Purpose. The purpose of the present study was to evaluate the accuracy of an intraoral scanner (IOS Medit i700) on tooth abutments with vertical and horizontal tooth-preparation designs, at different depths below the gingival margin, and to determine if the IOS can detect the surface beyond the finish area of these preparation geometries.

Materials and methods. Four abutments of a standard maxillary first molar were designed using CAD software with vertical and horizontal preparation geometries 1 and 2 mm deep below the gingival margin. These abutments were printed in resin and placed each on a reference model. Ten scans were made with the IOS on these preparation geometries to obtain 4 experimental groups. The experimental scans were named V-1 (vertical preparation at 1 mm from the gingival margin), V-2 (same at 2 mm), H-1 (horizontal at 1 mm) and H-2 (horizontal at 2 mm).

The scans were analyzed using a dedicated software to evaluate trueness and precision in µm. Descriptive statistics (95% C.I.), power analysis, and Kruskal-Wallis test were conducted to analyze differences among groups (α=.05).

Results. Statistically significant differences were found for the trueness between V-2 and H-2 (p=.010). As regards the precision, significant differences were found between H-1 and H-2 (p=.042).

Conclusions. Only vertical preparation designs allow to detect the surface beyond the finish area with IOS. Moreover, the mean accuracy values were clinically acceptable at both 1 and 2 mm below the gingival margin for each tested tooth preparations geometries.

The livestock industry has an important economic role in nearly all developing countries, and it is expected that these activities intensify in the coming decades [1]. Moreover, inadequate livestock management provides several environmental consequences at different levels which have not been sufficiently addressed in developing countries. This industry generates large volumes of wastewater which contains a high quantity of suspended solids content, organic matter (BOD₅ and COD), nutrients and faecal coliforms [2]. All these factors contribute to environmental degradation if it is discharged without proper treatment. Taking these factors into account, the aim of this work was the treatment of livestock wastewater from cattle (CW) farming using a coagulation-flocculation-decantation (CFD) process.

The CFD process was performed by organic coagulants derived from almond hull (AH) and cherry pit (CP). The CFD experiments were performed under a fast mix of 150 rpm/3 min and a slow mix of 20 rpm/20 min, at ambient temperature (25ºC). Four different coagulant concentrations were tested (0.1, 0.5, 1.0 and 2.0 g/L) and four different pH levels (3.0, 6.0, natural and 9.0). After sedimentation, samples were retrieved for analysis.

The results showed that pH 3.0 allowed to achieve turbidity, total suspended solids (TSS) and chemical oxygen demand (COD) removals of 60.8, 73.1 and 52.1%, respectively, using AH coagulant. Regarding CP coagulant, the results showed that a pH of 3.0 achieved turbidity, TSS and COD removal of, respectively, 59.3, 77.2 and 38.9%. Regarding the variation of coagulants concentrations, the results showed that 0.1 g/L of AH achieved turbidity, TSS and COD removals of, respectively, 38.3, 52.9 and 39.1% for CW. The CP concentration of 0.1 g/L accomplished turbidity, TSS and COD removals of, respectively, 88.8, 22.7 and 42.4%.

Based on these results, the AH and CP coagulants were able to reduce the organic load of cattle wastewaters being its efficiency affected by the pH and coagulant concentration. Moreover, the application of almond and cherry by-products as coagulants allows to reduce the waste resulting from these two food industries and treat the cattle wastewater.

Acknowledgements

Authors acknowledge the OBTain project (NORTE-01-0145-FEDER-000084), co-financed by the European Regional Development Fund (ERDF) through NORTE 2020, and FCT for the financial support to CQVR (UIDB/00616/2020).

References

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2. Cheng, D.L., et al., Bioprocessing for elimination antibiotics and hormones from swine wastewater. Sci Total Environ, 2018. 621: p. 1664-1682.

Wet wipes are widely used in everyday life. However, the composition of wet wipes contains various chemical compounds, primarily surfactants, which can negatively affect the environment and human health. For the practical purpose of determining the toxicity of substances and substrates, biotesting methods are used, in particular with garden cress (Lepidium sativum L.). The aim of this study was to investigate the toxicity of wet wipes of Ukrainian and foreign manufacturers using the growth test with garden cress.

The study used 9 variants of wet wipes produced in Ukraine, Turkey and the United Kingdom. To study the phytotoxicity of wet wipes, a circle with a diameter of 9 cm was cut out of each variant of the wipes, placed in a Petri dish and moistened with distilled water. The filter paper instead of wet wipes was used as a control. 10 seeds of garden cress were planted in each Petri dish for 5 days. The experiment was repeated three times. On the 3rd day, germination energy was determined, on the 5th day - germination and biometric and morphometric characteristics (root and above-ground part length). The results were processed statistically. The phytotoxic indexes were calculated - the seed germination index and the root length index.

It was established that 78% of the tested wet wipes (60% Ukrainian production and 100% foreign) were extreme toxicity. Therefore, the tested wet wipes contain toxic substances (in particular, surfactants), show phytotoxicity and can be a source of environmental pollution.

Mercury content is among parameters that characterise quality of Solid Recovered Fuels (SRF), which constitute alternative solid fuels of increasingly interest. In this study, a direct mercury analyser is utilised in the analyses of SRF samples originating from Automotive Shredded Residues (ASR). Mercury content is detected in analysis samples of four different particle sizes for each SRF sample in order to demonstrate the direct mercury analyser operation and to compare it as an alternative to mercury determination via Atomic Absorption Spectrometry. As an overall conclusion, the direct mercury analyser can be regarded as an efficient laboratory tool, offering a robust alternative to Atomic Absorption Spectrometry procedure, especially in terms of accuracy, speed, safety, and cost-effectiveness.

Hydrogen production has been dominated by gray hydrogen (hydrogen produced from fossil fuels without carbon capture). Historical data for 2019–2021 show nearly steady global production and demand of hydrogen, with an average annual of 92 Mt (million tonnes) for either production or demand. Each of the global hydrogen production or demand should grow to 180 Mt in 2030 for compliance with the Net Zero Emissions by 2050 scenario (NZE) of the International Energy Agency (IEA), to bring CO₂ emissions to net zero by 2050. Recently, green hydrogen (hydrogen produced by water electrolysis using electricity from renewables) received attention, with 11 countries (Australia, United States, Spain, Canada, Chile, Egypt, Germany, India, Brazil, Oman, and Morocco) identified as expected top producers may produce together 15.9534 Mt in 2030. All of these countries except Spain, Canada, and Germany, were classified by the global Hydrogen Council as having optimal production potential of green hydrogen. Blue hydrogen (hydrogen produced from fossil fuels with carbon capture) and green hydrogen together form clean hydrogen. The share of clean hydrogen in the global total final energy consumption (TFEC) was less than 0.1% in 2020. In alignment with the 1.5 °C pathway of the International Renewable Energy Agency (IRENA) to limit the global average temperature rise to 1.5 °C above pre-industrial levels, this share should grow to 3% in 2030 and 12% in 2050, with 154 Mt of clean hydrogen and its derivatives produced in 2030 (and 614 Mt in 2050), compared to only 0.8 Mt in 2020.

Olive washing wastewater (OWW) is generated before the olive oil extraction process, in a preliminary step which consists of washing the olives with potable water. The main characteristics of OWW are slightly-acidic pH, dark-brown colour, high turbidity and the presence of recalcitrant phenolic compounds, recognized for their phytotoxicity consequences. Approximately 1 m³ of OWW is generated per processed ton of olives, therefore it is necessary a suitable treatment for a safe disposal in the environment.

The aim of this work was to optimize the experimental conditions of (1) coagulation-flocculation-decantation process and (2) UV-A LEDs/Fenton process. Subsequently was evaluated the use of remaining ferrous ions in (3) CFD/UV-A LEDs/Fenton and (4) UV-A LEDs/Fenton/CFD for OWW treatment.

CFD process, operating at natural pH=4.1, T=25 áµ’C, [Fe²⁺]=3.60 mM, fast mix: 150 rpm/3 min and slow mix: 20 rpm/20 min and 6h of sedimentation, removed 87.9% of turbidity and 49.6% of TSS. UV-A LEDs/Fenton process achieved removals of 80.5% of DOC and 93.7% of COD, at natural pH conditions, T=25 áµ’C, [Fe²⁺]=3.60 mM and [H₂O₂]=116.4 mM, after 120 minutes of reaction. The use of coagulant/flocculant remaining of the CFD process like catalyst in oxidative process reached a total removal of 91.0% of DOC, 97.5% of COD, 95.7% of turbidity and 89.8% of TSS. In conversely way, was achieved a global removal of 80.8% of DOC, 94.1% of COD, 98.4% of turbidity and 91.0% of TSS. As a main conclusion, the combined CFD process followed by UV-A LEDs/Fenton can be selected has a promising approach to OWW treatment.

Glassy and glass-ceramic materials based on V₂O₅-P₂O₅ have been identified as highly promising cathode materials for rechargeable Li-ion, Na-ion, and all-solid-state batteries. These materials offer a compelling combination of high safety, exceptional energy density, and extended cycling life, making them highly promising¹. In addition, such materials are also recognized as effective catalysts in oxidation reactions². Furthermore, it has been acknowledged that the microstructural properties, electrical conductivity, and electrochemical properties of V₂O₅-P₂O₅-based glasses can be significantly improved through thermally controlled crystallization³. In light of this, this study aims to synthesize a glass with a nominal composition of 70V₂O₅-20Nb₂O₅-10P₂O₅ and investigate the influence of controlled crystallization at different temperatures and durations on the electrical and catalytic properties. The parent glass is prepared via the melt-quenching technique, and its thermal behavior is examined through differential thermal analysis (DTA). The samples subjected to controlled crystallization are qualitatively and quantitatively analyzed using powder X-ray diffraction (PXRD), while (micro)structural properties are assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and infrared attenuated total reflectance spectroscopy (IR-ATR). Electrical transport is investigated by solid-state impedance spectroscopy (SS-IS) across a wide frequency (0.01 Hz to 1 MHz) and temperature range (–90 °C to 240 °C). The catalytic activity of prepared samples is tested in oxidation reactions of stearic acid and is monitored using TG-IR system. The findings of this research demonstrate a remarkable enhancement in electrical conductivity through thermal treatment of the parent glass, with the sample heat-treated at 380 °C exhibiting the highest conductivity of 1.58 × 10^–3 S/cm @30 °C. Furthermore, these materials exhibit promising catalytic properties, unveiling new avenues for their application.

ACKNOWLEDGMENTS
This work is supported by the Croatian Science Foundation under the projects IP-2018-01-5425 and DOK-2021-02-9665.

1. Kindle, M., Cha, Y., McCloy, J. S. & Song, M. K. Alternatives to Cobalt: Vanadate Glass and Glass-Ceramic Structures as Cathode Materials for Rechargeable Lithium-Ion Batteries. ACS Sustain. Chem. Eng. 9, 629–638 (2021).
2. Ballarini, N. et al. VPO catalyst for n-butane oxidation to maleic anhydride: A goal achieved, or a still open challenge? Top. Catal. 2006 381 38, 147–156 (2006).
3. Pietrzak, T. K., Wasiucionek, M. & Garbarczyk, J. E. Towards Higher Electric Conductivity and Wider Phase Stability Range via Nanostructured Glass-Ceramics Processing. Nanomaterials 11, 1321 (2021).

The industrial wastewaters (IWW) are derived from industrial activities, which comprehend dairy or breweries, paper industry, wine and olive production, among others. The organic content can reach thousands of mg/L, with wide pH, and low biodegradability. Advanced oxidation processes (AOPs) are an efficient process for pollutants degradation, which are based on the generation of hydroxyl radicals (HO^•). These radicals are highly reactive and capable of oxidizing a wide range of contaminants, especially those refractory contaminants. Considering the different AOPs, in this review it will be studied the application of sulfate radical AOPs (SR-AOPs) for the treatment of IWW. The aim of this work is to study the different activation processes of sulfate radicals, evaluate the efficient of SR-AOPs in the treatment of IWW and review the advantages and disadvantages associated with the application of these radicals.

Both persulfate (PS) and peroxymonosulfate (PMS) can be activated by a variety of methods, such as heat, alkaline, radiation and transition metals. These methods have been applied to the treatment of IWW, with results showing an efficient degradation of different contaminants at laboratory and pilot scales. It was also observed that the reagents required in SR-AOPs were lower than the required in HR-AOPs. Despite these advantages, it was also pointed also some disadvantages associated to SR-AOPs, such as the energy required in heat activation, the poor penetration of UV radiation in dark waters and the generation of sludges with activation metals. As a final remark, it can be highlighted that SR-AOPs are feasible technologies for IWW treatment.

The acid red 88 (AR88) is a dye used by manufacturing sector like leather, cosmetic, textile, rubber, pharmaceutical, paper industry, printing etc. When disposed without proper treatment in water streams, dyes are not easily degradable since they are stable to light and resistant to oxidizing agents. Advanced oxidation processes (AOPs) have been recognized as successful and feasible technologies for recalcitrant and/or toxic contaminant removal. These processes are based in the production of hydroxyl radicals (HO^•) which are non-selective and highly reactive with an oxidation potential of 2.80 V.

The aim of this work was to create a statistical model using a Response Surface Methodology – Box-Behnken design, to better predict and understand the influence of different operational conditions. Three variables were studied: H₂O₂ concentration (0 – 8 mM), Fe²⁺ concentration (0 – 0.30 mM) and UV-A radiation intensity (0 – 32.7 W m^-2). For the best operational conditions obtained by the RSM model (pH = 3.0, [H₂O₂] = 7.9 mM, [Fe²⁺] = 0.22 mM, time = 30 min), different radiation sources were applied (UV-C, UV-A, ultrasound (US) and solar), with US and solar achieving the highest kinetic rates (k_US = 0.083 and k_solar = 0.179 min^-1) regarding UV-C and UV-A (k_UV-C = 0.064 and k_UV-A = 0.071 min^-1). In addition, it was observed that solar reactor had the lowest operational cost, regarding energy consumption. Based in the results it can be concluded that application of RSM models is a useful tool that allows to improve the optimization of AOPs in textile dye degradation.

The strength of lateritic soil bio-treated with Bacillus thuringiensis (Bt)-induced calcite precipitate was investigated using a pocket penetrometer (PPT). The effect of bacterial (Bt) and cementation concentration solutions (C_s) on the strength of the microbial-induced calcite precipitate (MICP) worked soil was also evaluated. Soil samples were treated with Bt and C_s using three mix ratios (i.e., 25 % Bt : 75 % C_s, 50 % Bt : 50 % C_s and 75 % Bt : 25 % C_s) based on natural soil liquid limit (LL = 36.0 %). Bt suspension densities of 0, 1.5 x 10⁸, 6.0 x 10⁸, 12 x 10⁸, 18 x 10⁸ and 24 x 10⁸ cells/ml were applied to the soil with four varying C_s concentrations (i.e., 0.25, 0.5, 0.75 and 1 M). The prepared specimens were allowed to homogenise and equilibrate at laboratory conditions. A pocket penetrometer-PPT was used to test the unconfined compressive strength (UCS) of the prepared specimens at 3, 5, and 7 days after bio-treatment to evaluate the strength of the MICP worked soil at different moisture contents. The results obtained show that UCS values increased with higher Bt and C_s as well as with reduction in moisture content as the bio-treated soil equilibrated with the environment. The recorded UCS values for the mix ratios considered are in the order: 50 % Bt : 50 % C_s > 25 % Bt : 75 % C_s > 75 % Bt : 25 % C_s. Therefore, PPT can be used as a quick check for strength of treated soil.