2024, Volume 70(74), Issue 2 (June)

Contents

pages 1- 8   Download

Studies on Energy Recovery of Textile Waste

LOREDANA-VASILICA POSTOLACHE, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
ALEXANDRU PALARII, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
ANA-MARIA NICUȚĂ, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
GABRIELA-CĂTĂLINA SĂVUC, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
LAURA-GABRIELA SMOC, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
GABRIELA LISA, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania, gabriela.lisa@academic.tuiasi.ro

pages 9 - 18   Download
DOI: 10.5281/zenodo.13307797
Abstract
In this work, the thermal and energy properties of four types of textile wastes were evaluated: cotton, wool, polyester and acrylic. For this purpose, thermogravimetric analysis in nitrogen atmosphere with three heating rates in the temperature range 25-600ºC was used. The processing of the thermogravimetric curves allowed the determination of the temperatures at which 5% (T5%) and 30% (T30%) of the sample mass was lost, with which the statistical heat resistance index (THRI) of the textile waste was evaluated. Using the recorded thermogravimetric curves, the activation energy for the main stage of thermal decomposition was calculated by applying the ASTM E-698 standard method. The enthalpy of combustion of the textile waste was also determined using the Berthlot-Mahler-Krocker calorimeter.
Keywords: textile waste, thermogravimetric characteristics, kinetic parameters, combustion enthalpy

Unconventional and Environmentally Friendly Technique for Increasing the Strength of Building Materials Through CO2-Absorbing and Trapping Inside

 LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania, lucianpaunescu16@gmail.com
ENIKÖ VOLCEANOV, Metallurgical Research Institute SA Bucharest, Romania, National University of Science and Technology POLITEHNICA Bucharest, Faculty of Engineering in Foreign Language, Bucharest, Romania
ADRIAN IOANA, National University of Science and Technology POLITEHNICA Bucharest, Faculty of Material Science and Engineering, Bucharest, Romania
BOGDAN VALENTIN PĂUNESCU, Consitrans SA Bucharest, Romania

pages 19 - 31   Download
DOI: 10.5281/zenodo.13307940
Abstract
Self-compacting concrete using the iron dust waste ability to produce FeCO3 by CO2-absorbing/trapping and favouring the increase of concrete strength was designed and tested. Except for iron dust, other materials rich in silica and alumina (clay brick waste and metakaolin) or CaO-rich (calcium carbonate) and a catalyst (oxalic acid) were added to the mixture, forming a carbon-negative binding material. The paper originality was obtained by adopting new methods of intensive hardening the fresh concrete by its immersing or exposure to CO2-enriched mediums, followed by free storage in air for 7 or 28 days for CO2-absorbing (recommended by the inventor). The results showed that replacing the cement with 12.3% carbon-negative material, using usual ratios of sand, coarse aggregate, lignosulfonate, and water and also applying the concrete hardening variant through the two methods of immersing/exposure in CO2-enriched mediums, concrete specimens with highest strength were made.
Keywords: carbon-negative, self-compacting concrete, iron dust, CO2-absorbing, iron carbonate

 Identification of Capsaicin from The Alcoholic and Oily Extracts of Hot Peppers Using FTIR Spectroscopy

CLAUDIA COBZARU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
ALEXANDRA BUJOR, “Grigore T. Popa” University of Medicine and Pharmacy Iași, Romania
MĂLINA-MARIA CERNĂTESCU, “Grigore T. Popa” University of Medicine and Pharmacy Iași, Romania
CORINA CERNĂTESCU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania, corina.cernatescu@academic.tuiasi.ro

pages 33 - 39   Download
DOI: 10.5281/zenodo.13308093
Abstract
In this study, an attempt was made to identify capsaicin from the hot pepper alcoholic and oily extracts, using FTIR spectroscopy. Both the oily and alcoholic maceration were preserved for 5 years. The spectra obtained show characteristics bands that confirm the presence of functional groups specific to capsaicin. The antioxidant activity of the alcoholic hot pepper extract was also determined by the spectrophotometric method using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Even after a long period of preservation, the alcoholic extract of hot pepper has a high antioxidant activity, which can be used to the preparation of cosmetic and food products to significantly increase their antioxidant properties and have a positive impact on the body.
Keywords: antioxidant activity over time, capsaicin, hot pepper, spectrophotometric analysis

The Pericarp of Citruses: Waste Product or Polyphenol Resource

IOSIF CIOANCA, Theoretical High School “Al. I. Cuza” Iași, Romania
GEORGE-ALEXANDRU MARIN, Faculty of Pharmacy, “Grigore T. Popa” University of Medicine and Pharmacy, Iași, Romania, george17marin@gmail.com
ȘTEFAN LUCA, Faculty of Pharmacy, “Grigore T. Popa” University of Medicine and Pharmacy, Iași, Romania
IONUȚ IULIAN LUNGU, Faculty of Pharmacy, “Grigore T. Popa” University of Medicine and Pharmacy, Iași, Romania
CLAUDIA-ADRIANA CHITIC, Theoretical High School “Al. I. Cuza” Iași, Romania

pages 41 - 52   Download
DOI: 10.5281/zenodo.13308164
Abstract
Citruses, members of the Rutaceae family, are globally renowned for their nutritional and health benefits. While the edible parts are widely consumed, the peels are often discarded despite their rich polyphenol content, particularly flavonoids like hesperidin, naringin, and quercetin. These polyphenols offer significant antioxidant, anti-inflammatory, and antimicrobial properties. The aim of our study was to evaluate the secondary metabolites profile and antioxidant potential of peels from four citrus species: sweet oranges, mandarins, grapefruits, and lemons. Fresh peels were cut and prepared for a microscopic identification, then methanolic maceration extracts were obtained in a ratio of 1:20 (m/v). The major group of active compounds were first screened by chemical reactions with sodium hydroxide, aluminium chloride, Folin-Ciocâlteu Reagent and by thin-layer chromatography (TLC). Total flavonoids, total polyphenols and carotenoids were quantified with spectrophotometric tests. Moreover, the antioxidant capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH•) assay. The obtained results indicated that although the chemical composition varies depending on species, there is a similar chemical profile for all samples. Nevertheless, lemon peel extracts exhibited the highest antioxidant activity, followed by mandarins and oranges, with grapefruit showing the lowest. The findings underscore the potential of citrus peels as a valuable resource for bioactive compounds, advocating for their utilization in nutritional and medicinal applications to promote sustainability and reduce waste.
Keywords: citrus peels, polyphenols, flavonoids, antioxidant activity, sustainable utilization.

Partial Replacement of Natural Aggregates by Incorporating Steel Slag for The Manufacture of Asphalt Mixture

BOGDAN VALENTIN PĂUNESCU, Consitrans SA Bucharest, Romania
ENIKÖ VOLCEANOV, National University of Science and Technology POLITEHNICA Bucharest, Faculty of Engineering in Foreign Language, Bucharest, Romania, Metallurgical Research Institute SA Bucharest, Romania
LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania, lucianpaunescu16@gmail.com

pages 53 - 63   Download
DOI: 10.5281/zenodo.13308225
Abstract
Creating high-durable asphalt mixtures by implementing steel slag in the mix aggregate as a partial substitute constituted the main objective of the work. The addition of slag is beneficial for increasing the asphalt strength, but simultaneously, high content of this by-product tends to reduce the Marshall stability. The experiment tested asphalt mixture making up to 76% slag content, but the best results were obtained for the specimen with 57% slag, i.e. compression strength after 24 hours of 4.8 MPa and after 28 days of 3.6 MPa. In addition, less expensive materials (4-8 mm-slag granulometric class and electro filter dust) were adopted, without negatively influencing the usual product characteristics.
Keywords: asphalt mixture, bitumen, natural aggregate, steel slag, filler

 Spectrophotometric Characteristics of Rifaximin Aqueous Solution and The Consequences for Quantitative Analysis

ELENA FASNIUC-PEREU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environment Protection, Department of Environmental Engineering and Management, Iaşi, Romania
ANDREI-EUGEN BULGARIU, Emergency Hospital “Professor Doctor Nicolae Oblu” of Iaşi, Romania
LAURA BULGARIU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environment Protection, Department of Environmental Engineering and Management, Iaşi, Romania, lbulg@ch.tuiasi.ro

pages 65 - 76   Download
DOI: 10.5281/zenodo.13308277
Abstract
Rifaximin is known as an oral antibiotic that can be used in a wide range of digestive diseases, but not only. Chemically, rifaximin is a yellow solid powder that can be relatively easily dissolved in methanol and which, because of its color, can be analyzed spectrophotometric. To be able to use such a simple method in the quantitative analysis of rifaximin, the most important spectrophotometric characteristics are required. In this study, these spectrophotometric characteristics (maximum wavelength (λmax, nm), spectral band width (Δλ1/2, nm), molar absorption coefficient (ε, L·mol-1·cm-1) are determined from VIS molecular spectra, recorded for aqueous solution containing a known concentration of rifaximin (4.22–16.88 mg·L-1) and different pH (1.0–7.0). Based on the obtained experimental results, the optimal conditions for the spectrophotometric analysis of rifaximin were established, namely: pH = 7.0 (distilled water or phosphate buffer) and λmax = 444 nm. These conditions are suitable for the quantitative analysis of rifaximin with a detection limit of 0.0125-0.0179 mg·L-1 and a precision of 2.12-2.43%. The very good agreement between theoretical and experimental values for rifaximin concentration in tap and sea water samples shows that this method is valid and can be used in quantitative analysis.
Keywords: rifaximin, spectrophotometric characteristics, aqueous solution, qualitative and quantitative analysis

Qualitative And Quantitative Analysis of Impurities in Chlorocholine Chloride: A Review

LILIANA LAZĂR, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania, liliana.lazar@academic.tuiasi.ro
GEORGIANA MARDARE (BĂLUȘESCU), “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania
DUMITRU COMAN, CHIMCOMPLEX S.A., Borzești, Romania

pages 77 - 91   Download
DOI: 10.5281/zenodo.13308330
Abstract
This study provides an overview of impurities in an active substance / active ingredient and selective analytical methods of impurities for their identification in chlorocholine chloride with applications and literature references. Moreover, its reviews the importance to understanding what determinates an impurity and identification of potential sources of this impurity is discussed. The analytes include 1,2-dichloroethane and trimethylamine which are relevant impurities acceptable by Food and Agriculture Organization of the United Nations and World Health Organization. After a concise resume introduction regarding the properties of chlorocholine chloride, attention is focused primarily to separation, identification and detection for qualitative and quantitative analysis of these two analytes. The determination method used after identification of impurities are also discussed. In comparation with spectroscopic (UV-Vis, FTIR, NMR), spectrometric (MS), chromatographic (GC, IC) characterization methods, applications in impurities analysis have demonstrated that coupled or tandem techniques (CG-MS, GLC-MS, HPLC-UV-VIS) gain popularity regarding selectivity, high sensitivity, reliability, good accuracy, robustness and precision for monitoring the impurities from chlorocholine chloride production. According to European Food Safety Authority, chromatographic techniques are recommended for identification purpose.
Keywords: characterization, detection, separation, 1,2-dichloroethane, trimethylamine

Sustainable Ergonomic Women's Clothing by Integrating Chemical Recycling of Textile Fabrics

CARMEN BLEJAN, “Gheorghe Asachi” Technical University of Iași, Faculty of Industrial Design and Business Management, Iași, Romania
ANTONELA CURTEZA, “Gheorghe Asachi” Technical University of Iași, Faculty of Industrial Design and Business Management, Iași, Romania

pages 93 - 107   Download
DOI: 10.5281/zenodo.13308363
Abstract
The textile industry is the second most polluting industry in the world, with a considerable impact on the environment due to greenhouse gas emissions, high water and energy use, chemical pollution, and by default the formation of a huge amount of textile waste. This has led to an imbalance in nature through loss of biodiversity and global warming. This analysis aims to provide an overview of the textile and fashion industry's impact on the environment, social and economic, promoting sustainable and ergonomic fashion. The paper also aims to punctually present the chemical textile recycling methods used in recent years to combat the environmental impact by transforming a waste product back into raw material.
Keywords: sustainability, ergonomic design, chemical recycling