Mechanochemical processing of limestone and sodium carbonate toward the development of reactive carbonate-based binder

Tungiasis is a cutaneous parasitic disease caused by the female flea Tunga penetrans. The World Health Organization recommends two-component dimeticone (NYDA®) as the sole treatment for tungiasis; however, this topical medication is not available in Kenya. In western Kenya, sodium carbonate has been adopted as a traditional village-based treatment. A pilot study found that the proportion of dead fleas on day 7 was higher with NYDA® treatment than that with 5% sodium carbonate treatment (87% vs. 64%, respectively). This study was aimed at assessing the 11-day cure rates of tungiasis by comparing the efficacy of sodium carbonate and NYDA® treatments in Vihiga County, Kenya. A randomised, observer-blinded, non-inferiority trial was conducted, with the non-inferiority margin set at 10%. A total of 160 eligible children with 941 flea infections were matched and randomised. The number of lesions per child per foot ranged from 1 to 10, with a median of 5 lesions. Each participant received both treatments, with one treatment applied to each foot. Health conditions, including inflammation scores and adverse events, were recorded. Observations were recorded on days 3, 5, 7, 9, and 11 using a digital microscope to determine flea viability. Data from 157 children aged 4-15years were analysed, comprising a total of 843 lesions. On day 11, the proportion of dead fleas was 88% for NYDA® and 77% for 5% sodium carbonate solution (p < 0.05). No significant differences were observed in inflammation scores or symptoms such as pain and itchiness between the two treatments. This study demonstrated that 5% sodium carbonate did not meet the non-inferiority margin compared with NYDA® in treating tungiasis. Nevertheless, in settings where NYDA® is not accessible, it may still be considered an alternative. Trial registration This study was registered with UMIN-CTR (Trial ID: UMIN000044320; reception desk number: R000050621) on 28 May 2021.

Understanding the phase equilibria and solubility behavior in multicomponent salt-water systems is essential for the development of efficient separation and resource recovery technologies, especially for lithium-containing compounds. However, reliable phase equilibrium data for the Na2CO3–LiCl–H2O system remain limited over a wide range of temperatures and concentrations. In this study, solubility relationships and phase transformations in the sodium carbonate–lithium chloride–water system were systematically studied using a visual polythermal method over a wide range of temperatures and compositions. The resulting phase diagram describes distinct crystallization regions corresponding to ice, Na2CO3∙10H2O, Na2CO3∙7H2O, LiCl∙5H2O, LiCl∙2H2O, LiCl∙H2O, and the newly identified Li2CO3 phase. The formation and stability of the new lithium carbonate phase were confirmed using combined chemical and physicochemical analysis, including infrared spectroscopy and X-ray diffraction, ensuring the reliability of the obtained equilibrium data. Characteristic absorption bands in the IR spectrum observed at 1437.03 cm-1 and 869.93 cm-1 were assigned to carbonate functional groups, providing further evidence for the formation of Li2CO3. The polythermal diagram shows that a significant portion of the system is occupied by crystallization fields, indicating the initially low solubility of lithium carbonate. This behavior highlights the possibility of selectively separating Li2CO3 from saturated solutions through controlled evaporation. Overall, the results provide fundamental thermodynamic insights and practical recommendations for lithium recovery processes and the development of effective separation strategies in aqueous carbonate-chloride systems.

This study reports 110 different alkaliphilic bacteria isolated from soda ash industrial effluents and sludge samples, employing an innovative κ-carrageenan-KCl-based solid medium (pH 13.0 ± 0.2). Primarily, they were subjected to morphological, physiological, and biochemical tests. Molecular characterization was carried out using 16S rRNA sequence homology analysis. They were also screened for halo-alkaline extracellular enzyme production like amylase, pectinase, caseinase, gelatinase, lipase, and xylanase and antibiotic sensitivity. Their phylogenetic analysis revealed that these extreme alkaliphiles belonged to 26 diverse genera: (Firmicutes, 61%) Paenibacillus, Bacillus, Exiguobacterium, Lysinibacillus, Planomicrobium, Aneurinibacillus, Staphylococcus; (Proteobacteria, 21%) Pseudomonas, Stenotrophomonas, Enterobacter, Alishewanella, Rheinheimera, Brevundimonas, Ochrobactrum, Alcaligenes; (Actinobacteria, 18%) Cellulosimicrobium, Nesterenkonia, Arthrobacter, Rhodococcus, Microbacterium, Brevibacterium, Janibacter, Dietzia, Micrococcus, Kocuria, Streptomyces. Majority of them produced were lipase (73%), pectinase (72%), and caseinase (71%). Fifteen percent of them produced all six alkaline enzymes. A large amount of extracellular polysaccharide (EPS) was produced by 19% of isolates, which might be useful for petroleum hydrocarbon or heavy metal bioremediation. Sixteen percent of the isolates were resistant to ≥ 5 antibiotics. Highest antibiotic resistance was observed against ceftazidime (39.09%) and penicillin (26.36%), while netlimycin, amikacin, ciprofloxacin, and gentamicin proved most effective against 99%-98% of isolates. There were 27 isolates whose 16S rRNA sequences showed ≤ 97% homology with ones in NCBI, suggesting the possibility of novel lineages in phylogeny. This is the first attempt where a diverse population of commercially important alkaliphilic bacteria has been isolated and characterized from soda ash industry, effluent, and sludge samples by using a specially devised culture media.

The coal-based direct reduction followed by magnetic separation (CDRMS) is an efficient iron extraction and dephosphorization process, which requires adding additives to improve the phosphorus removal rate. Compared with other additives, sodium carbonate has the advantages of good iron index, high phosphorus removal rate and less environmental pollution. Its role in phosphorus-rich oolitic iron ore (PROIO) where phosphorus exists in the form of apatite has been proved. However, the influence on the phosphorus transformation process in the lattice of iron minerals is not clear. In this paper, the effect of sodium carbonate on phosphorus removal in iron minerals and iron recovery during CDRMS was studied. Compared with not adding chemicals, the addition of sodium carbonate significantly reduced the phosphorus content of direct reduced iron (DRI) from 0.69% to 0.09%. The iron grade increased from 93.28% to 95.08%, and the iron recovery rate rose from 90.61% to 96.48%. The mechanism of sodium carbonate was revealed by using a synchronous thermal analyzer (TG–DSC), X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), scanning electron microscope and energy dispersive spectrometer (SEM–EDS), and vibrating sample magnetometer (VSM). The results show that sodium carbonate reacted with silicon and aluminum components to form nepheline, and the lattice substitution of phosphorus in iron minerals and silicon in nepheline prevents the reduction of phosphorus. In addition, sodium carbonate promotes the reduction of iron minerals, resulting in an increase in the magnetic properties of the reduction products.

In this study, biocarbon adsorbents were obtained from fennel and caraway seeds through microwave-assisted chemical activation with sodium carbonate. The activation process involved carbonizing the raw material at 300 °C for 30 min., followed by impregnation with sodium carbonate at a precursor-to-activator mass ratio of 1:2. Activation was performed at two distinct temperatures-500 °C and 600 °C-with an activation time of 15 min. The structural, textural, and surface chemical characteristics of the obtained biocarbons were investigated using complementary analytical techniques, including low-temperature nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Boehm titration, and pH analysis of aqueous extracts. The resulting adsorbents demonstrated low development of specific surface area (109-154 m2/g) and limited sorption capacity for methylene blue (20-32 mg/g). Adsorption experiments indicated that the Freundlich isotherm model most accurately described the data, suggesting multilayer adsorption on heterogeneous surfaces. Thermodynamic evaluations showed the adsorption to be both spontaneous and endothermic. The adsorption mechanism is primarily governed by electrostatic interactions between the cationic dye and surface functional groups, π-π interactions with the carbon structure, and diffusion within mesopores. This study provides a comparative evaluation of microwave-assisted Na2CO3 activation of fennel and caraway seed waste and assesses the potential of these biochars for dye removal from aqueous solutions.

Abstract The development of biocompatible and bioactive materials is essential for the advancement of regenerative medicine. Biocomposites of chitosan incorporated with pure and lithium- and magnesium-doped 45S5 bioglasses were developed by the sol–gel process for biomedical applications. The bioglass was synthesized from tetraethyl orthosilicate (TEOS), triethyl phosphate (TEP), calcium nitrate tetrahydrate, and sodium carbonate, with the addition of lithium and magnesium nitrates at concentrations of 1, 2, 5, and 10% by mass. After gel formation, the samples were dried at 60 °C and heat treated at 700 °C, dispersed in a 1% chitosan solution, freeze-dried, and neutralized. The samples were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), biodegradation studies, and cytotoxicity tests. The results indicated that higher concentrations of dopants increased mass loss and crystallinity. FTIR analyses revealed that metal ions served as network modifiers, with magnesium also acting as an intermediary, promoting more significant structural reorganizations. Thermal analyses indicated multistage decomposition and greater stability of the polymeric phase in the undoped samples. Lithium doping enhanced hydration and structural stability, while magnesium introduced greater disorder in the glass network, potentially increasing bioactivity. Swelling tests showed greater water absorption in the doped samples, the 10% formulations achieving the highest values, up to 260%. All samples exhibited nearly complete degradation in phosphate buffer solution after 28 days. Cytotoxicity assays demonstrated high cell viability (&gt; 95%) for all compositions, with Li-doped samples showing values up to 101± 5%. The developed biocomposites may represent a promising alternative for tissue engineering applications.

The Ivorian Antipollution Center discovered the toxics Waste from Probo Koala boat in 21 August, 2006. This boat had been used to refine oil named naphta of cokéfaction by Trafigura firm in the sea. The process of refine consist to caustic sodium carbonate washing and produced toxics waste. These toxic wastes have been unloading in 13 zones of the Abidjan district: Akouédo, Abobo, Abobo Alépé road (DJIBIvillage), civile prison road (MACA), industrial zone of Koumassi, Port-Bouët - Vridi CAP Logistic (Rue Saint-Sylvestre) … This situation caused a socio-political crisis and generated the death of many people. The first analyses showed that the substances coumpound of toxic waste are a petroleum factory origin. In the aim to know the environmental impact of these pollutes in Abidjan district (IvoryCoast) the samples of these toxic wastes have been sent to analyses in Wesling laboratory in France. These experiences showed thatthe toxic waste contain the Polycyclics Aromatics Hydrocarbons (PAH), the Volatile Aromatics Compound (VAC), the Mercaptans and sulphur molecules Aliphatic hydrocarbons, Linear hydrocarbons, Total Petroleum Hydrocarbons (TPH), Mercaptans, sulphur and also heavy metals.

This study evaluates the environmental footprint of producing a polymer flocculant synthesised from phenol–formaldehyde resin waste (novolak T) at a quarter-technical scale, with electricity supply assumed from photovoltaic (PV) generation. A cradle-to-gate life cycle assessment was performed in SimaPro Developer v9.4 using the Environmental Footprint (EF) 3.0 method and ecoinvent datasets. The functional unit was 100 kg of the sodium salt of the sulfonic derivative of novolak T. The characterization results indicate a climate change impact of 170.1 kg CO2 eq and an acidification impact of 5.99 mol H+ eq per functional unit. Hotspot analysis shows that process chemicals dominate most impact categories: sulphuric acid production drives acidification and several air-emission-related categories, while sodium carbonate is a major contributor to toxicity- and eutrophication-related indicators. In contrast, electricity has a marginal contribution across categories. Recycling of novolak waste provides a strong compensatory credit, leading to net negative results in selected categories, including resource use and fossils (−5.02 × 103 MJ). Overall, the results indicate that improving the upstream supply chains and the consumption of process reagents are the primary levers for reducing the environmental footprint of this waste-derived flocculant.

In this study, we investigate the reduction smelting of antimony concentrate, where sodium antimonate is the primary antimony-bearing component, in alkaline melts. This study aims to reduce the carbon footprint of metallic antimony production. It is shown that traditional carbon reduction is accompanied by significant formation of carbon-containing gases and sodium losses due to volatilization. Based on thermodynamic analysis and experimental investigations, carbon monoxide is established as the key active gaseous reducing agent for antimonate compounds, predominantly operating in the temperature range of approximately 320–900 °C, which corresponds to the stages of coke oxidation and sodium antimonate decomposition. The authors propose introducing sodium hydroxide into the charge to form an alkaline melt with a lowered melting point when mixed with the antimony concentrate, ensuring the sequestration of carbon dioxide through the formation of sodium carbonate. Experiments confirmed the possibility of chemically fixing up to 75.5% of CO2 into the slag phase at the laboratory stage and up to 87% of CO2 during pilot tests of reduction smelting under a flux layer. Crude metal with an antimony content of 94–96.2% Sb was obtained, while coke consumption was reduced by 16–20%. The proposed approach ensures a simultaneous increase in the degree of antimony recovery, the utilization of carbon-containing gases, and the formation of a stable eutectic slag melt. This allows the process to be considered an element of carbon-neutral pyrometallurgical technology for processing antimony concentrates.

This study is aimed to investigate the synthesis of Ni2⁺-Ni3⁺ LDH (layered double hydroxide) in the presence of sodium hypochlorite. Ni2⁺-Ni3⁺ LDH is a promising active material for use in supercapacitors and electrocatalysis. The syntheses were carried out at a temperature of 60°C by coprecipitation under conditions of high supersaturation and at constant pH values (8, 10, and 12). To obtain the guest metal cation Ni3⁺ from the initial Ni2⁺ during synthesis, sodium hypochlorite was introduced as an oxidizing agent into the alkaline sodium carbonate solution. As control samples, Ni-Al-carbonate LDH were synthesized using the same methods and conditions. The formation of Ni3⁺ hydroxo compounds during synthesis was visually confirmed by a color change. The crystal structure of the samples was investigated by X-ray diffraction analysis, and the total Ni and Ni3⁺ contents were determined by trilonometric and iodometric titration. The samples synthesized in the presence of hypochlorite exhibited a black color, confirming the successful formation of Ni3⁺ hydroxo compounds. All control samples corresponded to Ni-Al LDH. The nickel hydroxide sample synthesized by coprecipitation at high supersaturation was identified as β-Ni(OH)2, with a total Ni content of 59.5% and a Ni3⁺ fraction of 12.2%. The transformation of Ni2⁺ → Ni3⁺ occurred in the surface layer of the formed β-Ni(OH)2 particles because the oxidation rate was lower than the hydroxide formation rate. The samples synthesized by coprecipitation at constant pH exhibited a layered structure consisting of β-Ni(OH)2 and Ni2⁺–Ni3⁺ LDH with an α-type lattice, suggesting that the oxidation rate exceeded the hydroxide formation rate. Thus, the possibility of synthesizing Ni2⁺-Ni3⁺-carbonate LDH was experimentally demonstrated. Under the optimal conditions (pH 8), the proportion of the Ni-Ni LDH phase reached 55.9%. The synthesized Ni2⁺-Ni3⁺ LDH shows potential for application in supercapacitors and electrocatalysis, provided that its specific electrochemical characteristics are determined in further studies

— constitutes a substantial but chronically under-managed organic resource at holy places across India. Conventional disposal through river immersion or open landfilling leads to greenhouse gas emissions, groundwater contamination, and aesthetic degradation of sacred sites. This review critically examines the scientific and techno-economic feasibility of an integrated valorisation pathway that transforms templewaste into two commercially valuable outputs: methane rich biogas and nutrient-dense organic fertilizer (digestate). Drawing upon experimental evidence from anaerobic digestion studies conducted at analogous sites in Maharashtra, we evaluate the impact of alkaline chemical pretreatment (sodium carbonate and sodium bicarbonate), solar-assisted digester heating, and co digestion with canteen food waste on methane yields. Key findings indicate that Na2CO3 pretreatment improves biogas output by up to 106% and reduces chemical cost by 96% relative to NaOH; solar heating amplifies yield by a further 122%; and 30% food-waste co-digestion adds 32.6% incremental gain. The raw biogas methane content reaches 57.52%, surpassing previous floral-waste studies. Downstream purificationof hydrogen sulfide using zero-valent iron (Fe0) and activated carbon packed-bed adsorbers is reviewed, alongside CO2 removal technologies — water scrubbing, membrane separation, pressure-swing adsorption, chemical absorption, and emerging electrochemical separation — that upgrade the biomethane to near pipeline quality. The organic digestate is characterised for nitrogen, phosphorus, and potassium content, confirming suitability as a biofertilizer. Microbial fuel cell (MFC) as an alternative bioelectricity pathway is also assessed. Thisreview concludes that a decentralised, solar-integrated biogas plant co-located with temple premises in Sangli offers a socially acceptable, financially viable, and environmentally sound circular-economy solution for sacred-site waste management. Key Words: Anaerobic digestion; Temple floral waste; Biogas; Alkaline pretreatment; Solar digester heating; Co-digestion; Hydrogen sulfide removal; Biogas upgrading; Organic fertilizer; Circular economy

Water, a vital natural resource for sustaining life, has experienced a sharp rise in consumption due to increasing demand. Although many studies evaluate groundwater hydrogeochemistry and drinking suitability, its agricultural suitability remains largely underexplored. Recognizing the importance of irrigation to local agriculture, this study integrates multiple hydrochemical indices with the IWQI to comprehensively assess groundwater suitability for irrigation in the Aksum area. This study evaluates hydrochemical parameters, including total dissolved solids (TDS), electrical conductivity (EC), sodium adsorption ratio (SAR), sodium percentage (Na%), permeability index (PI), Kelley index (KI), and residual sodium carbonate (RSC), and employs the irrigation water quality index (IWQI). Results revealed that SAR (0.07-1.09), Na% (2.5-17.19), RSC (- 7.79 to - 1.23), and KI (0.02-0.17) values of all water samples were suitable for irrigation. However, 5.26% of samples exceeded recommended limits for TDS (206.8-2774), EC (290-3890), and PI (19.76-52.94). The calculated IWQI values ranged from 72.3 to 100, averaging 94.6. About 94.74% of samples showed no restrictions, while 5.26% had low restrictions. Spatial maps reveal a northeast-southwest decline in irrigation water quality. However, groundwater remains generally suitable for irrigation. The findings improve understanding of sustainable water quality, guiding planners, policymakers, and stakeholders in effective irrigation management.

Objective. To optimize the Folin–Ciocalteu (FC) method for estimating phenolic antioxidants in the shoots of Crataegus pinnatifida Bunge using surface response methodology and the Box–Behnken design. Materials and methods. The shoots of Crataegus pinnatifida Bunge were harvested in 2025 at the beginning of flowering from a natural population in Khabarovsk Krai. The measurements were performed using a UV-1700 spectrophotometer (Shimadzu, Japan). The response surface tool and the Box–Behnken design were applied to identify the combination of phenolic compound extraction factor levels that would yield the optimal response. Statistical processing of the results was carried out in accordance with the State Pharmacopoeia of the Russian Federation, 15th edition, OFS.1.1.0013 “Statistical processing of the results of physical, physicochemical, and chemical tests” using the Microsoft Office Excel 2010 and Statistica 6.0 software packages. Results. For the shoots of Crataegus pinnatifida Bunge, the optimal parameters for the FC reaction have been determined as 0.5 ml of FC reagent and 5 ml of a 20% sodium carbonate solution, which ensure the accuracy, reproducibility, and stability of the reaction products. The response surface methodology and Box–Behnken design revealed that the highest yield of phenolic compounds occurs when the following extraction parameters are combined: extractant is 54.87% ethyl alcohol; raw material to extractant mass ratio is 1:783, and extraction time is 65.99 min. Conclusion. Extraction conditions are optimized; a method for quantitative spectrophotometric determination of phenolic compounds in the shoots of Crataegus pinnatifida Bunge is developed, which is necessary for standardization of this type of raw material.

ABSTRACT The practical application of sodium–carbon dioxide (Na–CO 2 ) batteries is impeded by persistent challenges, including high charging overpotential and inadequate cycling stability, which originate from the insulating nature of the discharge product (Na 2 CO 3 ) and detrimental electrolyte decomposition at elevated voltages. Although substantial research has focused on cathode catalysts, the charging voltage typically remains above 4 V, resulting in irreversible side reactions and limited cycle life. In this study, we introduce a nitrate‐based molten‐salt electrolyte strategy to address these issues fundamentally. The NaNO 3– KNO 3– CsNO 3 eutectic electrolyte exhibits a high ionic conductivity of 96 mS cm −1 and a broad electrochemical window, enabling a Na–CO 2 battery with a Super P cathode to operate at a low charge plateau of 3.2 V and deliver a high discharge capacity of 4852 mAh g −1 over 150 cycles. Moreover, by incorporating a RuO 2 catalyst supported on Super P, the charge voltage is further reduced to 3.0 V, and the cycle life exceeds 300 cycles. This work underscores the synergistic effect of molten‐salt electrolytes and heterogeneous catalysts in overcoming kinetic and stability limitations, providing a viable pathway toward practical, high‐performance Na–CO 2 batteries.

Understanding the differences in the infiltration processes of soda saline–alkali soils with varying degrees of salinization and their underlying mechanisms is of great significance for the rational use of regional soil and water resources. This study was conducted in the Songnen Plain, one of the world’s three major saline–alkali soil distribution areas, where the salt composition is dominated by sodium bicarbonate and sodium carbonate. Five types of soda saline–alkali soils with different degradation levels were selected from the study area. Using a one-dimensional vertical constant-head single-ring infiltration method, characteristic parameters of the infiltration process were measured through in situ experiments. Based on principal component analysis (PCA), a comprehensive multi-parameter infiltration capacity index (SICI) was constructed. Pathway analysis was further employed to explore the potential relationship between soil physical and saline–alkali characteristics and the infiltration process. The results showed that compared to the initial infiltration rate, the steady-state infiltration rates of the five soils decreased significantly by 41.81%, 64.87%, 97.20%, 99.24%, and 99.59%, respectively. Notably, the steady-state infiltration rate of the most severely degraded saline–alkali soil (Suaeda glauca) was only 0.13 mm·h−1. Correspondingly, Suaeda glauca soil exhibited the lowest SICI. Correlation and pathway analyses indicated that SICI was significantly associated with physical and saline–alkali parameters of the soda saline–alkali soils. Besides the direct associations of the fractal dimension of particle size distribution (D), non-capillary porosity (NCP), and salt content (SC) on SICI, D was also linked to lower SICI indirectly through its relationship with NCP, sodium adsorption ratio (SAR), and SC. The findings suggest that soil physical structure, particularly the fractal dimension of particle size distribution and pore characteristics, appears to be a primary factor influencing the infiltration capacity of highly soda saline–alkali soils, and that improving soil texture structure and enhancing soil porosity could be prioritized in the restoration and management of severely degraded soda saline–alkali lands.

A novel engineering approach for assessing the robustness of fuzzy logic control (FLC) systems with modified parallel distributed compensation (MPDC) is presented. It addresses the problem of successful implementation and operation in industrial environment of designed systems for the control of complex plants with model uncertainty. The research steps on modified Takagi–Sugeno–Kang (MTSK) plant models MTSKn and MTSKlow already derived and validated for normal and low plant loads from experimental data for the level of the solution in an industrial carbonisation column for soda ash production. MPDC with PI linear local controllers are developed based on the MTSKn plant model, which differ in the parameters that are optimised by genetic algorithms for fitness functions with and without robustness requirements and different random initial parameter values. The MTSKn and each of the designed MPDC are represented according to suggested criteria by a nominal and varied linear plant model and controller, respectively. Then, robust stability and robust performance criteria are derived for the linearised MPDC–MTSKn systems. The system performance and robustness are investigated in the frequency domain and from the simulated reference step responses for MTSKn and MTSKlow, with the results benchmarked against an existing adaptive FLC.

Hydrothermal liquefaction (HTL) is gaining interest for the energy valorization of wet waste. While HTL performance is known to depend on biochemical composition, the role of inorganics remains poorly understood. This study evaluates the effects of the four most common metals (Na, K, Mg, and Ca) present as oxides, carbonates, phosphates, sulfates, and chlorides. Experimental results, supported by principal component analysis (PCA), revealed that inorganics significantly influence HTL performance, depending on both cation and anion type. More basic anions generally decreased solid production while favoring both biocrude and aqueous-phase yields, with carbonates performing better than oxides despite their lower basicity. Na and K enhanced these effects compared to Ca and Mg, while K and Ca led to higher HHVs and lower oxygen content in the biocrude than Na and Mg, respectively, indicating a specific role of the cations. Sodium and potassium carbonates performed best, increasing biocrude yield by 48% relative to the corresponding inorganic-free feedstock, while reducing solid production by 90%. CaCl2 was the only compound reducing biocrude yield, while increasing solid residue by 90%. This study highlights the critical influence of inorganics on HTL performance and provides a foundation for deeper insights into the underlying mechanisms.

Herein, we are demonstrating an earth-abundant manganese-catalyzed oxidative deamination of linear and branched primary amines to selectively form carboxylic acids and ketones using water as the oxygen atom source. A series of pincer and non-pincer Mn complexes were assessed for these deaminative transformations. A bio-inspired DAFO (4,5-diazafluoren-9-one) ligand-based [(DAFO)Mn(CO)3Br] complex (Mn-1) was found to be effective for the reaction proceeding under mildly basic aqueous medium, generating NH3 and H2 as sole by-products without the requirement of any oxidant. An optimized condition of 5mol% Mn-1, Na2CO3 (1equiv) at 150°C for 48h in water/1,4-dioxane mixture furnished 92% of the corresponding benzoic acid from benzylamine. A wide variety of electron-donating and withdrawing para-, meta-, and ortho-substituted benzylamines, including promising hetero and aliphatic linear primary amines, afforded moderate to excellent yield of the desired carboxylate product. We have also examined a few branched primary amines using 5mol% Mn-1 and catalytic sodium carbonate at 150°C for 48h, affording good yield of ketones. The reaction was found to be chemo-selective for primary amine moieties over alcohol functionalities. Further, stoichiometric mechanistic investigation and preliminary computational data provide insights into the possible mechanistic steps.

Taptapani Geothermal Spring (∼Eastern Ghat Terrain, India): Investigating Hydrogeochemistry, Solute Transport Mechanisms, Geothermometry, and Water Quality Index