International Journal of Environmental Science and Technology最新文献

{"title":"Anode substrate tailoring in fed-batch photosynthetic microbial desalination cell for industrial and domestic wastewater treatment","authors":"S. S. Ali,&nbsp;Z. Sheikh,&nbsp;W. Miran,&nbsp;Z. Ullah","doi":"10.1007/s13762-025-06619-7","DOIUrl":"10.1007/s13762-025-06619-7","url":null,"abstract":"<div><p>Photosynthetic microbial desalination cells (PMDCs) have recently been valued for their dual capabilities in desalination and effluent treatment, coupled with energy generation. As a green technology, they leverage photosynthetic microbes to continuously supply in-situ oxygen at the cathode, which enhances reduction reactions. PMDCs also aid in nutrient removal and algal biomass production. While substrate concentration is a crucial factor influencing PMDC performance, especially with high-strength wastewater, it remains underexplored. Most studies have used anodic wastewater concentration typically ranging from 75 to 3000 mgL^-1, with only one study focused on examining the impact of substrate concentration on PMDC using 500 and 1000 mgL^-1. Therefore, this research addresses this gap by evaluating the PMDC performance at 2000, 4000, and 6000 mgL^-1 anode substrate concentrations. The study employed <i>Scenedesmus obliquus</i> as a biocatalyst for domestic wastewater treatment at the cathode. It was found that MDCs exhibited better performance at a substrate concentration of 4000 mgL^-1, with PMDC achieving the highest efficiency owing to the availability of the substrate and the lowest internal resistance. PMDC achieved an average working voltage, anode COD removal, and desalination of 276 mV, 83%, and 27%, respectively, which were 38%, 6%, and 17% higher than MDC control at 4000 mgL^-1 substrate concentration. Additionally, PMDC at the cathode demonstrated a notable reduction in COD at 72%, NH₄⁺-N at 62%, and PO₄^3-- P at 43%, with an average algal growth rate of 418 mgL^-1d^-1. These findings prove that PMDCs are suitable and effective integrated desalination and wastewater treatment options.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"15095 - 15110"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revolutionizing clinic waste management: government intervention, clinic registration, investment strategies using predictive machine learning models","authors":"A. A. Khan,&nbsp;N. Memon,&nbsp;S. Nazir,&nbsp;S. G. A. Saif,&nbsp;R. K. Ahmad","doi":"10.1007/s13762-025-06594-z","DOIUrl":"10.1007/s13762-025-06594-z","url":null,"abstract":"<div><p>Contemporary healthcare organizations, especially smaller-scale clinics, are up against a rather significant waste disposal problem. Identifying that balance between bringing advanced healthcare services and being responsible with resources has never been more critical. Hence, this article seeks to discuss the topic with a particular focus on how government involvement, clinic mandatory registration, suitable clinic investment towards waste management, and inclusion of advanced prediction machine learning models can immensely change the current position. This work establishes the state of practice in minor healthcare institutions' waste disposal and highlights their challenges. Government legislative and regulatory measures are required to make clinics formally register and adhere to policies on waste disposal. In fact, the city of Hyderabad, which is nestled in the Sindh province of Pakistan, also suffers acute Healthcare waste management issues. Hence, this project aims to enhance healthcare institutions' waste management operations based on clinic registration with garbage management and the latest big data. Grievous results involve a 23% reduction in waste output that results from the implementation of strict controls as well as compliance with WHO specifications. A comprehensive result showed that appropriating an SDSS raised garbage collection efficiency by thirty-seven percent. The future success of the clinic might be predicted using linear regression (LR) and random forest (RF) algorithms. However, the prediction accuracy for RF was significantly higher at 87% than the above computed LR of 69.2%. The obtained outcomes shed light on the conceivable opportunities for enhancing healthcare waste management by applying new technologies that may help enhance sustainability and protect the environment.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"15003 - 15030"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing soil carbon sequestration capacity of cropland’s with cool farm tool under organic agriculture","authors":"S. K. Das","doi":"10.1007/s13762-025-06605-z","DOIUrl":"10.1007/s13762-025-06605-z","url":null,"abstract":"<div><p>The efficient use of nutrient is essential to achieving a number of Sustainable Development Goals (SDGs), including tackling climate change, decreasing poverty, and ending hunger. We also investigated how the soil organic carbon and the levels of nitrogen as well as phosphorus relates to one another. We used a program called the “cool farm tool,” which is already licensed by the IPCC, to carry out this investigation. One farmer was interviewed at each of the seven locations that were chosen in order to collect input data, and two hundred ten soil samples were examined in a lab to determine the soil pH as well as soil organic carbon content. The results showed that most of the discovered areas with low soil organic carbon had great potential for future carbon sequestration. Additionally, there was a range of 307.09–390.04 t ha⁻¹ (mean ± SD as 348.56 ± 0.78) for the total nitrogen concentration and 13.98 to 21.33 t ha⁻¹ (mean ± SD as 17.65 ± 0.04) for the total phosphate concentration. In addition, the total amount of soil organic carbon content was 1.39 to 0.96% (mean ± SD as 1.17% ± 0.01). The results of this study revealed that the tool was most effective for measuring soil carbon sequestration, nitrogen and phosphorus in crop land, which has the fewest uncertainties and data gaps. The program will therefore play a crucial role in efforts to mitigate climate change impacts.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"14993 - 15002"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal of chromium from electroplating wastewater using chitosan-coconut shell composite: kinetics, thermodynamics and artificial neural networks modeling","authors":"F. Batool,&nbsp;T A Kurniawan,&nbsp;B Pasaribu,&nbsp;T D Kusworo,&nbsp;S. Silviana,&nbsp;H S Kusuma,&nbsp;M. I. Khan,&nbsp;S. Haddout,&nbsp;J C C Casila,&nbsp;H. Harianingsih,&nbsp;W O Choo,&nbsp;M A Iqbal","doi":"10.1007/s13762-025-06591-2","DOIUrl":"10.1007/s13762-025-06591-2","url":null,"abstract":"<div><p>The electroplating industry releases large volumes of wastewater contaminated with toxic chromium, posing significant risks to both the environment and public health. Although progress has been made in water pollution control, the application of composite adsorbents for chromium removal, combined with simulations for process optimization, remains underexplored. In this study, the effectiveness of a chitosan-coated coconut shell composite in removing chromium from electroplating wastewater was investigated. Under optimal conditions (4 g/L dosage, pH 6.5, 308 K temperature, 200 rpm speed and 60 min time) the composite removed 99% of Cr and outperforming both chitosan and coconut shell. The adsorption process followed pseudo-second-order kinetics (<i>R</i>² = 0.999) and the Langmuir isotherm with a maximum adsorption capacity of 66.66 mg/g. The adsorption efficiency increased with temperature (298–313 K), indicating an endothermic process. The composite retained 98% of its initial capacity after regeneration with HNO₃, demonstrating its cost-effectiveness over multiple cycles. Simulations using artificial neural networks (ANNs) accurately predicted adsorption behavior by achieving a mean square error (MSE) as low as 0.0016. However, despite high Cr removal, the treated effluents did not meet legislative discharge standards, highlighting the need for further biological treatment using activated sludge.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"15057 - 15076"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal aging effects on LDPE greenhouse films: anisotropy and degradation","authors":"M. I. Babaghayou,&nbsp;A.-H. I. Mourad,&nbsp;S. Belaid,&nbsp;A. A. Yadav,&nbsp;Y. M. Hunge","doi":"10.1007/s13762-025-06601-3","DOIUrl":"10.1007/s13762-025-06601-3","url":null,"abstract":"<div><p>This study investigates the diverse and directional effects caused by artificial thermal aging in unstabilized Low-Density Polyethylene films that are commonly used in Laghouat's Greenhouses in Algeria. The films were subjected to three different temperatures (50 °C, 60 °C, and 68 °C) for 18 months. After the exposure, the films underwent mechanical and thermal assessments in three different orientations: machine direction, 45° inclination direction, and transversal direction. Anisotropic tendency was observed, notably in the machine direction orientation, resulting in an increase in yield stress and Young's modulus with a decrease in ductility especially at higher exposure temperatures. Morphological changes and secondary crystallization were identified in the degradation process. The increase of crystallinity confirmed by Differencial Scanning Calorimetry indicated that structural transformations occur during prolonged aging. Calculations highlighted a significant increase in crystallinity degree, influencing mechanical characteristics and causing time-dependent stiffening. Moreover, the increased activation energy with thermal aging time at higher temperatures, revealed an increase in energy demand during the thermal degradation process. Considering elongation at break as a service life criterion, films at 68 °C exhibited notable losses, reaching 50% by the 12th month for all orientations. By the 18th month, machine direction orientation experienced an 88% loss, while inclination direction and transversal direction orientations showed 86% and 96%, respectively, marking critical degradation. This study provides concise insights into the significance heterogeneity and anisotropy induced by artificial thermal aging in unstabilized low-density polyethylene films, which is crucial for optimizing materials in Laghouat's Greenhouses.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"14913 - 14926"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chromium reduction by indigenous Bacillus sp. isolate S1: optimal performance, characterization, and pathway","authors":"N. N. Ramli,&nbsp;A. R. Othman,&nbsp;N. S. M. Said,&nbsp;J. Alias,&nbsp;S. R. S. Abdullah,&nbsp;H. A. Hasan,&nbsp;N. ‘I. Ismail,&nbsp;S. B. Kurniawan","doi":"10.1007/s13762-025-06606-y","DOIUrl":"10.1007/s13762-025-06606-y","url":null,"abstract":"<div><p>Anthropogenic activities associated with the metal industry in Malaysia have led to an overabundance of heavy metal waste, particularly hexavalent chromium, Cr(VI), which is highly hazardous and has accumulated in the surrounding environment. No previous study has given sufficient consideration to Cr(VI) removal, and its management in Malaysia has led to conflicting findings about the presence of bacteria resistant to Cr(VI). Thus, the objectives of this study were to identify the Cr(VI)-resistant bacteria in metal waste, optimize Cr(VI) reduction by Response Surface Methodology (RSM), characterize bacteria through Scanning Electron Microscope (SEM), and propose the Cr(VI) reduction pathway. The BLAST finding of a 16S rDNA sequence analysis revealed an isolated bacterium resistant to 1,000 mg/L of Cr(VI), identified as <i>Bacillus</i> sp., and chosen to optimize Cr(VI) reduction. The Analysis of Variance (ANOVA) of the quadratic model suggested that the model was acceptable, as it still had Prob &gt; F (0.0263), which signifies significance for determining the model's reliability. The optimum conditions for <i>Bacillus</i> sp. S1, resulting in a 100% reduction of Cr(VI) with an initial Cr(VI) concentration of 50 mg/L, was at pH 6 and an exposure period of 3 days. The Cr(VI)-resistant bacterium <i>Bacillus</i> sp. could eliminate Cr(VI) under suitable conditions. SEM examination demonstrated that the reduction of Cr(VI) by <i>Bacillus</i> sp. S1 took place inside the cell. This study provides a scientific reference on the Cr(VI) reduction pathway for research on Cr(VI)-resistant bacteria.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"15045 - 15056"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green synthesis of zinc oxide nanoparticles for inactivation of antibiotic-resistant bacteria in real prawn farm wastewater","authors":"N. H. Kamaruzaman,&nbsp;A. A. Siyal,&nbsp;R. M. S. Radin Mohamed,&nbsp;W. A. Bin Wan Mohamed,&nbsp;N. Fitriani","doi":"10.1007/s13762-025-06590-3","DOIUrl":"10.1007/s13762-025-06590-3","url":null,"abstract":"<div><p>Antibiotic-resistant bacteria are widespread in prawn farm wastewater, contaminating water resources and threatening human health. This paper describes the synthesis of zinc oxide nanoparticles through a green technique using <i>Nymphaea</i> leaf extract to inactivate antibiotic-resistant bacteria in the prawn farm wastewater. NLE has not been previously reported for the synthesis of zinc oxide nanoparticles. The <i>Nymphaea</i> leaf extract and zinc oxide nanoparticles were characterized, and the optimization of the effect of parameters of zinc oxide nanoparticles loading (0.01–0.1 g/L), pH (7–9), and reaction time (30–60 min) on the inactivation of antibiotic-resistant bacteria of gram-negative <i>Escherichia coli</i> and gram-positive <i>Bacillus cereus</i> was determined using central composite design of response surface methodology. <i>Nymphaea</i> leaf extract contains terpenoids, flavonoids, tannins, phenols, and glycosides. Zinc oxide nanoparticles were spherical, evenly distributed, less agglomerated with small particles (31.2–80.5 nm), and nearly homogeneous grain size distribution on the surface. It has a hexagonal wurtzite crystalline structure with a crystallite size of 42.6 nm. The <i>p</i>-value of &lt; 0.05 displayed the best fitting of the data to the quadratic model with a 95% confidence level. The best inactivation of 99.18% and 97.39% for <i>Escherichia coli</i> and <i>Bacillus cereus</i> in prawn farm wastewater was obtained at optimum zinc oxide loading of 0.1 g/L, pH 7, and 30 min of reaction time. <i>Escherichia coli</i> and <i>Bacillus cereus</i> were inactivated by damaging the bacterial cell wall. The green zinc oxide nanoparticles efficiently inactivated <i>Escherichia coli</i> and <i>Bacillus cereus</i> growth in prawn farm wastewater. Zinc oxide nanoparticles can be used to inactivate other bacteria in other types of wastewaters.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"15077 - 15094"},"PeriodicalIF":3.4,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13762-025-06590-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental governance, green finance, and mitigation technologies: pathways to carbon neutrality in European industrial economies","authors":"B. Li,&nbsp;X. Wang,&nbsp;A. Khurshid,&nbsp;S. Fawad Saleem","doi":"10.1007/s13762-025-06608-w","DOIUrl":"10.1007/s13762-025-06608-w","url":null,"abstract":"<div><p>This study intends to analyze the impact of environmental governance (EGOV), green finance (GFN), and mitigation technology on industrial output (IVA) and carbon neutrality (CN) in six major European industrial economies. It further analyzes the influence of several critical variables, including environmental policy (EPY), energy efficiency (EEF), and renewable energy consumption (RENG), on achieving these objectives. The period from 2003 to 2022 is used for empirical analysis conducted using advanced econometric methodologies, such as the Pooled and Augmented Mean Group (PMG, AMG) estimators. Findings show that EGOV, GFN, and mitigation technologies related to production (MTPP) and energy generation (MTEG) have positive effects on IVA and contribute to CN when used independently. Meanwhile, the interactive terms MPRE (<i>MTEG*RENG</i>) and EPRE (EPY*RENG) have even stronger positive effects on achieving CN in selected European countries. It was also found that EPY and EEF have positive effects on CN. In contrast, IVA and demand-based emissions (DBE) have a negative impact on CN. These outcomes highlight the need for an integrated policy framework that encompasses governance reform, green financial investment, and technological innovation to achieve sustainable industrialization and the CN in Europe.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"14899 - 14912"},"PeriodicalIF":3.4,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strengthening test of water treatment performance of foamed fly ash filler based on magnetic modification","authors":"T. Xia,&nbsp;Y. Ji,&nbsp;J. Bi,&nbsp;J. Xia,&nbsp;J. Bai,&nbsp;L. Peng,&nbsp;S. Xia","doi":"10.1007/s13762-025-06595-y","DOIUrl":"10.1007/s13762-025-06595-y","url":null,"abstract":"<div><p>The fly ash water treatment filler prepared using the foaming method is characterized by low energy consumption and a simple preparation process, effectively promoting the resource utilization of fly ash. To further enhance the filler's water treatment performance, this study employed the co-precipitation method to synthesize Fe₃O₄ magnetic particles and optimize the magnetic modification of the foamed fly ash filler. The results show that the specific surface area of the magnetically modified foamed fly ash filler increased by 30.51%, and the average pore diameter increased by 26.47% compared with the original filler before modification. In the simulated domestic wastewater treatment test, the magnetically modified filler achieved COD and ammonia nitrogen removal rates of 74.61% and 70.18%, respectively. These values are higher than those of the unmodified and sintered ceramic fillers and represent improvements of 21.99% and 9.76% over the unmodified filler. Illumina MiSeq sequencing revealed that the microbial community on the magnetically modified filler was more abundant, with <i>Proteobacteria</i> and <i>Bacteroidetes</i> as the dominant phyla. Magnetic modification is more effective in promoting the formation of biofilms on the surface of fillers, enhancing microbial diversity, and increasing the proportion of functional bacteria.</p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 15","pages":"14939 - 14952"},"PeriodicalIF":3.4,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effect of using recycled polypropylene waste on the sound absorption coefficient of micro-perforated panels as a green absorber","authors":"R. Hajizadeh,&nbsp;A. Montazeri,&nbsp;M. Esnaasharieh,&nbsp;M. Mosayebian,&nbsp;M. H. Beheshti,&nbsp;H. Hosseini","doi":"10.1007/s13762-025-06571-6","DOIUrl":"10.1007/s13762-025-06571-6","url":null,"abstract":"<div><p>The use of sound absorbers as fillers behind micro-perforated panels can enhance sound absorption coefficients while offering a sustainable approach to reducing plastic waste. This study aimed to investigate the effect of polypropylene waste, as a recycled material, on the sound absorption coefficient of micro-perforated panels and propose an eco-friendly solution. After preparing the required equipment, composites were manufactured based on experimental runs as single-layer and double-layer panels with varying densities. The micro-perforated panels were made from plexiglass with pore diameters of 0.7 mm, a thickness of 1 mm, and a porosity of 1%. Polypropylene waste was used as a filler behind the micro-perforated panels to evaluate its impact on the sound absorption coefficient. The sound absorption coefficients of the samples were measured according to the ISO 10534-2 standard using the impedance tube apparatus (BSWA, Model SW360). Data design and analysis were performed using Design Expert software (version 11) and SPSS24. After conducting the experiments, variance analysis models were employed to describe relationships between the investigated parameters and response variables to predict optimal conditions. The evaluation of sound absorption coefficients of micro-perforated panels revealed that coefficients at high and medium frequencies were significantly higher than at low frequencies. For single-layer panels, the highest sound absorption coefficient at high frequencies was observed with a thickness of 1.5 cm and a density of 250 kg/m³ (0.8759), while the highest coefficient at medium frequencies corresponded to a thickness of 2.5 cm and a density of 200 kg/m³ (0.7512). For double-layer panels, higher sound absorption coefficients were noted at lower densities and a thickness of 2 cm, with superior performance at high frequencies. Using sound-absorbing materials behind micro-perforated panels and increasing thickness improved sound absorption coefficients, whereas increasing density had a negative effect. Single-layer panels generally performed better than double-layer ones. Furthermore, the incorporation of polypropylene waste enhanced the sound absorption properties of the panels, and the optimized panel with polypropylene waste was recommended for further investigation. The use of recycled polypropylene in micro-perforated panels enhances noise reduction while promoting sustainability, with applications in buildings, transportation, and industrial noise control. </p></div>","PeriodicalId":589,"journal":{"name":"International Journal of Environmental Science and Technology","volume":"22 11","pages":"10599 - 10612"},"PeriodicalIF":3.4,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145164159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}