dissolved ions
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2021 ◽  
Author(s):  
Kevin Spicka ◽  
Lisa Holding Eagle ◽  
Chris Longie ◽  
Kyle Dahlgren ◽  
AJ Gerbino ◽  
...  

Abstract The Bakken formation is well known for producing brine very high in total dissolved solids (TDS). Halite, calcium carbonate, and barium sulfate scales all can pose substantial production challenges. Trademarks of Bakken produced brine include elevated concentrations of sodium (>90,000 mg/L), chloride (>200,000 mg/L), and calcium (>30,000 mg/L), contrasted against low concentration of bicarbonate (50-500 mg/L). In the past 3 years, operators have experienced unexpected instances of severe calcium carbonate scale on surface where produced fluids from the production tubing commingled with the gas produced up the casing. Initially treated as one-off scale deposits despite the application of scale inhibitor, acid remediation jobs or surface line replacement were typical solutions. As time has passed, this issue has become more and more prevalent across the Bakken. Investigation of this surface issue discovered a most unexpected culprit: a low TDS, high alkalinity brine (up to 92,000 mg/L alkalinity measured to date) produced up the casing with the gas. When mixing with the high calcium brine typically produced in the Bakken, the resulting incompatibility posed remarkable scale control challenges. The uniqueness of this challenge required thorough analytical work to confirm the species and concentrations of the dissolved ions in the brine produced with the gas. Scale control products were tested to evaluate their abilities and limitations regarding adequate control of this massive incompatibility. The theory that corrosion contributed to this situation has been supported by a unique modelling approach. Once corrosion was identified as the likely source of the high alkalinity brine, corrosion programs were instituted to help address the surface scaling. This paper highlights the evaluations conducted to fully grasp the severity of the incompatibility, the theories put forth to date, work conducted to try to replicate the phenomena in the lab and in models, and chemical programs used in the field to address corrosion and scale. While not known to exist in other oilfield basins, conventional or unconventional, this discovery may have implications for the broader industry if similar situations occur. The possible explanations for why this may be happening may have implications for scale control, asset integrity, and potentially even the methods by which wells are produced.


Author(s):  
Saúl A. Villafañe-Barajas ◽  
María Colín-García

Abstract Since their discovery, submarine hydrothermal vent systems have been pointed out as important places where chemical evolution on Earth could have occurred; and their role in the process has been highlighted. Similarly, some hypotheses have considered these systems in origin of life scenarios. In this way, many experiments have been developed, and the knowledge about these systems has increased. Due to their complexity, many experimental simulations have only included a few of the geochemical variables present in these environments, pressure and temperature. Other main variables have hardly been included, such as mineralogy, thermal and pH gradients, dissolved ions and/or redox reactions. As it has been understood, the dynamism and heterogeneity of these environments are huge, and it comprises different scales, from single vents to full hydrothermal fields. However, the vast majority of experiments focus on a specific part of these systems and do not include salinity, mineralogy and pH gradients. For this reason, in this paper, we pointed out some considerations about how this dynamism can be interpreted, and included in some models, as well their importance in prebiotic chemistry experiments and their extrapolations regarding the hypothesis about the origins of life.


2021 ◽  
Vol 21 (11) ◽  
pp. 5436-5442
Author(s):  
Wenhe Luo ◽  
Tao Li ◽  
Meng Wang ◽  
Wanqin Dai ◽  
Chunlei Jiao ◽  
...  

Quantitatively studying the biodistribution and transformation of nanomaterials is of great importance for nanotoxicological evaluation. Recently, laser ablation inductively coupled plasma mass spectrometry has been employed to distinguish nanoparticles (NPs) with their dissolved ions in biological samples. The principle of the proposal is based on a hypothesis that the intact NPs sampled by laser ablation will generate discrete sharp pulses of signals in ICP-MS measurement, being totally different from the continuous, relatively lower signals generated by ions. However, it is still a controversy whether NPs could maintain their intactness during the laser ablation. This work found a way to exactly determine the number of NPs sampled for each LA-ICP-MS measurement. It made possible to reveal the signal profile of a single NP in LA-ICP-MS analysis. The results suggest that AuNR, AgNP and TIO2 NP were broken into much smaller secondary NPs during the laser ablation, therefore generating continuous signals in the analyzer. There was a certain probability that the fragmentation of large-sized NP or multiple NPs by laser ablation was not sufficient, leaving some NPs unbroken or some secondary NPs with relatively large sizes to generate discrete pulses of signals in the analyzer. When the intactness of NPs during laser ablation cannot be assured, it is impossible to determine the attribution of mass spectrum signals. These findings compromise the reliability of distinguishing NPs from their dissolved ions by LA-ICP-MS.


2021 ◽  
Author(s):  
Rama Mohan Kurakalva ◽  
Sravya Sai Guddeti ◽  
Anjana Nath ◽  
Eswara Venkata Ravi Kishore Vemana

Abstract Anthropogenic activities such as the rapid leap of industrialization and urbanization constitute a significant concern in megacities and have become a key source of groundwater contamination. Twenty-five (25) groundwater samples were collected from tube wells and handpumps from Nacharam watershed, greater Hyderabad. The water samples were analyzed for 13 physicochemical parameters and major dissolved ions using the standard methods. WQI has been computed using a weighted arithmetic index method and integrated with GIS to identify the hotspots of contamination and their spatial distribution. The analytical data plotted on the Piper diagram showed that dominance of Ca-Mg-Cl (52%) type followed by Na-Cl type of water is dominant in 44% of samples might be resulting due to increase in anthropogenic activities such as discharge of waste water from industries. Results reveal that 96% of the samples exceed the F - concentrations compared with WHO permissible limits suggested unfit for drinking. WQI values indicate that 56% of samples fall in the poor category, 28% belong to very poor water, and 4% are unsuitable for drinking. These findings will provide valuable information to policymakers and stakeholders on the proper management and supply of potable water that reduces human health concerns .


Substantia ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 97-120
Author(s):  
Ernst Kenndler

This review is the first in a series that deals exclusively with electrophoresis of ions. Since in modern terminology "electrophoresis is the movement of dispersed particles relative to a fluid under the influence of a spatially uniform electric field”, electrophoresis is not limited to colloidal particles, it includes ions as well. The history of electrophoresis of ions therefore begins in 1800 at the same time as that of electrolysis, because the two phenomena are so inextricably linked “that one cannot happen without the other” (Faraday, 1834). Between 1800 and 1805 about half a dozen different theories of electrolytic decomposition and the movement of the particles - for which we coin the term electrophoretic current - were formulated, all contributing to the discourse, but lacking consistency and none fully convincing. They are discussed nonetheless because most of them fell into oblivion, even though they are interesting for historical reasons. However, from 1805/1806 the predominant theory, formulated by Theodor von Grotthuß and independently by Humphry Davy assumed that polarized molecules of water or dissolved ions form chains between the two electrodes. Only the terminal atoms of these chains were in direct contact with the electrodes and were liberated by galvanic action, but are immediately replaced by neighboring atoms of the same type. This decomposition and recombination of the molecules driven by electric forces which follow the “action at a distance” principle like in Coulomb´s law takes place over the entire chains; they represent the electrophoretic current. However, in 1833 Michael Faraday refuted all previous theories. Two of his groundbreaking findings were of particular importance for the electrophoresis of ions: one was that electricity consists of elementary units of charge. The ions thus carry one or a multiple of these units. The other was the revolutionary theory of the electric lines of force in early 1840s, and of what was later called the electric field. With these findings Faraday fundamentally changed the previously prevailing view of the electrophoresis of ions.


2021 ◽  
Vol 62 (3b) ◽  
pp. 9-21
Author(s):  
Hai Thanh Pham . ◽  
Urs Peuker ◽  

Steam pressure filtration is the combination of mechanical and thermal in one equipment. This process shows the advantages in comparison to conventional pressure filtration by the characteristic of its distinction mechanism. Application of steam pressure filtration can be listed: dewatering the suspension of fine solid, remove the contaminant, dangerous chemical, dissolved ions, protecting the human health as well as the environment. This paper shows the mechanism of steam pressure filtration as well as the result of tests, the comparison related to the efficiency between steam pressure filtration and conventional pressure filtration. The steam pressure filtration shows the high efficiency in mechanical displacement phase in both input parameters: solid volume fraction of suspension and the height of filter cake. The residual moisture content and saturation of filter cake using steam pressure filtration are lower 10÷20% than those values of filter cake using conventional pressure filtration. Moreover, some preliminary tests taking account to the drying phase of steam pressure filtration are also showed. The moisture of fine material filter cakes is around 6÷13%. Through the result of tests, interpretation and discussion, the application of steam pressure filtration is possible in the field of mineral processing and metallurgy.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 633
Author(s):  
Philippe Colomban ◽  
Burcu Kırmızı ◽  
Gulsu Simsek Franci

Minerals able to colour in blue (and green in combination with yellow pigments) are limited in number and geologically. After presenting a short history of the use of cobalt as a colouring agent of glass, glaze and enamel in the Western/Mediterranean, Islamic and Asian worlds since Antiquity, we will present the different forms (dissolved ions, natural and synthetic crystalline phases/pigments) of cobalt and associated elements regarding primary (transition metals) and secondary geological deposits (transition metals and/or arsenic, bismuth, silver). Attempts to identify the origin of cobalt have been made by many authors considering the associated elements but without considering the important modifications due to different processing of the raw materials (extraction/purification/formulation). We review the information available in the ancient reports and present literature on the use of cobalt, its extraction and production from the ores, the different geological sources and their relationship with associated elements (transition metals, bismuth, arsenic, and silver) and with technological/aesthetic requirements. (Partial) substitution of cobalt with lapis lazuli is also addressed. The relative application of non-invasive mobile Raman and pXRF analytical instruments, to detect mineral phases and elements associated with/replacing cobalt is addressed, with emphasis on Mamluk, Ottoman, Chinese, Vietnamese and Japanese productions. The efficiency of Ni-Zn-As diagram proposed by Gratuze et al. as a classification tool is confirmed but additionally, CoO-Fe2O3−MnO and CoO-NiO-Cr2O3 diagrams are also found as very efficient tools in this research. The relationship between the compositional data obtained from the artefacts and historical questions on the origin and date of their production are discussed in order to obtain a global historical view. The need of a better knowledge of (ancient) deposits of cobalt ores and the evolution of cobalt ore processing with time and place is obvious.


2021 ◽  
Author(s):  
Valentin Iglesias ◽  
Carlos Pintado-Grima ◽  
Jaime Santos ◽  
Marc Fornt ◽  
Salvador Ventura

Proteins microenvironments modulate their structures. Binding partners, organic molecules, or dissolved ions can alter the protein's compaction, inducing aggregation or order-disorder conformational transitions. Surprisingly, bioinformatic platforms often disregard the protein context in their modeling. In recent work, we proposed that modeling how pH affects protein net charge and hydrophobicity might allow us to forecast pH-dependent aggregation and conditional disorder in intrinsically disordered proteins (IDPs). As these approaches showed remarkable success in recapitulating the available bibliographical data, we made these prediction methods available for the scientific community as two user-friendly web servers. SolupHred is the first dedicated software to predict pH-dependent aggregation, and DispHred is the first pH-dependent predictor of protein disorder. Here we dissect the features of these two software applications to train and assist scientists in studying pH-dependent conformational changes in IDPs.


2021 ◽  
Author(s):  
Subhrajit Das ◽  
Sivaprakasam Vasudevan

Abstract To grasp meltwater chemistry and geochemical processes influencing hydrogeochemistry, major ion chemistry of the glacial lake Satopanth Tal was carried out to provide relevant details on the dissolved ions sources, weathering, and hydrogeochemical processes as well as anthropogenic activities taking place throughout the lake setting. Twenty-one surficial water samples were collected and 12 different physicochemical parameters were analyzed to understand the hydrogeochemistry of the study area. The mean pH value was estimated to be 6.9 in the lake water, which indicates a marginally acidic. The ionic contribution through the organic matter decomposition has been indicated by the observation of dominancy of the total anions over the total cations. The most abundant anion was Cl− in Satopanth Tal, while Ca2+ and Mg2+ were significant cations in the water. The high ratios of (Ca2+ + Mg2+)/TZ+, (Ca2+ + Mg2+)/(Na+ + K+), HCO3̶/(Ca2+ + Mg2+), and the higher Ca+/ Na+, Mg+/ Na+ and HCO3̶/ Na+ ratio indicate the supremacy of the weathering of carbonate as a significant source of dissolved ions in the study area's lake water. The lower equivalent ratios of Na+/Cl− and K+/Cl− are measured and substantially comparable results are observed that have been expected from the Gibbs plot and the stable isotope analysis suggests a reasonably significant contribution to the chemical composition of the Satopanth Tal water by these ions from atmospheric precipitation. The correlation and factor analysis show that water chemistry at Satopanth Tal is primarily influenced by weathering processes such as weathering of carbonate and silicate, pyrite oxidation.


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