Advances in geochemical modeling for geothermal applications

AbstractLoss of phosphorus from agricultural land through water runoff causes serious detrimental effects on the environment and on water quality. Phosphorous runoff from excessive use of fertilizers can cause algal blooms to grow in nearby water systems, producing toxins that contaminate drinking water sources and recreational water. In this study, a risk analysis of the algal toxin micro-cystin-LR and the mitigation of phosphorus from agriculture runoff is discussed. A risk analysis was performed on the algal bloom toxin microcystin-LR considering the Lake Erie algal bloom event of 2011 as a case study. Toxicity risk analysis results show that relatively low concentrations of microcystin-LR compared to recent case studies pose an acute health risk to both children and adults, and a significant increase in the risk of developing cancer is suggested but subject to further study given the assumptions made. This study investigated the potential of using wollastonite to mitigate phosphorus pollution, considering thermodynamic conditions of a constructed wetland receiving influent water from agriculture runoff, by using geochemical modelling. Geochemical modelling results show that wollastonite can react with phosphorus and capture it in the stable mineral form of hydroxyapatite, offering a possible strategy for risk mitigation of phosphorous runoff. A removal efficiency of 77% of phosphorus using wollastonite is calculated with the help of geochemical modelling.

Download Full-text

Solubility Product of Vanadinite Pb5(VO4)3Cl at 25 °C—A Comprehensive Approach to Incongruent Dissolution Modeling

Minerals ◽

10.3390/min11020135 ◽

2021 ◽

Vol 11 (2) ◽

pp. 135

Author(s):

Justyna Topolska ◽

Bartosz Puzio ◽

Olaf Borkiewicz ◽

Julia Sordyl ◽

Maciej Manecki

Keyword(s):

Nuclear Waste ◽

Solubility Product ◽

Geochemical Modeling ◽

Incongruent Dissolution ◽

Mineral Solubility ◽

Actual Application ◽

Universal Approach ◽

Solubility Constant ◽

First Time

Although vanadinite (Pb5(VO4)3Cl) occurs in abundance in various terrestrial geochemical systems of natural and anthropogenic origin and is seriously considered as a potential nuclear waste sequestering agent, its actual application is severely limited by a lack of understanding of its basic thermodynamic parameters. In this regard, the greatest challenge is posed by its incongruent dissolution, which is a pivotal hurdle for effective geochemical modeling. Our paper presents an universal approach for geochemical computing of systems undergoing incongruent dissolution which, along with unique, long-term experiments on vanadinites’ stability, allowed us to determine the mineral solubility constant. The dissolution experiments were carried out at pH = 3.5 for 12 years. Vanadinite has dissolved incongruently, continuously re-precipitating into chervetite (Pb2V2O7) with the two minerals remaining in mutual equilibrium until termination of the experiments. The empirically derived solubility constant Ksp,V,298 = 10–91.89 ± 0.05 of vanadinite was determined for the first time. The proposed modeling method is versatile and can be adopted to other mineral systems undergoing incongruent dissolution.

Download Full-text

Seasonal fluctuations and geochemical modeling of acid mine drainage in the semi-arid Puna region: The Pan de Azúcar Pb–Ag–Zn mine, Argentina

Journal of South American Earth Sciences ◽

10.1016/j.jsames.2021.103197 ◽

2021 ◽

Vol 109 ◽

pp. 103197 ◽

Cited By ~ 1

Author(s):

Jesica Murray ◽

D. Kirk Nordstrom ◽

Bernhard Dold ◽

Alicia Kirschbaum

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Geochemical Modeling ◽

Seasonal Fluctuations ◽

Acid Mine ◽

Semi Arid

Download Full-text