Jing-Jie Li

Analyzing the hydrochemical characteristics and formation mechanism of metasilicic acid (H₂SiO₃) enrichment in the groundwater of Sanjiang Plain is conducive to guiding the rational development and utilization of mineral water resources in this region. Taking the groundwater in the typical black soil area of the northeastern Sanjiang Plain (from Qindeli Farm to Chuangye Farm) as an example, 104 groups of groundwater samples were collected to analyze enrichment and controlling factors of H₂SiO₃ by comprehensive methods such as hydrochemical analysis, rock geochemistry, water–rock interaction analysis, and ion ratio analysis. The results showed that the groundwater was generally in a reducing environment with low mineralization and weak acidity. The main cations were Ca²⁺ and Mg²⁺, and the main anion was HCO₃⁻. The hydrochemical types were mainly HCO₃–Ca and HCO₃–Ca·Mg, followed by HCO₃·Cl–Ca·Mg mixed type, and the H₂SiO₃ enrichment rate of groundwater reached 80.77%. The enrichment of H₂SiO₃ in the groundwater was related to the local geological structure and specific hydrogeochemical processes, and mainly controlled by the hydrolysis process of silicate rock minerals (such as albite, plagioclase, and olivine). The silicates and aluminosilicates contained in the basalt, diorite, and gneiss distributed in the area provided a rich material basis for the enrichment of H₂SiO₃. Its migration and distribution were simultaneously affected by leaching and cation exchange, while NO₃⁻ and SO₄²⁻ input from anthropogenic sources also participated in the rock weathering, specifically the enrichment process of H₂SiO₃ in the groundwater. From the perspective of mineralization conditions, Qinglongshan Farm and Qindeli Farm are potential areas for developing H₂SiO₃-rich mineral water. However, the main direction for the development and utilization of groundwater in this area should be to explore natural H₂SiO₃-rich groundwater with good comprehensive water quality.