The biogenic element that is most actively involved in the processes of biohydrocenosis is ammonium nitrogen.
Environmental situation
In reservoirs, one can observe a change in the content of this element: in spring it becomes less, but in summer, due to favorable temperature conditions, its concentration increases significantly, as organic matter decomposes massively.
And this drastically affects the sanitary condition of water bodies, which makes it necessary to strengthen control over the viability of the ecosystem. The maximum permissible concentration in water bodies where fish are caught is one where ammonium nitrogen does not exceed 0.39 milligrams per liter.
In the 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 source of carbon nutrition for the cells. Intensive use occurs during periods of their growth phase, andwhen oxidation begins, ammonium nitrogen is released as ammonia. Then it is oxidized to the state of nitrites and then nitrates, or it is re-participated in a new synthesis.
In order to remove ammonium nitrogen from the reservoir, clinoptilolite is used, then the water restores its qualities. Cooling towers are installed in the warm season, and in winter they are replaced by ion-exchange plants, thanks 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 sample taken, and then its amount is determined in the resulting distillate.
How to clean the pond
There is an ion-exchange material in nature called clinoptilolite (a class of zeolites). It is with its help that it is advisable to restore the purity of water. Ammonium nitrogen does not completely dissolve in water, so you first need to free it from all suspended solids, and then supply water to clinoptilolite filters. This is a rather expensive cleaning, but it is the most effective - it reaches ninety-seven percent.
Regeneration will require the addition of a solution of sodium chloride - five or ten percent. The load must then 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 nitrogen in wastewater, as well as nitrogen-containing organic compounds, are removed by various types of distillation, extraction, adsorption.
Methods of obtaining fertilizers
This method is good if the determination of ammonium nitrogen is required. Its other forms, which are found in the same fertilizers - amide, nitrate - cannot be determined by this method. First you need to extract ammonium nitrogen, in wastewater, for example, there is plenty of it. This method has been discussed above. Next, a portion of the future fertilizer must be placed in a flask and spilled with a solution of hydrochloric acid (the concentration should be molar - 0.05 mol per dm3). 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.
Next, shake the solution again and filter through a pleated 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 to the original volume 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 ammonium nitrogen content is less than twenty milligrams, the test will fail and this method is not applicable.
Sources of pollution
The most characteristic features of industrial wastewater are an unstable chemical composition, a necessary period of adaptation for the development of microflora, an excess of compounds of organic and mineral origin of nitrogen. BeforeBy performing biological treatment at treatment facilities, wastewater is mixed with domestic and household wastewater and thus averaged. Ammonium nitrogen (formula NH4+) is an essential component of wastewater.
Sources of pollution can be wastewater from a variety of industries - from food and medical to metallurgical, coke, microbiological, chemical and petrochemical. This also includes all household waste, manure, agricultural - from the fields. As a result, proteins and urea are decomposed, and nitrites and nitrates are anaerobically restored.
Effect on the body
Such compounds have an extremely negative effect on the human body. Ammonia denatures proteins by reacting with them. Then the cells and, accordingly, the tissues of the body stop breathing, damage to the central nervous system, liver, respiratory organs is observed, and the work of blood vessels is disrupted. If you regularly use water with a high content of ammonium, acid-base balance suffers, acidosis begins.
reach toxic levels. Children are especially affected by this. Methemoglobinemia develops, the oxygen regime in the bodyis quickly destroyed, the gastrointestinal tract begins to suffer first.
Dose limits
Individual cases of methemoglobinemia begin when the content of nitrates in the water is up to fifty milligrams per liter, and when their concentration reaches ninety-five milligrams per liter, the disease becomes widespread. In the USA, France, the Netherlands, 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. Groundwater and well water carry concentrations of nitrates ten times higher than the limit - up to one and a half thousand milligrams per liter, while the World He alth Organization has set a limit of forty-five milligrams. And that's the water people drink!
And wastewater is treated in many ways - both biological filtration, and ozone oxidation, and alkaline earth metal hypochlorites, and aeration, and sorption, which uses sodium form zeolites, and ion exchange resins, and is treated with strong alkalis, and flotation, and restore ammonium with metallic magnesium, and add solutions of magnesium chloride with trisodium phosphate. However, cleaning technologies are always far behind pollution technologies.
Nutrients
In natural waters, the gas (NH3) ammonia dissolves when biochemical decomposition of organic compounds, including ammonium nitrogen, occurs. Then other compounds are formed and accumulated - ammonium ion and ammonium nitrogen. Dissolved ammonia enters water bodies with underground or surface runoff, with sewage, with atmospheric precipitation. If the concentration of ammonium ion (NH4+) exceeds the background value, this will mean the emergence of a new and close source of pollution. It can be either livestock farms or manure accumulations, or abandoned nitrogen fertilizers, industrial lagoons, or municipal treatment facilities.
And the compounds of nitrogen, carbon, phosphorus, which are contained in wastewater, getting into water bodies, cause significant environmental damage in 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, often just rolls over. This affects not only drinking water. Almost all vegetables and fruits quickly accumulate nitrates, they are found in the grass and grain that livestock eats.
Content of NH3 and NH4 in water bodies
Reservoirs always contain nitrogen in several transitional forms: ammonium s alts and ammonia, albuminoid nitrogen (organic), nitrites (s alts of nitrous acid) and nitrates (s alts of nitric acid). All this is formed together with the process of nitrogen mineralization, but to a greater extent comes with wastewater. Now the reservoirs need to be cleaned. Nitrogen compounds come to wastewater treatment plants in the form of nitrate nitrogen, nitrite nitrogen, ammonium nitrogen and nitrogen bound by organic compounds. Waste water of the household plan hasa small concentration of such substances, industry sends most of them to water bodies.
During the purification process, the ratio of mass concentrations of all forms of nitrogen compounds is constantly changing. The composition of wastewater 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 sewerage network, the further this process will go. Sometimes the content of ammonium ion at the entrance to the treatment 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, polypepsides (high molecular weight compounds), amino acids, carbamides (low molecular weight compounds), amines, amides. All organic matter, including nitrogen-containing ones, enters wastewater, after which nitrogen compounds are subjected to ammonization. There is a lot of organic nitrogen in wastewater, sometimes up to seventy percent of all nitrogen compounds. But as a result of ammoniation, no more than fifteen percent of organic nitrogen comes to the sewage treatment plant on the sewer path.
Next, man-made biological treatment takes place. The first stage is nitrification, that is, the conversion of nitrogen compounds due to certain types of microorganisms that oxidize ammonium nitrogen into a nitrate ion and a 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 his death, because 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 sewage penetrates through the soil, then ammonium nitrogen under the influence of some bacteria turns first into nitrites, then into nitrates. The predominance and content of various forms depends on the conditions that develop at the time of the entry of compounds with the presence of nitrogen into the soil, and then into the reservoir.
During a flood, the concentration of its organic forms increases significantly, since organic residues are washed away from the soil surface, and in summer they decrease just as significantly, because they serve as "food" for various aquatic organisms. Nitrite is an intermediate form of oxidation of ammonium nitrogen tending to become nitrate. In natural waters, nitrates are usually not so high, unless there was a washout of fertilizers from the fields.
