The problem of wastewater treatment from noxious compounds, especially nitrogen, using chemical methods as the process control, is particularly relevant today. Nitrogen compounds come into the treatment plants mainly in the form of ammonia, nitrates, nitrites, and nitrogen bonded in organic compounds. The concentration of total nitrogen in domestic wastewater may vary depending on the origin of wastewater.
Changes in the composition begins during the wastewater transportation to municipal treatment facilities. In particular, the organic compound urea contained in domestic wastewater decomposes to ammonium form because of interaction with bacteria (ammonification process). Accordingly, the longer sewer network is, the deeper this process works.
There are no chemical methods of determining the total inorganic nitrogen. The value of this parameter is calculated mathematically as the sum of nitrogen compounds in the form of ammonium, nitrate and nitrite ions.
For the determination of total nitrogen by the Kjeldahl method (the sum of organically bonded nitrogen and ammonia nitrogen) use the following equipment:
The main sources of anthropogenic origin phenols in water are wastewater of many industries – chemical, chemical-recovery and petrochemical, textile, pulp and paper, and others. Some phenols may be formed in environmental waters by natural metabolic processes of aquatic organisms, biological degradation and decomposition of organic matter.
Phenol in water may be dissolved in the form of free phenol and phenolate-ion.
The phenol content in the non-contaminated natural water is typically less than a few tenths microgram per liter. Elevated levels of phenols indicates the pollution of waterways.
The quantitative chemical analysis of natural or treated wastewater for determining the mass concentration of volatile phenols is performed by photometric method based on the steam distillation without dilution or concentration of the sample.
Nitrogen is essential for industry, medicine, agriculture. This macro element plays a crucial role in the physiological processes of the crop-plants. Nitrogen is an important building block of proteins, nucleic acids and other cellular constituents, which are essential for all forms of life.
In agronomic practice, Nitrogen is called the element of growth. This is true because all growth processes, photosynthesis, metabolism would have been impossible without the participation of this element, as it forms the crop and its quality. Nitrogen deficiency symptoms are expressed on the slowdown of crop and reducing of yields: the leaves are small, pale green or yellow, stems are thin and slightly branched.
Phosphorus is an essential natural component; it acts as a prominent nutrient in soil. However, excessive amounts of phosphorus is detrimental. Therefore, the Phosphorus determination is an indispensable parameter in the study of soils. In Phosphorus determination, a digestion of soil is used with adding of sulphuric acid, oxide agents and catalyst that eliminates losses.