Modeling Changes in the Composition of River Water with Discharged Wastewater: A Case Study in NW Russia

Abstract

The technogenic impact of the development of the Lomonosov diamond deposit is associated with the discharge of quarry and drainage water into the river, which has a special conservation status. Earlier studies on the composition of bottom sediments showed that there are signs of increased accumulation of heavy metals and radionuclides at wastewater discharge sites. The purpose of this work was to predict changes in the composition of surface water and bottom sediment in the river during the further development of mining operations with brackish and salty water captured by drainage systems, the presence of which was established in the zone of their future influence. For this, a simulation of changes in the composition of the water in the river was carried out using the GEOCHEQ software package by minimizing the free energy of the system using a convex simplex algorithm. It was found that the maximum salinity of surface water can reach 1.51 g/L. In this case, the MPC of Cl−, Na+, SO42−, Mg2+, Sr, V, and U can be exceeded for fishery watercourses. The genetic basis of the accumulation of these components in solutions for mixing was considered. According to the calculations, when about 5000 m3/h of drainage water is discharge d into the river, the mass of precipitated chemical elements will be 56–191 t/h, including up to 2.1 t/h of iron; therefore, accumulation in the discharge zone must be controlled.

The Influence of DOC on the Migration Forms of Elements and Their Sedimentation from River Waters at an Exploited Diamond Deposit (NW Russia)

“…In contrast to Fe, the concentrations of Ca, Mg, and C in the solutions with DOC are somewhat higher in winter than in summer: 10.2-76.5, 6.76-47.9, and 14.2-28 mg/kg H 2 O and 9.55-76.2, 5.25-46.4, and 12.4-26.1 mg/kg H 2 O, respectively (Figure 7e,g, Table 6). At the same time, the summer concentrations of these elements in the solutions with DOC are identical to the concentrations in the solutions without DOC [25]. Accordingly, their precipitation is somewhat worse in winter than in summer.…”

“…We have already considered this problem in previous studies [25] using the calculation of the equilibrium composition of mixed solutions. Our task was to estimate the maximum possible scale of sedimentation of secondary minerals from discharged waters.…”

Fate of Heavy Metals in the Surface Water-Dump Rock System of the Mine Lupikko I (Karelia): Field Observations and Geochemical Modeling

“…Risk assessment of natural water and soil pollution and the planning of dump disposal in mining areas is crucial for environmental sustainability [1]. Such ecological aspects of ore development are considered by geochemists [2][3][4][5], together with the transport of typical pollutants of mining areas [6][7][8][9][10]. Another urgent problem is the environmental impact of abandoned mines: dumps, tailings, and flooded mines, which are out of supervision, lead to pollution of soils and natural waters [11][12][13].…”