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Worldwide, different strategies are being developed in order to ensure optimum conditions for the development and growth of economic competitiveness, as well as for increasing the quality of life and environmental protection. All these strategies are closely linked to the development and modernization of systems for producing energy from clean and renewable sources. In this context, the present paper presents the results of research regarding the evaluation of the sustainability of briquette production using biomass resulting from vine winter pruning as the raw material. An analysis of the scientific literature indicates that nearly 8 Mt of biomass would result from the over 7.4 million hectares of vine plantations in the world, biomass that could be valorized through densification in order to produce solid biofuels with a lower calorific value of more than 17 MJ/kg. This study examines the production of briquettes from vineyard winter pruning with consideration of two types of densification technologies: baling and natural drying of the tendrils, and collection, shredding, and artificial drying of the lignocellulose debris. The quality indices and energy consumption and energy efficiency of the briquettes were evaluated to determine their feasibility as an alternative fuel source. When designing the scientific endeavor, the following aspects were considered: defining the aim and objectives of the research; designing the research algorithm; collecting, preparing, and conditioning the biomass; conducting a chemical analysis of the briquettes; and evaluating the energy consumption and energy efficiency for producing the briquettes, taking into account two drying methods (natural and artificial drying). In the meantime, some specific laboratory equipment was designed and built for the artificial drying of biomass, evaluation of mechanical durability, measurement of energy consumption, etc. Analysis of the experimental data has led to the conclusion that the agricultural waste from vine pruning can constitute an important and sustainable source of energy in the form of briquettes that fulfill most of the requirements imposed by international standards. [ABSTRACT FROM AUTHOR]

L-poly(lactic acid), poly(3-hydroxybutyrate), and poly-hydroxybutyrate-co-hydroxyvalerate are biodegradable polymers that can be obtained from renewable biomass sources. The aim of this study was to develop three types of environmentally friendly film biocomposites of altered microstructure by combining each of the above-mentioned polymers with cellulose nanocrystal fillers and further processing the resulting materials via space-confined solvent vapor annealing. Cellulose was previously obtained from renewable biomass and further converted to cellulose nanocrystals by hydrolysis with the lactic acid. The solutions of biodegradable polymers were spin-coated onto solid substrates before and after the addition of cellulose nanocrystals. The obtained thin film composites were further processed via space-confined solvent vapor annealing to eventually favor their crystallization and, thus, to alter the final microstructure. Indeed, atomic force microscopy studies have revealed that the presence of cellulose nanocrystals within a biodegradable polymer matrix promoted the formation of large crystalline structures exhibiting fractal-, spherulitic- or needle-like morphologies. [ABSTRACT FROM AUTHOR]

Due to the current concern with the environmental impacts produced by the construction industry, many studies have been conducted to capitalize on the advantages of waste to develop sustainable materials. The study reports an innovative, non-conventional cement-based composite material containing 10 wt.% vine shoot waste, representing a step forward toward the use of this lignocellulosic waste. The investigations were carried out using scanning electron microscopy with energy dispersive X-ray analysis, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and solid-state 27Al and 29Si nuclear magnetic resonance spectroscopy. The addition of vine shoot waste to the cement paste increases the amount of hydration products (calcium silicate hydrate (CSH), calcium hydroxide (CH), calcium carbonate (CaCO3) and ettringite), leading to a more compact and dense structure. The structural characterization techniques also confirmed the formation of a higher amount of hydration products in the case of vine shoot waste added to the cement paste. [ABSTRACT FROM AUTHOR]

This study's objective was to separate cellulose, hemicellulose, and lignin after high-pressure supercritical carbon dioxide pretreatment for further valorization. The study investigated the supercritical carbon dioxide pretreatment of apple orchard waste at temperatures of 160–200 °C, for 15–45 min, at a pressure of 10 MPa. Response Surface Methodology (RSM) was used to optimize the supercritical process and to improve its efficiency. The change of functional groups during different pretreatment conditions was examined by Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed the structural changes in the biomass structure before and after pretreatment. A new ultra-high performance liquid chromatography (UHPLC) coupled with an evaporative light scattering detector (ELSD) method was developed and validated for the determination of carbohydrates in the liquid fraction that resulted after pretreatment. The estimated uncertainty of the method ranged from 16.9 to 20.8%. The pre-treatment of high-pressure supercritical CO2 appears to be an effective and promising technique for the recovery of sugars and secondary by-products without the use of toxic solvents. [ABSTRACT FROM AUTHOR]

Vineyard solid wastes are regarded as an alternative source of renewable raw materials for the production of hemicellulosic sugars and their conversion into furfural. In this work, a liquid hemicellulosic fraction was extracted from vineyard wastes in order to produce a higher furfural yield. A simple ultra-high-performance liquid chromatography with diode array detection (UHPLC-DAD) method was used for determining furfural from vineyard wastes. The UHPLC-DAD method was validated for the determination of furfural from vineyard wastes. The described method shows good linearity with a coefficient of determination higher than 0.998. The limits of detection (LOD) and quantification (LOQ) were 0.3 µg mL−1 and 1.0 µg mL−1, respectively. The recoveries determined by the spiking solutions varied between 95.1 and 100.8%. The relative expanded uncertainty of the method was evaluated based on a bottom-up approach and was 13.5%. [ABSTRACT FROM AUTHOR]

The goal of this study was to investigate the effect of thermal treatment (200, 400, and 600 °C) on the adsorption capacity of a natural clinoptilolite-rich zeolite (NZ) of different particle sizes for methylene blue removal from aqueous solution. The physical properties and chemical composition of the natural zeolites treated at several temperatures were determined. Powder X-ray diffraction, Brunauer–Emmett–Teller, and scanning electron microscopy were used to characterize the thermally treated zeolites. X-ray diffraction showed that the main crystalline phases of the thermally treated zeolites were clinoptilolite-Na, quartz, muscovite, and albite. The equilibrium measurements were analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The experimentally fitted Freundlich isotherm was a better fit than the Langmuir model for methylene blue adsorption onto the thermally treated zeolites. The adsorption of methylene blue on the thermally treated natural zeolites was shown to involve chemisorption. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the adsorption of rhodamine B (RB) from synthetic water using natural zeolites from Romania. The adsorption capacity of zeolite for RB removal was improved by heat treatment at 200, 400 and 600 °C. The chemical and structural characterization of untreated and thermally treated zeolites was performed using advanced techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The adsorption behavior of RB on activated zeolites was studied using Langmuir, Freundlich and Dubinin- Radushkevich isotherms. The thermally treated zeolite at 200°C gave the highest adsorption efficiency (97.9%) for RB adsorption from aqueous solutions. According to the obtained results, it can be concluded that thermally treated zeolite can be used as an effective adsorbent for the removal of RB from wastewater. [ABSTRACT FROM AUTHOR]

Ba and Sr may occur in relatively high content in natural zeolites and can contribute to the zeolites ion-exchange properties. In addition, some soluble compounds of Ba and Sr can be toxic, thus their determination is important. The aim of this paper was the development and validation of a method for determination of Ba and Sr in zeolites based on microwave-assisted acid digestion and inductively coupled plasma optical emission spectrometry (ICP-OES). For validation, a certified reference material (BCS-CRM 375/1) was used in the accuracy study, and the obtained recoveries were 92 ± 10 % for Ba and 95 ± 12 % for Sr. A mixture of HNO3:HCl:HF of 3:9:2 (v/v/v) and a digestion time of 40 min were found to give recoveries in the range of 80-120 %. The obtained LOQs in ICP-OES allowed the quantification of concentrations above 5.0 mg kg-1 Ba and 3.8 mg kg-1 Sr. The method was applied for the determination of Ba and Sr in five zeolite samples, and concentrations of 422 – 580 mg kg-1 for Ba and 115 – 183 mg kg-1 for Sr were found. The obtained performance parameters were in agreement with the requirements of international guidelines regarding methods validation. [ABSTRACT FROM AUTHOR]

The paper presents the validation of a method for the determination of exchangeable cations (K+, Na+, Ca2+ and Mg2+) in zeolites by inductively coupled plasma optical emission spectrometry (ICP-OES), after extraction in ammonium chloride solution. Amongst the analytical techniques that can be used for exchangeable cations measurement, ICP-OES provides rapid, robust, multi-element analysis on a wide range of concentrations. The exchange capacity is one of the most important parameters of zeolites since it indicates their adsorption capacity in different processes. Method validation is an essential requirement for testing laboratories in order to provide trustworthy results in accordance with ISO/IEC 17025:2017 standard. The main figures of merit were studied, and the measurement uncertainty was assessed. The selectivity assay showed no significant non-spectral matrix effect. The linearity study was conducted for the calibration curves in the range of 0.02–20 mg L−1 for each exchangeable cation. Limits of quantification were 0.005 mEq 100 g-1 for Na+, 0.011 mEq 100 g-1 for Mg2+, 0.002 mEq 100 g-1 for K+, 0.003 mEq 100 g-1 for Ca2+. Relative standard deviations of repeatability (RSDr) (n=6 parallel samples) were 4.50 % for Na+, 4.43 % for Mg2+, 6.55 % for K+ and 5.53 % for Ca2+. Recoveries (%) estimated using a certified reference material (CRM BCS-CRM 375/1), for total content of cation oxides were in the range 92–103 %. Fourteen zeolite samples from Racos deposit, Romania were analysed, and according to the chemical composition and Xray diffraction the main mineral in zeolitic tuffs is clinoptilolite-type. The obtained figures of merit demonstrate that the method has a suitable level of precision and accuracy for the intended purpose. [ABSTRACT FROM AUTHOR]

Nanotechnology is an attractive and challenging science focused on the materials at nanoscale level and their employment in a wide variety of applications. Its applications in (nano)medicine are constrained due to the main concerns in understanding and predicting the behavior of nanoparticles (NPs) in complex biological fluids. The properties of NPs can be strongly influenced by the surrounding conditions, such as pH and composition, in terms of aggregation status, chemical reactivity and surface chemistry. In this regard, this review intents to provide some insight into the performance of complex biological fluids associated with nanomaterials. In particular, the behavior of AgNPs and AuNPs in simulated biological fluids that must be addressed to develop an appropriate system for medical applications, from a chemical perspective, mostly related to the physico-chemical characteristics of NPs and simulated biological fluids and their possible interactions (mechanisms) was considered. Furthermore, the fate of AgNPs and AuNPs during the gastrointestinal transit from an in vivo experimental perspective, as well as their potential impact on gut microbiota was also systematized. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the fatty acids content from Rosa canina and Prunus spinosa plant fruit oil via ultrasound-assisted process. The extracted oil’s fatty acids were converted into fatty acid methyl esters (FAME) before gas chromatography analyses (GC) equipped with flame ionization detection (FID). Results showed that Rosa canina oils contain mainly polyunsaturated fatty acids with the linoleic acid as the major fatty acids (62.3%) followed by oleic acid (28.6%), whereas Prunus spinosa oils contain 46.2% oleic acid and 32.6% linoleic acid. Rosa canina oil could be used as potential source of linoleic acid. [ABSTRACT FROM AUTHOR]