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SEDIMENTS OF WASTEWATER WASHED WITH SULFURIC ACID
Temirov O.Sh.
Najmitdinova M.U.
Jo‘raqulov B.A.
Jabborova M.U.
Navoi State University of Mining and Technologies
https://doi.org/10.5281/zenodo.16760565
Currently, industrial wastewater is generated as a result of using water in
various technological processes. The volume, composition, and concentration of
pollutants in such wastewater are determined by several factors: the type of
industrial production and characteristics of the technological process, the
composition of raw materials and final products, the quality of clean water used,
and the operational regime of the technological process. The concentration of
pollutants in wastewater varies widely across enterprises, over time, and
between different workshops of the same factory. This inconsistency in flow and
composition reduces the efficiency of treatment facilities and complicates their
operation [1-2].
Contaminated wastewater is generally divided into three groups: water
polluted mainly with organic substances, mainly with mineral substances, and
mixtures containing both types of substances. In most enterprises, wastewater
contains a mix of organic and mineral components in various proportions.
In this study, the elemental composition of ash from wastewater treatment
sediments (WTS) formed at wastewater treatment plants in the city of Navoi
was examined after being washed with sulfuric acid.
Figure 1. X-ray fluorescence analysis of WTS ash from Navoi city
MODELS AND METHODS IN MODERN SCIENCE
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Figure 2. X-ray fluorescence analysis of WTS ash from Navoi city after
washing with sulfuric acid
In the unwashed sample, calcium oxide (CaO) had the highest content—
45.7%. Other significant oxides identified include:
SiO₂ – 22.1%
P₂O₅ – 14.14%
SO₃ – 11.8%
Fe₂O₃ – 7.6%
Al₂O₃ – 5.8%
Additionally, chlorine (Cl) – 0.958%, chromium oxide (Cr₂O₃) – 0.841%, and
zinc oxide (ZnO) – 0.371% were detected. These levels of pollutants—
particularly Cr, Zn, Cu, Pb, and U—indicate the presence of hazardous waste
components.
After washing with sulfuric acid, the concentration of harmful metal oxides
was significantly reduced:
Lead oxide (PbO) decreased from 0.0754% to 0.0055%
Iron(III) oxide (Fe₂O₃) from 7.6% to 2.11%
Chromium(III) oxide (Cr₂O₃) from 0.841% to 0.102%
Uranium oxide (U₃O₈) from 0.0111% to 0.0007%
These results demonstrate that the washing process with sulfuric acid not
only helps reduce active pollutants but also assists in purifying components that
may be used as fertilizers.
References:
1.Shtamm E.V. et al. Biotesting in the evaluation of wastewater treatment
technologies // Water Resources. – 2011. – Vol. 38. – No. 2. – P. 232–238.
2.Maslova A.A., Fursova D.S. Wastewater and its treatment // Proc. XX Int.
Scientific and Technical Conference "Modern Problems of Ecology". Tula,
Innovative Technologies. – 2018. – P. 49–50.
