INVESTIGATION INTO THE COMPOSITION AND PHYSICOCHEMICAL PROPERTIES OF TECHNOGENIC WATERS ACCUMULATED IN MINING SITES

ABSTRACT

This study examines the composition and hardness of technogenic waters from mining areas through ion analysis and atomic absorption spectroscopy. Results show elevated calcium, magnesium, and sodium levels, mostly as hydrosulfates, chlorides, and nitrates. Total hardness ranged between 58–63 mg/L, exceeding WHO standards for drinking water. Seasonal variations in solubility were observed, with higher concentrations in summer. Due to high hardness, these waters are unsuitable for consumption without softening. However, with proper treatment, they may be used in industrial and agricultural processes. The findings support the development of efficient reuse strategies for mine-affected water resources.

АННОТАЦИЯ

В этом исследовании изучается состав и жесткость техногенных вод из районов добычи полезных ископаемых с помощью ионного анализа и атомно-абсорбционной спектроскопии. Результаты показывают повышенные уровни кальция, магния и натрия, в основном в виде гидросульфатов, хлоридов и нитратов. Общая жесткость варьировалась в пределах 58–63 мг/л, что превышает стандарты ВОЗ для питьевой воды. Наблюдались сезонные колебания растворимости с более высокими концентрациями летом. Из-за высокой жесткости эти воды непригодны для употребления без смягчения. Однако при надлежащей очистке их можно использовать в промышленных и сельскохозяйственных процессах. Результаты подтверждают разработку эффективных стратегий повторного использования водных ресурсов, пострадавших от шахт.

Keywords: Technogenic waters, water hardness, calcium and magnesium ions, mining wastewater, industrial water reuse.

Ключевые слова: Техногенные воды, жесткость воды, ионы кальция и магния, сточные воды горнодобывающих предприятий, повторное использование промышленных вод.

Water reservoirs formed in mining areas are often shaped under the influence of both natural and technogenic processes. The composition and properties of these waters are of ecological and economic importance [1]. Determining the chemical and physical parameters of waters accumulated in mines is a key focus of modern research, as these waters may serve as potential technological resources [2].

Such waters are typically rich in minerals, heavy metals, and other chemical elements, creating opportunities for efficient resource utilization [3]. For instance, technologies for extracting metals such as iron, copper, and zinc from these waters are actively being developed. At the same time, ensuring environmental safety during these processes remains a pressing issue [4].

In-depth study of the physicochemical composition of mine waters allows researchers to assess their environmental impact and explore possibilities for their adaptation to industrial and agricultural needs. Reprocessing such waters can contribute to solving ecological problems, conserving natural resources, and enhancing economic efficiency [5].

The aim of this research is to study the composition and characteristics of technogenic waters collected in reservoirs formed during mining operations, to evaluate their utilization potential, and to develop applicable treatment technologies. Technogenic waters generated in mining sites were selected as the research object [6]. Several samples were collected from various zones and depths of these reservoirs. Their composition was analyzed using atomic absorption spectroscopy, and the results are presented in Tables 1 and 2.

Table 1.

Concentration of cations in technogenic waters

Table 2.

 Concentration of anions in technogenic waters

The ionic composition of technogenic waters presented in Tables 1 and 2 shows that the concentrations of calcium, magnesium, and sodium ions are significantly higher compared to other metal ions. These elements are mainly present in dissolved form as hydrosulfate, chloride, and partially nitrate salts. Continuous investigations have revealed that the solubility of these salts varies seasonally. For instance, samples collected during the summer contain higher salt concentrations than those taken in winter. This phenomenon is explained by the general principle that the solubility of most salts increases with rising temperature.  

Water hardness is a key parameter based on the concentrations of calcium (Ca²⁺) and magnesium (Mg²⁺) ions in water, and it plays an important role in assessing water quality. Hardness affects drinking water standards, industrial processes, and the environment. It is generally caused by carbonates and other dissolved salts, and is categorized into temporary and permanent hardness. Temporary hardness results from carbonates and bicarbonates that can be removed by boiling, while permanent hardness is caused by sulfates and chlorides, which remain in water after boiling.

The issue of water hardness is critical for industry, agriculture, and ecological sustainability. For example, hard water can lead to scale formation in heating systems, reducing energy efficiency and damaging equipment. In drinking water, high hardness levels may negatively affect human health and cause inconveniences in daily life. Therefore, studying water hardness and identifying ways to reduce it is of practical and scientific importance.

In this study, the hardness of technogenic waters was evaluated using specific formulas. These formulas allow calculation of the contribution of calcium (Ca²⁺), magnesium (Mg²⁺), carbonate (HCO₃⁻ and CO₃²⁻), and other ions to total hardness.

In this study, the hardness of various technogenic waters was determined based on measured concentrations of calcium, magnesium, carbonates, and other ions. Using the above formulas, temporary, permanent, and total hardness values were calculated for each sample. The analytical results are presented in Table 3.

Table 3.

Analytical results of technogenic water hardness determination

Based on the hardness indicators of water samples presented in Table 3, total, temporary, and permanent hardness values were determined. Calculations showed that the total hardness of the samples ranged between 58–63 mg/L, indicating that these waters fall under the category of very hard water. According to general classification, water with a hardness level above 6 mg/L is considered very hard. Such high hardness limits the suitability of the water for drinking purposes. According to the World Health Organization (WHO) and other international standards, the hardness of drinking water should not exceed 10 mg/L. Consumption of hard water may lead to health issues such as kidney stone formation and other related complications. Therefore, these samples are not suitable for direct consumption. Before using such water for drinking or technological purposes, softening treatments – such as ion exchange, redistillation, or chemical treatment – are necessary.

For technical uses, such as in industry, agriculture, or technological processes, these waters may still be applicable. However, due to high hardness, they can cause scale buildup in boiler systems or heat exchangers, reducing equipment efficiency and shortening service life. Therefore, hardness reduction measures must be taken prior to technical application. These analytical results contribute to a deeper understanding of water composition and help develop recommendations for appropriate use. By calculating temporary and permanent hardness levels, it is possible to optimize water treatment technologies. These analyses are particularly important for ensuring clean and safe water sources, as well as for efficient use in industrial and agricultural sectors.

References:

1. Khojiev, S.T. Processing of copper slag using waste tires // Metallurgist. – 2025. – Vol. 68.  – № 8. – PP. 1-10.
2. Bikmishev, V.M. Hydrochemistry: Theory and Application. Moscow: Mir, 2020. – PP. 320.
3. Kudryashov, N.I., Grigoriev, A.P. Purification and recovery of waste water in industry. Leningrad: Science, 2019. – PP. 290.
4. Mustafin, R.Kh. Resource-oriented use of man-made waters. Kazan: Book Publishing House, 2021. - PP. 345.
5. Kholikulov D., Khojiev Sh., Khaydaraliev Kh., Boltayev O., Khujayev T., Abdiev O., Yusupov A. Application of ozone for the treatment of process solutions and wastewater in copper production // International Journal of Mechatronics and Applied Mechanics. – 2025. – Vol. 1.  – № 19. – PP. 193-197.
6. Samadov A.U., Karimov M.M., Jabbarova B.I., Usmanov Sh.A. Development of technology for the reuse of water from a man-made reservoir Joint-Stock Company ‘AGMK’ // Mining Bulletin of Uzbekistan. - 2024. - Vol. 4, No. 99. - PP. 84–87.