The peculiarity of the growth and purification of Chlorella sp from mineral substances in the northern collector water of the Bukhara Region

. The composition of collector water formed as a result of pumping underground wastewater is rich in biogenic elements. Of the chemical elements, the water of the Northern Collector contains more chlorides (780 mg/l), as well as sulfates (3900 mg/l) compared to other elements. When cleaning collector waters with microscopic algae Chlorella sp, the biogenic elements in the wastewater were not recorded after the experiment. Chlorides were reported to have decreased by 6,5% and sulfates by 5,2 %.


Introduction
With the growth of the Earth population in various natural systems, firstly, anthropogenic impacts on different types of water ponds have also increased.This led to the physical and chemical change of environmental indicators and destruction of natural state of ecological systems.This has affected the survival and reproduction of many organisms, that is, flora and fauna living in these reservoirs.Some classes of plants can grow, thrive and reproduce in polluted reservoirs.Plant species that grow in reservoirs rich in organic substances may exhibit the property of purification from mineral substances.In addition to water purification, a large amount of green biomass is formed.This huge amount of biomass can be used in various fields of agriculture.Currently, microscopic algae are used as additional nutrients in various fields of agriculture [1].For feeding calves and cows, a dry mass of chlorella is used as an additional nutrient.This feed has a complex effect on increasing the biochemical, hematological and morphological indicators of the blood of cattle [2].
When feeding with Chlorella pyrenoidos and Moina micrura, this positively effected to the growth and weight of the larvae of Misgurnus anguillicaudatus compared to other species [3].
Another feature of microscopic algae is the purification of wastewater from organomineral substances.It is noted that the use of algae for the effective removal of biogenic elements contained in the wastewater of livestock enterprises provides high advantages of new methods compared to traditional anaerobic methods [4].The peculiarities of the composition of wastewater are related to the activities of the production enterprise.It is believed that the most suitable species for the treatment of wastewater contaminated with phenolic compounds is the green algae Cladophora aegagropila [5].Scientists from the University of Turku, Finland, and Lomonosov Moscow State University noted that the most effective method of wastewater treatment from organic compounds, as well as nitrogen and phosphorus is the biological method, while the resulting algae biomass proved suitable for processing into biofuels.
Under optimal growth conditions, Chlorella biomass consists of 25-50% protein, 5-35% carbohydrates and 5-20% fats, which are present in the form of unsaturated fatty acids, most of which consist of stearic, oleic, arachidonic, linolenic and linoleic acids, 5-10% minerals, mainly phosphorus, sulfur and magnesium, as well as carotene, with vitamins C and K and B vitamins [6].

Research methodology
Having determined the species composition of algae common in reservoir waters, an algologically pure cell of Chlorella sp., representatives of green algae, rich in protein, carbohydrates, vitamins and antibiotics, was picked.The experiments were carried out in laboratory conditions to study the reproduction of algologically pure cells in ditch waters and the purification of waters from organomineral substances.The water brought for the experiment was placed in special 5-liter plastic bottles, and selected cells of Chlorella sp with a volume of 1,5 million/ml into the waste water of a container, were planted and mixed using a microcompressor (SB-648).The change in the chemical composition of wastewater was measured before and after sowing Chlorella sp cells.

Results and discussion
For conducting experiments, samples were brought from the Northern collector water and their physicochemical distribution was determined (Table 1).The content of nitrates in northern collector water was 7.8 mg/l, chlorides 780 mg/l, sulfates 3900 mg/l, respectively.In wastewater, we mixed Chlorella sp using microcompressors to increase its reproduction.During the experiment, the water temperature was 25-30 ° C, and the illumination was about 10-15 thousand lux.Several experiments have been conducted on water purification using Chlorella sp.There was an increase in the number of Chlorella cells, and their number was calculated using Goryaev's camera.
Growing Chlorella sp in ditch water took 6 days.At the end of the experiment, the number of cells in the water from the Northern Ditch increased to 10.5 ml/ml (Table 2).At the end of the experiment, Chlorella sp cells were splitted up using centrifuge.And the physicochemical composition of the waters was found (Table 3).
Experiments carried out in laboratory conditions showed a certain decrease in the content of unvarying substances in waters, as well as dry residue.The mineral substances contained in the dry residues are spent on the development of algae.As a result of the growth of Chlorella sp cells, that is, due to the process of photosynthesis, the amount of oxygen in the water increased to 12.5 -13.5 mg/l.At the end of the experiment, the physicochemical composition of the wastewater was determined.According to this, the biogenic elements contained in waters were completely absorbed.Therefore,the number of chlorella sp cells increased from 1.5 million/ml to 10.5 million/ml.Nitrogencompounds, nitrites, nitrates, phosphates and iron elements contained in the waters were completely absorbed by algae.As a result of the experiments, there was a decrease in the content of chlorides in water by 6.5%, and sulfates -by 5.2%.
The amount of dissolved oxygen in the water of the Northern Ditch, the biochemical oxygen consumption and the degree of oxidation, as well as the amount of mineral salt depend on various dirty wastewater discharged into the sewer and minerals used on agricultural land.As a result of the creation of biotechnological purification of reservoirs from various organo-mineral substances with the help of algae, the hydrobiological conditions of the reservoir are improved and the proportion of natural food for phytophagous fish increases, which leads to an improvement in the living conditions of fish, which are considered the last link in the trophic chain in reservoirs.

Conclusion
As a result of growth and development Chlorella sp enriches ditch water with oxygen, while oxygen is used for decomposing of organic substances, turning them into minerals with the help of microorganisms.Consequently, this provides green algae to grow and develop at the expense of minerals and cleanses them of various toxic chemicals contained in the ditch water.

Table 1 .
Physicochemical composition of Northern collector water.

Table 2 .
Daily growth of Chlorella sp in Northern ditch waters.

Table 3 .
Physical chemical composition of Northern ditch waters after Chlorella sp cultivation (6th day).