Moamen Saeed Talha, Mostafa E Elshobary, Hanan M Khairy, Ahmed E Alprol
{"title":"Phycoremediation of dairy industry wastewater using Chlorella sorokiniana: a cost-effective strategy for biodiesel production.","authors":"Moamen Saeed Talha, Mostafa E Elshobary, Hanan M Khairy, Ahmed E Alprol","doi":"10.1007/s11356-025-36488-z","DOIUrl":"https://doi.org/10.1007/s11356-025-36488-z","url":null,"abstract":"<p><p>This study explored the potential of a newly isolated strain of Chlorella sorokiniana for dairy wastewater (DWW) phycoremediation and biodiesel production. Microalgae were cultivated in various dilutions of dairy wastewater (50%, 60%, 70%, 80%, and 90%) and compared with growth in synthetic Amaral medium. The results demonstrated that C. sorokiniana exhibited robust growth across all wastewater dilutions, with the 90% dilution outperforming the synthetic medium in terms of cell concentration and biomass production (0.47 g/L/d). Chlorophyll a content increased with higher wastewater concentrations, peaking at 20.24 µg/L in 90% DWW. Lipid content analysis revealed the highest accumulation in 90% DWW, reaching 40.33% of the dry weight biomass. Fatty acid profiling revealed a predominance of palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2) across all treatments. The proportion of saturated fatty acids slightly increased with higher wastewater concentrations, while monounsaturated fatty acids decreased and polyunsaturated fatty acids remained relatively stable. The results indicated that moderate dilution of 60% wastewater resulted in the highest nitrate removal efficiency (75%). Phosphate removal remained consistently high (85-98%) across all dilutions. The biodiesel properties derived from wastewater-cultivated algae met the ASTM D6751 and EN14214 standards, with improvements in the cetane number and cloud point at higher wastewater concentrations. This study demonstrated the feasibility of using dairy wastewater as a cost-effective and sustainable medium for microalgal cultivation, offering the dual benefits of wastewater phycoremediation and high-quality biodiesel feedstock production. The findings highlight the potential for integrating algal cultivation with dairy industry waste management, contributing to circular economic principles in the biofuel sector.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143962785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Kulbir Singh, Rajesh Kumar Lohchab, Gaurav Goel, Sadiq Abdullahi Waziri, Hakim Aguedal, Yacine Allab, Mohamed El Amine Elaissaoui Elmeliani, Abdelkader Iddou, Bing Liu, Mitsuharu Terashima, Suresh Kaswan
{"title":"Innovative use of immobilized zinc oxide-impregnated activated carbon (ZnO@CB) for effective treatment of leachate: modeling and predictive assessment.","authors":"Kulbir Singh, Rajesh Kumar Lohchab, Gaurav Goel, Sadiq Abdullahi Waziri, Hakim Aguedal, Yacine Allab, Mohamed El Amine Elaissaoui Elmeliani, Abdelkader Iddou, Bing Liu, Mitsuharu Terashima, Suresh Kaswan","doi":"10.1007/s11356-025-36476-3","DOIUrl":"https://doi.org/10.1007/s11356-025-36476-3","url":null,"abstract":"<p><p>This study examined the viability of column method utilizing the immobilized zinc oxide-loaded activated carbon obtained from corncob (ZnO@CB) to treat the landfill leachate. Instrumental techniques like BET, FTIR, SEM-EDX, and XRD were applied for the characterization of the adsorbents. The break through curve (BTC) was evaluated by altering the flow rate, bed height, and initial concentration of NH<sub>3</sub>-N and COD. At 35 cm bed height with an initial level of 3264 mg-COD/L, the optimal adsorption capacity was observed to be 35.44 mg-COD/g. Meanwhile, the optimal NH<sub>3</sub>-N adsorption capacity was 4.81 mg-NH<sub>3</sub>-N/g at a flow @ 1 mL/min, with an initial concentration of 460 mg-NH<sub>3</sub>-N/L, and a bed height of 35 cm. Both NH<sub>3</sub>-N and COD adsorption exhibited a correlation coefficient higher than 0.98 as calculated by linear plots of bed depth service time (BDST) equations, indicating that the column structure model was appropriate. The results reveal that the performance of the adsorption process could be well predicted by artificial neural network (ANN) at 4, 7, and 1 neuron for input, middle, and output layers, with a mean absolute error of 0.0096 and 0.0093 for COD and NH<sub>3</sub>-N reduction, respectively. In the RF model, higher values of R<sup>2</sup> (0.9876 for COD and 0.9874 for NH<sub>3</sub>-N) indicate the model accuracy. The regenerated adsorbent achieved 54.2% and 54.1% removal of COD and NH<sub>3</sub>-N and adsorbent usage was feasible for up to three cycles. Results of BDST, ANN, and RF models revealed that packed column with immobilized ZnO@CB adsorbent is an efficient method for treating landfill leachate, highlighting the potential of ZnO@CB for industrial applications.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Gbemisola Oyindamola Akinbi, Qi Lin, Tolulope Elizabeth Fiola, Rajesh Singh Rathore, Veera Lakshmi Devi Badisa, Benjamin Mwashote, Gang Chen, Victor Ibeanusi
{"title":"Ecosystem assessment to support innovative advancements in soil sustainability in the major land resource areas of Mississippi through geochemical and metagenomics studies.","authors":"Gbemisola Oyindamola Akinbi, Qi Lin, Tolulope Elizabeth Fiola, Rajesh Singh Rathore, Veera Lakshmi Devi Badisa, Benjamin Mwashote, Gang Chen, Victor Ibeanusi","doi":"10.1007/s11356-025-36490-5","DOIUrl":"https://doi.org/10.1007/s11356-025-36490-5","url":null,"abstract":"<p><p>In the present study, the ecosystem of Roebuck (RF) and Nesbit blueberry plantation (NBP) farms in Mississippi state, USA that differed by type of fertilizer treatment was assessed using soil samples through geophysical-chemical parameters and metagenomics studies. Soil geophysical-chemical parameters such as pH, moisture, organic content, nutrients, and toxic metal concentrations were measured. Metagenomic analysis was performed to identify the bacterial communities in the soil samples. The results revealed that the pH of the NBP farm (organic fertilizer) was lower than that of the RF farm (chemical fertilizer). The NBP soil samples exhibited higher moisture and organic contents than the RF soil samples. The tested heavy metal concentrations in both farm soil samples were within the limits recommended by the EPA (United States Environmental Protection Agency). Different concentrations of nutrients were observed between these two farms soil samples. RF soil indicated greater species richness and a more balanced distribution of species abundances. Proteobacteria, Bacteroidota, and Actinobacteriota were the most abundant phyla observed in RF soil, whereas Proteobacteria, Acidobacteriota, and Actinobacteriota were the most abundant phyla observed in NBP soil. This study clearly demonstrated the effects of fertilizer type on the soil through variations in geophysical-chemical parameters, which subsequently changed the microbial communities. This study suggests that organic fertilizer application could be an effective method for sustainable soil quality as the organic fertilized soils exhibited higher moisture and organic content that promotes plant growth.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Abdellah Ait Baha, Nidal Zrikam, Rachid Idouhli, Kamal Tabit, Loubna El Fels, Mohy Eddine Khadiri, AbdesselamAbouelfida
{"title":"Strengthened pollutants abatement in wastewater through electrocoagulation and zeolite adsorption: analytical and microbial assessment.","authors":"Abdellah Ait Baha, Nidal Zrikam, Rachid Idouhli, Kamal Tabit, Loubna El Fels, Mohy Eddine Khadiri, AbdesselamAbouelfida","doi":"10.1007/s11356-025-36492-3","DOIUrl":"https://doi.org/10.1007/s11356-025-36492-3","url":null,"abstract":"<p><p>As the global population rapidly increases, so does the water demand, making effective wastewater treatment essential to mitigate pollutants, including heavy metals, organic compounds, and microbial contaminants. These pollutants pose significant health risks, exacerbate environmental crises, and disrupt ecosystems, emphasizing the urgent need for sustainable solutions. This study explores the electrocoagulation-adsorption (EC-Ads) integrated treatment process as a promising approach for contaminant removal from wastewater. The method simultaneously generates in situ coagulants while leveraging the retention capabilities of zeolite. A NaOH-prefusion-mediated hydrothermal synthesis was employed to convert clay-rich illite and fumed silica by-product into pure analcime-C zeolite. This material demonstrated high crystallinity (89%), a specific surface area of 23.76 m<sup>2</sup>/g, and a cation exchange capacity (CEC) of 510 meq/100g. Initially, the EC process was optimized for chromium (VI) removal from synthetic solutions, achieving an 85% removal efficiency at an energy consumption of 0.5 kWh/g under optimal conditions (initial pH 5, current density 10 mA/cm<sup>2</sup>, and electrolysis time 40 min). Subsequently, the EC and EC-Ads processes were applied to real wastewater samples. Under optimized conditions, the EC-Ads process achieved 97.85% chromium removal with an energy consumption of 7.32 Wh/L. Additionally, reductions in chemical oxygen demand (COD) and total organic carbon (TOC) were observed at 60.19% and 94.09%, respectively. Notably, complete eradication (100%) of microbial contaminants, including microflora, fungi, and coliforms, was achieved. These findings highlight the efficiency and sustainability of the EC-Ads integrated approach in removing diverse pollutants from wastewater, offering a reliable solution to enhance water quality in treatment facilities.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143961706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Weiran Zheng, Yi Liu, Guoguang Yu, Ling Lei, Xiajun Wang, Xiaxia Ren, Pengfei Sun
{"title":"A π-π composited photocatalyst of aminobenzaldehyde and graphitic carbon nitride for photocatalytic elimination of antibiotics.","authors":"Weiran Zheng, Yi Liu, Guoguang Yu, Ling Lei, Xiajun Wang, Xiaxia Ren, Pengfei Sun","doi":"10.1007/s11356-025-36415-2","DOIUrl":"https://doi.org/10.1007/s11356-025-36415-2","url":null,"abstract":"<p><p>In order to improve the photocatalytic performance of graphitic carbon nitride (GCN), a composite photocatalyst of aminobenzaldehyde (ABA) modified GCN (ABA/GCN) was prepared through facile π-π stacking approach. Characterization results demonstrated that introduction of ABA could widen absorption of visible light and decrease the recombination of photogenerated charges. The composite photocatalyst could completely degrade moxifloxacin (MOX, 20 mg L<sup>-1</sup>) under 80 min visible light irradiation, and the apparent rate constant is 2.4 times higher than that of the GCN. We further optimized the reaction conditions through studying the effects of pH value, photocatalyst dosage and MOX concentration on the activity. The modified photocatalyst presented high stability, durability and photocatalytic universality, as well as good potential in practical application. On basis of determined band structure and main active species, we proposed a possible photocatalytic mechanism. This work provides a possible strategy to enhance the photocatalytic performance through rational design of aromatic guest modified GCN.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Konan Bertin Kouadio, Eléonore Resongles, Kouassi Ernest Ahoussi, Zié Ouattara, Ibrahim Konaté, Noémie Fayol, Daniel Borschneck, David Baratoux, Sophie Delpoux, Aurélien Domeau, Mylène Marie, Kouakou Alphonse Yao, Odile Bruneel
{"title":"Environmental contamination by metals, metalloids, and cyanides in the historic and active ASGM area of Kokumbo in Côte d'Ivoire.","authors":"Konan Bertin Kouadio, Eléonore Resongles, Kouassi Ernest Ahoussi, Zié Ouattara, Ibrahim Konaté, Noémie Fayol, Daniel Borschneck, David Baratoux, Sophie Delpoux, Aurélien Domeau, Mylène Marie, Kouakou Alphonse Yao, Odile Bruneel","doi":"10.1007/s11356-025-36403-6","DOIUrl":"https://doi.org/10.1007/s11356-025-36403-6","url":null,"abstract":"<p><p>In Côte d'Ivoire, despite an intense development of artisanal and small-scale gold mining (ASGM) activities in the last two decades, the environmental impacts of this activity are poorly documented. This study aimed to document the concentrations of geogenic and exogenous contaminants potentially released by ASGM (metals and cyanides) in different sources (ore, mining wastes) and environmental compartments (soils, surface and ground waters, sediments) in the Kokumbo area, part of the Au-rich Birimian greenstone belt. Alluvial ore material is enriched in various metal(oid)s (As, Co, Cu, Cr, Fe, Mn, Ni, Sb, and V) compared to the average composition of the upper continental crust while other metals (Cd, Pb, Ti, Zn) show no geochemical anomalies. High Hg concentrations were found in cyanidation residues (up to 8.32 mg/kg) and sediments (up to 20.4 mg/kg) compared to unprocessed alluvial ores (0.06 ± 0.01 mg/kg) indicating that Hg used in amalgamation is the source of Hg contamination. Cyanidation residues contain up to 100 mg/kg of total cyanides but generally less than 3% are in the form of free cyanides, the most mobile and toxic form. Arsenic concentrations in water are low (< 2.5 µg/L) despite its relatively high content in sediments and soils (76 ± 54 mg/kg), showing a low mobility of As, likely due to its adsorption on iron oxy(hydr)oxides. Apart from Mn, metals have low dissolved concentrations in water except in a stream draining a cyanidation site suggesting that the cyanidation effluent discharge may contribute to metal dispersion in rivers.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Examining the relationship between persistent organic pollutants and metabolic-associated fatty liver disease: a cross-sectional analysis using NHANES data.","authors":"Carlina Colussi, Jean-Patrice Baillargeon, Gérard Ngueta","doi":"10.1007/s11356-025-36493-2","DOIUrl":"https://doi.org/10.1007/s11356-025-36493-2","url":null,"abstract":"<p><p>Recently, the term Metabolic-Associated Fatty Liver Disease (MAFLD) has been adopted to better reflect the underlying pathology and association with metabolic issues. Beyond dietary factors and physical activity, previous studies have suggested that persistent organic pollutants (POPs) may contribute to the etiology of MAFLD; however, this disease can also develop at very low POP exposure levels, making it challenging to discern their specific effect. This study aims to investigate the potential link between exposure to POPs and the prevalence of MAFLD. Data from the National Health and Nutrition Examination Survey (NHANES) was utilized for this cross-sectional study. Participants were categorized based on their MAFLD status and levels of various POPs measured in their blood serum. Cox regression to estimate adjusted prevalence ratio (aPR) of MAFLD was used. Hazard Index (HI), Proportion of Maximum Scaling (POMS), and Toxicity Burden Index (TBI) were applied to assess exposure to mixtures. A total of 4,224 participants were included, 47 (33-65) years, 53.0% were women, and 50.1% had MAFLD. No significant sex differences were observed in the main analysis regarding the association between individual POPs and MAFLD prevalence. However, sensitivity analyses revealed an inverse relationship between certain POPs and MAFLD prevalence, particularly in women. Higher levels of specific PCBs were associated with a lower prevalence of MAFLD in women. This study highlighted the effects of individual pollutants, mixtures, and sex-specific differences. The combined use of HI, POMS, and TBI provided a more detailed risk assessment. Findings suggest that biological sex and metabolic stressors play significant roles in how POPs influence MAFLD, warranting further investigation into mechanisms and health outcomes in different exposure ranges.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143957281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pedro Delgado-Plana, Miguel Ángel Gómez-Casero, Salvador Bueno-Rodríguez, Pedro José Sánchez-Soto, Dolores Eliche-Quesada
{"title":"Correction to: Impact of incorporating spent oil filtering earths into the formulation of alkali‑activated cements based on electric arc furnace slag.","authors":"Pedro Delgado-Plana, Miguel Ángel Gómez-Casero, Salvador Bueno-Rodríguez, Pedro José Sánchez-Soto, Dolores Eliche-Quesada","doi":"10.1007/s11356-025-36504-2","DOIUrl":"https://doi.org/10.1007/s11356-025-36504-2","url":null,"abstract":"","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143957279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"First online observations of greenhouse gases over the Central Himalayas: insights in fluxes, vegetation links, and meteorological controls.","authors":"Priyanka Srivastava, Manish Naja","doi":"10.1007/s11356-025-36428-x","DOIUrl":"https://doi.org/10.1007/s11356-025-36428-x","url":null,"abstract":"<p><p>Ground observations with diurnal variability over the Himalayas are crucial to validate climate mitigation efforts, build accurate emissions inventories, and better forecasting. This study bridges the acute scarcity of such measurements by making the first online observations of CO<sub>2</sub> and CH<sub>4</sub> with CO at a mountain site (Nainital, 29.4° N, 79.5° E, 1958 m a.m.s.l.) continuously for 5 years in the Central Himalayas. Observed levels of CO<sub>2</sub> and CH<sub>4</sub> are higher than those at other background sites. The boundary layer evolution and upslope winds determine the diurnal pattern of CH<sub>4</sub> and CO, while CO<sub>2</sub> diurnal and seasonal variations are governed by biospheric uptake. Bivariate analysis shows that higher levels (> 1.98 ppm) of CH<sub>4</sub> are mostly localized and that the distribution of CO<sub>2</sub> is representative of the terrestrial ecosystem. Diurnal variations in CO<sub>2</sub> relate to the meteorology, except during spring when the anthropogenic influence breaks this covariation. Excess and background CO<sub>2</sub> and CH<sub>4</sub> are segregated, and the role of biomass burning in spring and fossil fuel combustion in raising CO<sub>2</sub> is revealed. The role of vegetation is also evaluated with the Normalized Difference Vegetation Index (NDVI) and fluxes from the CarbonTracker model. During autumn, the impact of agricultural and waste emissions on high CH<sub>4</sub> is evidenced. The limited online observations from this region also showed an increasing trend in CO<sub>2</sub> (2.66 ± 0.17 ppm yr<sup>-1</sup>) and CH<sub>4</sub> (9.53 ± 0.09 ppb yr<sup>-1</sup>), while CO has a decreasing trend (3.15 ± 1.32 ppb yr<sup>-1</sup>). The results highlight the complex interplay of anthropogenic emissions, biospheric uptake, and weather patterns with mountain features in shaping CO<sub>2</sub> and CH<sub>4</sub> levels, especially at the diurnal scale.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143962095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Ana Vitória de Paiva Gonçalves, Markssuel Teixeira Marvila, Leonardo Carvalho Mesquita, Marília Gonçalves Marques
{"title":"Effect of partial substitution of recycled concrete aggregate in reinforced concrete beams: analysis of dry and pre-saturated conditions.","authors":"Ana Vitória de Paiva Gonçalves, Markssuel Teixeira Marvila, Leonardo Carvalho Mesquita, Marília Gonçalves Marques","doi":"10.1007/s11356-025-36483-4","DOIUrl":"https://doi.org/10.1007/s11356-025-36483-4","url":null,"abstract":"<p><p>The preservation of natural resources and the pursuit of sustainability in civil construction have promoted academic interest in research related to the reuse of construction and demolition waste (CDW). The partial replacement of conventional aggregates with CDW in cementitious materials has yielded satisfactory results in terms of the mechanical and rheological behavior of the resulting material. However, further studies are needed to demonstrate the feasibility of this application in a standardized manner. Accordingly, the present study aims to assess the impact of recycled concrete aggregates (RCAs) on the behavior of reinforced concrete (RC) beams. To this end, natural coarse aggregates were replaced with RCAs at substitution levels of 0% and 30%, while maintaining the same mixture composition across all samples. The main properties of concrete with RCAs were evaluated, including the slump test, compressive strength, tensile strength, and modulus of elasticity after 7 days and 28 days of curing. Subsequently, RC beams containing RCAs were analyzed through for four-point bending tests. The prototypes were cast using RCAs in water saturated and unsaturated conditions. The results revealed that incorporating RCAs enhanced workability by 62.5% while reducing compressive concrete strength by less than 15% in 28 days. Despite this reduction, concrete incorporating RCAs achieved the projected compressive strength of 25 MPa. No significant changes in tensile resistance were observed. Regarding the beams containing RCAs, it was observed that the failure mode remained unchanged, and their collapse loads did not differ significantly from those of the conventional reference RC beam, with variations of less than 10%. These findings are significant, given that several studies have documented notable changes in the mechanical properties of concrete containing RCAs. Overall, it can be concluded that using RCAs at a 30% substitution level is a viable option for RC beam applications. Furthermore, although saturating RCAs might enhance the adhesion between the aggregate and the cement matrix, this effect was not confirmed in the present study.</p>","PeriodicalId":545,"journal":{"name":"Environmental Science and Pollution Research","volume":" ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}