Vehicle traffic pollution requires complex physicochemical analysis besides emission level measuring. The current study is focused on two campaigns of emissions measurements held in May and September 2019 in Alba Iulia City, Romania. There was found a significant excess of PM_2.5 for all measuring points and PM₁₀ for the most circulated points during May, along with significant VOC and CO₂ emissions. September measurements reveal threshold excess for all PM along with increased values for VOC and CO₂ emissions. These are the consequences of the complex environmental interaction of the traffic. Street dust and air-suspended particle samples were collected and analyzed to evidence the PM_2.5 and PM₁₀ sources. Physicochemical investigation reveals highly mineralized particulate matter: PM_2.5 fractions within air-suspended particle samples predominantly contain Muscovite, Kaolinite, and traces of Quartz and Calcite, while PM₁₀ fractions within air-suspended particle samples predominantly contain Quartz and Calcite. These mineral fractions originate in street dust and are suspended in the atmosphere due to the vehicles’ circulation. A significant amount of soot was found as small micro-sized clusters in PM_2.5 and fine micro-spots attached over PM₁₀ particles, as observed by Mineralogical Optical Microscopy (MOM) and Fourier Transformed Infrared Spectroscopy (FTIR). GC-MS analysis found over 53 volatile compounds on the investigated floating particles that are related to the combustion gases, such as saturated alkanes, cycloalkanes, esters, and aromatic hydrocarbons. It proves a VOC contamination of the measured particulate matters that make them more hazardous for the health. Viable strategies for vehicle traffic-related pollutants mitigation would be reducing the street dust occurrence and usage of modern catalyst filters of the combustion gas exhausting system.

The aim of the study is to evaluate the suitability of a local strain of the microalga Scenedesmus opoliensis in remediation of water pollution with different amounts of chromium(VI), and also to identify new biochemical and physiological markers for a more reliable indication of sustainability and efficiency of bioextraction and phytoaccumulation processes. Quantitative analysis of photosynthetic pigments reveals that the chlorophylls to carotenoids ratio is a sensitive marker of chromium toxicity and of algal metal tolerance on which the remediative capacity relies. From among the chlorophyll fluorescence parameters, the Fv/Fm ratio, related to potential quantum yield of photochemical reactions, indicates that alkaline pH of the medium (8.65-9.15) favors algal vitality as compared to acidic conditions with pH values around 5. The highest extraction rate (91%) is achieved upon exposure of algae for one week to lower chromium concentrations (5 µM) in alkaline water environment, and a longer exposure time does not increase bioaccumulation. These results may directly contribute to optimization of remediation technology for chromium-polluted water, providing new markers and a new algal strain to be introduced in wastewater treatment.

Problem statement: Contaminated mixed plastic waste—bearing metallic, paper, cardboard and organic residues—remains largely excluded from mechanical recycling because conventional routes require a costly, water- and energy-intensive washing–drying pretreatment. Research gap: No published study combines a fully dry, washing-free valorisation route for such waste with certified mechanical characterisation and a quantified CO₂ mass balance that explicitly credits elimination of the washing–drying stage. Methodology: This study presents DMP (Downcycled Mixed Plastic), a patented (OSIM, Romania) dry valorisation process based on continuous single-screw extrusion (D = 150 mm, L/D = 17.3), characterised through differential scanning calorimetry (DSC), certified mechanical/thermal testing at accredited Romanian laboratories, Weber-number dispersion analysis, and a process-parameter sensitivity study. Key findings: The composite exhibits certified mechanical properties (tensile strength 9.22 MPa, elongation at break 112.8%, compressive strength 14.5 MPa); composition–property analysis across four batches shows that increasing the PP weight fraction from 20 to 28 wt% raises tensile strength by 8.3% while reducing elongation by 5.2%; a computed Weber number (We = 166.7 ≫ We_crit) is consistent with fine PP-phase dispersion within the PE matrix; the sensitivity study confirms statistically robust structure–property relationships (R² = 0.93–0.98); and the CO₂ mass balance establishes a net avoidance of 3.150 t CO₂ eq per tonne of waste processed relative to conventional wet recycling. Significance: dry, washing-free processing is a technically promising pathway for valorising plastic waste streams currently considered non-recyclable, potentially reducing production cost by 60–70% relative to wet recycling, pending additional characterisation identified as priorities for future work.

This study investigates the full production and characterisation chain of an eco-innovative polymer composite — designated DMP (Downcycled Mixed Plastic) — manufactured from hard-to-recycle, contaminated plastic waste streams via a continuous single-screw extrusion process. The composite, comprising approximately 60–70% polyethylene (PE), 20–30% polypropylene (PP), and 5–10% other polymers (ABS, PET, PS) with 2% impurities, was characterised by differential scanning calorimetry (DSC), density measurement, tensile testing (SR EN ISO 527-1:2020 / SR EN ISO 527-2:2012), impact resistance, bending, compressive strength, wear resistance (Bohme method), water absorption, thermal resistance, and microbiological analysis, performed by accredited Romanian laboratories. The single-screw extruder (D = 150 mm, L/D = 17.3, 30 rpm, barrel 200–220 °C, die 80–120 °C, pressure 60–120 MPa) converts unsorted, unwashed mixed polyolefin waste into dimensionally stable construction profiles without compatibilisers or virgin polymer input. DSC confirmed PE (softening 50–114 °C), PP homopolymer (melt 200–212 °C, crystallisation ~230 °C), and PP copolymer (melt 219–235 °C) fractions. Tensile strength was 9.22 ± 0.38 MPa (elongation 112.8 ± 8.4%, n = 5, unexposed); after 300 h UV weathering: 10.28 ± 0.42 MPa (76.6 ± 5.8%); after 50 freeze–thaw cycles: 9.55 ± 0.35 MPa (57.3 ± 4.9%). Compressive strength: 14.5 ± 0.9 MPa; static failure load: 29.03 ± 1.2 kN; thermal conductivity: 0.162 ± 0.008 W/m·K. All values meet applicable standard reference thresholds. Results confirm DMP composites as technically viable for non-structural load-bearing construction applications while diverting non-recyclable waste from landfill and incineration.

Recycled-plastic panels are increasingly proposed for noise barriers, but certifying their airborne sound insulation (EN 1793-2) requires full-size specimens and accredited facilities. This communication proposes a screening step for use before certification. It combines the field-incidence mass law with a coincidence correction, Monte Carlo propagation of the unmeasured stiffness and damping, the EN 1793-2 single-number rating DL_R over 100–5000 Hz, and a decision rule: proceed to certification if the 5th percentile of DL_R is at least 25 dB. The in situ rating DL_SI is then estimated from published DL_SI–DL_R correlations. The method reproduced the laboratory R_w of six commercial polycarbonate and poly(methyl methacrylate) barrier sheets within −2 to +3 dB, and the certified DL_R of seven products within −1.8 to +1.3 dB (root-mean-square error 0.9 dB), with no false passes when the threshold was varied from 24 to 34 dB; random- and normal-incidence models were biased by −3.1 and +5.8 dB. Applied to 25 mm panels extruded from unsorted, unwashed mixed plastic waste, it gave a median DL_R of 33 dB and a 5th percentile of 32 dB (29–34 dB for ribbed panels), so the material warrants certification. As the validation covers solid polymer sheets only, testing must confirm the prediction for the recycled material.

Post-combustion CO₂ capture is a key mitigation pathway for natural gas compression and processing infrastructure; the chilled ammonia process (CAP) and advanced amine-based capture (AAC) are the most technologically mature commercial options. Methods: This study presents a technical and economic comparison of CAP and AAC, combined with historical field emission measurements (11 June 2013) at two Romanian natural gas compression stations (S.N.G.N. Romgaz S.A., Mediaș, Romania): Cristur (downstream of a CAP unit) and Brateiu (uncaptured baseline), using a Multilyzer NG Series 213 analyzer (SYSTRONIK Elektronik und Systemtechnik GmbH, Illmensee, Germany). As the stations were not sampled under a controlled before/after protocol, the comparison is cross-sectional. Results: Flue gas CO₂ was lower at Cristur (at or below detection limit) than at Brateiu (6.8%), but this reading could not be reconciled with the analyzer’s own O₂-based calculation formula and is reported as an unresolved historical data-quality issue rather than as evidence of capture performance; co-pollutants (NO, NO_x, CO) were also lower at Cristur. An independent van’t Hoff-based thermodynamic estimate, anchored to ammonia-specific literature data, yields a CAP capture efficiency of 89.6–90.3% at typical operating temperature. A theoretical mass balance, using representative flow rates and literature capture efficiency, estimates 42,600–85,200 t CO₂/year captured. Literature capture costs range from 40 to 77 EUR/t (CAP) and 47 to 90 EUR/t (AAC), both largely below the current EU ETS price (81.35 EUR/t, June 2026), though no net economic benefit is quantified due to missing capital and ancillary cost data. Conclusions: CAP is thermodynamically capable of high CO₂ removal efficiency; the historical field data are directionally consistent but do not independently validate this. Beyond the historical dataset itself, this study contributes a reusable diagnostic cross-check for flue gas analyzer CO₂ readings, a recalibrated ammonia-specific thermodynamic estimation method, and a transparent framework for assessing capture technologies from incomplete legacy data; it is presented as a historical, illustrative case study and methodological reference for future, instrumentally verified monitoring campaigns.