Sulfate Concentrations Research Articles

Assessment of the in situ biomethanation potential of a deep aquifer used for natural gas storage.

The dihydrogen (H2) sector is undergoing development and will require massive storage solutions. To minimize costs, the conversion of underground geological storage sites, such as deep aquifers, used for natural gas storage into future underground hydrogen storage sites is the favored scenario. However, these sites contain microorganisms capable of consuming H2, mainly sulfate reducers and methanogens. Methanogenesis is, therefore expected but its intensity must be evaluated. Here, in a deep aquifer used for underground geological storage, 17 sites were sampled, with low sulfate concentrations ranging from 21.9 to 197.8µM and a slow renewal of formation water. H2-selected communities mainly were composed of the families Methanobacteriaceae and Methanothermobacteriaceae and the genera Desulfovibrio, Thermodesulfovibrio, and Desulforamulus. Experiments were done under different conditions, and sulfate reduction, as well as methanogenesis, were demonstrated in the presence of a H2 or H2/CO2 (80/20) gas phase, with or without calcite/site rock. These metabolisms led to an increase in pH up to 10.2 under certain conditions (without CO2). The results suggest competition for CO2 between lithoautotrophs and carbonate mineral precipitation, which could limit microbial H2 consumption.

Schoenoplectus americanus as a potential phytoremediator: in vitro assessment of its ability to remove contaminants in domestic and tannery wastewater

ABSTRACT Growing industrialization and urbanization have led to increased water pollution due to the inadequate treatment and disposal of domestic wastewater (DW) and wastewater produced by industries such as tanneries (TW). These wastewaters are characterized by high concentrations of organic matter, nutrients, sulphates, chlorides and high microbial load. TW also contains phenols and chromium, which disturb and harm the ecosystem the local. The decontamination of wastewater prior to their discharge through biological tools, especially the use of species that are native to the site in need of treatment, has been described as effective and advantageous. This study evaluated the ability of Schoenoplectus americanus, a native plant species from Cordoba (Argentina), to phytoremediate local DW and TW samples at a laboratory scale. The aim was to ascertain whether this system could potentially be considered for the remediation of wastewater in real-world scenarios. S. americanus was able to tolerate pure DW and a 1/20 (v/v) dilution of TW for 30 days under hydroponic conditions. Removal rates ranging from 50% to 89% were obtained for residual organic matter (determined as chemical oxygen demand or COD), total nitrogen (TN) and total phosphorus (TP). Significant removal of total chromium (TCr) and total phenols (TPhs) was also observed in TW (85% and 98%). The number of total coliforms (TC), was reduced by about 96% and 99%. These results indicate that S. americanus is a good candidate for the phytoremediation of regional DW and TW. For this reason, it may be considered for full-scale applications in the future.

Fiddler crab bioturbation stimulates methane emissions in mangroves: Insights into microbial mechanisms

Mangrove ecosystems are pivotal in blue carbon capture, yet they can also release varying levels of methane (CH4). Fiddler crabs are known players in carbon (C) cycling within mangrove ecosystems, but their precise contributions to CH4 emissions and microbially-driven processes are not yet well understood. We compared CH4 emissions, soil physicochemical properties, and methanogenic and methanotrophic communities in non-bioturbated and bioturbated soils within two mangrove communities: Sonneratia apetala (SA) and Pongamia pinnata (PP). The presence of fiddler crabs led to an increase in CH4 emission rates in the bioturbated soil, ranging from 86% to 430% compared to un-bioturbated soil. The bioturbated soil also exhibited higher levels of ammonium, pH, and dissolved organic carbon (DOC) but with lower concentrations of nitrate, sulfate, salinity, and total nitrogen. Moreover, an increase was observed in the abundance methanogenic communities, but the abundance and diversity of methanotrophic communities was reduced in the bioturbated soil. The increased abundance of Methanosarcina and reduced abundance of type II methanotrophs in the bioturbated soil could result in an overall increase in CH4 emissions. This study result highlights that bioturbation can greatly influence CH4 emissions in mangroves and emphasizes the importance of considering the ecological role of fiddler crabs in the evaluation of coastal blue carbon sequestration.

Carbon-Sulfur isotope and major and trace element variations across the Permian–Triassic boundary on a shallow platform setting (Xiejiacao, South China)

We examined microbialites deposited near the Permian–Triassic boundary (PTB) at the Xiejiacao section of South China, including the size and morphology of pyrite framboids, carbonate carbon isotopes (δ13Ccarb), carbonate associated sulfur isotope (δ34SCAS), major and trace elements, and total organic carbon (TOC) concentrations. The microbialite unit is much thicker than the PTB beds in deeper water sections, providing more detailed geochemical records from that time. A prominent negative δ13Ccarb excursion was recognized in association with the second phase of the Permian–Triassic mass extinction (PTME), comparable with that of several other shallow platform facies sections worldwide. δ34SCAS stratigraphic profiles also show a negative excursion, with minimum values occurring slightly later than those of δ13Ccarb. The minimum peak can be calibrated to the middle part of the conodont Isarcicella staeschei Zone, corresponding to the second phase of PTME. Over all, the carbon and sulfur isotopes demonstrate a coupled long-term relationship with large negative excursions during the Permian–Triassic transition followed by gradual recovery in the lowest Triassic, represented an extremely low concentration of sulfate in the ocean during this period. In contrast, the CS isotopes are strongly decoupled within the microbialite unit, which could be linked with the oxygen-poor conditions and microbial sulfate reduction (MSR: Sulfate reducing microorganisms facilitated the precipitation of sulfide and carbonate, such as SO42− + 2CH2O → H2S + 2HCO3−). The second phase of PTME was calibrated to the top of the microbialite unit, which was marked by the second δ13Ccarb-δ34SCAS negative excursions. The distinct marine oxygen deficiency was indicated by the small pyrite framboids, relatively high values of UEF (>1) and Ce/Ce* (>0.8). Combined with the previous biostratigraphic work, we propose that continuous volcanic activity induced intensified marine anoxia, leading to biotic mortality in the second phase of the PTME. Overall, our isotopic and geochemical data, integrated with results of previous studies, provided a new explanation for the carbon and sulfur isotope variations and additional evidences into the concurrent environmental changes during the Permian–Triassic transition.

Nitrification inhibitors impose distinct effects on comammox bacteria and canonical ammonia oxidizers under high N fertilization regimes

The response of complete ammonia-oxidizing (comammox) bacteria to variable nitrogen (N) inputs and nitrification inhibitors (NIs) remains poorly understood. We conducted two experiments, in a soil where both clade A and B comammox Nitrospira were present, to identify the type (ammonium sulphate vs. urea) and the level of N-fertilization (0–500 mg-N-kg‐1d.w. soil) that are conducive to the growth of comammox, compared to canonical ammonia-oxidizing microorganisms (AOM), and subsequently to assess their response to three commercial (DCD, nitrapyrin, DMPP) and a new potent (ethoxyquin) NI under these favourable N fertilization regimes. The highest concentration of ammonium sulphate stimulated comammox compared to canonical AOM which showed a dose-dependent increase by both N sources. DMPP primarily, and DCD, imposed a more persistent inhibition on nitrification than nitrapyrin and ethoxyquin, a result which did not concur with the soil persistence of NIs (DMPP was the least persistent among the commercial NIs) but was mostly driven by their selective inhibitory activity on ammonia-oxidizing bacteria (AOB) that prevailed in the studied soil. The inhibition of AOB by DMPP and DCD was complemented by the proliferation of comammox and ammonia-oxidizing archaea (AOA). NIs induced significant changes on AOB and comammox communities. Comammox Nitrospira clade B were enriched by DCD and DMPP but depleted by nitrapyrin and ethoxyquin. We showed that (i) releasing comammox Nitrospira and AOA from AOB competition allows them to proliferate efficiently, even under high inorganic ammonium conditions; (ii) comammox clade B are more responsive than clade A to high inorganic N input and NIs.

In-depth analysis of MgAl layered double oxide AC composite for sulfate removal from United Arab Emirates Ground Water: Synthesis optimization, fixed-bed performance, and economic feasibility

Excessive sulfate (SO42−) concentrations in groundwater pose health and environmental risks that require effective treatment strategies. This study focuses on optimizing the synthesis conditions of activated carbon doped MgAl layered double oxide (MgAl LDO/AC) and addresses the treatment of SO42− contamination in United Arab Emirates (UAE) groundwater. The study delves into key parameters such as the Mg/Al molar ratio and calcination temperature, unveiling optimal adsorption performance at a 3:1 M ratio and 500 ℃ calcination. The optimized MgAl LDO/AC(3:1/500 ℃) demonstrated notable selectivity for SO42− in the presence of NO3–, while exhibiting competition with H2PO4−, CO32−, HCO3−, and Cl−. In fixed-bed column studies, optimal performance was achieved with a lower influent concentration (50 mg/L), longer bed height (10 cm), and reduced flow rate (5 mL/min), resulting in a prolonged saturation time of 31.7 h, adsorption capacity of 429.5 mg/g, reduced axial dispersion coefficient, and enhanced mass transfer process. The real groundwater treatment demonstrated the composite's efficiency in reducing SO42− from 2606.6 to 817.5 mg/L, with additional removal of Cl− and NO3− ions, emphasizing its potential as an efficient pretreatment stage for highly contaminated and saline groundwater. Material characterization revealed the dominance of the chemical adsorption process of SO42− including surface complexation and ion exchange. Economic feasibility evaluation underscored the practicality of the composite, indicating its potential application in real plants with a cost below 20 US$/kg. Overall, MgAl LDO/AC(3:1/500℃) stands as a promising and cost-effective solution for removing SO42− in real-world water treatment scenarios, especially in regions facing water challenges.

Enhanced reduction of sulfate by iron-carbon microelectrolysis: interaction mechanism between microelectrolysis and microorganisms.

Sulfate wastewater has a wide range of sources and greatly harms water, soil, and plants. Iron-carbon microelectrolysis (IC-ME) is a potentially sustainable strategy to improve the treatment of sulfate (SO42-) wastewater by sulfate-reducing bacteria (SRB). In this study, an iron-carbon mixed micro-electrolysis bioreactor (R1), iron-carbon layered bioreactor (R2), activated carbon bioreactor (R3), and scrap iron filing bioreactor (R4) were constructed by up-flow column experimental device. The performance and mechanism of removing high-concentration sulfate wastewater under different sulfate concentrations, hydraulic retention times (HRT), and chemical oxygen demand (COD)/SO42- were discussed. The results show that the iron-carbon microelectrolysis-enhanced SRB technology can remove high-concentration sulfate wastewater, and the system can still operate normally at low pH. In the high hydraulic loading stage (HRT = 12h, COD/SO42- = 1.4), the SO42- removal rate of the R1 reactor reached 98.08%, and the ORP value was stable between - 350 and - 450mV, providing a good ORP environment for SRB. When HRT = 12h and influent COD/SO42- = 1.4, the R1 reactor sulfate removal rate reached 96.7%. When the influent COD/SO42- = 0.7, the sulfate removal rate was 52.9%, higher than the control group. Biological community analysis showed that the abundance of SRB in the R1 reactor was higher than that in the other three groups, indicating that the IC-ME bioreactor could promote the enrichment of SRB and improve its population competitive advantage. It can be seen that the synergistic effect between IC-ME and biology plays a vital role in the treatment of high-concentration sulfate wastewater and improves the biodegradability of sulfate. It is a promising process for treating high-concentration sulfate wastewater.

High copper levels induce premature senescence in 3T3-L1 preadipocytes

Copper (Cu) dyshomeostasis has been linked to obesity and related morbidities and also to aging. Cu levels are higher in older or obese individuals, and adipose tissue (AT) Cu levels correlate with body mass index. Aging and obesity induce similar AT functional and structural changes, including an accumulation of senescent cells. To study the effect of Cu-mediated stress-induced premature senescent (Cu-SIPS) on preadipocytes, 3T3-L1 cell line was exposed to a subcytotoxic concentration of copper sulfate. After Cu treatment, preadipocytes acquired typical senescence characteristics including diminished cell proliferation, cell and nuclei enlargement and increased lysosomal mass (higher Lamp2 expression and a slight increased number of cells positive for β-galactosidase associated with senescence (SA-β-Gal)). Cell cycle arrest was due to upregulation of p16Ink4aInk4a and p21Waf1/Cip1. Accordingly, protein levels of the proliferation marker KI67 were reduced. Cu-SIPS relates with oxidative stress and, in this context, an increase of SOD1 and HO-1 expression was detected in Cu-treated cells. The mRNA expression of senescence-associated secretory phenotype factors, such as Mmp3, Il-6 and Tnf-α, increased in Cu-SIPS 3T3-L1 cells but no effect was observed on the expression of heterochromatin-associated protein 1(HP1).Although the downregulation of Lamin B1 expression is considered a hallmark of senescence, Cu-SIPS cells presented higher levels of Lamin B1. The dysregulation of nuclear lamina was accompanied by an increase of nuclear blebbing, but not of micronuclei number.To conclude, a Cu-SIPS model in 3T3-L1 preadipocytes is here described, which may be an asset to the study of AT dysregulation observed in obesity and aging.

Trends in estuarine pyrite formation point to an alternative model for Paleozoic pyrite burial

The early Paleozoic Era (∼540–420 Ma) was an interval of profound biogeochemical changes including increasing oxygen (O2) and the onset of bioturbation (sediment mixing by animals). It is hypothesized that incipient bioturbation caused a monotonic decrease in sedimentary burial of pyrite (FeS2), which would have slowed atmospheric O2 accumulation. However, pyrite accumulation can exhibit complex responses to dynamic, low-O2 environmental conditions. To assess pyrite burial in a potential modern analogue to early Paleozoic environments, we collected sediment cores from the Chesapeake Bay, an estuary with multiple gradients in sulfate concentration, hypoxia intensity, organic carbon flux and lability, and bioturbation. Results indicate that pyrite accumulation is maximized not under strong sulfate depletion in highly reducing sediments, but rather in sediments that occupy the mid-range of sulfate–chloride ratios. This probably occurs through efficient replenishment of pore water sulfate and/or through the generation of sulfur redox intermediates, which promote pyrite formation via the polysulfide reaction pathway. In light of these results and in contrast to earlier models, we hypothesize that mild early Paleozoic bioturbation temporarily increased pyrite burial efficiency by stimulating higher sulfate reduction rates and increasing sedimentary sulfide retention. Compiled sulfur and carbon data from a geochemical database indicate that median sulfur-carbon ratios of fine-grained marine siliciclastic rocks increased from the Ediacaran through the Ordovician, then decreased and became much less variable from the Silurian onward. Thus, the Cambrian and Ordovician Periods may constitute a distinct interval of the Proterozoic-Phanerozoic transition in which bioturbation temporarily accelerated O2 buildup. This transition probably ended in the Silurian, when pO2 rose to sufficient levels to homogenize sedimentary carbon–sulfur cycling.

Microbial hydrogen sinks in the sand-bentonite backfill material for the deep geological disposal of radioactive waste.

The activity of subsurface microorganisms can be harnessed for engineering projects. For instance, the Swiss radioactive waste repository design can take advantage of indigenous microorganisms to tackle the issue of a hydrogen gas (H2) phase pressure build-up. After repository closure, it is expected that anoxic steel corrosion of waste canisters will lead to an H2 accumulation. This occurrence should be avoided to preclude damage to the structural integrity of the host rock. In the Swiss design, the repository access galleries will be back-filled, and the choice of this material provides an opportunity to select conditions for the microbially-mediated removal of excess gas. Here, we investigate the microbial sinks for H2. Four reactors containing an 80/20 (w/w) mixture of quartz sand and Wyoming bentonite were supplied with natural sulfate-rich Opalinus Clay rock porewater and with pure H2 gas for up to 108 days. Within 14 days, a decrease in the sulfate concentration was observed, indicating the activity of the sulfate-reducing bacteria detected in the reactor, e.g., from Desulfocurvibacter genus. Additionally, starting at day 28, methane was detected in the gas phase, suggesting the activity of methanogens present in the solid phase, such as the Methanosarcina genus. This work evidences the development, under in-situ relevant conditions, of a backfill microbiome capable of consuming H2 and demonstrates its potential to contribute positively to the long-term safety of a radioactive waste repository.

Selective phosphate removal by lanthanum carbonate @ anion exchange resin with fixed-bed column: RSM for process optimization and DFT for mechanistic study

Lanthanum carbonate @ anion exchange resin (LC@AER) has shown promise in adsorption processes due to its high maximum adsorption capacity and excellent stability in comparison with other lanthanum-based adsorbents. Nevertheless, there is a lack of significant investigation in evaluating the collective effect of the most influential parameters and determining the molecular complexes between the adsorbent and phosphate. This work aims to comprehensively evaluate and optimize the phosphate adsorption performance in fixed-bed columns and to determine the most favourable molecular configurations. Firstly, a response surface model (RSM) was developed to describe the phosphate adsorption performance in fixed-bed columns under the collective effect of selected independent variables, including influent pH, co-existing sulfate concentration, and empty bed contact time (EBCT). The RSM analysis reveals the significant effects of influent pH and co-existing sulfate concentration on phosphate adsorption. Moreover, the model achieves a correlation coefficient of >0.9, demonstrating its suitability for describing the experimental data. Secondly, various phosphate-lanthanum carbonate configurations were formulated, and the respective adsorption energies were compared using density functional theory (DFT) calculations. Subsequently, bidentate mononuclear complexes are determined as the most favourable configurations. The successful matching of the simulated peak locations with the experimental deconvoluted spectra further confirms the presence of such complexes in the system. Overall, this work provides an improved foundation and underlayer theory for potential future scale-up work on phosphate adsorption over LC@AER.

Characterization of Surfactant Adsorption Profile in Carbonates Under Severe Reservoir Conditions With Geochemical Modeling Approach

Abstract Chemical flooding has gained ample popularity as an effective technique to increase oil displacement and sweep efficiencies. However, very limited numerical applications of chemical flooding (surfactant and polymer) in carbonates are reported in the literature. Therefore, a geochemical-based surface complexation model is developed to characterize the adsorption profile of surfactants for the first time across the length of a core/reservoir. The proposed model is validated with various zeta-potential measurements and also with a recently conducted chemical flooding study. Additionally, sensitivity analysis of various parameters is performed, and it is found that surfactant effluent concentration decreases with the increase in flood temperature. It is observed that salinity reduction decreases the surfactant adsorption, increases the ionic repulsion amid the rock surface charge and the chemical species polarity. Similarly, when the concentration of surfactant is increased, the adsorption of surfactant concentration increases. However, the increase in surfactant adsorption is insignificant. The effect of sulfate spiking in chemical flooding is also investigated and it is found that an increase in sulfate concentration reduces the adsorption of surfactant across the reservoir. Moreover, the lowermost surfactant adsorption level is achieved through the injection of diluted water (<0.1 mg/g).

Accumulation and Potential Remediation of Copper in Golf Course Putting Greens

The objective of this study was to determine the potential accumulation of copper (Cu) within a USGA golf green profile and analyze potential remediation techniques of soils containing toxic Cu concentrations. Accumulation study utilized: copper phthalocyanine pigment (Par), copper hydroxide (Junction DF), varying concentrations of copper sulfate (CuSO4) within irrigation, and combinations of each. Products were applied over 13 weeks at Clemson University horticulture greenhouses with samples taken at thatch depth, 0-5.1 cm below thatch, and 5.1-10.2 cm below thatch at conclusion of study. Average Cu concentrations in thatch layer was 634.7 kg Cu ha-1, with 0 - 5.1 cm and 5.1 - 10.2 cm depth concentrations of 11.26 and 6.84 kg Cu ha-1, respectively. Remediation studies exposed 5 mg Cecil sandy loam to 15 ml 1000 ppm of CuSo4-Cu followed by 4 sequential 20 ml filtration cycles of 1 N ammonium sulfate, 1 N calcium nitrate, 1 N gypsum, or water. Single filtration of ammonium sulfate removed similar or greater amount of Cu than cumulative impact of 4 filtrations of any other products with 2064 mg Cu kg-1. Studies suggest that the management or removal of thatch may alleviate toxic accumulation of copper, however the use of ammonium sulfate in irrigation water may provide additional remediation options to turfgrass managers.

Biostimulation of sulfate reduction for in-situ metal(loid) precipitation at an industrial site in Flanders, Belgium

A 30-month pilot study was conducted to evaluate the potential of in-situ metal(loid) removal through biostimulation of sulfate-reducing processes. The study took place at an industrial site in Flanders, Belgium, known for metal(loid) contamination in soil and groundwater. Biostimulation involved two incorporations of an organic substrate (emulsified vegetable oil) as electron donor and potassium bicarbonate to raise the pH of the groundwater by 1–1.5 units. The study focused on the most impacted permeable fine sand aquifer (8–9 m below groundwater level) confined by layers of non-permeable clay. The fine sands exhibited initially oxic conditions (50–200 mV), an acidic pH of 4.5 and sulfate concentrations ranging from 600 to 800 mg/L. At the central monitoring well, anoxic conditions (−200 to −400 mV) and a pH of 5.9 established shortly after the second substrate and reagent injection. Over the course of 12 months, there was a significant decrease in the concentration of arsenic (from 2500 to 12 μg/L), nickel (from 360 to <2 μg/L), zinc (from 78,000 to <2 μg/L), and sulfate (from 930 to 450 mg/L). Low levels of metal(loid)s were still present after 34 months (end of study). Mineralogical analysis indicated that the precipitates formed were amorphous in nature. Evidence for biologically driven metal(loid) precipitation was provided by compound specific stable isotope analysis of sulfate. In addition, changes in microbial populations were assessed using next-generation sequencing, revealing stimulation of native sulfate-reducing bacteria. These results highlight the potential of biostimulation for long-term in situ metal(loid) plume treatment/containment.

How non-equilibrium aerosol chemistry impacts particle acidity: the GMXe AERosol CHEMistry (GMXe–AERCHEM, v1.0) sub-submodel of MESSy

Abstract. Aqueous-phase chemical processes in clouds, fog, and deliquescent aerosols are known to alter atmospheric composition and acidity significantly. Traditionally, global and regional models predict aerosol composition by relying on thermodynamic equilibrium models and neglect non-equilibrium processes. Here, we present the AERosol CHEMistry (GMXe–AERCHEM, v1.0) sub-submodel developed for the Modular Earth Submodel System (MESSy) as an add-on to the thermodynamic equilibrium model (i.e. ISORROPIA-II) used by MESSy's Global Modal-aerosol eXtension (GMXe) submodel. AERCHEM allows the representation of non-equilibrium aqueous-phase chemistry of varying complexity in deliquescent fine aerosols. We perform a global simulation for the year 2010 by using the available detailed kinetic model for the chemistry of inorganic and small oxygenated organics. We evaluate AERCHEM's performance by comparing the simulated concentrations of sulfate, nitrate, ammonium, and chloride to in situ measurements of three monitoring networks. Overall, AERCHEM reproduces observed concentrations reasonably well. We find that, especially in the USA, the consideration of non-equilibrium chemistry in deliquescent aerosols reduces the model bias for sulfate, nitrate, and ammonium when compared to simulated concentrations by ISORROPIA-II. Over most continental regions, fine-aerosol acidity simulated by AERCHEM is similar to the predictions by ISORROPIA-II, but simulated aerosol acidity tends to be slightly lower in most regions. The consideration of non-equilibrium chemistry in deliquescent aerosols leads to a significantly higher aerosol acidity in the marine boundary layer, which is in line with observations and recent literature. AERCHEM allows an investigation of the global-scale impact of aerosol non-equilibrium chemistry on atmospheric composition. This will aid in the exploration of key multiphase processes and improve the model predictions for oxidation capacity and aerosols in the troposphere.

Metabolomic Profiles in Patients with Cervical Cancer Undergoing Cisplatin and Radiation Therapy.

This study was aimed to evaluate endogenous metabolic changes before and after cisplatin and radiation therapy in patients with cervical cancer via untargeted metabolomic analysis using plasma samples. A total of 13 cervical cancer patients were enrolled in this study. Plasma samples were collected from each patient on two occasions: approximately one week before therapy (P1) and after completion of cisplatin and radiation therapy (P2). Of the 13 patients, 12 patients received both cisplatin and radiation therapy, whereas one patient received radiation therapy alone. The samples were analyzed using the Ultimate 3000 coupled with Q ExactiveTM Focus Hybrid Quadrupole-OrbitrapTM mass spectrometry (Thermo Fisher Scientific, Waltham, MA, USA). Chromatographic separation utilized a Kinetex C18 column 2.1×100 mm (2.6 μm) (Phenomenex, Torrance, CA, USA), and the temperature was maintained at 40°C. Following P2, there were statistically significant increases in the concentrations of indoxyl sulfate, phenylacetylglutamine, Lysophosphatidyethanolamine (LysoPE) (18:1), and indole-3-acetic acid compared with the concentrations observed at P1. Specifically, in the human papillomavirus (HPV) noninfection group, indoxyl sulfate, LysoPE (18:1), and phenylacetylglutamine showed statistically significant increases at P2 compared with P1. No significant changes in metabolite concentrations were observed in the HPV infection group. Indoxyl sulfate, LysoPE (18:1), phenylacetylglutamine, and indole-3-acetic acid were significantly increased following cisplatin and radiation therapy.

New experimental findings on the separation of cobalt and nickel from an ammonia-ammonium-based leach liquor using ammonium-saponified Cyanex 272

There is a need to improve cobalt and nickel recovery from industrial waste streams such as secondary leach solutions and rechargeable battery leach solutions due to the increasing economic value of these critical metals. Ammonia is an important lixiviant due to its limited environmental impact compared to acid based lixiviants, however, the subsequent selective extraction of cobalt and nickel from the leach liquor is a major challenge. This study presents new experimental findings on the treatment of a Base metal Refinery (BMR) secondary leach liquor that contains high concentrations of ammonia and ammonium sulphate, and low concentrations of cobalt (∼442 mg/L) and nickel (∼1624 mg/L) using partially saponified Cyanex 272. New knowledge that can be applied in the treatment of ammonia based leachates from various industrial wastes that contain residual cobalt and nickel is presented herein. The investigation was conducted through the determination of the optimum extraction temperature, percentage saponification, and organic to aqueous ratios. Partial saponification of Cyanex 272 increased ammonia-metal complex stability at the interphase and this limited cobalt extraction between 30 °C and 50 °C. However, a high cobalt extraction percentage, and a high separation factor of 94.07 %, and 1189.76 respectively were achieved at 60 °C, 20 % saponification, and 0.5 O/A loadings in a single contact. A second-stage batch extraction produced a nickel aqueous stream with no cobalt. Stripping of the loaded organic phase with dilute sulphuric acid produced a pure cobalt aqueous stream. Further, the extractant was successfully regenerated post stripping. Overall, partial ammonium-saponification increased the extent of cobalt extraction, and selectivity. The novel process conditions reported herein can be used to design sustainable cobalt-nickel separation processes.

Evaluation of sulfate rhizofiltration by Carpobrotus chilensis for treating mining waters

Chile, the world’s leading copper producer, generates significant volumes of mining waters, some of which cannot be recirculated into the production process. These mining waters are characterized by elevated sulfate ( SO 4 2 − ) concentrations, requiring sustainable management strategies for potential reuse. This study aims to evaluate the rhizofiltration technique using Carpobrotus chilensis for treating mining waters with a high SO 4 2 − concentration. Initially, the mining waters exhibited a pH of 7.97 ± 0.16 and a SO 4 2 − concentration of 2,743 ± 137 mg L−1, while the control water had a pH of 7.88 ± 0.08 and a SO 4 2 − concentration of 775 ± 19.0 mg L−1. The plants were hydroponically cultivated in 40 L containers with mining waters and drinking water as a control. Over an 8-week period, the pH of the mining water decreased to 3.12 ± 0.01, and the SO 4 2 − concentration declined to 2,200 ± 110 mg L−1. Notably, the fresh weight of roots was significantly higher in plants grown in mining water (22.2 ± 6.66 g) compared to those in the control treatment (14.3 ± 4.28 g). However, an undesirable increase in the acidity was observed in the mining waters after rhizofiltration, which was attributed to hydrogen sulfate (HSO4 -) and/or root exudates. Despite the unexpected increase in acidity, C. chilensis effectively reduced the concentration of SO 4 2 − in mining waters by 20%. Additionally, the C. chilensis roots accumulated 4.84 ± 1.40% of sulfur (S), a level comparable to thiophore plants. This study provides evidence that this non-aquatic plant can be used in sulfate rhizofiltration.

A Study on the Treatment and Recovery of Sodium Sulfate (Na&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;) Generated When Recovering Valuable Metals (Ni, Co, Mn, Li) from Waste Lithium Ion Batteries(LIBs)

Concerns have arisen regarding the high concentrations of sodium sulfate in wastewater resulting from the waste Li-ion battery wet recycling process. In addressing this issue, Bipolar electrodialysis was employed to desalinate high-concentration sodium sulfate and recover it as sulfuric acid and sodium hydroxide. The investigation encompassed various experimental variables, such as applied voltage (maintained at a constant level), feed solution concentration, the initial concentrations of sulfuric acid and sodium hydroxide, and volume ratio (F/A/B). Optimal conditions were determined by assessing water migration (%), the recovery rates (%) of sulfuric acid and sodium hydroxide, concentration of the recovered substances, process time, and energy consumption. A higher applied voltage was found to reduce process time while increasing energy consumption, with the 25 V condition considered preferable. When utilizing a high-concentration feed solution, energy consumption rises; however, it decreases per unit of processed solution, rendering a 1.30 M Na&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; feed solution preferable. Increasing initial concentrations of sulfuric acid and sodium hydroxide substantially prolonged process time and increased energy consumption, emphasizing the advantage of commencing with low initial concentrations. Adjusting the volume ratio facilitated the concentration and recovery of sulfuric acid and sodium hydroxide with minimal impact on process time or energy consumption. Under the identified optimal conditions, the recovery of 1.70 M sulfuric acid and 2.44 M sodium hydroxide was achieved.

Changes in the composition of the gut microbiota and content of microbial-derived uremic toxins in patients undergoing hemodialysis

Recent data highlight a significant role of the gut microbiota in the pathogenesis of chronic kidney disease, particularly in its terminal stage. However, little is known about the features of intestinal dysbiosis in people undergoing programed hemodialysis. Changes in the intestinal microbiota and blood levels of uremic toxins of microbial origin in patients with terminal renal insufficiency receiving hemodialysis were analyzed. This cross-sectional study included 80 patients receiving hemodialysis and 20 individuals with normal kidney function. The state of the microbiocenosis of the colon was studied using a polymerase chain reaction with a commercial set Colonoflor 16 (premium) manufactured by Alfalab (Russia). Serum levels of trimethylamine and its metabolite trimethylamine-N-oxide were determined by liquid chromatography/mass spectrometry. The concentrations of indoxyl sulfate and p-cresyl sulfate were evaluated by enzyme immunoassay according to the instructions of a commercial kit. In patients undergoing programed hemodialysis, increased colonization of enterococci was combined with the reduction of lacto and bifidophlora, E. coli, ruminococci, bacteria producing short-chain fatty acids (Faecalibacterium prausnitzii, Eubacterium rectale, Roseburia inulinivorans, and Blautia spp.) and microorganisms involved in maintaining the integrity of the intestinal barrier (Bacteroides thetaomicron and Akkermansia muciniphila). In addition, high titer levels of representatives of opportunistic and even pathogenic flora were often found in this group. Intestinal dysbiosis in patients undergoing programed hemodialysis was accompanied by a significant increase in the concentration of uremic toxins in the blood. Compared with individuals with normal renal function, the trimethylamine level in patients undergoing programed hemodialysis was increased 22 times; trimethylamine-N-oxide, 23 times; indoxyl sulfate, 21 times; and p-cresyl sulfate, 5 times. Thus, patients receiving hemodialysis exhibited pronounced pathological changes in intestinal microbiocenosis, accompanied by a significant increase in serum levels of uremic toxins of microbial origin.