«Water-granite» system: time of formation of freshwater composition

The relevance of the research is caused by the necessity to evaluate the changes in groundwater chemical composition due to water-rock interaction. Usually the source of water, the H2O molecules namely, and the source of dissolved components are considered separately. In the study the atmosphere precipitates is the source of H2O. As water is used for different purposes (potable water supply, industrial water supply), it must correspond to the specified water use standards. Water quality depends on it quality and composition. Water chemical composition depends, on its turn, on the structure of rock at interaction, interaction time and contact with atmosphere. The main aim of the study is to determine granite alteration and age of potable water chemical composition formation due to granite -meteoritic water interaction. Methods of research: thermodynamic simulation of water-rock interaction using HCh code developed by Yu.V. Shvarov. The equilibrium state algorithm is based on Gibbs free energy minimization and on chemical reactions system solution. The results. It is shown that in the «water-granite» system, open in respect to O2 and CO2, the Na-HCO3 composition of potable water forms during 3000 years. The aqueous solution pH value, which resulted from water-rock interaction, increases up to 7,8 but aqueous solution Eh value decreases from 0,79 to 0,62 V. The aqueous calcium concentration is limited by secondary minerals formation and deposition: dolomite and apatite

Acidic drainage in carbonate rocks

Thermodynamic simulation of the system “Rocks of Pavlovskoe polymetallic deposit – water – atmosphere gases” predicts aqueous concentrations from mineral solubilities and speciation with the HCh geochemical code. It is shown the model solutions are alkaline and rich in some microelements (As, Cd, Se, Co, Cr, Cu, Ni, Pb, Ga, Ge, Sr, In); their concentrations are overcome MPC, especially on the ore storage site

Theoretical evaluation of iodine and selenium speciation in the natural waters of iodine-deficient territories

Water migration of iodine, selenium are in many cases directly related to manifestation of thyroid pathologies, in particular, the endemic goiter. The main aim was to evaluate species and conditions of migration of these elements in natural waters from different water-bearing rocks in areas with a natural iodine deficiency. Evaluation of iodine and selenium species in aqueous solutions has been carried out by thermodynamic modeling basing on chemical composition of 81 water samples taken in the Bryansk region in the period of 2015-2017. The study has showed that the predominant species of iodine in the natural waters is iodide-ion (89%), which may also associate with typomorphic ions (Ca, Mg, Na, K, Sr) forming mineral complexes with them. In the latter state iodine may be removed from solution by fixation on a carbonate barrier. Selenium dominates in natural waters as hydroselenide ion (91%). In the presence of a significant amount of iron, this trace element may form the FeSe mineral phase which may be fixed in reduction conditions

«Water-granite» system: time of formation of freshwater composition

Актуальность работы обусловлена необходимостью оценки изменения химического состава вод в результате взаимодействия воды с горными породами. Следует рассматривать отдельно происхождение самой H2O и растворенных в ней компонентов. В данном исследовании источником H2O являются атмосферные осадки. Поскольку вода используется в тех или иных целях (хозяйственно-питьевое, техническое водоснабжение), она должна соответствовать установленным нормативам водопользования. Качество воды зависит от её свойств и химического состава. В свою очередь, химический состав полученной воды будет зависеть от состава породы, с которой она взаимодействует, времени воздействия, контакта с атмосферой. Цель работы: определение времени формирования химического состава пресных вод (до 1 г/л) при взаимодействии атмосферной воды с гранитом и ионно-солевого состава полученной воды; оценка изменения гранита в результате его взаимодействия с водой. Методы исследования: термодинамическое моделирование взаимодействия «вода-порода» с применением программного комплекса HCh (разработчик Ю.В. Шваров). Алгоритм программы основан на комбинированном использовании метода минимизации свободной энергии Гиббса системы и констант равновесия между компонентами системы. Результаты. Показано, что в системе «вода-гранит» открытой по кислороду и углекислоте пресные воды формируются за период до 3000 тысяч лет. Химический состав полученной воды - гидрокарбонатно-натриевый. pH раствора в результате взаимодействия возрастает до 7,8. Eh снижается в от 0,79 до 0,62 В. Рост кальция в растворе ограничивается выпадением вторичных минералов: доломит и апатит.The relevance of the research is caused by the necessity to evaluate the changes in groundwater chemical composition due to water-rock interaction. Usually the source of water, the H2O molecules namely, and the source of dissolved components are considered separately. In the study the atmosphere precipitates is the source of H2O. As water is used for different purposes (potable water supply, industrial water supply), it must correspond to the specified water use standards. Water quality depends on it quality and composition. Water chemical composition depends, on its turn, on the structure of rock at interaction, interaction time and contact with atmosphere. The main aim of the study is to determine granite alteration and age of potable water chemical composition formation due to granite -meteoritic water interaction. Methods of research: thermodynamic simulation of water-rock interaction using HCh code developed by Yu.V. Shvarov. The equilibrium state algorithm is based on Gibbs free energy minimization and on chemical reactions system solution. The results. It is shown that in the «water-granite» system, open in respect to O2 and CO2, the Na-HCO3 composition of potable water forms during 3000 years. The aqueous solution pH value, which resulted from water-rock interaction, increases up to 7,8 but aqueous solution Eh value decreases from 0,79 to 0,62 V. The aqueous calcium concentration is limited by secondary minerals formation and deposition: dolomite and apatite

Abstracts of The Second Eurasian RISK-2020 Conference and Symposium

This abstract book contains abstracts of the various research ideas presented at The Second Eurasian RISK-2020 Conference and Symposium.The RISK-2020 Conference and Symposium served as a perfect venue for practitioners, engineers, researchers, scientists, managers and decision-makers from all over the world to exchange ideas and technology about the latest innovation developments dealing with risk minimization