Physicochemical Processes Research Articles

Biogeochemical Migration of Some Rare Elements in the “Leaf Debris–Soil” System of the Catenary Landscapes in Tropical Mountainous Forests in Southern Vietnam

Expeditionary studies of the functioning of landscapes of mid-mountain monsoon (including fog) forests have been being conducted within the landscape and ecological station in the territory of the Bidoup-Nui Ba National Park and the adjacent Hon Giao since 2018 and are currently underway. One of the research objectives is to clarify the biogeochemical migrations of the material composition of soils in the “leaf debris–soil” system. We have consistently studied natural objects for their material composition as well as the intensity and rate of involvement of chemical elements in physicochemical migration processes in the “leaf debris–soil” system. Our findings indicate an active influx of a select group of examined elements (Se, Pd, Ag, Cd, Sn, Bi), particularly Bi, Pd, Se, and Cd, through the leaf debris and the detachment of aboveground plant organs, warranting their integration into organogenic soil horizons. Subsequently, lateral migration (Pd, Cd, Se) ensues. Slope processes within subordinate landscape facets, in addition to soil moisture and aeration processes, contribute to the subsequent redistribution of elemental volumes introduced into organogenic soil horizons.

LOW-TEMPERATURE CALORIMETRIC CHARACTERIZATION OF DEEP EUTECTIC SOLVENTS WITH ADDED WATER

Deep eutectic solvents (DES) are combinations of hydrogen bonds donors and acceptors, characterized by significantly lower freezing temperatures than their components. NADES (with natural, biologically compatible components) are becoming popular for a wide applications variety, for their wide solvent capacities, non-toxicity, biodegradability, and inexpensive components. Applications include new means for bioactive compounds extraction and enzymatic reactions, polymer solubilizing and a variety of physicochemical processes, including those taking place at low temperature. Four DES (β-alanine and DL-malic or citric acid (plus water) and choline chloride and ethylene glycol or glycerol) were investigated by differential scanning calorimetry (DSC) at low temperature. Pure DES behave completely reversibly, proof of physicochemical stability. Alanine-DES present glass transitions between -40 and -80°C. Meanwhile, choline-DES show no thermal events between 0° and -80°C. Increasing water produce glass transitions in all DES at decreasing temperatures, and devitrifications and freezing events. Choline-DES show no effects up to 20% water. However, alanine-DES show strong water effects, possibly phase separation into different water populations. Calcium alginate-sucrose beads were used as structural model for diffusion systems. Beads were incubated in DES (20 min/20 hours) and their low-temperature properties characterized. Short incubation periods were enough to radically alter their thermal behavior.

An<em> in-vitro</em> gastric digestion model with peristalsis function for the analysis of the food gastric digestion

In vitro models of the human stomach offer a robust platform to explore the physicochemical processes during gastric digestion. In Sri Lanka, limited research has been conducted on the digestion behavior of diverse food structures using in vitro digestion models. This study aims to create a custom-built in vitro gastric digestion model, specifically designed for Sri Lankan laboratories to analyze food digestion in a simulated stomach environment. The physical model comprises a butyl rubber chamber simulating the stomach, 4 nylon rollers with 2 rubber belts, driven by geared motors, and 6 nylon pulleys, creating continuous contractions of the rubber chamber. The model simulates the peristaltic movements of the stomach wall, with contraction waves occurring at a frequency of approximately 3 cycles per minute, mimicking in vivo peristaltic movement. Gastric sieving, secretion, emptying, and temperature control mechanisms are employed to recreate dynamic gastrointestinal conditions. A polyester mesh bag with a pore size of 1.5 mm replicates the gastric sieving function, while manual gastric emptying is performed. Gastric juice is secreted into the chamber at a rate of 2.5 mL/min using a programmed peristaltic pump, and an automated temperature control system maintains the ambient temperature at 37 °C. In conclusion, this developed gastric device serves as an effective tool for studying the gastric digestion of various food structures within a simulated stomach environment.

Optimal Control of the Dynamics of Physical and Chemical Processes of Blending and Melting of Copper Concentrates

This paper presents the developed model of dynamics of the physicochemical processes of electromelting of copper concentrates, which was obtained taking into account the available a priori information, which makes allowance for the main features of an object and describes the change of the basic variables of the process state (quantitative aspects of material flows and power, the composition of charge, matte, and slag). Such a model can be used in the field of automation of technological processes in metallurgical and mechanical engineering, and manufacturing. Due to the complexities of the technological process, it was advisable to use classical methods.

Ready, Set, Grow: From Micelles to Giant Vesicles via Biocatalytic Activation.

Controlling physicochemical processes that drive changes in supramolecular aggregates is an important objective toward creating artificial soft micro- and nanomachines. Previous research explored the morphology control of membrane-based materials subjected to externally imposed chemical stimuli. Here, we modulate the microscale morphology of pH-responsive assemblies by using biocatalysis to internally generate changes in global pH. Catalytic reactions offer flexibility in the mechanism and rate at which stimuli are introduced to responsive assemblies, ultimately enabling precision and control over size and morphology. We observed, by dynamic light scattering and fluorescence microscopy, substantial microscale differences between assemblies subjected to manually titrated pH changes compared to biocatalytically activated pH changes, including the growth of giant vesicles from micelles. Coarse-grained molecular dynamics simulations of these metastable self-assembled structures provided insight into the thermodynamics and kinetics of the preferred structures. These results demonstrate the feasibility of using biocatalytic reactions to modulate the size and morphology of supramolecular assemblies, from micelles to giant vesicles.

Mathematical Tools for Simulation of 3D Bioprinting Processes on High-Performance Computing Resources: The State of the Art

Three-dimensional (3D) bioprinting belongs to the wide family of additive manufacturing techniques and employs cell-laden biomaterials. In particular, these materials, named “bioink”, are based on cytocompatible hydrogel compositions. To be printable, a bioink must have certain characteristics before, during, and after the printing process. These characteristics include achievable structural resolution, shape fidelity, and cell survival. In previous centuries, scientists have created mathematical models to understand how physical systems function. Only recently, with the quick progress of computational capabilities, high-fidelity and high-efficiency “computational simulation” tools have been developed based on such models and used as a proxy for real-world learning. Computational science, or “in silico” experimentation, is the term for this novel strategy that supplements pure theory and experiment. Moreover, a certain level of complexity characterizes the architecture of contemporary powerful computational resources, known as high-performance computing (HPC) resources, also due to the great heterogeneity of its structure. Lately, scientists and engineers have begun to develop and use computational models more extensively to also better understand the bioprinting process, rather than solely relying on experimental research, due to the large number of possible combinations of geometrical parameters and material properties, as well as the abundance of available bioprinting methods. This requires a new effort in designing and implementing computational tools capable of efficiently and effectively exploiting the potential of new HPC computing systems available in the Exascale Era. The final goal of this work is to offer an overview of the models, methods, and techniques that can be used for “in silico” experimentation of the physicochemical processes underlying the process of 3D bioprinting of cell-laden materials thanks to the use of up-to-date HPC resources.

The Capability of Amphibole in Tracing the Physicochemical Processes of Magma Mixing

AbstractThis study explores the capability of amphibole in tracing the physicochemical process of magma mixing through spatially associated gabbros, mafic microgranular enclaves (MMEs) and granodiorites from central Tibet. These rocks share similar zircon ages as well as zircon Hf‐O and plagioclase Sr isotopes. However, the amphiboles within the gabbros and granodiorites have different Sr and B isotope compositions, while amphiboles with both heterogeneous isotopic imprints occur in the MMEs. According to data and modeling, significant mixing of two isotopically distinct magmas is recorded by amphibole but not by zircon and plagioclase. Based on a synthesis of petrography, geochemistry and thermobarometry, we interpret this inconsistency by the crystallization order of minerals and propose that magma mixing occurred after the parent magma was emplaced at ∼10 km and cooled to ∼750°C. Our study highlights that amphibole may be a more sensitive tracer of magma mixing relative to other commonly used methods.

Carbonnanotubes: New Chemotherapeutic Drug Delivery Systems for Targeted Cancer Treatments

The complexity of the management of cancerous conditions requires innovative strategies, including the pharmacotechnical optimization of treatments. The improvement of galenic forms, or more generally of drug delivery, represents a rapidly developing area of research, particularly in oncology, in order to remedy side effects and drug resistance remains a worrying problem. Carbon nanotubes CNTs consist of thin sheets of benzene carbons coiled into a seamless tubular structure. These CNTs have remarkable size and surface properties that make them the ideal vehicle for targeted and selective drug delivery. Different in vitro and in vivo experiments have proven that these particles can be easily modified in such a way that the chemical drug can be delivered directly to the tumor site. Additionally, different types of ligands can be loaded on the surface of CNTs to improve selectivity or modulate drug release. On the other hand, advances in carbon nanotubes could well lead to a more effective understanding of biological and physicochemical processes. This will make it possible to find compounds more compatible with carbon nanotube technology and facilitate their use.

Enhancing effects and mechanisms by reductive iron on constructed wetland with perfluorooctanoic acid exposure: Comparison between zero-valent and ferrous iron

Reductive iron caused efficient enhancement of constructed wetlands (CWs) under toxic stress like perfluorooctanoic acid (PFOA), while effects and mechanisms brought by different iron have not been illustrated. In this study, impacts of zero-valent (Fe(0)) and ferrous iron (Fe(II)) on CW systems with PFOA exposure were compared. Higher ammonium removal above 98 % was discovered with Fe(0) addition than Fe(II), according with more expression of hydroxylamine dehydrogenase [EC:1.7.2.6]. On the contrary, Fe(II) was more prone to stimulate activities of ammonia monooxygenase and nitrite oxidoreductase, consisting with higher abundance of Nitrosomonas and Nitrospira than Fe(0). Fe(II) had more potential to improve denitrification, with total nitrogen removal 2.64–6.83 % higher compared to Fe(0) group. It was aligned with boost of dominant denitrifying bacteria like Zoogloea (53.48 %), which probably resulted from promotion of metabolism pathways related to nitrite reduction. Phosphorus removal with Fe(II) addition was 4.59–19.04 % higher than Fe(0). Higher TP removal in Fe(II) group could result from more enhancement of physicochemical processes, compared with Fe(0). Moreover, decrease of reactive oxygen species production by citrate and activation of mitochondrial metabolism was explanation for alleviation of PFOA stress with reductive iron introduction, particularly Fe(II). As for plants, Fe(0) led to higher chlorophyll contents and lower activity of antioxidant enzymes like catalase and malondialdehyde. Current work offered new information about comparative effects of reductive iron on CWs under PFOA exposure.

Floating treatment wetlands to improve the water quality of the Hang Bang canal, Ho Chi Minh City, Vietnam: Effect of plant species

Floating treatment wetlands (FTWs) are artificial platforms that allow aquatic emergent plants to grow in water. Aquatic macrophytes and microorganisms attached to plant roots contribute to the remediation of the contaminated water through physicochemical and biological processes. The pollutant removal treatment performance is affected by various factors, including the plant species. In this study, several plant species, i.e. Canna generalis, Phragmites australis, Pennisetum purpureum, Cyperus alternifolius rottb, Kyllinga brevifolia rottb, and Cyperus ordoratus were investigated for their potential to clean-up water from the Hang Bang canal in Ho Chi Minh City (Vietnam). Canna generalis, Phragmites australis, and Cyperus alternifolius were found to be suitable for FTWs with the highest performance compared to that of other plant species investigated. The organic and nitrogen removal rates amounted to 48–70 g COD m−3 d−1 and 0.7–1.2 g N m−3 d−1, respectively, whereas the reduction of pathogens was around 1.86–3.00 log. Furthermore, FTW systems bring other benefits such as improving ecosystem functioning and biodiversity, producing value-added products from plant biomass, as well as attracting the attention of communities, thus increasing social acceptance of environmental technology interventions.

Studying species distribution in laser-induced plasma by molecular and atomic fluorescence

The spatial distribution profiles of particles in plasma sources push forward our understanding of plasma evolution and physicochemical processes occuring inside. Optical probe methods, such as laser-induced fluorescence, are advanced tools for spatially resolved plasma studies. In our work, we focused on investigation of distribution of neutral Ca and Fe atoms and CaO and FeO molecules in laser-induced plasma by means of laser-induced fluorescence. The development of excitation-emission schemes for Fe and FeO and the practical implementation of schemes for Ca and CaO allowed us to construct distribution maps of these species in laser plasma at 10 and 100 Torr pressures. Both atomic and molecular fluorescence were observed much further from the plasma formation point than the region of bright spontaneous atomic emission. Additionally, by comparing fluorescence intensity distributions with plasma imaging data, we explain the origin of some pecularities in observable plasma inhomogeneity. Distributions of Ca and CaO fluorescence intensity, as well the distribution of CaO/Ca intensity ratio, demostrate that the monoxide is distributed within the plume by the shock wave, but its concentration in the outer layers of plasma is influenced by recombination with atmospheric oxygen.

Robust and effective ab initio molecular dynamics simulations on the GPU cloud infrastructure using the Schrödinger Materials Science Suite

Ab initio Born-Oppenheimer molecular dynamics (AIMD) is a valuable method for simulating physico-chemical processes of complex systems, including reactive systems, and for training machine learning models and force fields. Speed and stability issues on traditional hardware preclude routine AIMD simulations for larger systems and longer timescales. We postulate that any practically useful AIMD simulation must generate a trajectory of a minimum 1000 MD steps a day on a moderate cloud resource. In this work, we implement a computing workflow that enables routine calculations at this throughput and demonstrate results for several non-trivial atomistic dynamical systems. In particular, we have employed the GPU implementation of the Quantum ESPRESSO code which we will show increases AIMD productivity compared to the CPU version. In order to take advantage of transient servers (which are more cost and energy effective compared to the stable servers), we have implemented automatic restart/continuation of the AIMD runs within the Schrödinger Materials Science Suite. Finally, to reduce simulation size and thus reduce compute time when modeling surfaces, we have implemented a wall potential constraint. Our benchmarks using several reactive systems (lithium anode surface/solvent interface, hydrogen diffusion in an iron grain boundary) show a significant speed up when running on a GPU-enabled transient server using our updated implementation.

Numerical modeling and simulation of microbially induced calcite precipitation on a cement surface at the pore scale

Accurate estimation of contaminant transport in cementitious material using numerical tools plays a key role in the risk assessments of nuclear waste disposal. At the pore scale, the increase of microbial activity, such as microbially induced calcite precipitation on cementitious material, causes changes in solid surface topography, pore network geometry, and pore water chemistry, which affect contaminant transport at the core scale and beyond. Consequently, a meaningful estimation of contaminant migration in the subsurface requires a pore-scale investigation of the influence of microbial activity on transport processes. In this study, a pore-scale reactive transport model is presented to simulate the physicochemical processes resulting from microbially induced calcite precipitation on a cement surface. Numerical investigations focus on modeling the reactive transport in a two-dimensional flow-through cell. The model results are validated by experimental data showing an increase in pH and a decrease in calcium concentration due to microbially induced calcite precipitation. Our results show heterogeneous calcite precipitation under transport-limited conditions and homogeneous calcite precipitation under reaction-limited conditions, resulting in non-uniform and uniform changes in the material surface topography. Moreover, power spectral density analysis of the surface data demonstrates that microbially induced calcite precipitation affects the surface topography via both general changes over the entire frequency and local modifications in the high-frequency region. The sensitivity studies provide a comprehensive understanding of the evolution of surface topography due to the microbially induced calcite precipitation at the pore scale, thus contributing to an improved predictability of contaminant transport at the core scale and beyond.

Short Communication: Candida sp. isolated from mangrove soils for biological decolorization of textile reactive dyes

Abstract. Boontanom P, Chantarasiri A. 2024. Short communication: Candida sp. isolated from mangrove soils for biological decolorization of textile reactive dyes. Biodiversitas 25: 2595-2602. Effluent discharge from dye-related industries is a significant environmental pollution problem and a concern for human health. Dyes have harmful effects on aquatic organisms due to their toxic properties. One possible solution is using microorganisms for the biological decolorization of textile reactive dyes as an eco-friendly and potentially lucrative alternative to physicochemical processes. Therefore, this study isolated an effective dye-decolorizing yeast from mangrove soil samples in Thailand and investigated the decolorization efficiency of eight textile reactive dyes under experimental conditions. Yeasts have several advantages over other bacteria and fungi for the biological decolorization of textile reactive dyes, but the number of dye-decolorizing yeasts discovered in mangrove soils remains scarce. The most effective dye-decolorizing yeast, isolate RY21703, showed Remazol Brilliant Blue R (RBBR) decolorization of 37.50±0.07% within 72 h of incubation. This yeast isolate was genetically and phylogenetically identified as Candida sp. strain RY21703 and produced 0.97±0.08 U/mL of crude laccase activity, an essential enzyme in dye decolorization mechanisms. Candida sp. strain RY21703 showed strong decolorization efficiency after 72 h of incubation in all azo-reactive dyes, ranging from 27.32±3.34% (CI Reactive Orange 122) to 61.45±1.43% (CI Reactive Green 19). This strain also decolorized phthalocyanine reactive dye (CI Reactive Blue 21) by 60.71%. Findings suggested that this mangrove yeast can be used for the biological decolorization of dyeing wastewater.

The smart nanocarrier containing zein/starch co-biopolymers enhanced by graphitic carbon nitride; exploring opportunities in brain cancer treatment

In this investigation, we present an innovative pH-responsive nanocomposite designed to address challenges associated with using 5-Fluorouracil (5-FU) in cancer therapy. The nanocomposite containing zein (Z), starch (S), and graphitic carbon nitride (g-C3N4) macromolecules is synthesized by a water-in-oil-in-water (W/O/W) double emulsion technique, serving as a carrier for 5-FU. The S/Z hydrogel matrix's entrapment and loading efficiency are greatly improved by adding g-C3N4 nanosheets, reaching noteworthy values of 45.25 % and 86.5 %, respectively, for drug loading efficiency and entrapment efficiency. Characterization through FTIR and XRD validates the successful loading of 5-FU, elucidating the chemical bonding within the nanocomposite and crystalline characteristics. Structural analysis using FESEM, along with DLS and zeta potential measurements, reveals an average nanocomposite size of 193.48 nm, indicating a controlled structure, and a zeta potential of −42.32 mV, signifying a negatively charged surface. Studies on the in vitro release of drugs reveal that 5-FU is delivered more effectively and sustainably in acidic environments than in physiological circumstances. This highlights the fact that the created nanocarrier is pH-sensitive. Modeling release kinetics involves finding the right mathematical conditions representing underlying physicochemical processes. Employing curve-fitting techniques, predominant release mechanisms are identified, and optimal-fitting kinetic models are determined. The Baker kinetic model performed best at pH 7.4, indicating that the leading cause of the drug release was polymer swelling. In contrast, the Higuchi model was most accurate for drug release at pH 5.4, illuminating the diffusion and dissolution mechanisms involved in diffusion. To be more precise, the mechanism of release at pH 7.4 and 5.4 was anomalous transport (dissolution-controlled), according to the Korsmeyer-Peppas mathematical model. The pH-dependent swelling and degradation behavior of S/Z/g-C3N4@5-FU nanocomposite showed higher swelling and faster degradation in acidic environments compared to neutral conditions. Crucially, outcomes from the MTT test affirm the significant cytotoxicity of the 5-FU-loaded nanocomposite against U-87 MG brain cancer cells, while simultaneously indicating non-toxicity towards L929 fibroblast cells. These cumulative findings underscore the potential of the engineered S/Z/g-C3N4@5-FU as a productive and targeted therapeutic approach for cancer cells.

The role of the carapace in the accumulation of metals from seawater in the green crab (Carcinus maenas): Studies with radio-labeled calcium, zinc, and nickel

The role of the carapace in the uptake and storage of newly accumulated metals was investigated in the green crab exposed to environmentally relevant concentrations of calcium ([Ca] = 389 mg L−1 or 9.7 mmol L−1), zinc ([Zn] = 82 μg L−1 or 1.25 μmol L−1), and nickel ([Ni] = 8.2 μg L−1 or 0.14 μmol L−1) in 12 °C seawater, using radio-tracers (45Ca, 65Zn, 63Ni). After 24-h exposure, carapace exhibited the highest concentration of newly accumulated Ca, whereas carapace and gills exhibited the highest concentrations of both newly accumulated Zn and Ni relative to other tissues. For all three metals, the carapace accounted for >85 % of the total body burden. Acute temperature changes (to 2 °C and 22 °C) revealed the highest overall temperature coefficient Q10 (2.15) for Ca uptake into the carapace, intermediate Q10 for Ni (1.87) and lowest Q10 (1.45) for Zn. New Ca uptake into the carapace continued linearly with time for 24 h, new Zn uptake gradually deviated from linearity, whereas Ni uptake reached a plateau by 6 h. Attachment of a rubber membrane to the dorsal carapace, thereby shielding about 20 % of the total crab surface area from the external water, eliminated both new Zn and Ni incorporation into the shielded carapace, whereas 36 % of new Ca incorporation persisted. When recently euthanized crabs were exposed, new Zn uptake into the carapace remained unchanged, whereas Ca and Ni uptake were reduced by 89 % and 71 %, respectively. We conclude that the carapace is a very important uptake and storage site for all three metals. All of the uptake of new Zn and new Ni, and most of the uptake of new Ca into this tissue comes directly from the external water. For Zn, the mechanism involves only physicochemical processes, whereas for Ca and Ni, life-dependent processes make the major contribution.

Recent advances in engineering fast-growing cyanobacterial species for enhanced CO2 fixation

Atmospheric CO2 removal (CDR) is a fundamentally endergonic process. Performing CDR or Bioenergy with Carbon Capture and Storage (BECCS) at the gigatonne scale will produce a significant additional burden on the planet’s limited renewable energy resources irrespective of the technology employed. Harnessing photosynthesis to drive industrial-scale CO2 fixation has been of significant interest because of its minimal energy requirements and potential low costs. In this review, we evaluated the thermodynamic considerations of performing atmospheric carbon removal using microalgae and cyanobacteria versus physicochemical processes and explore the implications of these energetic costs on the scalability of each respective solution. We review the biomass productivities of recently discovered fast-growing cyanobacterial strains and discuss the prospects of genetically engineering certain metabolic pathways for channeling the fixed carbon into metabolic ‘carbon sinks’ to further enhance their CO2 capture while concurrently extracting value. We share our perspectives on how new highly productive chassis strains combined with advanced flux balance models, essentially coupling synthetic biology with industrial biotechnology, may unlock more favorable methods for CDR, both from an economic and thermodynamic perspective.

Advancements in Metal‐Organic, Enzymatic, and Nanocomposite Platforms for Wireless Sensors of the Next Generation

AbstractAdvanced wireless sensors, incorporating metal‐organic frameworks (MOFs), enzymatic systems, and nanocomposites, offer unparalleled solutions for monitoring analytes and human physiological signals. These cutting‐edge sensors, when used with external devices, enable real‐time monitoring of analytes and physicochemical processes within the human body, thereby enhancing the understanding of complex biological systems. This study presents advancements in sensor development, fabrication techniques, and user‐friendly protocols. The performance of these sensors is evaluated based on their selectivity, sensitivity, and detection limits. Moreover, this article explores limitations, challenges, and key strategies to enhance analyte recognition from onsite environmental and biological species, ensuring human point‐of‐care safety.

Unraveling the interaction of co-encapsulated Saccharomyces cerevisiae and Metarhizium brunneum in calcium alginate-based attract-and-kill beads.

Attract-and-kill (AK) beads are biological, microbial insecticides developed as an alternative to synthetic soil insecticides. For wireworm control, beads are based on calcium alginate/starch co-encapsulating the carbon dioxide (CO2) producing yeast Saccharomyces cerevisiae H205 as the attract component, and the entomopathogenic fungus Metarhizium brunneum CB15-III as the kill component. However, the physicochemical processes inside beads during co-cultivation are still unclear. Here we reveal for the first time the spatiotemporal conditions of oxygen and pH inside AK beads measured with microelectrodes and describe the impact of S. cerevisiae on CO2 and conidia formation. Measurements revealed a steep oxygen gradient already 2 days after co-encapsulation, with an internal hypoxic zone. Encapsulating either S. cerevisiae or M. brunneum already decreased the average pH from 5.5 to 4.7 and 4.6, respectively. However, on day 3, co-cultivation lead to temporal strong acidification of beads down to pH 3.6 which followed the maximum CO2 productivity and coincided with the maximum conidiation rate. Decreasing the yeast load decreased the total CO2 productivity to half, and the conidial production by 93%, while specific productivities normalized to 1% yeast load increased eight-fold and three-fold, respectively, with day 3 being an exception. Our findings indicate a general beneficial interaction between M. brunneum and S. cerevisiae, but also suggest competition for resources. These findings will contribute to develop innovative co-formulations with maximum efficiency to save application rates and costs. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Enhancing flotation beneficiation efficiency of complex ores using ionometry methods

Flotation beneficiation plays a leading role in the processing most ores. The efficiency of this process is ensured by the correct selection of operating modes, which involves choosing the most selective reagents and determining their optimal consumption. Despite the significance of this issue, the classic approach to determining beneficiation parameters involves testing followed by the processing of the results obtained and the determination of the reagent consumption. However, such studies do not reveal the essence of the physicochemical processes occurring within the pulp, and the results of testing one sample may not correspond to the optimum when the properties of the sample change.The purpose of this work is to develop and implement a methodological approach to the study of ore flotation beneficiation using ionometry methods. The data obtained from ion-selective sensors significantly deepen our insight into the transformations occurring during the flotation process and allow for consideration of possible adverse factors that hinder effective process progression.To achieve this goal, a comparative analysis of two approaches to flotation beneficiation testing was performed using complex sulfide ores as examples. In the first stage, a flotation beneficiation study was conducted through D-optimal factor testing, which included 20 individual tests to determine the optimal consumption of modifying reagents, yielding qualitative indicators. In the second stage, flotation tests were conducted using electrochemical monitoring with pH, Ag2S, Pt, and membrane electrodes. A universal flowchart for flotation studies with ion-selective sensors has been developed, facilitating the application of this approach to various ores. The implementation of the results from this comparative analysis has led to a 7.8% increase in beneficiation efficiency while reducing reagent consumption. Additionally, the insights gained into the electrochemical processes occurring allowed for assumptions about the adverse factors affecting flotation outcomes. In conclusion, a model for the potential application of this approach at existing enterprises was proposed, including the implementation of an “intelligent assistant” for flotation operators based on the developed electrochemical models.