to fifty milligrams per liter, and when their concentration reaches ninety-five milligrams per liter, the disease takes on a massive scale. In the United States, France, the Netherlands, and the Federal Republic of Germany, detailed surveys were carried out, which showed that more than fifty milligrams of nitrates per liter can be found in fifty percent of cases. Ground and well waters carry a concentration of nitrates ten times the limit - up to one and a half thousand milligrams per liter, while the World Health Organization has set a limit of forty-five milligrams. And this is the water that people drink!
And sewage is purified in many ways - by biological filtration, and by oxidation by ozone, and alkaline earth metal hypochlorites, and by aeration, and sorption, in which sodium zeolites are used, and ion-exchange resins, and treated with strong alkalis, and flotation, and ammonium is reduced by metal magnesium, and solutions of magnesium chloride with trisodium phosphate are added. However, cleaning technologies are always far behind pollution technologies.
Nutrients
In natural waters, gas (NH 3 ) ammonia dissolves when the biochemical decomposition of organic compounds, including ammonia nitrogen, occurs. Then other compounds are formed and accumulate - ammonium ion and ammonium nitrogen. Dissolved ammonia gets into reservoirs with underground or surface runoff, with waste water, with atmospheric precipitation. If the concentration of ammonium ion (NH 4+ ) exceeds the background value, this will mean the emergence of a new and close source of pollution. This can be either livestock farms or accumulations of manure, or nitrogen-free fertilizers abandoned by the owner, as settling tanks of industry, and sewage treatment facilities.
And the compounds of nitrogen, carbon, phosphorus, which are contained in wastewater, falling into water bodies, cause significant damage to the environment of almost all regions of Russia. Wastewater treatment is becoming more and more relevant day by day, since the concentration of harmful substances, including nitrogen compounds, is often just off scale. This affects not only drinking water. Almost all vegetables and fruits quickly accumulate nitrates; they are found in grass and grain that livestock eat.
Water content NH3 and NH4
Ponds always in several transitional forms contain nitrogen: 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 to a greater extent comes from wastewater. Now reservoirs must be cleaned. Nitrogen compounds come to wastewater treatment plants in the form of nitrogen nitrates, nitrogen nitrites, ammonium nitrogen and nitrogen bound by organic compounds. Wastewater of the household plan has a small concentration of such substances, most of it is sent to reservoirs by industry.
During the cleaning process, the ratio of mass concentrations of all forms of nitrogen compounds is constantly changing. The composition of the wastewater becomes different already during transportation, because the urea, which is contained in domestic and household wastewater, interacting with bacteria, decomposes and forms an ammonium ion. The longer the sewer network, the further this process will go. Sometimes the content of 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 part of organic substances - proteids and proteins, polypepsides (high molecular weight compounds), amino acids, urea (low molecular weight compounds), amines, amides. All organics, including nitrogen-containing, fall into wastewater, after which nitrogen compounds undergo ammonization. There is a lot of organic nitrogen in wastewater, sometimes up to seventy percent of all nitrogen compounds. But as a result of ammonization, no more than fifteen percent of organic nitrogen comes to sewage treatment plants on the sewer path.
Next, there is already man-made biological treatment. The first stage is nitrification, that is, the conversion of nitrogen compounds due to certain types of microorganisms that oxidize ammonia nitrogen into a nitrate ion and nitrite ion. You can not be afraid of nitrifying bacteria - they are very susceptible to external conditions and are easily displaced. But nitrates, if they fall into a body of water, lead to its death, since they are an excellent nutrient medium for a variety of microflora. That is why nitrates must be removed from the ecosystem.
Nitrites and nitrates
If wastewater penetrates the soil, then ammonia nitrogen, under the influence of some bacteria, turns first into nitrites, then into nitrates. The prevalence and content of various forms depends on the conditions that are formed at the time of the arrival of compounds with the presence of nitrogen in the soil, and then in the reservoir.
During the flood, the concentration of organic forms increases significantly, since organic residues are washed off the surface of the soil, and in the summer they decrease just as much, because they serve as “food” for various aquatic organisms. Nitrites are an intermediate form of oxidation of ammonium nitrogen, which tends to become nitrates. In natural waters, nitrates are usually not so much if there is no flushing of fertilizers from the fields.