2025, Volume 71(75), Issue 4 (December)

Contents

pages 1- 8   Download  

Valorization of Prunus Spinosa Extract as Sustainable Coloring Agents in Textile Finishing: A Green Chemistry Approach

NICOLETA TOFĂNESCU (MIHAI), “Gheorghe Asachi” Technical University of Iași, Faculty of Industrial Design and Business Management (DIMA), Romania, nicoleta.mihai@student.tuiasi.ro
VASILICA POPESCU, “Gheorghe Asachi” Technical University of Iași, Faculty of Industrial Design and Business Management (DIMA), Romania

pages 9 - 25   Download
DOI: 10.5281/zenodo.19660106
Abstract
In the context of the need to develop sustainable textile technologies, this research investigates the application of Prunus spinosa extracts as environmentally friendly coloring agents. The fruits and bark of this species are rich sources of bioactive compounds, including tannins, flavonoids, and anthocyanins, characterized by antioxidant, antimicrobial, and dyeing properties, thus providing a viable alternative to synthetic dyes. Pigment extraction from Prunus spinosa fruits can be conducted through various methods such as maceration, boiling, and pressing. The chemical composition of the extracts can be characterized using advanced analytical techniques, including High-Performance Liquid Chromatography (HPLC), Proton Nuclear Magnetic Resonance (1H-NMR), and Fourier Transform Infrared Spectroscopy (FTIR). Employing these extracts in environmentally friendly textile dyeing processes significantly contributes to the reduction of environmental pollution by eliminating the necessity of harmful chemical agents. The stability and fixation properties of these natural dyes can be evaluated using spectroscopic analyses, wash, light, and rub fastness tests, as well as colorimetric measurements. Literature studies have indicated a high affinity of these natural dyes towards natural textile fibers, such as cotton and wool, ensuring strong adherence and enhanced color durability. In addition to ecological advantages, this method supports the development of a more sustainable textile industry by providing products with additional functional properties, such as ultraviolet (UV) protection and antimicrobial activity. Therefore, the valorization of Prunus spinosa extracts in textile dyeing aligns with green chemistry principles, promoting innovative and eco-friendly alternatives to conventional dyes. This approach represents a significant step towards reducing the ecological impact of the textile industry by demonstrating the feasibility of utilizing natural resources in sustainable processes. Future studies will focus on extending the applicability of these natural dyes to synthetic fibers, optimizing extraction procedures, and maximizing pigment fixation efficiency. Thus, the application of Prunus spinosa extracts as natural coloring agents not only offers a viable and environmentally friendly alternative to synthetic dyes, thereby reducing the negative environmental impact of the textile industry but also opens new perspectives for the development of functional textiles with antimicrobial and UV-protective properties, contributing to the transition towards more sustainable production processes aligned with circular economy and green chemistry principles.
Keywords: Natural dyes; Prunus spinosa; textile dyeing; green chemistry; sustainability.

Key Design Parameters for Optimizing Tertiary Wastewater Treatment

ALEXANDRU-ION PASCARIU, S.C. HYDROPROCONS S.R.L., Iași, Romania, alexandru-ion.pascariu@student.tuiasi.ro
MIHAI DIMA, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering, Iași, Romania
MARIUS TELIȘCĂ, “Gheorghe Asachi” Technical University of Iași, Faculty of Hydrotechnics, Geodesy and Environmental Engineering, Iași, Romania
AANDREEA SILVIA POPA, River Basin Authorities “Siret”, SGA Vrancea, Focșani, Romania

pages 27 - 45   Download
DOI: 10.5281/zenodo.19660149
Abstract
The main goal of the work consists in the optimization from the point of view of energy efficiency and the reduction of the implementation and operation costs of the advanced (tertiary) treatment stage of urban and industrial treatment plants, through the correct choice of the staged sequence of calculation of the still used primary parameters from the design phase of the tertiary stage component equipment. In the evaluation of the biological treatment stage within a wastewater treatment plant, several critical operational and design parameters must be rigorously analyzed. Primarily, the focus is on quantifying the concentration of organic pollutants (CBO5) in the influent to the biological reactor, alongside the total pollutant load, which includes both organic and inorganic constituents. These concentrations are essential for dimensioning the reactor and determining the oxygen demand. Furthermore, a detailed mass balance is performed for nutrients, particularly nitrogen and phosphorus.
Keywords: energy efficiency, improvement and dimensioning of the parameters.  

Phosphorus Recovery from Sewage Sludge Ash: Chemical Processing and Granulation for Sustainable Fertiliser Production

SEBASTIAN JAN BARANYAI, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania, sebastian-jan.baranyai@student.tuiasi.ro
MARIA GAVRILESCU,, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania; Academy of Romanian Scientists, Bucharest, Romania; Academy of Technical Sciences of Romania, Bucharest, Romania

pages 47 - 80   Download
DOI: 10.5281/zenodo.19660259
Abstract
The recovery of phosphorus from sewage sludge and sewage sludge ash (SSA) is a crucial step toward achieving sustainable resource management and closing nutrient cycles. This manuscript provides a comprehensive overview of current technologies for phosphorus recovery, focusing on both chemical and thermochemical processes, including acid leaching, struvite precipitation, and high-temperature treatments. Special attention is given to industrially implemented approaches such as the KomPhos, PHOS4green (GLATT/SERAPLANT), AshDec, and RecoPhos processes. The discussion addresses the technical, environmental, and economic aspects of each method, highlighting their advantages, limitations, and regulatory challenges. Economic evaluation criteria such as investment and operating costs, potential revenue, and environmental impacts are also examined. Additionally, the paper presents illustrative process flow diagrams and evaluates the prospects for large-scale implementation. By integrating technological innovation with sustainability goals, phosphorus recovery from SSA emerges as a vital strategy for reducing dependency on imported phosphate rock and promoting circular economy practices.
Keywords: circular economy, fertilizer, phosphorus recovery, secondary phosphate recycling, sewage sludge ash

Rheological Study of Three Cosmetic Creams Obtained with Different Extracts of Lemon

CLAUDIA COBZARU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental, Iași, Romania
MARTA-VERONICA GRIGORE, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental, Iași, Romania
MARICEL DANU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental, Iași, Romania
GABRIELA-ANTOANETA APOSTOLESCU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental, Iași, Romania
CORINA CERNĂTESCU, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental, Iași, Romania, corina.cernatescu@academic.tuiasi.ro

pages 81 - 91   Download
DOI: 10.5281/zenodo.19660322
Abstract
In this study, three cosmetic creams containing/with different lemon extracts were formulated and studied from a rheological point of view. Rheological tests such as: the flow test, amplitude sweep and frequency sweep were determined by specific measurements and showed that the products formulated based on lemon extracts are stable at different temperatures and can easily be applied to the skin. Additional microbiological tests and clinical studies are required for cosmetic creams to be marketed.
Keywords: rheological study, lemon extract, cosmetic cream, oily maceration.

Unconventional Heat Insulation Birch Wood Material Made Through Delignification Procedure

LUCIAN PĂUNESCU, National University of Science and Technology “Politehnica”, Faculty of Applied Chemistry and Materials Science, Research Center for Environmental Protection and Eco-Friendly Technologies, Bucharest, Romania, lucianpaunescu16@gmail.com
ENIKÖ VOLCEANOV, National University of Science and Technology “Politehnica”, Faculty of Engineering in Foreign Language, Bucharest, Romania
ADRIAN IOANA, National University of Science and Technology “Politehnica”, Faculty of Materials Science and Engineering, Bucharest, Romania
SORIN MIRCEA AXINTE, National University of Science and Technology “Politehnica”, Faculty of Applied Chemistry and Materials Science, Bucharest, Romania; Daily Sourcing & Research SRL, Bucharest, Romania
BOGDAN VALENTIN PĂUNESCU, , Consitrans SA, Bucharest, Romania

pages 93 - 104   Download
DOI: 10.5281/zenodo.19660415
Abstract
Wood waste delignification is a process known and used for longer time in the pulp and paper industry, whose technological adoption is necessary for producing wood foam. The new cellular wood manufacturing procedure is attractive for the production of a cheap and effective insulating material for the building construction sector. Experimental testing of several tree wood types was initiated in recent decades and the team of the current paper authors was also recently involved in this research. The current paper aimed at testing the behaviour of birch wood in foaming made by delignification of waste in the form of sawdust. The work originality results from the premiere use of birch wood in the manufacturing process of a stable foam. Utilizing wood waste, nanoclay, an adequate surfactant, and distilled water as well as a heat treatment at 75ºC, products with peculiarities suitable to established objective were obtained.
Keywords: birch wood, lignin, delignification, sawdust, insulation properties.

Optimization of the Preparation Parameters of PCL Particles Obtained by an Emulsification/Evaporation Method

OANA CUCOVEICA, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania; Faculty of Medicine, Apollonia University of Iași, Iași, Romania, oanacucoveica@yahoo.com
LEONARD IONUȚ ATANASE, “Gheorghe Asachi” Technical University of Iași, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iași, Romania; Faculty of Medicine, Apollonia University of Iași, Iași, Romania; Academy of Romanian Scientists, Bucharest, Romania

pages 105 - 116   Download
DOI: 10.5281/zenodo.19660537
Abstract
Nanotechnology represents a sector with high potential for the treatment of human diseases. Among different types of drug delivery systems, polymer nanoparticles (NPs) are of main importance in the biomedical field. They are mainly used as vehicles for the delivery of active compounds, thus protecting the drug against enzymatic and chemical degradation and directing it to the various target tissues and cells. Many factors can influence the size of NPs such as stirring speed, polymer concentration, organic phase addition speed or surfactant concentration. The aim of this study was to find the optimum conditions for the preparation of nanoparticles using an emulsification/evaporation method. Using dynamic light scattering technique, it was possible to assess the optimal conditions for the preparation of NPs with size less than 200 nm, such as: 1 wt. % concentration in CHCl3, 1 wt. % concentration of PVA in the aqueous phase and 5 min homogenization. These optimized parameters ensure a stable and monodisperse colloidal suspension suitable for future parenteral administration.
Keywords: poly(ε-caprolactone), drug delivery systems, optimization parameters, dynamic light scattering, colloidal stability.

Light Cellular Gypsum-Based Material for Construction Applications

LUCIAN PĂUNESCU, National University of Science and Technology “Politehnica”, Faculty of Applied Chemistry and Materials Science, Research Center for Environmental Protection and Eco-Friendly Technologies, Bucharest, Romania, lucianpaunescu16@gmail.com
ENIKÖ VOLCEANOV, National University of Science and Technology “Politehnica”, Faculty of Engineering in Foreign Language, Bucharest, Romania
ADRIAN IOANA, National University of Science and Technology “Politehnica”, Faculty of Materials Science and Engineering, Bucharest, Romania
SORIN MIRCEA AXINTE, National University of Science and Technology “Politehnica”, Faculty of Applied Chemistry and Materials Science, Bucharest, Romania; Daily Sourcing & Research SRL, Bucharest, Romania
BOGDAN VALENTIN PĂUNESCU, Consitrans SA, Bucharest, Romania

pages 117 - 129   Download
DOI: 10.5281/zenodo.19660611
Abstract
The procedure of preparing a light gypsum-based material using aluminium powder activated in aqueous Ca(OH)2 solution was tested in this work. The aluminium was recycled from post-consumer soft drink packaging waste, melted under the action of microwaves and atomized into very fine particles by direct contact with concentrated nitrogen jets. Except for calcined gypsum as the main raw material, other additive materials were used: coal ash, vermiculite, polypropylene fibres, polystyrene beads, silica fume, and carboxymethyl cellulose. The process took place at room temperature. The obtained product had good thermal insulation properties (density between 527-595 kg·m-3 and heat conductivity in the range of 0.147-0.180 W·m-1·K-1) as well as satisfactory compression strength (between 1.2-2.0 MPa).
Keywords: gypsum, aluminium, Ca(OH)2 solution, microwave, vermiculite.

Development of an Analysis Methodology for the Characterization of Leachate Samples

DUMITRIŢA NUŢU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iaşi, Romania
LAURA BULGARIU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iaşi, Romania, laura.bulgariu@academic.tuiasi.ro

pages 131 - 143   Download
DOI: 10.5281/zenodo.19660738
Abstract
Landfill leachate (leachate) is a liquid generated during the storage process of municipal waste. Due to its complex composition (which often includes highly toxic inorganic and organic compounds), leachate samples must be detailed characterized to ensure their effective treatment and environmental protection. The most commonly used indicators for the characterization of leachate samples are color, temperature, pH, electrical conductivity (1/R), turbidity, total suspended solids (TSS), chemical oxygen demand (COD), ammonium nitrogen (N-NH4+), chlorides (Cl-), and heavy metal content. However, the measured values of these indicators largely depend on the time elapsed between sample collection and their actual determination. In order to obtain accurate values, this study presents a methodology for leachate sample analysis, in which the order of indicator determination was established experimentally. The experimental studies were conducted using the same leachate sample, and each indicator was measured periodically over four days. By following such a methodology, accurate values for the qualitative, physical and chemical indicators characteristic of the leachate samples can be obtained, which may be useful in waste management.
Keywords: leachate sample, characteristic indicators, analytical measurements, experimental methodology.