Search Results (87)

The aim of this study was the hydrothermal leaching of silver from waste monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) photovoltaic panel (PV) cells using organic acids, namely oxalic acid (OA) and citric acid (CA). Before leaching, two different pretreatment procedures were applied. First, the fluoropolymer backsheet was manually removed from the panel pieces and, then, the samples were subjected to high-temperature heating for the thermal degradation of the ethylene vinyl acetate (EVA) polymer. When removal by hand was not feasible, the second pretreatment procedure was followed by toluene immersion to remove the EVA and backsheet and separate the cells, glass, and films. After pretreatment, 4 M HCl leaching was applied to remove the aluminum layer from the cells. The remaining cells were subjected to hydrothermal leaching with organic acids to extract the silver. Several hydrothermal parameters were investigated, such as acid concentration (1-1.5-2 M), processing time (60-105-150 min), and temperature (150-180-210 °C), while the liquid-to-solid (L/S) ratio was fixed at 30 mL: 1 g, based on preliminary tests. Response surface methodology (RSM) was applied to optimize the hydrothermal leaching parameters. The optimized parameters were 210 °C, 95 min, 2 M CA or 210 °C, 60 min, 1 M OA. OA was more effective in Ag leaching than CA. The results were compared to HNO₃ leaching. The green leaching of silver from end-of-life PV panels with organic acids is an environmentally beneficial route. Full article

Background: This study delves into the potential use of real-time UV imaging of the dissolution process combined with convolutional neural networks (CNNs) to develop multidimensional models representing the relation between in vitro and in vivo performance of drugs. Method: We utilised the capabilities of the SDi2 apparatus (Pion) to capture multidimensional dissolution data for two distinct Glucophage tablets: immediate-release 500 mg tablets and extended-release 750 mg tablets. The dissolution process was studied in various media, including a compendial pH 1.2 HCl solution, reverse osmosis water, and pH 6.8 phosphate buffer. Result: Moreover, results were captured at different wavelengths (255 nm and 520 nm) to provide a comprehensive view of the process. Our investigation focuses on two primary approaches: (1) analysing numerical data extracted from SDi2 images via a surface characterisation tool, using traditional machine learning techniques, including Scikit-learn, Tensorflow, and AutoML, and (2) utilising raw SDi2 images to train CNNs for direct prediction of in vivo metformin plasma concentrations. Conclusions: This dual approach allows us to assess the impact of data extraction on model performance and explore the potential of CNNs to capture complex dissolution patterns directly from images, potentially revealing hidden information not captured by traditional numerical data extraction methods. Full article

Chitosan is recognized by its capacity to bind lipids based on the viscosity and degree of deacetylation. We analyzed the in vitro binding of Procambarus clarkii chitosan (PCC) with extra virgin olive oil and sunflower oil at temperatures and pH levels that approximate gastric-like conditions. In the tube test, 4 mg of PCC and 0.3 g of either EVO or of SO oils were mixed by stirring in test tubes with 4 mL of water acidified with HCl to a pH of 3. The PCC binding capability was determined by measuring the differences between the suspension without PCC and the suspension with PCC added. A scanning electron microscope (SEM) was utilized to further observe the uniformity and morphology of the emulsified PCC/oil hydrogels. In the test tube, PCC was shown to have a 1:11 (w/w) binding capacity for EVO and 1:15 (w/w) for SO. The SEM-based examination demonstrated a smooth surface with fine porosity of the microstructure of either PCC/oil hydrogel, proving successful emulsification. Under conditions similar to those in the stomach after a meal, including acidity, mixed composition, and temperature, PCC efficiently binds and emulsifies EVO and SO. Full article

Chlorine gas and hydrogen chloride are highly reactive chemicals that pose a significant hazard to living organisms upon direct contact. Also, chlorine-containing gases are often by-products of industrial chemical synthesis and can be released into the air as a result of accidents. This can lead to great pollution of the environment. To remove toxic gases, various filter systems can be used. Filters based on carbon nanomaterials can be suitable for capturing gaseous chlorine-containing substances, preventing their spread into the air. In this work, the sorption activity of various carbon-based nanomaterials (graphene oxide, modified graphene oxide, reduced graphene oxide, multi-walled carbon nanotubes, carbon black) in relation to gaseous chlorine and hydrogen chloride was investigated for the first time. It has been shown that employed carbon nanomaterials have an excellent ability to remove chlorine and hydrogen chloride from the air, exceeding the performance of activated carbon. Modified graphene oxide with an increased surface area showed the highest sorption capacity of 73.1 mL HCl and 200.0 mL Cl₂ per gram of the sorbent, that is almost two and five times, respectively, higher than that of activated carbon. The results show that carbon nanomaterials could potentially be used for industrial filters and membrane fabrication. Full article

Objectives: This study aims to develop a tablet press machine (TPM) integrated with machine learning (ML) and deep learning (DL) models for in-line detection of defective tablets as a Process Analytical Technology (PAT) tool. This study aimed to predict tablet defects, including capping occurrence and inappropriate tablet breaking force (TBF), using real-time processing data. Methods: Free-flowing metformin HCl (MF) granules produced using the granulation method were compressed into tablets using a TPM. Commercial-scale experiments were conducted to determine the MF tablets’ defect criteria. Random Forest (RF) and Artificial Neural Network (ANN) models were designed and trained using sensed in-line data, including compression force, ejection force, and compression speed, to predict tablet quality defects. Subsequently, the TPM was designed and manufactured for in-line PAT using an RF model. The TPM was verified by sorting defective tablets in-line using a pretrained defect-detection algorithm. Results: The RF model demonstrated the highest predictive accuracy at 93.7% with an Area Under the Curve (AUC) of 0.895, while the ANN model achieved an accuracy of 92.6% with an AUC of 0.878. The TPM successfully sorted defective tablets in real time, achieving 99.43% sorting accuracy and a defective tablet detection accuracy of 93.71%. Conclusions: These results suggest that a ML-based TPM applied during the tableting process can detect defects non-destructively during the scale-up of wet granulation. In particular, it can serve as the base TPM model for an in-line PAT process during a scale-up process that produces small batches of multiple products, thereby reducing additional labor, time, and API consumption, and decreasing environmental pollution. Full article

Neonatal piglets with intrauterine growth restriction (IUGR) exhibit reduced rates of growth and survival. The present study tested the hypothesis that L-arginine supplementation can mitigate this problem. One hundred and twelve (112) IUGR piglets (with a mean birth weight of 0.84 kg) from 28 sows (four IUGR piglets/sow) were assigned randomly into one of four groups. Piglets were nursed by sows and orally administered 0, 0.1, 0.2, or 0.4 g L-arginine (in the form of L-arginine-HCl) per kg body weight (BW) twice daily between 0 and 14 days of age. The total doses of L-arginine were 0, 0.2, 0.4, or 0.8 g/kg BW/day. Appropriate amounts of L-alanine were added to L-arginine solutions so that all groups of piglets received the same amount of nitrogen. Piglets were weighed on days 0, 7, and 14 of age. On day 14, blood samples (5 mL) were obtained from the jugular vein of piglets at 1 h after suckling, and their milk consumption was measured over a 10-h period using the weigh–suckle–weigh technique. Milk intake did not differ (p > 0.05) among the four groups of piglets. Oral administration of 0.4 g L-arginine/kg BW/day increased (p < 0.05) the circulating levels of arginine, creatine, and anabolic hormones (insulin, growth hormone, and insulin-like growth factor-I), but decreased (p < 0.05) plasma concentrations of ammonia and cortisol (a catabolic hormone). Compared to the control group, IUGR piglets administered 0.2 and 0.4 g L-arginine/kg BW/day increased (p < 0.05) weight gain by 19% and 31%, respectively. Growth did not differ (p > 0.05) between the control and 0.8 g L-arginine/kg BW/day groups. The survival rates of IUGR piglets were 50%, 75%, 89%, and 89%, respectively, for the 0, 0.2, 0.4, and 0.8 g L-arginine/kg BW/day groups. Collectively, these results indicate that the growth and survival of IUGR piglets can be improved through L-arginine supplementation. Full article

This research focused on the precipitation of amorphous forms of nilotinib with high physical stability through the manipulation of various parameters in the neutralization reaction, specifically the quantity of nilotinib, the pH value, and the concentration of HCl. To assess the physical stability of the amorphous nilotinib, various characterization techniques, including PXRD, DSC, and FBRM, were utilized in conjunction with analytical methods such as PDF, PCA, and R_c value. The findings demonstrated that the ideal physical stability was attained with a nilotinib quantity of 0.5 g, a pH value of 11.70, and 7.5 mL of HCl with a concentration of 2.0 mol/L. It is important to acknowledge that this observation is specific to the current experimental configuration and may not hold in the context of a scaled-up experiment. Furthermore, the combination of PDF and R_c was identified as an innovative and effective method for assessing physical stability, demonstrating advantages over traditional accelerated stability testing approaches. Full article

Pharmaceutical waste is a type of bio-waste inevitably generated by the pharmaceutical industry, often due to regulatory changes, product deterioration, or expiration. However, their collection and valorization can be approached from a sustainable perspective, offering potential energy-efficient solutions. In this work, the expired Eslicarbazepine acetate drug (ESLD) was utilized as a sustainable anticorrosive agent against mild steel in a 3 M HCl wash solution. Experimental tests combined with theoretical Density Functional Theory (DFT) and Monte Carlo (MC) simulations revealed the corrosion inhibition potential of ESLD. The gasometrical results revealed a high inhibition efficiency rate of 98% upon increases in concentration of expired ESLD from 0.25 to 1.00 mg·L⁻¹, whereas hydrogen gas evolution decreased to 0.7 mL. An impedance investigation evidenced the pivotal role of charge transfer in reducing the disintegration process. As per DFT computations and MC simulation, electron-rich elements in the expired ESLD were key in controlling the dissolution through the adsorption process. Contact angle studies revealed that the increment in the contact angle from 61° to 80° in the presence of expired ESLD validates the chemical, electrochemical, and computational results. This approach not only mitigates pharmaceutical pollution, but also exemplifies the integration of green chemistry principles into corrosion protection, contributing to energy-efficient and sustainable industrial practices. Full article

Owing to the intensive development of electrical and electronic equipment, there is an increasing demand for precious metals, which are often used for its production. Due to their scarce supply, it is important to recover them from secondary sources. A promising way to recover precious metals are impregnated resins. In this research, Amberlite XAD-16 was impregnated with TBP at the weight ratios of 1:2 and 1:3 using the ‘warm impregnation’ method. Studies were carried out on the sorption of Au(III), Pd(II), Pt(IV), and Rh(III) ions from the model chloride solutions as well as the real solution formed after leaching the smart card chips. Only Au(III) ions were efficiently sorbed on the prepared impregnated sorbents. The best results were obtained at 6 M HCl and the sorbent mass: 0.1 g/25 mL. The maximum sorption capacity for the impregnated sorbents was: 147.91 mg/g (ratio 1:2) and 149.66 mg/g (ratio 1:3). Recovery of Au(III) ions from the real leaching solution was: 97.36% and 97.77%, respectively. The Langmuir isotherm was the best-fit model for the experimental results. Thermodynamic studies proved that the investigated sorption process is spontaneous and exothermic. The desorption process can be easily carried out with 1 M HCl/1 M TU. Full article

Efficient wastewater treatment, particularly the removal of heavy metal ions, remains a challenging priority in environmental remediation. This study introduces a novel sandwich-structured nanocomposite, RGO-CuS-PPy, composed of reduced graphene oxide (RGO), copper sulfide (CuS), and polypyrrole (PPy), synthesized via a straightforward hydrothermal method. The unique combination of RGO, CuS, and PPy offers enhanced adsorption capacity for Ni(II) ions due to RGO’s high surface area and CuS’s active binding sites, supported by PPy’s structural stability contributions. This study is among the first to explore this specific nanocomposite architecture for Ni(II) removal, achieving an adsorption capacity of 166.67 mg/g and a high removal efficiency of 94.9% within 210 min for 55 mg/L of Ni(II) concentration at pH 6 and adsorbent dose of 3 mg/15 mL. The kinetic analysis shows the best fitted time-dependent experimental data with the pseudo-second-order model, indicating chemisorption. Isotherm studies confirmed the Langmuir model as the best fit, yielding a high monolayer adsorption capacity of 166.67 mg/g. Thermodynamic analysis shows the adsorption process was endothermic (ΔH° = 80.23 kJ/mol) and spontaneous (ΔG° ranging from −6.985 to −14.399 kJ/mol). Additionally, reusability tests using 0.1 M HCl for desorption demonstrated good reusability, emphasizing the RGO-CuS-PPy nanocomposite’s potential as a sustainable adsorbent for Ni(II) removal in wastewater treatment applications. Full article

The chitin and chitosan biopolymers are extremely valuable because of their numerous industrial and pharmacological uses. Chitin and chitosan were extracted from the exoskeleton of Periplaneta americana (cockroaches) and termites using various acid and alkali techniques. The extraction process involves an initial demineralization step, during which integument dry powder was subjected to 500 mL (2.07 mol/L) of concentrated HCl at 100 degrees Celsius for 30 min, followed by meticulous rinsing with distilled water to restore the pH to its baseline. Deproteinization was conducted at 80 degrees Celsius using 500 mL (1 mol/L) of NaOH solution, which was repeated for 24 h. A total of 250 mL (0.06 mol/L) of NaOH was added at 100 degrees Celsius for 4 h to obtain chitosan, followed by extensive washing and subsequent drying. FTIR analysis was used to identify the functional groups in Periplaneta americana and termites. The crystallinity of these biopolymers, which have a face-centered cubic structure, was determined by X-ray diffraction analysis. This study assessed the analgesic properties of chitin and chitosan via an acetic-acid-induced writhing test in mice, revealing a significant reduction in writhing behavior following the chitin and chitosan extract. Notably, chitin exhibits the highest degree of analgesic activity compared to chitosan. Both chitin and chitosan show anti-inflammatory effects, with chitosan absorbing proton ions at sites of inflammation, while chitin effectively inhibits ear edema and elicits an analgesic response in mice. Furthermore, the present study revealed antipyretic activity, with termite chitin demonstrating the most significant effect at a concentration of 500 µL/mL, followed by chitosan and chitin at 100 µL/mL. These findings indicate the potential of using chitin and chitosan derived from termites and Periplaneta americana as natural anti-inflammatory compounds, implying prospective uses in anti-inflammatory, antipyretic, and analgesic capabilities. Full article

Microcystins (MCs) and nodularins (NODs) are cyanotoxins that can be found in water bodies during cyanobacterial harmful algal blooms (cyanoHABs). Consumption of water contaminated with cyanotoxins leads to health risks for humans and animals. Herein, corncob-based biochar and activated carbon (AC) were initially investigated for the sorption of six common MC congeners (MC-RR, MC-YR, MC-LR, MC-LA, MC-LW, and MC-LF) and nodularin-R (NOD-R) from spiked water. Biochar was prepared by refluxing commercial corncob with HCl and heating it to 250, 300, or 350 °C. AC was prepared by chemical activation of corncob with H₃PO₄ at 500 °C under a nitrogen atmosphere. Low-temperature nitrogen adsorption measurements confirmed that H₃PO₄-AC has a higher specific surface area (≈1100 m²/g) and total pore volume (≈0.75 cm³/g) than biochar and commercial AC. H₃PO₄-AC showed the maximum efficacy, among all corncob-based sorbents, to remove MCs and NOD-R from water as confirmed by experiments that involved sample analyses by ultrahigh-pressure liquid chromatography-mass spectrometry (UHPLC-MS). The effect of natural organic matter (NOM) on the adsorption of MCs was checked by incubating sorbents with Lake Erie water collected during cyanoHABs from 2020 to 2022. The total concentration (extracellular and intracellular) of studied MC congeners ranged from 1.37 µg/L to 438.51 µg/L and 50 mg of H₃PO₄-AC completely removed them from 3 mL of lake water. The effect of water pH on cyanotoxin adsorption was studied at pH values of 5.5, 7.0, and 8.5 at both a lower (10 μg/L each) and a higher (50 μg/L each) toxin concentration. Removal was influenced by solution pH at both concentrations when using biochar, while only at higher toxin concentration when using H₃PO₄-AC. At higher MC and NOD-R concentrations, competitive adsorption was prominent, and overall, the adsorption increased at acidic pH (5.5). The study results suggest that processed corncobs can remove a significant amount of MCs and NOD-R from water, and the measured sorption capacity of H₃PO₄-AC was ~20 mg of MC-LR and NOD-R per g of this sorbent. Full article

A method for the determination of trace levels of silicon from biological materials by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. The volatility of water-soluble silicon species, hexafluorosilicic acid (H₂SiF₆), and sodium metasilicate (Na₂SiO₃) was investigated by evaporating respective solutions (50 µg/mL silicon) in nitric acid (HNO₃), nitric acid + hydrochloric acid (HNO₃ + HCl), and nitric acid + hydrochloric acid + hydrofluoric acid (HNO₃ + HCl + HF) at 120 °C on a hot-block to near dryness. The loss of silicon from H₂SiF₆ solutions was substantial (>99%) regardless of the digestion medium. Losses were also substantial (>98%) for metasilicate solutions heated in HNO₃ + HCl + HF, while no significant loss occurred in HNO₃ or HNO₃ + HCl. These results show that H₂SiF₆ species were highly volatile and potential losses could confound accuracy at trace level determinations by ICP-MS if digestates prepared in HF are heated to eliminate HF. Among the various matrices comprising major elements, sodium appeared to be effective in reducing silicon loss from H₂SiF₆ solutions. Excess sodium chloride (NaCl) matrix provided better stability, improving silicon recoveries by up to about 80% in evaporated HF digestates of soil and mine waste samples, but losses could not be fully prevented. To safely remove excess acids and circumvent the adverse effects of excess HF (e.g., risk of high Si background signals), a two-step digestion scheme was adopted for the preparation of biological samples containing trace silicon levels. A closed-vessel digestion was performed either in 4 mL of concentrated HNO₃ and 1 mL of concentrated HCl or 4 mL of concentrated HNO₃, 1 mL of concentrated HCl and 1 mL of concentrated HClO₄ on a hot plate at 140 °C. Digestates were then evaporated to incipient dryness at 120 °C to remove the acids. A second closed-vessel digestion was carried out to dissolve silicates in 0.5 mL of concentrated HNO₃ and 0.5 mL of concentrated HF at 130 °C. After digestion, digestates were diluted to 10 mL. The solution containing about 5% HNO₃ and 5% HF was directly analyzed by ICP-MS equipped with an HF-inert sample introduction system. The limit of detection was about 110 µg/L for ²⁸Si when using the Kinetic Energy Discrimination (KED) mode. The method was used to determine silicon in various plant and tissue certified reference materials. Data were acquired for ²⁸Si using KED and standard (STD) modes, and ⁷⁴Ge and ¹⁰³Rh as internal standard elements. There was not any significant difference between the accuracy and precision of the results obtained with ⁷⁴Ge and ¹⁰³Rh within the same measurement mode. Precision, calculated as relative standard deviation for four replicate analyses, varied from 5.3 (tomato leaves) to 21% (peach leaves) for plant and from 2.2 (oyster tissue) to 33% (bovine liver) for tissue SRM/CRMs. Poor precision was attributed to material heterogeneity and the large particle size distribution. An analysis of lung tissue samples from those with occupational exposure to silica dust revealed that tissues possessed substantial levels of water-soluble silicates, but the most silicon was present in the particulate matter fraction. Full article

Based on ground observed data, S-band dual-polarization radar data, and ERA-5 reanalysis data, the statistical characteristics of polarimetric parameters and the application of melting layer (ML) and hydrometeor classification (HCL) products during eight snowstorm events in Jiangsu Province from 2020 to 2022 were investigated. A heavy snowstorm that went through different phases of rain, sleet, and pure snow and that occurred on 29 December 2020 was also analyzed as a typical example. The results showed the following: During the phase transition between rain and snow in the Jiangsu region, the basic reflectivity factor Z_H ≥ 27 dBZ, the zero-order lag correlation coefficient CC ≤ 0.93, and the differential reflectivity Z_DR ≥ 1.0 dB were important indicators for judging the melting layer while the specific differential phase K_DP changed slightly. The snowstorm event was well observed and recorded by the Yancheng dual-polarimetric radar, whose low value area of CC coincided mostly with the melting layer. The ML products and HCL products based on fuzzy-logic hydrometeor classification algorithms can help identify the melting layer and the properties of precipitation particles. ML products are more reliable when the melting layer is high and can better show the trends of melting layer decline. They can certainly serve as a reference for detecting and judging precipitation phase changes in winter in Jiangsu Province. Full article

Due to the high cost and limited sources of cerium coagulants, it is extremely important to take measures to recycle this raw material. This paper presents the new possibility of recovering cerium(III) chloride, cerium(III) sulphate, cerium(IV) sulphate, and potentially phosphate from sewage sludge (101.5 g/kg Ce and 22.2 g/kg total P) through a brewery wastewater treatment process using recycled CeCl₃ as a coagulant. In order to recover the Ce and P, the sludge was subjected to extraction using an HCl solution. Optimal process conditions were determined by means of central composite design and response surface methodology (CCD/RSM) for three input parameters (HCl mass, reaction time, and extractant volume). Under optimal conditions (0.35 g HCl per 1 g of sludge, 40 min reaction time, extractant volume of 25 mL per 1 g of sludge), the highest efficiency obtained was 99.6% and 97.5% for Ce and P, respectively. Cerium(III) oxalate as Ce₂(C₂O₄)₃∙10H₂O was precipitated from the obtained solution using H₂C₂O₄ (99.97%) and decomposed into CeO₂ (at 350 °C), which was afterwards subjected to a reaction with HCl (30%, m/m) and H₂O₂ (30%, m/m), which led to the crystallisation of CeCl₃∙7H₂O with a purity of 98.6% and a yield of 97.0%. The obtained CeO₂ was also subjected to a reaction with H₂SO₄ (96%, m/m) and H₂O₂ (30%, m/m), which produced Ce₂(SO₄)₃ with a yield of 97.4%. The CeO₂ was also subjected to a reaction with only H₂SO₄ (96%, m/m), which produced Ce(SO₄)₂ with a yield of 98.3%. The filtrate obtained after filtering the Ce₂(C₂O₄)₃∙10H₂O contained 570 mg/L of P, which enabled its use as a source of phosphorus compounds. The presented processes of Ce and potentially P recovery from sewage sludge originating from brewery wastewater contribute to the idea of a circular economy. Full article