Water Sulfate Research Articles

Effects of Sulfur Thermal Water inhalations in long-COVID syndrome: spa-centred, double-blinded, randomised case-control pilot study

BackgroundThe long-COVID syndrome is characterised by a plethora of symptoms. Given its social and economic impact, many studies have stressed the urgency of proposing innovative strategies other than hospital settings. In this double-blind randomised case-control trial, we investigate the effects of sulfur thermal water inhalations, rich in H2S, compared to distilled water inhalations on symptoms, inflammatory markers, nasal microbiome in long-COVID patients. Methods30 outpatients aged 18-75, with positive diagnosis for long-COVID were randomised in two groups undergoing 12 consecutive days of inhalations. The active Group (STW) received sulfur thermal water inhalations whereas the placebo group received inhalations of sterile distilled non-pyrogenic water (SDW). Each participant was tested prior treatment at day 1 (T0), after the inhalations at day 14 (T1) and at 3 months follow-up (T2). At each time point, blood tests, nasal swabs for microbiome sampling, pulmonary functionality tests (PFTs) and pro-inflammatory marker measure were performed. ResultsThe scores obtained in the administered tests (6MWT, Borg score, and SGRQ) at T0, showed a significant variation in STW group, at T1 and T2. Serum cytokine levels and other inflammatory biomarkers reported a statistically significant decrease. Some specific parameters of PFT's showed ameliorations in STW group only. Changes in the STW nasopharyngeal microbiota composition were noticed, especially from T0 to T2. ConclusionsInhalations of sulfur thermal water exerted objective and subjective improvements on subjects affected by long-COVID. Significant reduction of inflammatory markers, dyspnea scores and quantitative and qualitative changes in the nasopharyngeal microbiome were also assessed.

FORMULATION AND EVALUATION OF HERBAL TOOTHPASTE

The present study is concerned with the formulation and evaluation of herbal toothpaste, which contains various properties like tooth abrasives, tooth whitening, anti-caring, antibacterial, anti-inflammatory, desensitivity, etc. The herbal toothpaste was prepared using mango leaf extract and guava leaf extract as active ingredients, along with various excipients, which include calcium carbonate, sodium chloride, sodium lauryl sulphate, sodium benzoate, glycerine, camphor, honey and distilled water. The toothpaste was prepared by homogeneous mixing of all the excipients and the herbal extract. Four formulations were prepared using mango leaf extract as an active ingredient along with varying excipient concentrations, four formulations were prepared using guava leaf extract as an active ingredient along with varying excipient concentrations, and a polyherbal formulation consisting of four formulations containing both mango leaf extract and guava leaves extract as active ingredients along with varying excipient concentrations. The formulations were tested for various parameters such as homogeneity, abrasiveness, foamability, moisture content, Spreadability, extrudability, colour, PH, and antibacterial activity. The study concluded that polyherbal formulation showed best results and was found to be best among all batches. The polyherbal formulation, F4 showed was found to be best among all other formulations.

Integral and Surface Treatment Method of Waterproofing: A Review and Comparative Analysis

Water seepage into concrete can cause deterioration and other aesthetic issues that limit the life of concrete constructions. This paper examines and contrasts the various kinds of waterproofing techniques. There are essentially two types: surface treatment method and integral method. Water repellents, crystalline admixtures, and densifiers are examples of integral methods. Surface treatment methods encompass pore-blocking, hydrophobic impregnation, surface coating, and multifunctional surface treatment. The processes of various approaches are examined in this article, followed by a comparison of their durability and mechanical properties. We discuss several properties, such as sulfate attack, chloride penetration, carbonation, reinforcement corrosion, water absorption and permeability, compressive, flexural, and tensile strength. The findings indicate that each has merits and demerits of their own. The inclusion of an integral admixture to concrete offers a number of advantages over surface protection, including convenience of application, the removal of the need for ongoing maintenance, and minimal to no deterioration over time. While surface treatment methods significantly reduce water permeability and porosity. In conclusion, we give a succinct summary of certain issues regarding the present state of research and future directions for the hydrophobic modification of concrete.

Eficacy of sulfurous water from Mangalia in Helicobacter Pylori infection: a clinical study

Mangalia balneary resort is situated in the south of the Black Sea and uses sulphurous water springs for rehabilitation therapy. The purpose of this study is to demonstrate the effectiveness of Mangalia sulphurous water on Helicobacter Pylori (H. Pylori) infection. Considering that sulfurous water has a bacteriostatic effect and that most gastritis are caused by H. Pylori infection, we propose that a group of 27 H. Pylori positive patients with or without digestive symptoms ingest sulfurous water daily, for a few days. At the end of the study, 15 of the patients tested negative for H pylori antigen. The curative effects are due to the bacteriostatic effect of sulfurous water and its stimulating action on the digestive tube.

Identifying sulphurous water discharge from legacy oil and gas wells using spectral band analysis of aerial and satellite imagery

Legacy oil and gas wells are a significant source of hydrogen sulphide and methane gas release to the atmosphere. Unanticipated occurrences of gas release in urbanized areas can pose human health risks. Several high hydrogen sulphide-emitting wells have been identified in Norfolk County, Ontario, Canada, based on the remote detection of sulphurous water discharging to the surface along the wellbore. Although oil and gas well records report well status and location, community reports of noxious hydrogen sulphide odours suggest potentially compromised well seals and inaccuracies in their documented location. Given the broad-scale nature of this issue and limitations in site access, a remote-sensing based methodology utilizing satellite and high-resolution aerial photography could support identification of undocumented sulphurous water leaks associated with compromised oil and gas wells and subsequent characterization of hydrological and ecohydrological impacts over time. This study presents a multifaceted approach to identifying sulphurous leaking wells utilizing complimentary remote sensing imagery and image analysis tools within ArcGIS. Southwestern Ontario Orthophotography Project air photos and Sentinel-2 satellite imagery were determined to be the most applicable sources of imagery based on their respective advantages in resolution and revisit time. The application of a normalized difference vegetation index showed that major well leaks could exhibit signs of vegetative scarcity, while minor well leaks may have only a limited impact on vegetation. A band combination utilizing the green and near infrared bands was created to enhance the detection of sulphurous water leaks. Utilizing the identified band combination, a pair of potentially undiscovered leaks were located west of a fluvial river channel. Continued research should attempt to employ an automated approach for discerning additional sulphurous water leaks in the region or at different points in time. Possible techniques may involve the deep learning object and change detection models incorporated in ArcGIS.

Efficient elimination of organic contaminants via a non-radical pathway involving activation of sulfite by synergistic adsorption-catalysis bifunctional chitosan-modified MOF derivative

Usually, Metal-based sulfite activation systems follow a radical generation pathway but are rare in non-radical pathways. Singlet oxygen (1O2) generation-targeted catalyst was synthesized by introducing non-redox metal oxides ZnO into chitosan-modified cobalt-zinc bimetallic oxides (CZ1.0C) via template method. Compared with Co3O4, the catalyst CZ1.0C coupled to the sulfite system (CZ1.0C/SO32-) maintained good adaptability in a common water background and a wide pH range (7–11). In addition, the CZ1.0C/SO32- system showed high efficiency in the degradation of Congo red (kobs = 0.190 min−1) and 100 % sulfite utilization. EPR, probe experiments, and DFT calculations proved the dominant role of 1O2, with a concentration three orders of magnitude higher than that of radicals. The controlled generation of non-radicals was achieved owing to the doping of ZnO and the conversion of lattice oxygen and oxygen vacancies. The catalytic oxidation intermediate HSO5- has also been demonstrated in the system, which achieves non-radical pathway oxidation through electron-mediated interactions. This article aims to develop a new “waste control by waste” strategy, which combines high selective adsorption and catalysis to achieve sulfur resource recovery and water pollutants elimination.

Selective extraction of lithium and solidified fluoride from overhaul slag by the calcium sulfate roasting and water leaching

Overhaul slag is a hazardous waste which is from the process of aluminum electrolysis industry. In this work, a technology of calcium sulfate roasting and water leaching was developed to dispose of overhaul slag. The effects of roasting and leaching parameters were investigated in detail. Under the optimal roasting conditions, the fluorine could be stably solidified into CaF2, and lithium could be converted into soluble NaLi(SO4). The roasted clinker was then subjected to water leaching for the selective extraction of lithium. About 99.74 % of lithium was extracted and 99.82 % of fluoride was solidified by the leaching process under the optimal leaching conditions. After water leaching, the concentration of lithium can reach 2.3 g/L. XRD analysis shows that the main phases of the aqueous solution after evaporation and crystallization are NaLi(SO4) and Na2SO4, and a small amount of impurities can be further removed and concentrated to prepare Li2CO3. The main components of leaching slag are C, Al2O3 and CaF2, which can be used as fast setting cement. The process proposed in this paper is not limited to the recovery of high-value lithium from overhaul slag, and can be applied to the extraction of other valuable waste substances in aluminum industry.

Tracing sulfate sources in a tropical agricultural catchment with a stable isotope Bayesian mixing model

Sulfate (SO42−) is an essential anion in drinking water and a vital macronutrient for plant growth. However, elevated sulfate levels can impact ecosystem or human health and could be an important indicator of acid rock drainage or pollution. Therefore, monitoring SO42− sources and transport is important for water quality assessments. This study focused on exploring the sources and transformations of SO42− as well as estimating the proportional contribution of the potential SO42− pollutant sources to groundwater and surface water in a tropical river basin, the Densu River Basin. The study used major ions combined with stable sulfur and oxygen isotope compositions and a Bayesian isotope mixing model, MixSIAR. The major ion characteristics indicate that SO42− concentrations remain stable throughout the rainy and dry seasons but originate from diverse sources. The multi-isotope model (δ34SSO4, δ18OSO4) identified four potential SO42− sources: detergent, precipitation, sewage, and sulfate fertilizer. However, the δ34SSO4 and δ18OSO4 values of the fertilizer source signatures overlapped with those of precipitation and sewage. Nevertheless, the contributions from each source were disentangled using the MixSIAR model, which revealed sewage as the most dominant SO42− pollutant in the Densu Basin, accounting for ~47 % of sulfate in groundwater and ~ 56 % of sulfate in surface water. Sulfate fertilizer (~33 %) was the second most important source after sewage for groundwater, while detergent (~23 %) was the second most important source for surface water. The redox processes of bacterial sulfate reduction and sulfide oxidation were determined to have a minimal impact on the sulfur isotope fractionation within the basin. This study highlights the benefits of combining major ions, sulfur isotopes and the MixSIAR model for identifying sources of sulfate. This approach accounts for uncertainties in source contributions which allows for more robust and reliable apportionment of sulfate sources. The study emphasizes the need for effective waste management and pollution control measures to protect water quality and provides vital guidelines on how to partition sulfate sources on a large catchment scale and evidence for making pollution management decisions on water resources.

Potential Possibilities of Using Peat, Humic Substances, and Sulfurous Waters in Cosmetology

Balneology is one of the oldest fields of medicine related to the use of natural raw materials (medicinal waters, medicinal gases, peloids, climatic values) in the treatment, prevention, and rehabilitation of many diseases but also increasingly in cosmetology. Currently, balneotherapy (spa therapy) combines tradition and modernity. The interest in spa treatments, the popularity of a healthy lifestyle, as well as the constant search for active substances of a natural origin for cosmetics make peloids, medicinal, and mineral waters very popular in the cosmetics industry. The main aim of this review was to present current, scientifically proven knowledge about the potential use of peat, huic substances, and sulfurous water in cosmetology. The work describes the potential possibilities of using medicinal waters, especially sulfurous waters, as well as peats and humic compounds, which are the source of active substances with biological activity e.g., antibacterial, anti-inflammatory, and antioxidant, and possess a positive effect on psoriasis, atopic dermatitis, or acne. The therapeutic effects of these substances have been well documented in the literature; however, the validity of their use in cosmetology requires further confirmation.

Analisis Uji Kuat Tekan Beton pada Campuran Air Payau Desa Tellumpanua Kecamatan Suppa

Increased economic growth in the city of Parepare with the presence of buildings around the estuary. In general, the composition of concrete making materials is taken from good materials. The problem encountered in the field is that the quality of concrete in construction decreases due to brackish water, causing structural elements in the construction to become porous. Meanwhile, preventive measures are rarely or never taken. As a result, the construction life is very short. Brackish water is one of the causes of structural failure. This is due to the content of sulfate and chloride ions in water containing salt/salts that react with chemical elements in reinforcing steel resulting in corrosion of the reinforcement. The purpose of the study was to analyse the compressive strength of concrete with a mixture of clean water against the percentage of brackish water with a maintenance age of 7, 14, 21, and 28 days. The results showed that brackish water had an impact on reducing the compressive strength of concrete due to the high chemical content in brackish water such as Sulfate (SO²¯) of 52.5 in brackish water in Kenjeran and 62.5 in brackish water in mangrove. Dissolved Solids (TDS) of 15188 mg/l in kenjeran brackish water and 3436 mg/l in mangrove brackish water. Organic Content (KMnO) of 8.05 mg/l in kenjeran brackish water and 6.69 mg/l in mangrove brackish water is too high, so the chemical content contained in brackish water can damage the compounds in the cement content and decrease the strength of the materials contained in the concrete. In this case it can result in concrete having a very low durability.

Structuring of sodium tungstate with sodium dodecyl sulphate in aqueous media and its implications for advanced materials development

This article explores the structuring sodium tungstate with sodium dodecyl sulphate (SDS) in water and characterizing the resulting products post-destabilization with hydrochloric acid and calcination. Utilizing nuclear magnetic resonance (NMR), small-angle X-ray scattering (SAXS), fluorescence spectroscopy with a pyrene probe, conductivity, and pH analyses, the study elucidates the system's structure and interactions. SDS serves as a structuring agent for tungstate anions in water, with sulphate anions interacting with tungsten d-orbitals. The presence of SDS significantly influences final structures after calcination. Higher precursor/structuring agent ratios result in higher proportion of tungsten oxide, alongside Na2W2O7 and Na2W4O13. Varying calcination temperatures yield different crystal structures and morphologies, including flower petals and roses at 500 °C and nanorods at 700 °C. These findings shed light on material structuring processes. The obtained materials exhibit to utilize solar radiation for chemical reactions.

Geophysical and geochemical investigations of underwater sulphurous seeps from Western Black Sea (Mangalia area, Romania), in support of habitat conservation

Mangalia area harbors in the western Black Sea a distinctive marine environment thriving under specific hydrochemical conditions, largely influenced by a significant number of sulphurous springs occurring in shallow marine waters. These springs led to the designation of the area as part of the Natura 2000 Marine Protected Area (MPA) network at European level (Underwater Sulphurous Springs from Mangalia - ROSAC0094), as unique hydro-geomorphological features in the region. In 2021 and 2023, two research cruises led by GeoEcoMar investigated underwater sulphurous springs primarily located offshore of Mangalia (Constanţa County, Romania). The study area, located between 17-29 meters water depth and 1.8-3 km offshore, encompasses two marine protected areas: the Underwater Sulphurous Springs from Mangalia (ROSAC0094) and Cape Aurora (ROSCI0281). The research combined geophysical and geochemical techniques and sediment sampling. Considering the susceptibility of these natural systems to human activities such as fishing and dredging, as well as the impact of ecological and climate changes, this paper offers significant insights contributing to the development of effective conservation and management strategies for these environments. The surveys were conducted for benthic habitats mapping, with the objective of improving our understanding of these ecosystems’ distribution, composition and dynamics. As these sulphurous waters are rich in methane, a powerful greenhouse gas, our results also contribute to the inventory of greenhouse gas sources. The results presented in this paper provide valuable new insights into this specific environment, contributing to the understanding of its complex functioning and evolution.

Clean and efficient extraction of lithium from montebrasite ore by aluminum sulfate roasting method: Thermal behavior and process optimization

Amidst the surge of Li demand, technology development for Li extraction from diverse Li resources has gained considerable interest. Montebrasite, a significant lithium ore, is distinguished by its high Li content. Despite its potential, research into its processing technologies are scarce, leading to its limited and slow industrial adoption. On this basis, a novel process combining aluminum sulfate roasting and water leaching was proposed in this study to achieve its clean and efficient utilization. Firstly, thermal behaviors of montebrasite were investigated through various characterizations. It was observed that montebrasite underwent obvious decomposition above 700 °C, and began to melt after 800 °C. The mineral phases transformed into Li3PO4, AlPO4 and Al2O3 after decomposition. Thermodynamic calculation indicated that when Al2(SO4)3 was used as roasting agent, Li+ can be entirely substituted by Al3+ to form soluble Li2SO4, while Al3+ combined with PO43− to form insoluble AlPO4, enabling selective and efficient Li extraction. The experimental results demonstrated a high agreement with thermodynamic analysis. Under the optimal conditions (roasting: 760 ℃, 1.0 h, 29.4 % Al2(SO4)3), 94.1 % Li was extracted selectively, while only 0.04 % Al and 0.3 % P entered into solution. The leach residue, primarily composed of AlPO4, SiO2, mullite and Al2O3, can be recycled for further utilization. This process offers distinct advantages over traditional salt roasting methods, including reduced reagent usage and elimination of solid waste discharge. It presents an efficient, cost-effective and environmentally benign pathway for the utilization of montebrasite.

Polythermal Solubility of the Sodium Chlorate–Triethanolammonium Sulfate–Water System

Polythermal Solubility of the Sodium Chlorate–Triethanolammonium Sulfate–Water System

Artificial High- and Low-density Materials in Bone Mineral Densitometry Using Dual-energy X-ray Absorptiometry: A GATE Monte Carlo Simulation of “Black-hole” Artifact

Objective: The objective of the study was to evaluate the effect of artificial high- and low-density materials on Bone mineral density (BMD)scans in dual-energy X-ray absorptiometry (DXA) method and emergence of black-hole artifact through GATE Monte Carlo simulation. Materials and Methods: GATE Monte Carlo code was utilized to simulate the artifact encountered in clinical scans acquired by HOLOGIC® bone densitometer. Two simplified phantoms were designed. The first one was a rectangular box with six smaller cubes inside and the second one was a body torso. Materials of cubes were spine bone, polymethyl methacrylate (PMMA), barium sulfate suspension in water, stainless steel, titanium alloy, and gold. The torso phantom contained objects of 5 vertebrae, bowel and 3 small spherical objects near the surface of the torso as piercing objects on the abdominal wall, each overlying the vertebrae. Using 100 and 140 kVp, spectral X-rays were generated to simulate DXA. For both phantoms, two simulations were carried out. The pair of projections acquired for each phantom were then subtracted and analyzed by curve fitting techniques. Results: Except for spine bone, in which radio-opacity decreases with increasing spectral X-ray energy (from 100 to 140 kVp), other squares exhibit little changes over different energies. PMMA shows consistently very low radio-opacity. Four other materials (barium sulfate in water, stainless steel alloy, titanium alloy, and gold), all attenuate the X-ray photons substantially. Except for spine bone, other materials are barely noticeable in pairwise subtracted images. In torso phantom, piercing objects are visualized as “holes” in vertebrae. Conclusion: Both artificial high- and low-density materials, compared to bone, are eliminated during the subtraction of dual-energy X-ray profiles and therefore, can create black-hole artifact.

Enhancing bioactivity and biocompatibility of polyetheretherketone (PEEK) for dental and maxillofacial implants: A novel sequential soaking process

Polyetheretherketone (PEEK) exhibits excellent biocompatibility, fatigue resistance, and an elastic modulus similar to bone, presenting broad application prospects in the field of dental and maxillofacial implants. However, the bioinertness of PEEK limits its applications. In this study, we developed a method to generate biocompatible and bioactive PEEK through a simple sequential soaking process, aimed at inducing bone differentiation and enhancing antibacterial properties. Initially, a three-dimensional (3D) porous network was introduced on the PEEK surface by soaking in concentrated sulfuric acid and water. Subsequently, the sulfonated PEEK surface was treated with oxygen plasma, followed by immersion in a dopamine solution to coat a polydopamine (PDA) layer. Finally, polydopamine phosphate ester-modified 3D porous PEEK was obtained through the reaction of phosphoryl chloride with surface phenolic hydroxyl groups. Systematic studies were conducted using scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle analysis, cell proliferation and adhesion, osteogenic gene expression detection, alkaline phosphatase staining, alizarin red staining, and bacterial culture. Overall, compared to unmodified PEEK, the modified PEEK significantly enhanced in vitro cell proliferation and adhesion, osteogenic differentiation, and antibacterial properties. The simple surface modification measures combined in this study may represent a promising technology and could facilitate the application of PEEK in dental and maxillofacial implants.

Selective extraction of lithium from montebrasite and clean treatment of tailings

To realize the efficient utilization of montebrasite, we conducted a systematic study of sulfuric acid roasting and water leaching processes. In this study, we propose a roasting process at a lower temperature than that proposed in previous studies, which can achieve the selective extraction of lithium from montebrasite and effective enrichment of aluminum and phosphorus. The thermodynamic simulation results of the reaction between montebrasite and sulfuric acid showed that the method was feasible in theory. Under the optimal conditions determined by theoretical analysis and experimental results, Li extraction reached 97.5 %, whereas Al and P extraction only reached 1.9 % and 0.1 %, respectively. The results of XRD characterization and analysis of roasting slag and leaching residue demonstrated that montebrasite was decomposed into Li2SO4, Al2(SO4)3, and H3PO4 by sulfuric acid. The temperature increase facilitated the conversion of these intermediates into Li2SO4 and AlPO4, confirming the absence of SO3 generation within the studied temperature range. Selective extraction of Li achieved water leaching through water leaching, resulting in a leaching residue with over 95 % AlPO4 content. The leaching liquor underwent purification and precipitation, resulting in the attainment of Li2CO3 with a purity level of 99.8 %. This process enables selective extraction of Li from montebrasite while efficiently enriching Al and P components. It represents an efficient and environmentally friendly approach for lithium extraction.

Sustainable bacteria-based self-healing steel fiber reinforced concrete

Self-healing concrete presents an innovative and eco-friendly solution with the potential to reduce maintenance costs through self-activated crack repair. This study examined the effect of varying bacterial content across different environmental conditions. Additionally, the coupling effect between bacteria and steel fiber to enhance the mechanical and physical properties at different ages has been investigated. Bacillus Sphaericus (B. Sphaericus) was incorporated into the concrete at concentrations of 2 × 109 (CFU/ml), and different bacterial percentages selected utilizing calcium lactate as a nutrient source. Bacterial content of 0.0 %, 0.25 %, 1.0 %, and 2.5 %, cured in both fresh water and magnesium sulfate water solution, were tested to examine concrete behavior in harsh environments. Additionally, steel fibers at volume fraction percentages (Vf%) of 1.0 % and 1.5 %, along with 1.0 % bacterial content, were tested to highlight their combined effect. Tests were conducted at different ages to measure compressive, tensile, and flexural strengths. In addition, SEM and EDS analyses for cracked and uncracked specimens were performed. The results showed a significant increase in the long-term compressive, tensile, and flexural strengths at 180 days by 47 %, 80 %, and 50 %, respectively, with a bacterial content of 2.5 %. Moreover, the incorporation of steel fibers, 1.0 % and 1.5 % content, in the bacterial concrete resulted in a long-term compressive strength increase at 180 days by 45 % and 55 %, respectively with 1.0 % bacterial content, compared to 15 % and 27 % for 0 % bacteria. Curing in sulfate-rich water, concrete specimens exhibited increasing compressive strength at 180 days from 47 MPa for 0 % bacteria to 77 MPa with 2.5 % bacteria content. Despite lower initial strength of 29 MPa at 7 days, bacterial incorporation led to significant strength improvements, highlighting effective self-healing even in aggressive curing environments.

Redox-switchable microemulsions with efficient phase separation and surfactant recycling

HypothesisSwitchable microemulsions (MEs) are those capable of adaptively responding to the action of internal or external stimuli. For redox-switchable MEs to obtain high-efficiency phase separation and surfactant recycling, it may be one of the keys to adequately turn off the interfacial activity of surfactants and reduce the solubility of the closed surfactants in the oil phase. ExperimentsMonophasic MEs consisting 11-butylselanyl-undecyl sulfate sodium (C4SeC11SO4Na), n-butanol, n-octane, and water were fabricated using the pseudo-ternary phase diagram method. Their structural features and droplets size were characterized by conductivity, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM), respectively. The redox response of MEs was studied using a combination of visual observations and DLS, cryo-TEM, nuclear magnetic resonance (NMR) and thin-layer tomography. The efficient recycling of C4SeC11SO4Na from a well-emulsified eluent is conceptually demonstrated. FindingsThe reversible transition between C4SeC11SO4Na and C4SeOC11SO4Na is achieved under the alternating action of H2O2 and N2H4, by which C4SeC11SO4Na-based monophasic MEs are able to efficiently demulsify and regenerate, respectively, regardless of their type. After H2O2-induced demulsification of the MEs, C4SeOC11SO4Na can be efficiently recycled with the water phase. We hope that such a redox-switching method may benefit some technological applications. For example, it offers exciting possibilities for simultaneous recycling C4SeC11SO4Na and removal of oil from a well-emulsified eluent. Around 97.1 ± 0.3 % of C4SeC11SO4Na could be recycled over five cycles with no apparent loss. After a simple and conventional treatment with anion-exchange resin and active carbon, the total organic carbon and chemical oxygen demand of the waste water were 17.4 ± 2.8 and 26.2 ± 1.4 mg/L, respectively.

Geochemical and Isotopic Techniques Constraints on the Origin, Evolution, and Residence Time of Low‐enthalpy Geothermal Water in Western Wugongshan, SE China

AbstractGeothermal resources are increasingly gaining attention as a competitive, clean energy source to address the energy crisis and mitigate climate change. The Wugongshan area, situated in the southeast coast geothermal belt of China, is a typical geothermal anomaly and contains abundant medium‐ and low‐temperature geothermal resources. This study employed hydrogeochemical and isotopic techniques to explore the cyclic evolution of geothermal water in the western Wugongshan region, encompassing the recharge origin, water–rock interaction mechanisms, and residence time. The results show that the geothermal water in the western region of Wugongshan is weakly alkaline, with low enthalpy and mineralization levels. The hydrochemistry of geothermal waters is dominated by Na‐HCO3 and Na‐SO4, while the hydrochemistry types of cold springs are all Na‐HCO3. The hydrochemistry types of surface waters and rain waters are Na‐HCO3 or Ca‐HCO3. The δD and δ18O values reveal that the geothermal waters are recharged by atmospheric precipitation at an altitude between 550.0 and 1218.6 m. Molar ratios of major solutes and isotopic compositions of 87Sr/86Sr underscore the significant role of silicate weathering, dissolution, and cation exchange in controlling geothermal water chemistry. Additionally, geothermal waters experienced varying degrees of mixing with cold water during their ascent. The δ13C values suggest that the primary sources of carbon in the geothermal waters were biogenic and organic. The δ34S value suggests that the sulfates in geothermal water originate from sulfide minerals in the surrounding rock. Age dating using 3H and 14C isotopes suggests that geothermal waters have a residence time exceeding 1 kaBP and undergo a long‐distance cycling process.