The improper disposal of hydrodesulfurization (HDS) catalysts poses significant environmental risks due to the presence of toxic materials and metals. This study investigates a method for recovering valuable resources, specifically aluminum, vanadium, and nickel, from industrial waste HDS catalyst residue. The process involves roasting the HDS residue at 300 degrees C for 120 min with a 1:1 solid-to-liquid (S/L) ratio of residue to sodium hydroxide (NaOH). Subsequent water leaching resulted in the recovery of approximately 99% of Al(III) and V(V). The leaching kinetics of Al(III) and V(V) were found to follow the Shrinking-Core model, described by the equations X = kc.t and 1- (1- X)1/2 = kc.t, with activation energies (Ea) of 7.39 kJ/mol and 4.61 kJ/mol, respectively. The leach liquor containing Al(III) V(V) was treated with concentrated hydrochloric acid (HCl) at pH 9.5 to precipitate aluminum salt, while vanadium was extracted using ammonium chloride (NH4Cl) by adjusting the pH to 7.1 at 50 degrees C for 30 min. The residual material was leached with 5% (v/v) sulfuric acid (H2SO4) in the presence of 15% (v/v) hydrogen peroxide (H2O2) to achieve maximum nickel dissolution, resulting in the recovery of 99% of aluminum as Al(OH)3 with 99.8% purity and 99% of nickel as NiSO4.6H2O.

The current study investigated a comprehensive hydrometallurgical process designed for the selective recovery of vanadium (V) and aluminum (Al) from spent catalysts used in sulfuric acid manufacturing (SAM), to promote sustainable recycling of industrial waste. The process began with alkaline leaching using 0.5 M NaOH which effectively dissolved both metals under optimized conditions (25 degrees C, 10 min, and a solid-to-liquid ratio of 100 g/L), resulting in a silica-rich residue. The resulting leach liquor, containing vanadium (V(V)) and aluminum (Al(III)), was subjected to solvent extraction with 10% Aliquat 336. Vanadium was selectively extracted at a pH of approximately 2, using an organic-to-aqueous (O/A) ratio of 1:1. Then, vanadium was stripped from the loaded organic phase using NaOH, producing a vanadium-enriched aqueous solution. Vanadium precipitated as ammonium metavanadate (NH4VO3) at 60 degrees C and a pH around 7, using ammonium chloride. Concurrently, aluminum was recovered from the raffinate by precipitation as aluminum hydroxide (Al(OH)3) at a pH of approximately 7.1, using sodium hydroxide and sulfuric acid as pH adjuster. The developed process demonstrated high metal recovery rates with minimal environmental impact. This study underscores the effectiveness of integrating leaching, solvent extraction, and precipitation techniques for sustainable resource recycling from industrial waste.

The relatively high concentration of thorium and uranium in monazite poses significant environmental issues in the extraction process of rare earth elements from monazite if left untreated. A new process route that recovers both thorium and uranium as oxides has been proposed, and an analysis of its economic feasibility is presented in the current paper, based on analysis and processing of a Korean monazite sample. Comparative evaluations with existing acidic and alkaline routes have also been carried out. It was estimated that the largest proportion of the operational cost for the new process related to the materials and reagent costs. Sensitivity analysis predicted that the value of neodymium oxide followed by Heavy Rare Earth Oxides (HREO) and praseodymium oxide affect the revenue significantly. Increasing the average basket price of the total rare earths oxide by 1.5 times would result in revenues of US$158.8 million/year for the proposed route, compared to US$161.5 and US$156.3 million/year for the alkaline and acidic routes, respectively. The discounted cash flow analysis and the resulted Net Present Value (NPV) suggested that the proposed processing route was in fact the only process estimated to be economically feasible with the payback period expected to be around 4.5 years. The sale of thorium oxide and uranium oxide by-products of the proposed route contributed to the positive discounted NPV. It was also estimated that a minimum sale price of US$20/kg total rare earth oxide is required to ensure all the processes generate a positive discounted NPV. These results shown that the proposed new processing route is estimated to be economically feasible.

Thiazolines and their derivatives hold significant importance in the field of medicinal chemistry due to their promising potential as pharmaceutical agents.

Electronic manufacturing industries use copper in highest proportion in metals due to its unique properties. But there is a gap in demand and supply of this metal to the industry due to its huge requirement and lack of its proper recycling of copper containing equipments. Also, effluent generated from these industries carries substantial amount of this metal, which get discharged, and loss of metals to the environment. Present paper discusses about valuable copper metal recovery from industrial effluent in powder form using novel process flow-sheet. At start, bio-adsorptiontechnique was used to recover copper from industrial effluent due to its advantages like low cost, feasible method showing faster kinetics. Datura root powder was found to be potential bio-adsorbent for copper recovery from effluent having 997 mg/g adsorption capacity. It follows second-order rate reaction and Freundlich adsorption isotherm with 0.9711 regression coefficient. Further, copper-enriched solution obtained from this technique was subjected to cementation process using scrap iron rods to get copper powder. This can be used to produce value added products using its ingots. This is one of the approaches towards waste to wealth creation having tremendous potential to get commercialized.

The liquid-liquid extraction process for Mo(VI) in the presence of W(VI) from a sulfate solution with di-(2ethylhexyl) phosphoric acid (D2EHPA) was studied using an artificial neural network (ANN) model coupled with a particle swarm optimization (PSO) algorithm. This study examined the influence of several operating parameters, including equilibrium pH, mixing time, reaction temperature, extractant concentration, and organic/ aqueous (O/A) ratio, on the selective extraction of molybdenum from tungsten. In addition, the effects of different concentrations of ammonium bicarbonate on the metal stripping process from the loaded organic phase were analyzed. Subsequently, intelligent predictions regarding the molybdenum separation from tungsten were made using the ANN methodology in conjunction with the PSO technique. The numerical modeling results indicated that the coupled ANN-PSO approach demonstrated superior predictive performance, as evidenced by a higher correlation coefficient (R2) and lower absolute average relative error (AARE), in comparison to the simple ANN approach for predicting the selective extraction of molybdenum from tungsten. A Monte Carlo simulation (MCS) using a pseudo -random algorithm was employed to evaluate the uncertainty principle associated with the measurement -based input parameters that affect the separation factor response. The PERT distribution function was used to conduct the sensitivity analyses by incorporating mathematical formulae to generate sequences of random numbers. The findings of these analyses revealed that the factors with the greatest influence, arranged in descending order, were the equilibrium pH, D2EHPA concentration, O/A ratio, mixing time, and reaction temperature.

Reclamation of copper from waste printed circuit boards (WPCBs) is critical in advancing eco-friendly manufacturing methods by considering viable secondary metal resources. Herein, this study introduced a novel hybrid intelligence model that relies on a support vector regression-grey wolf optimization (SVR-GWO) approach to predict, validate, and optimize the leaching of WPCBs in nitrate solution and copper purification using LIX 973 N. The hybrid model's performance surpassed that of the standalone SVR model due to fine-tuning hyperparameters using the GWO approach, as indicated by the lower values of MSE and narrow error distribution in the leaching, extraction, and stripping experiments. The modeling data indicated that 96.1 % of the copper in the WPCB material was dissolved during leaching at 75(degrees)C, using a pulp density of 7 % for 2 h. During the extraction phase, the hybrid model optimized the structure performance of equilibrium pH, extractant concentration, contact time, and O/A ratio, resulting in values of 2.5, 30 %, 20 min, and 1, respectively. The predicted isotherm data for the McCabe-Thiele diagram, derived from the developed model, suggested four operational stages for extracting copper from the leach solution. Under optimized conditions of 2 M H2SO4 and 0.3 A/O phase ratio at 25( degrees)C for 20 min, the complete stripping process from the loaded organic phase required applying three counter-current stages. These developments highlight the capability of the SVR-GWO method to improve copper extraction from WPCBs, thereby making a substantial contribution to sustainable recycling efforts.

Uranyl ammonium carbonate (AUC), with the chemical formula UO2CO3 center dot 2(NH4)(2)CO3, plays a crucial role in the wet conversion of uranium hexafluoride (UF6) into uranium dioxide (UO2) or triuranium octaoxide (U3O8) for nuclear fuel production, and is used in commercial and research reactors. In this study, the precipitation of AUC from uranyl fluoride (UO2F2) solution and its subsequent conversion into U3O8 powder were investigated. AUC precipitation was performed at uranium concentrations in UO2F2 solution of 80-120 gL(-1), ammonium carbonate (NH4)(2)CO3 concentrations of 200-400 gL(-1), and (NH4)(2)CO3 to U (C/U) ratios of 5-9. The conversion of AUC into U3O8 powder was studied and sintering of the U3O8 nuclear material derived from ammonium uranyl carbonate (ex-AUC U3O8) was conducted at temperatures of 1000-1800 degree celsius. The kinetics of AUC precipitation from the UO2F2 solution were studied using fundamental kinetic equations, and the kinetics of AUC conversion into UO3 were examined using an isoconversion method based on the thermogravimetric analysis of AUC. The final product of U3O8 nuclear material was characterized using typical techniques, such as thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. This study provides valuable insights into the production and characterization of AUC and U3O8 nuclear materials, which are key materials in the nuclear fuel industry.

Due to their comparable physicochemical characteristics, light rare earth elements (LREEs), such as lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd), the separation of these elements is a challenging process. In this study, a strategy involving hydrometallurgical unit operations is presented, including oxidation, precipitation, solvent extraction (SX), and stripping. Separation of Ce(III) can be achieved by selective oxidation with potassium permanganate (KMnO4), which is a strong oxidizing agent and proven to be effective in selec-tively precipitating Ce(III). By using solvent extraction with 0.5 mol L-1 of Cyanex 572 at an A/O ratio of 1:3 and four stages in a counter-current configuration, La(III) can be separated from Nd(III) and Pr(III) with 100% and 99% extraction, respectively. Cross-current scrubbing with a low concentration of HCl can be used to remove La (III), which becomes the contaminant that is left in the loaded organic. Other mineral acids, including HNO3, H2SO4, and H3PO4 were also investigated as alternative scrubbing/stripping agents.

The liquid-liquid extraction types of equipment are of substantial significance in industrial fields due to their effectiveness in facilitating the separation and purification of substances. Different types of rotatory agitated columns, such as RDC, ARDC, PRDC, Oldshue-Rushton, K & uuml;hni, and Scheibel, are evaluated for their performance. The nonlinearity and complexity of the mechanisms in these columns present challenges for accurately predicting the droplet behavior using available empirical models. Hence, this paper developed machine learning (ML) models, adaptive neuro-fuzzy inference system (ANFIS), artificial neural network (ANN), support vector regression (SVR), and gradient boosting algorithm (GBA) utilizing a dataset of 1135 experimental points to predict mean droplet size (d32) 32 ) under different mass transfer conditions. The ANFIS model surpasses ANN, SVR, and GBA models, demonstrating enhanced precision and resilience. The mean squared error (MSE) values for the ANFIS were recorded at 0.004 and 0.009, while the root mean squared error (RMSE) values stood at 0.065 and 0.094 during both the training and validation stages, respectively. Subsequently, the Monte Carlo simulation (MCS) was utilized, employing the PERT distribution function to model uncertain variables within the ANFIS model, considering their asymmetric distributions. The simulations revealed a mean d 32 of 2.0482 mm with a 90% confidence interval of [2.0398 mm, 2.0567 mm], a standard deviation of 0.5154 mm, skewness of-0.5882, and kurtosis of 3.6297. The sensitivity analysis based on permutation importance highlighted agitation speed as the most influential parameter, followed by fractional free area and interfacial tension, indicating their significant impact on d32. 32 . The optimized model's capacity to efficiently manage the intricacies and non-linearities present in dispersed phase droplets represents the first comprehensive progression from conventional empirical approaches, opening up possibilities for enhanced efficiency and dependability in industrial applications.

This study explores the separation and optimization of molybdenum (Mo) from mixed mineral acids derived from semiconductor industry waste streams with tributyl phosphate (TBP) by implementing machine learning (ML) models. Considerable experimental tests were performed to evaluate the impact of various operational variables on the effectiveness of Mo extraction and stripping. The support vector regression (SVR) paired with harmony search algorithm (HSA), genetic algorithm (GA), and shuffled frog leaping algorithm (SFLA) were employed for enhancement in the separation process and structural optimization. The SVR-SFLA model yielded the most meticulous predictions, identifying optimal extraction conditions with a TBP concentration, mixing time, temperature, and O/A ratio of 50%, 30 min, 25 °C, and 1, respectively, achieving 77.8% efficiency. The derived results from the SVR-SFLA model, in tandem with the McCabe-Theil diagram, indicated a four-stage counter-current extraction process required to achieve a yield exceeding 99%. For the stripping process, the hybrid model indicated optimal conditions with 3 M NH4OH and an A/O ratio of 0.5 at 50 °C for 20 min, requiring two counter-current stages for nearly complete stripping. Feature importance analysis using a random forest algorithm (RFA) highlighted the NH4OH concentration and phase ratio as the most significant factors, contributing 40.3% and 29.1%, respectively, to the stripping from the loaded TBP phase. The final product, obtained after crystallization and thermal decomposition of the strip solutions, was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), revealing 99.74% purity for molybdenum trioxide.

Nd-Fe-B magnets find wide range of applications due to its high magnetic properties. At its end-of-life, huge quantity of scrap Nd-Fe-B magnetsScrap Nd-Fe-B magnets are generated, which are promising alternative resource for rare earth elements (REEsREEs). RecyclingRecycling of scrap Nd-Fe-B magnetsScrap Nd-Fe-B magnets will mitigate the demand supply gap of REEsREEs. Thus, the present paper reports development of feasible hydrometallurgical flow sheet to recover REEsRecover REEs from Nd-Fe-B magnets. The process consists of roastingRoasting of magnets with 20% NaCl at 750 °C for 2 h followed by water leachingLeaching of the roasted mass at 75 °C for 60 min to produce REEsREEs containing leach liquor. About 99.9% REEsREEs was recovered, and the left residue contained Fe, which was further calcined at 600 °C for 2 h to get red oxide pigment.

One of the most harmful air contaminants is nitrogen oxides (NOX) produced usually in combustion processes. To reduce the effluents, the most effective technology to date is selective catalytic reduction (SCR) where nitrogen oxides are reduced into nitrogen to be released freely. Due to the increasingly strict environmental regulations, the demand for SCR catalystsSCR catalyst has increased, and inevitably, the necessity of disposal of those spent catalysts has increased accordingly. Most catalysts for stationary applications contain around 0.5–1.5

The Nd-Fe-B permanent magnet was treated through integrated hydrometallurgical approach to recover neodymium. Leaching kinetics and process optimization using dilute HCl was investigated. The kinetics results ensures on following of leaching behaviour of Nd to Shrinking-Core model governed by diffusion control model (1-2X/3-(1-X) 2/3). The kinetic fitting result was strongly supported by the Ea of 13.79KJ/mole obtained from the Nd dissolution study while examined at varying temperatures. The leach liquor obtained at the optimum leaching condition contains Fe: 12.6 g/L, Nd: 9.167 g/L, Pr: 0.122 g/L and B: 0.202 g/L was subjected to the recovery of Fe2O3 using slaked lime at pH 4.0 and was confirmed from XRD analysis of precipitated product. The Bifunctional ionic liquid like R4NPC was introduced for extraction of REMs (Nd and Pr) from the leach solution. The Solvent extraction carried out at the condition; pH 4.0, R4NPC of 0.35 M and A: O = 1 showed high selectivity towards REM (Nd and Pr) leaving Boron in the raffinate. The association of 3-mole of Extractant was apprehend from the resulted slope of the plot logD against log[R4NPC]. Extraction isotherm results suggested on requirement of 2-numbers of stages for complete extraction of Nd at A: O = 2:1 and was validated in 6 cycles counter current study. First stage stripping was carried out at low concentration of oxalic acid to separate out Pr (0.243 g/L) and in which 2.357 g/L Nd was also stripped. In second stage of stripping remaining 15.975 g/L Nd was fed into stripping isotherm followed by simulation by 0.6 M oxalic acid. The obtained enriched (3.5 times) neodymium oxalate out of stripping circuit was calcined at 400 degrees C to yield Nd2O3 and confirmed from XRD analysis.

Nitrogen oxides (NOX) are often produced in industrial combustion processes and are among the most harmful air contaminants. Selective catalytic reduction (SCR) is currently the most effective technology for reducing effluents. Due to increasingly strict environmental regulations, the demand for SCR catalysts has increased, and inevitably, the need to dispose of the spent catalysts has increased and produced an environmental burden. The necessity for disposal while finding secondary sources for the vanadium, tungsten and titanium present in the catalyst makes recycling of spent SCR catalysts a pressing issue. During this investigation, two tertiary amines were compared to determine their effectiveness in extracting vanadium and tungsten from a spent SCR catalyst. The enrichment process was optimized, and the loaded organic solution (9-fold increased concentration) was further stripped to prepare a mixed metal oxide (MMO) based active sensing material for use in H2S gas detection. The H2S gas sensing characteristics of the MMO material were studied systematically. The MMO sensor showed an excellent sensing response to H2S gas with a high sensitivity of 12.73 % for 100 ppm and quick response/recovery times (t(r) = 101 s/t(f) = 133 s) at a low operating temperature of 130 degrees C. In addition, the sensor exhibited enhanced selectivity, long-term stability, and a detection limit of similar to 47 ppb to H2S gas. The experimental findings of this work suggest that the recycled materials from spent SCR catalysts could have sustainable potential in reproducing the active sensing catalyst materials for the practical applications in the field of environmental protection.

Thorium is a naturally occurring radioactive element that has been identified as a potential alternative fuel for nuclear energy production. Additionally, thorium-based nuclear reactors have inherent safety features that reduce the risk of nuclear accidents and proliferation. As a result, there has been growing interest in the development of thorium-based nuclear energy as a viable alternative to fossil fuels. This paper looks at the present status of thorium nuclear fuel technology, providing an overview of thorium as a prospective natural resource for future energy, the global availability of mineral supplies, and discusses the technical, economic, and environmental factors that may influence its implementation. Potential advantages and challenges critical to further development associated with thorium-based nuclear energy are highlighted as well, and an outlook on its future prospects is provided. Thorium offers advantageous physical and chemical properties over uranium, has a higher energy density, and produces less waste, in addition to its greater natural abundance, making it to be considered a “future nuclear fuel”. There are concerns about the cost and scalability of thorium-based nuclear energy, with uncertainty around the cost to develop, build, and operate thorium reactors, as it has not yet been demonstrated in large-scale commercial reactors—although almost all current reactor types have been built and run using thorium—as it is the case with Uranium-based nuclear technology—the dominant form of nuclear energy for over half a century, having received much more investment and attention than thorium-based technology. Thorium has the potential to contribute towards a more sustainable nuclear industry, including lower lifecycle emissions and more efficient resource utilization, but for this, an acceleration of efforts to date is needed to ensure that this becomes an important climate change stabilizing wedge by the mid-21st century.

As technology keeps developing, India has become an emerging market in the world in consuming lithium-ion battery (LIB) in numerous applications such as portable electronics, energy storage system (ESS) and the latest into electric vehicles. The high-end consumption of such batteries would generate a significant quantity of end-of-life batteries in coming seven to eight years. Currently, there is no dedicated legislation or infrastructure to handle such waste stream, which could be beneficial economically, environmentally and socially. The present review explains the current situation of LIB recycling in India, the challenges and possibilities to adopt a recycling business in India. In addition, information about the importance of waste as a resource and the current government legislation about battery disposal and various process methodologies to recover the economically valuable metals in the discarded batteries are presented.

The potential of cellulose nanocomposites in the new-generation super-performing nanomaterials is huge, primarily in medical and environment sectors, and secondarily in food, paper, and cosmetic sectors. Despite substantial illumination on the molecular aspects of cellulose synthesis, various process features, namely, cellular export of the nascent polysaccharide chain and arrangement of cellulose fibrils into a quasi-crystalline configuration, remain obscure. To unleash its full potential, current knowledge on nanocellulose dispersion and disintegration of the fibrillar network and the organic/polymer chemistry needs expansion. Bacterial cellulose biosynthesis mechanism for scaled-up production, namely, the kinetics, pathogenicity, production cost, and product quality/consistency remain poorly understood. The bottom-up bacterial cellulose synthesis approach makes it an interesting area for still wider and promising high-end applications, primarily due to the nanosynthesis mechanism involved and the purity of the cellulose. This study attempts to identify the knowledge gap and potential wider applications of bacterial cellulose and bacterial nanocellulose. This review also highlights the manufacture of bacterial cellulose through low-cost substrates, that is, mainly waste from brewing, agriculture, food, and sugar industries as well as textile, lignocellulosic biorefineries, and pulp mills.

Abstract Modified nucleosides are the core precursors for the synthesis of artificial nucleic acids, and are important in the field of synthetic and medicinal chemistry. In order to synthesize various triazolo-compounds, copper and ruthenium catalysed azide–alkyne 1,3-dipolar cycloaddition reactions also known as click reaction have emerged as a facile and efficient tool due to its simplicity and convenient conditions. Introduction of a triazole ring in nucleosides enhances their therapeutic value and various photophysical properties. This review primarily focuses on the plethora of synthetic methodologies being employed to synthesize sugar modified triazolyl nucleosides, their therapeutic importance and various other applications.