Influences of pH and CO2 on the formation of Metasilicate mineral water in Changbai Mountain, Northeast China

Abstract

Mineral dissolution reactions actively participate in controlling the composition of mineral water. In this study, water soluble, acidic-alkaline and carbonated solution experiments were designed, and mineral reaction mechanisms were researched using chemical kinetics and the minimum free-energy method. The results showed that the release of metasilicate was controlled by pH, CO 2 , and rock characteristics. In the water soluble experiment, the release process of metasilicate in powdered rocks reached equilibrium after 40 days, while metasilicate in solid rocks took 170 days. The release process of metasilicate in solid rocks satisfied an asymptotic model, while in powdered rocks it accorded with the Stanford reaction kinetic model. In the acidic-alkaline experiment, metasilicate was released earlier under acidic conditions (2.46 \ pH \ 7) than under alkaline conditions (7 \ pH \ 10.61). The release process of metasilicate under acidic conditions reached equilibrium in 40 days, compared with 60 days for alkaline conditions. The addition of CO 2 to the water solution was beneficial to the formation of metasilicate. Under neutral pH conditions, the reaction barely occurred. Under alkaline conditions, metasilicate was produced by the hydrolysis of metasilicate minerals. Under acidic and additional CO 2 conditions, metasilicate formation was mainly via the reaction of H ? , CO 2 , and metasilicate minerals. From these results, we concluded that the metasilicate mineral water from the Changbai Mountains, Jingyu County, is generated by a combination of the hydrolysis of metasilicate minerals and the reaction of H ? , CO 2 , and metasilicate minerals. These results can contribute to a better development and protection of the mineral water resources in the Changbai Mountains.

Influence of pH on Cr(VI) reduction by organic reducing substances from sugarcane molasses

“…v initial is the initial reaction rate of Cr(VI) reduction with sugarcane molasses: Based on the k obs obtained at different pH values on the conditions of sterilization and unsterilization environment, the relationship between pH and reaction rate (k obs ) was determined by regression analysis method. The relationship between pH and reaction rate (k obs ) on the conditions of sterilization and unsterilization was described by Boltzmann reaction kinetic model (Yan et al 2017) as Eq. (5).where k obs is the pseudo-first-order rate constant, and pH is the reaction solution pH.…”

Influence of Caprock Morphology on Solubility Trapping during CO2 Geological Sequestration

“…The aforementioned pH range of 3.5-5 is considered optimal enough to promote both dissolution reaction and precipitation reaction and thereby enhance the storage of CO 2 in the domain [58].…”

Sources of metasilicate in mineral water of Jingyu County, northeastern China

“…The characteristic component of Jingyu County natural mineral water is metasilicate, and its content is normally 30-49 mg/L [5]. The interpretation of geophysical exploration and drilling from the view of hydrogeology shows that thickness of the basalt in Jingyu County is less than 150 m, and the lower part is the Neogene mudstone and sandstone with a thickness of less than 50 m, which is in turn underlain by the Archean metamorphic rock stably distributed and forming a water-resistant floor in the area.…”