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The recovery of scandium (Sc) from highly acidic industrial effluents is currently hindered by the use of large quantities of flammable and toxic organic solvents. This study developed an extraction system using ionic liquids (ILs) and phenylphosphinic acid (PPAH) as diluents and an extractant, respectively, to selectively recover Sc from the aqueous phase. The effect of IL chemical structure, aqueous pH and temperature on the extraction of Sc was systematically investigated and the findings revealed that ILs with longer alkyl side chains had reduced Sc extraction ability due to the presence of continuous nonpolar domains formed by the self-aggregation of the IL alkyl side chain. The IL/PPAH system maintained high extraction ability toward Sc across a wide temperature range (288 K to 318 K) and the extraction efficiency of Sc could be improved significantly by increasing the aqueous pH. The extraction process involved proton exchange, resulting in the formation of a metal−ligand complex (Sc(PPA)3). [ABSTRACT FROM AUTHOR]

To improve the resource utilization of dredged silt and industrial waste, this study explores the efficacy of using ground granulated blast furnace slag (GGBS), active calcium oxide (CaO), and sodium silicate (Na2O·nSiO2) as alkali activators for silt stabilization. Through a combination of addition tests, response surface method experiments, and microscopic analyses, we identified key factors influencing the unconfined compressive strength (UCS) of stabilized silt, optimized material ratios, and elucidated stabilization mechanisms. The results revealed the following: (1) CaO exhibited the most pronounced stabilization effect, succeeded by Na2O·nSiO2, whereas GGBS alone displayed marginal efficacy. CaO-stabilized silt demonstrated rapid strength augmentation within the initial 7 d, while Na2O·nSiO2-stabilized silt demonstrated a more gradual strength enhancement over time, attributable to the delayed hydration of GGBS in non-alkaline conditions, with strength increments noticeably during later curing phases. (2) Response surface analysis demonstrated substantial interactions among GGBS-CaO and GGBS-Na2O·nSiO2, with the optimal dosages identified as 11.5% for GGBS, 4.1% for CaO, and 5.9% for Na2O·nSiO2. (3) X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses clarified that the hydration reactions within the GGBS-Na2O·nSiO2 composite cementitious system synergistically enhanced one another, with hydration products wrapping, filling, and binding the silt particles, thereby rendering the microstructure denser and more stable. Based on these experimental outcomes, we propose a microstructural mechanism model for the stabilization of dredged silt employing GGBS-CaO-Na2O·nSiO2. [ABSTRACT FROM AUTHOR]

The partial replacement effect of Portland cement by geothermal nano-SiO2 waste (GNSW) for sustainable Portland-cement-based concrete was investigated to improve the properties of concrete exposed at high critical temperatures. Portland cement was partially replaced by 20 and 30 wt.% of GNSW. The partial replacement effect on Portland-cement-based concrete subjected to 350, 550, and 750 °C was evaluated by measuring the weight changes, ultrasonic pulse velocity, thermogravimetric and differential thermal analysis, X-ray diffraction, surface inspection, and scanning electron microscopy under residual conditions. The ultrasonic pulse velocity results showed that the GNSW specimens maintained suitable stability after being heated to 350 °C. The SEM analysis revealed a denser microstructure for the 20 wt.% of partial replacement of Portland cement by GNSW specimen compared to the reference concrete when exposed to temperatures up to 400 °C, maintaining stability in its microstructure. The weight losses were higher for the specimens with partial replacements of GNSW than the reference concrete at 550 °C, which can be attributed to the pozzolanic activity presented by the GNSW, which increases the amounts of CSH gel, leading to a much denser cementitious matrix, causing a higher weight loss compared to the reference concrete. GNSW is a viable supplementary cementitious material, enhancing thermal properties up to 400 °C due to its high pozzolanic activity and filler effect while offering environmental benefits by reducing industrial waste. [ABSTRACT FROM AUTHOR]

In recent years, the demand for natural and synthetic zeolites has surged due to their distinctive properties and myriad industrial applications. This research aims to synthesise crystalline zeolites by co-recycling two industrial wastes: salt slag (SS) and rice husk ash (RHA). Salt slag, a problematic by-product of secondary aluminium smelting, is classified as hazardous waste due to its reactive and leachable nature, though it is rich in aluminium. Conversely, RHA, an abundant and cost-effective by-product of the agro-food sector, boasts a high silicon content. These wastes were utilised as aluminium and silicon sources for synthesising various zeolites. This study examined the effects of temperature, ageing time, and sodium concentration on the formation of different zeolite phases and their crystallinity. Results indicated that increased Na+ concentration favoured sodalite (SOD) zeolite formation, whereas Linde type–A (LTA) zeolite formation was promoted at higher temperatures and extended ageing times. The formation range of the different zeolites was defined and supported by crystallographic, microstructural, and morphological analyses. Additionally, the thermal behaviour of the zeolites was investigated. This work underscores the potential to transform industrial waste, including hazardous materials like salt slag, into sustainable, high-value materials, fostering efficient waste co-recycling and promoting clean, sustainable industrial production through cross-sectoral industrial symbiosis. [ABSTRACT FROM AUTHOR]

Urban construction generates significant amounts of construction residue soil. This paper introduces a novel soil stabilizer based on industrial waste to improve its utilization. This stabilizer is primarily composed of blast furnace slag (BFS), steel slag (SS), phosphogypsum (PG), and other additives, which enhance soil strength through physical and chemical processes. This study investigated the mechanical properties of construction residue soil cured with this stabilizer, focusing on the effects of organic matter content (Oo), stabilizer dosage (Oc), and curing age (T) on unconfined compressive strength (UCS). Additionally, water stability and wet–dry cycle tests of the stabilized soil were conducted to assess long-term performance. According to the findings, the UCS increased with the higher stabilizer dosage and longer curing periods but reduced with the higher organic matter content. A stabilizer content of 15–20% is recommended for optimal stabilization efficacy and cost-efficiency in engineering applications. The samples lost their strength when immersed in water. However, adding more stabilizers to the soil can effectively enhance its water stability. Under wet–dry cycle conditions, the UCS initially increased and then decreased, remaining lower than that of samples cured under standard conditions. The findings can provide valuable data for the practical application in construction residual soil stabilization. [ABSTRACT FROM AUTHOR]

Highlights: Data analysis revealed that an appropriate amount of BPG can enhance the mechanical properties of cementitious materials, with compressive strength increasing by an average of 7–30%. The mechanical properties and underlying mechanisms of BPG-based cementitious materials were summarized. This study analyzed the mechanisms of the conversion and utilization of elements of impurities in BPG, as well as the solidification mechanisms of hazardous elements. The mechanisms of synergistic utilization between BPG and silica–alumina-based solid waste, as well as alkaline solid waste, are summarized, showcasing innovative waste management strategies. A sustainable solution for promoting the collaborative low-carbon development of various industrial solid wastes using BPG is proposed. Industrial byproduct gypsum (BPG) is a secondary product that is mainly composed of calcium sulfate discharged during industrial production. BPG primarily consists of desulfurized gypsum, phosphogypsum, and titanium gypsum, which account for 88% of the total BPG in China. The large-scale utilization of these three types of solid waste is crucial for the safe disposal of BPG. BPG contains various impurities and harmful elements, limiting its applications. The continuous accumulation of BPG poses a serious threat to the safety of the environment. Based on a literature review (2021–2023), it was found that 52% of BPG is used in the preparation of cementitious materials, and the addition of BPG results in an average improvement of 7–30% in the mechanical properties of cementitious materials. Moreover, BPG has a positive impact on the immobilization of hazardous elements in raw materials. Therefore, the utilization of BPG in cementitious materials is beneficial for its large-scale disposal. This study primarily reviews the effects and mechanisms of BPG on the mechanical properties of cementitious materials and the solidification of hazardous elements. Most importantly, the review reveals that BPG positively influences the hydration activity of silica–alumina-based solid waste (such as steel slag and blast furnace slag) and alkaline solid waste (such as carbide slag and red mud). This improves the proportion of solid waste in cement and reduces production costs and carbon emissions. Finally, this article summarizes and proposes the application of BPG in cementitious materials. The application of BPG + silica–alumina solid waste + alkaline solid-waste-based cementitious materials is expected to realize a new type of green ecological chain for the joint utilization of multiple industrial solid wastes and to promote the low-carbon sustainable development of industrial clusters. [ABSTRACT FROM AUTHOR]

River temperature is a critical parameter influencing aquatic ecosystems and water quality. However, it can be changed by natural (e.g., flow and depth conditions) and human factors (e.g., waste and industrial water drainage). Satellite-based monitoring offers a valuable tool for assessing river temperature on a large scale, elucidating the impacts of various factors. This study aims to analyze the spatiotemporal dynamics of surface water temperature (SWT) in the medium-sized Tisza River in response to natural and anthropogenic influences, employing Landsat satellites and in situ water temperature data. The validity of the Landsat-based SWT estimates was assessed across different channel sections with varying sizes. The longitudinal thermal profile of the Tisza was analyzed by mosaicking, monthly, four Landsat 9 images, covering the entire 962 km length of the Tisza in 2023. The impact of climate change was evaluated by analyzing SWT trends at a specific site from 1984 to 2024, utilizing 483 Landsat 4–9 images. The findings indicated elevated accuracy for Landsat-based SWT estimation (R2 = 0.94; RMSE = 3.66 °C), particularly for channel sizes covering ≥ 3 pixels. Discharge, microclimatic conditions, and channel morphology significantly influence SWT, demonstrating a general increasing trend downstream with occasional decreases during the summer months. Dams were observed to lower the SWT downstream due to cooler bottom reservoir water discharge, with more pronounced differences during the summer months (1–3 °C). Tributaries predominantly (75%) elevated the SWT in the Tisza River, albeit with varying magnitudes across different months. Over the 40-year study period, an increasing trend in SWT was discerned, with an annual rise rate of 0.0684 °C. While the thermal band of Landsat satellites proved valuable for investigating the Tisza River's thermal profile at a broad scale, finer spatial resolution bands are necessary for detecting small-scale phenomena such as thermal plumes and localized temperature variations in rivers. [ABSTRACT FROM AUTHOR]

This review embarks on a comprehensive journey, exploring the application of lignocellulosic biomass materials as highly effective adsorbents for the removal of textile dyes (cationic and anionic dyes) from wastewater. A literature review and analysis were conducted to identify existing gaps in previous research on the use of lignocellulosic biomass for dye removal. This study investigates the factors and challenges associated with dye removal methods and signifies their uses. The study delves into the pivotal role of several parameters influencing adsorption, such as contact time, pH, concentration, and temperature. It then critically examines the adsorption isotherms, unveiling the equilibrium relationship between adsorbent and dye and shedding light on the mechanisms of their interaction. The adsorption process kinetics are thoroughly investigated, and a detailed examination of the adsorbed rate of dye molecules onto lignocellulosic biomass materials is carried out. This includes a lively discussion of the pseudo-first, pseudo-second, and intra-particle diffusion models. The thermodynamic aspects of the adsorption process are also addressed, elucidating the feasibility and spontaneity of the removal process under various temperature conditions. The paper then dives into desorption studies, providing insights into the regeneration potential of lignocellulosic biomass materials for sustainable reusability. The environmental impact and cost-effectiveness of employing lignocellulosic biomass materials in textiles including Congo Red, Reactive Black 5, Direct Yellow 12, Crystal Violet, Malachite Green, Acid Yellow 99, and others dyes from wastewater treatment are discussed, emphasizing the significance of eco-friendly solutions. In summary, this review brings together a wealth of diverse studies and findings to present a comprehensive overview of lignocellulosic biomass materials as adsorbents for textile cationic and anionic dye removal, encompassing various aspects from influential parameters to kinetics, adsorption isotherms, desorption, and thermodynamics studies. Its scope and other considerations are also discussed along with its benefits. The collective knowledge synthesized in this paper is intended to contribute to the advancement of sustainable and efficient water treatment technologies in the textile industry. [ABSTRACT FROM AUTHOR]

The utilization of industrial solid waste in mines is an important approach to resource utilization. The backfill material in mines is mainly composed of solid waste, which plays a supporting role. The excitation effect of lime on phosphogypsum and fly ash in backfill was studied in this paper. The macroscopic and microscopic characteristics of the backfill material were tested using uniaxial compression, nuclear magnetic resonance, scanning electron microscopy, and electrochemical techniques, and a relationship model was established between them. Furthermore, the influence of industrial solid waste on the properties of the backfill material under the action of lime and the hydration mechanism between different industrial solid wastes were studied. The results show that (1) under the action of lime, fly ash reacts with lime to produce C-S-H and C-A-H, and then C-A-H reacts with phosphogypsum to produce AFt. (2) The excess phosphogypsum also fills the pores. Therefore, 1.8% lime reduces the porosity of the backfill by 17.88% and increases the strength by 21.57%. (3) The cross-scale relationship shows that strength is inversely proportional to each type of pore content and fractal dimension, and it logarithmically increases with impedance at different frequencies. The lower the frequency, the stronger the relationship is. (4) This study indicates that industrial solid waste is a suitable cement replacement. [ABSTRACT FROM AUTHOR]

Red mud (RM), a hazardous solid waste generated in the alumina production process, of which the mineral composition is mainly hematite, is unable to be applied directly in the cement industry due to its high alkalinity. With the rise of geopolymers, RM-based grouting materials play an essential role in disaster prevention and underground engineering. To adequately reduce the land-based stockpiling of solid wastes, ultrafine calcium oxide, red mud, and slag were utilized as the main raw materials to prepare geopolymers, the C-R-S (calcium oxide–red mud–slag) grouting cementitious materials. The direct impact of red mud addition on the setting time, fluidity, water secretion, mechanical properties, and rheological properties of C-R-S were also investigated. In addition, a scanning electron microscope (SEM), X-ray diffraction (XRD), three-dimensional CT (3D-CT), Fourier transform infrared spectroscopy (FT-IR), and other characterization techniques were used to analyze the microstructure and polymerization mechanism. The related results reveal that the increase in red mud addition leads to an enhanced setting time, and the C-R-S-40 grouting cementitious material (40% red mud addition) exhibits the best fluidity of 27.5 cm, the lowest water secretion rate of 5.7%, and a high mechanical strength of 57.7 MPa. The C-R-S polymer grout conforms to the Herschel–Bulkley model, and the fitted value of R2 is above 0.99. All analyses confirm that the preparation process of C-R-S grouting cementitious material not only substantially improves the utilization rate of red mud, but also provides a theoretical basis for the high-volume application of red mud in the field of grouting. [ABSTRACT FROM AUTHOR]

The intricate composition of wastewater impedes the recycling of agricultural and industrial effluents. This study aims to investigate the potential of sisal leaf wastewater (SLW), both water-treated (WTSLW) and alkali-treated (ATSLW), as a substitute for the alkali activator (NaOH solution) in the production of slag-powder- and fly-ash-based composites, with a focus on the effects of WTSLW substitution ratios and sisal leaf soaking durations. Initially, the fresh properties were assessed including electrical conductivity and fluidity. A further analysis was conducted on the influence of both WTSLW and ATSLW on drying shrinkage, density, and mechanical strength, including flexural and compressive measures. Microstructural features were characterized using SEM and CT imaging, while XRD patterns and FTIR spectra were employed to dissect the influence of WTSLW substitution on the composite's products. The results show that incorporating 14 wt% WTSLW into the composite enhances 90-day flexural and compressive strengths by 34.8% and 13.2%, respectively, while WTSLW curtails drying shrinkage. Conversely, ATSLW increases porosity and decreases density. Organic constituents in both WTSLW and ATSLW encapsulated in the alkaline matrix fail to modify the composites' chemical composition. These outcomes underscore the potential for sustainable construction materials through the integrated recycling of plant wastewater and solid by-products. [ABSTRACT FROM AUTHOR]

The presence of pharmaceuticals or their active metabolites in receiving waters is a sign of the inefficient removal of bioactive substrates from wastewater. Adsorption seems to be the most effective and inexpensive method of their removal. Waste management aimed at sorbents is a promising way to sustain several sustainable development goals. In the presented paper, the removal of the two most widely used drugs in the wastewater was examined. Diclofenac and carbamazepine were removed from water and wastewater using textile waste-derived sorbents. Their removal efficiency was verified by testing several process parameters such as the time of the sorption, the presence of interfering inorganic ions, the presence of dissolved organic matter, the initial pH and ionic strength of the solution, and various water matrices. The adsorption capacity was noted for diclofenac (57.1 mg/g) and carbamazepine (21.25 mg/g). The tested process parameters (pH, presence of inorganic ions, dissolved organic matter, ionic strength, water matrix) confirmed that the presented waste materials possessed a great potential for pharmaceutical removal from water matrices. [ABSTRACT FROM AUTHOR]

The increasing global demand for cement significantly impacts greenhouse gas emissions and resource consumption, necessitating sustainable alternatives. This study investigates fresh geopolymer (GP) pastes incorporating 20 wt.% of five industrial wastes—suction dust, red mud from alumina production, electro-filter dust, and extraction sludges from food supplement production and from partially stabilized industrial waste—as potential replacements for traditional cement. Consistent synthesis methods are used to prepare the geopolymers, which are characterized for their physicochemical, mechanical, and biological properties. Ionic conductivity and pH measurements together with integrity tests, thermogravimetry analysis (TGA), and leaching analysis are used to confirm the stability of the synthesized geopolymers. Fourier-transform Infrared (FT-IR) spectroscopy is used to follow geopolymerization occurrences. Results for ionic conductivity, pH, and integrity revealed that the synthesized GPs were macroscopically stable. TGA revealed that the main mass losses were ascribable to water dehydration and to water entrapped in the geopolymer networks. Only the GP filled with the powder of the red mud coming from alumina production experienced a mass loss of 23% due to a partial waste degradation. FT-IR showed a red shift in the main Si-O-(Si or Al) absorption band, indicating successful geopolymer network formations. Additionally, most of the GPs filled with the wastes exhibited higher compressive strength (37.8–58.5 MPa) compared to the control (22 MPa). Only the GP filled with the partially stabilized industrial waste had a lower mechanical strength as its structure was highly porous because of gas formation during geopolymerization reactions. Despite the high compressive strength (58.5 MPa) of the GP filled with suction dust waste, the concentration of Sb leached was 25 ppm, which limits its use. Eventually, all samples also demonstrated effective antimicrobial activity against Escherichia coli and Staphylococcus aureus due to the alkaline environment and the presence of metal cations able to react with the bacterial membranes. The findings revealed the possibility of recycling these wastes within several application fields. [ABSTRACT FROM AUTHOR]

Catalysts for the selective catalytic reduction (NOX SCR) of nitrogen oxides can be obtained from sludge in industrial waste treatment, and, due to the complex composition of sludge, NOX SCR shows various SCR efficiencies. In the current work, an SCR catalyst developed from the sludge produced with Fe/C micro-electrolysis Fenton technology (MEF) in wastewater treatment was investigated, taking into account various sludge compositions, Fe/C ratios, and contaminant contents. It was found that, at about 300 °C, the NOX removal rate could reach 100% and there was a wide decomposition temperature zone. The effect of individual components of electroplating sludge, i.e., P, Fe and Ni, on NOX degradation performance of the obtained solids was investigated. It was found that the best effect was achieved when the Fe/P was 8/3 wt%, and variations in the Ni content had a limited effect on the NOX degradation performance. When the Fe/C was 1:2 and the Fe/C/P was 1:2:0.4, the electroplating sludge formed after treatment with Fe/C MEF provided the best NOX removal rate at 100%. Moreover, the characterization results show that the activated carbon was also involved in the catalytic reduction degradation of NOX. An excessive Fe content may cause agglomeration on the catalyst surface and thus affect the catalytic efficiency. The addition of P effectively reduces the catalytic reaction temperature, and the formation of phosphate promotes the generation of adsorbed oxygen, which in turn contributes to improvements in catalytic efficiency. Therefore, our work suggests that controlling the composition in the sludge is an efficient way to modulate SCR catalysis, providing a bridge from contaminant-bearing waste to efficient catalyst. [ABSTRACT FROM AUTHOR]

Phosphogypsum (PG) occupies a large amount of land due to its large annual production and low utilization rate, and at the same time causes serious environmental problems due to toxic impurities. PG is used for mine backfill, and industrial solid waste is a curing agent for PG, which can save the filling cost and reduce environmental pollution. In this paper, PG was used as a raw material, combined with steel slag (SS) and ground granulated blast-furnace slag (GGBS) under the action of an alkali-activated agent (NaOH) to prepare all-solid waste phosphogypsum-based backfill material (PBM). The effect of the GGBS to SS ratio on the compressive strength and toxic leaching of PBM was investigated. The chemical composition of the raw materials was obtained by XRF analysis, and the mineral composition and morphology of PBM and its stabilization/curing mechanism against heavy metals were analyzed using XRD and SEM-EDS. The results showed that the best performance of PBM was achieved when the contents of PG, GGBS, and SS were 80%, 13%, and 7%, the liquid-to-solid ratio was 0.4, and the mass concentration of NaOH was 4%, with a strength of 2.8 MPa at 28 days. The leaching concentration of fluorine at 7 days met the standard of groundwater class IV (2 mg/L), and the leaching concentration of phosphorus was detected to be less than 0.001 mg/L, and the leaching concentration of heavy metals met the environmental standard at 14 d. The hydration concentration in PBM met the environmental standard. The hydration products in PBM are mainly ettringite and C-(A)-S-H gel, which can effectively stabilize the heavy metals in PG through chemical precipitation, physical adsorption, and encapsulation. [ABSTRACT FROM AUTHOR]

As an industrial waste residue, Electrolytic Manganese Residue (EMR) can greatly promote sludge dewatering and further particle-size optimization can significantly strengthen sludge dewaterability. In this study, the effects of ammonium sulfate, calcium sulphate dihydrate, and manganese carbonate in EMR on sludge dewatering performance were investigated using the response surface optimization method. It was found that the optimized ratio of three components in EMR was 1.0:1.6:2.2 based on capillary suction time (CST), specific resistance of filtration (SRF), and zeta potential of dewatered sludge. The composition ratio of particle-size optimized EMR was modified based on the above optimization, resulting in a significant increase in sludge dewatering performance (CST and SRF reduced by 8.7% and 11.2%, respectively). Compared with those in original sludge, the content of bound extracellular polymeric substances in the conditioned sludge with optimized ratio was drastically reduced while that of soluble extracellular polymeric substances was slightly increased, which was in accordance with the decline of fluorescence intensity. These findings indicated the disintegration of extracellular polymeric substances, the enhancement of hydrophobicity, and dewatering properties of the sludge. In summary, optimized EMR can effectively intensify the dewaterability of sludge, providing a competitive solution for dewatering and further disposal of sludge. [ABSTRACT FROM AUTHOR]

The routine dredging of waterways produces huge volumes of sediments. Handling contaminated dredged sediments poses significant and diverse challenges around the world. In recent years, novel and sustainable ex situ remediation technologies for contaminated sediments have been developed and applied. This review article focuses on cement-based binders in stabilizing contaminants through the stabilization/solidification (S/S) technique and the utilization of contaminated sediments as a resource. Through S/S techniques, heavy metals can be solidified and stabilized in dense and durable solid matrices, reducing their permeability and restricting their release into the environment. Industrial by-products like red mud (RM), soda residue (SR), pulverized fly ash (PFA), and alkaline granulated blast furnace slag (GGBS) can immobilize heavy metal ions such as lead, zinc, cadmium, copper, and chromium by precipitation. However, in a strong alkali environment, certain heavy metal ions might dissolve again. To address this, immobilization in low pH media can be achieved using materials like GGBS, metakaolin (MK), and incinerated sewage sludge ash (ISSA). Additionally, heavy metals can be also immobilized through the formation of silicate gels and ettringites during pozzolanic reactions by mechanisms such as adsorption, ion exchanges, and encapsulation. It is foreseeable that, in the future, the scientific community will increasingly turn towards multidisciplinary studies on novel materials, also after an evaluation of the effects on long-term heavy metal stabilization. [ABSTRACT FROM AUTHOR]

In the context of sustainability, the integration of renewable energy into industrial processes not only minimizes dependence on fossil fuels but also contributes to the efficient management of industrial waste. By transforming organic waste, including agri-food and urban waste, into biogas, green energy can be generated, thus reducing the impact on the environment and closing the loop of material used in the economic circuit. Thus, a sustainable system can be promoted, where resources are continuously reused and exploited. Statistical methods and a decision tree with the Classification and Regression Trees (CRT) algorithm were employed to analyze data. The paper focuses on the importance of industrial waste and biogas for the generation, transformation, and consumption of energy in the EU (European Union)-27 countries. To provide a thorough analysis, we have divided these countries based on real gross domestic product (GDP) per capita, grouping them above/below the annual average for the period 2012–2021/2022. Descriptive statistics revealed observable differences between the two groups, but the paper aimed to provide evidence regarding the existence of these differences as statistically significant. Using the Kolmogorov–Smirnov test, the non-normal distribution of the data was confirmed, requiring non-parametric inferential methods. The Mann–Whitney U test revealed statistically significant differences between the two groups for all the studied variables. This comprehensive approach highlights the distinct energy-related characteristics influenced by economic development in the EU-27. [ABSTRACT FROM AUTHOR]

The main concept involved in this study explains the theme of complex t-intuitionistic fuzzy graphs (CTIFGs), which act as a powerful tool in analyzing and displaying the relationships among various applications that are difficult to recognize. The manuscript also demonstrates the capability of CTIFGs to create complex associations with multiple domains when considering a physical situation. Following this, the basic set of operations for CTIFGs is projected. The ideas on isomorphism and homomorphism of the CTIFGs are also presented. Moreover, the manuscript describes the importance of the above-mentioned technique in an effective way, giving a solution to the practical application associated with rubber processing industrial wastewater. The contributing factors and corresponding interdependencies are considered when calibrating the complex nature of industrial wastewater associated with the CTIFGs. The results highlight the adaptability and possible efficiencies of CTIFGs, which act as a decision-making tool and also indicate their importance for policy planners in important societal issues. [ABSTRACT FROM AUTHOR]

In recent years, technical processes for the sequestration of CO2 through industrial waste mineral carbonation have been explored and developed. There is a large portfolio of carbon capture, utilisation, and storage (CCUS) techniques that have been employed in laboratories and at pilot scale. These include geological storage, ocean storage, and mineralisation by carbonate ores. In view of this, the main purpose of this research was to investigate and explore chemical variables, particularly ammonium salts as lixiviants for calcium mineral extraction from iron-making slag. The slag in use was acquired from a steel mill in the Vaal Triangle Region in Gauteng, South Africa. The experimental test work was conducted using different ammonium lixiviants, namely, NH4NO3, NH4Cl, and CH3COONH4, to understand the influence of anion type as well as possible differences in mechanisms of interactions. Lixiviant concentration as well as reaction time were varied in this research study. The three selected ammonium-based lixiviants showed different extents of calcium extraction owing to differences in the anion groups. NH4NO3, NH4Cl, and CH3COONH4 were found to be capable of dissolving 50% to 80% of the calcium from the selected slag for different molar concentrations. Anion type and leaching time also had significant influences on the leaching of calcium from the slag. Rapid pH degradation resulted in better calcium extraction capabilities. This work has shown that the selected ammonium salts have the potential to be lixiviants for calcium dissolution from iron-making blast furnace slags. These lixiviants would, therefore, be important to consider during calcium mineral carbonation for CO2 sequestration. [ABSTRACT FROM AUTHOR]

This research is aimed at studying the properties of polymer anticorrosion coatings based on ED-20 resin widely used in practice and industrial wastes. In this work, three basic types of nanoscale nanofillers were chosen: dispersed particles—microsilica, microspheres obtained at Kazakh enterprises, and carbon nanotubes. Physicochemical research methods were used in the research: a laser analyzer for studying the dispersibility of industrial waste and spectrometric research methods. The properties of materials were investigated by standardized methods. The obtained results show that the introduction of microsilica and microspheres obtained at Kazakhstani enterprises, used as additives, improves both the physical and mechanical properties of epoxy composites compared to the standard (control) material. The results of experiments have shown that the optimal content of additives of microsilica and microspheres provides an improvement in the physical and mechanical properties of epoxy composites in comparison with the standard (control) material. Studies have shown that the introduction of microspheres into ED-20 polymer increases impact toughness. The introduction of microsilica into the matrix contributes to the increase of elastic modulus. Experimental studies of optical properties of samples of carbon composite polymer films based on polystyrene (PS) with additives of carbon nanotubes C60 and C70 and multilayer carbon nanotubes were also carried out. The experimental results obtained for the optical properties of polymer composites based on basic polymers from solid waste and carbon nanotubes showed that the optical properties of polymer composites undergo noticeable changes. [ABSTRACT FROM AUTHOR]

Ethanol possesses high economic value, but as an industrial waste, it poses harm to human health and the environment. The paper describes the preparation of a thermoplastic polyurethane-poly(n-isopropylacrylamide) (TPU-PNIPAM) copolymer designed to selectively uptake alcohol in aqueous solution. The material was created by bonding TPU and PNIPAM together through intermolecular hydrogen bonds, enhancing its hydrophobic properties and making it easier to interact with alcohol molecules. As the amount of PNIPAM in TPU increases, the number of hydrophobic isopropyl groups in TPU-PNIPAM also increases, leading to an enhanced selective uptake ability of TPU-PNIPAM for alcohols in aqueous solution. When the temperature reaches 55 °C, the hydrophobic groups in TPU-PNIPAM are more exposed, further enhancing the selective uptake ability of TPU-PNIPAM for alcohols in aqueous solution. TPU-PNIPAM demonstrates selective preferential uptake for various concentrations and types of alcohol in aqueous solutions. The material's selective uptake performance for alcohols increases with their hydrophobicity, so TPU-PNIPAM exhibited the best adsorption performance for a 10 wt% n-propanol solution under the combined effect of steric hindrance. In addition, TPU-PNIPAM exhibited selective adsorption for other organic solvents, which demonstrated the universality of TPU-PNIPAM in removing contaminants from aqueous solutions. [ABSTRACT FROM AUTHOR]

The genus Trichoderma holds economic significance due to its widespread distribution and diverse applications, including biological control, enzyme production, and various biotechnological uses. The accurate identification of Trichoderma species is crucial given their close association with human activities. Despite previous efforts in classification, a comprehensive analysis combining morphological and molecular approaches is necessary. This study focuses on the isolation of four Trichoderma species from industrial wastewater in Pakistan, expanding on the known diversity in the region; isolation involved collecting samples from industrial wastewater effluents at specific sites in Punjab, Pakistan. Trichoderma strains were cultured and purified on solid media, with subsequent biomass production for bisorptional activity. Morphological characterization included colony features and microscopic examinations. DNA extraction, polymerase chain reaction (PCR), and sequencing of the internal transcribed spacer (ITS) region were conducted for molecular analysis. Phylogenetic analysis was performed using the Maximum Likelihood Algorithm. The study identified three Trichoderma species, viz. T. citrinoviride, T. erinaceum, and T. longibrachiatum. Each species was characterized morphologically and supported by molecular–phylogenetic analysis. Illustrations of microscopic features and a phylogenetic tree based on the ITS-nrDNA region were recorded. T. citrinoviride and T. longibrachiatum, isolated from steel mill and tanneries wastewater, respectively, were differentiated based on morphological characteristics such as phialides and conidia. The combination of morphological and molecular techniques enhances the accuracy of species identification. The study highlights the significance of Trichoderma in industrial wastewater environments and underscores the need for continued research in this area. Future research should focus on exploring the ecological roles and potential applications of the newly identified Trichoderma species. Additionally, further investigations into the biotechnological potential of these species, including enzyme production and bioremediation capabilities, would contribute to their practical applications. [ABSTRACT FROM AUTHOR]

Rarely has a chemical elicited as much controversy as dichloroacetate (DCA). DCA was initially considered a dangerous toxic industrial waste product, then a potential treatment for lactic acidosis. However, the main controversies started in 2008 when DCA was found to have anti-cancer effects on experimental animals. These publications showed contradictory results in vivo and in vitro such that a thorough consideration of this compound's in cancer is merited. Despite 50 years of experimentation, DCA's future in therapeutics is uncertain. Without adequate clinical trials and health authorities' approval, DCA has been introduced in off-label cancer treatments in alternative medicine clinics in Canada, Germany, and other European countries. The lack of well-planned clinical trials and its use by people without medical training has discouraged consideration by the scientific community. There are few thorough clinical studies of DCA, and many publications are individual case reports. Case reports of DCA's benefits against cancer have been increasing recently. Furthermore, it has been shown that DCA synergizes with conventional treatments and other repurposable drugs. Beyond the classic DCA target, pyruvate dehydrogenase kinase, new target molecules have also been recently discovered. These findings have renewed interest in DCA. This paper explores whether existing evidence justifies further research on DCA for cancer treatment and it explores the role DCA may play in it. [ABSTRACT FROM AUTHOR]

Obtaining natural pigments from microorganisms is an alternative with high potential for biotechnological application. The use of agro-industrial wastes as substrate for cultivations enables a reduction of the production cost and may add value to potentially polluting byproducts. In this work, the extraction of pigments produced by the bacterium Chryseobacterium sp. strain kr6 was evaluated, employing feather meal as the sole carbon source for bacterial growth. The maximum production of the yellow pigments was observed for cultivation at 30 °C, during 48 h, with 5 g/L feather meal. The pigment extraction from the bacterial biomass was performed with the aid of physical methods and the testing of different organic solvents. The conditions that provided better extraction were using ultrasound with acetone as the solvent, reaching a yield of 180 μg/g biomass after optimization. The pigment was partially characterized via UV-visible, FTIR and mass spectroscopy and CIELAB color parameters, suggesting the presence of molecules belonging to the flexirubin group (aryl polyenes). The antioxidant capacity of the pigment was confirmed via the scavenging of DPPH radical and thiobarbituric acid reactive substances (TBARS) methodologies. Moreover, the pigment extract showed antimicrobial activity against Staphylococcus aureus and Enterococcus faecalis. [ABSTRACT FROM AUTHOR]

The utilization of CO2 mineralization fly ash (F) and coal gangue (G) technology is proposed in this research work to prepare underground backfilling materials. The test process can be divided into pre-treatment and post-treatment stages. In the pre-treatment stage, a sealed stirring vessel is used to conduct CO2 wet mineralization. The ratios of F and G were selected as follows: 20%:60% (F2G6), 30%:50% (F3G5), 40%:40% (F4G4), 50%:30% (F5G3), and 60%:20% (F6G2). The ratios were prepared into Φ50 mm × 100 mm cylindrical samples, with curing durations of 3 d, 7 d, 14 d, and 28 d. In the post-processing stage, the SANS microcomputer-controlled electronic universal testing machine and FLIR A615 infrared thermal imager were used to carry out uniaxial loading and temperature detection, respectively. The unconfined compressive strength (UCS), X-ray diffraction (XRD), average infrared radiation temperature (AIRT), variance of original infrared image temperature (VOIIT), and variance of successive minus infrared image temperature (VSMIT) of the samples were compared and analyzed. The results indicated that when curing reaches 14 d, the strength approaches its peak, with minimal changes in strength over a delayed period; furthermore, as the ratio of F to G continues to increase, the mineralization effect gradually strengthens, reaching its optimum level at a ratio of 5:3. However, when the ratio exceeds 5:3, signs of deteriorating mineralization effect start to appear. During the loading process, the AIRT of the mineralized samples showed a continuous increase, but the VOIIT and VSMIT of the mineralized sample both exhibited significant fluctuations or rapid increases during damage rupture. Moreover, the rise in the AIRT value was found to be linked to the increase in the ratio of F to G. This indicates that F has a higher thermal–mechanical conversion efficiency compared to G, so the temperature change will be greater during the loading process. The drastic changes in the VOIIT and VSMIT indicate that they can be used as sensitive response indicators for sample rupture, and can predict and warn of damage rupture in mineralized samples. Research work can provide practical guidance and reference for underground backfilling of CO2 mineralization industrial waste. [ABSTRACT FROM AUTHOR]

Researchers have focused on deriving environmentally benign materials from biomass waste and converting them into value-added materials. In this study, cellulosic crystals derived from sugarcane bagasse (SCB) are augmented with magnetite (M) nanoparticles. Following the co-precipitation route, the composite was prepared, and then the mixture was subjected to a green microwave solvent-less technique. Various mass ratios of SCB:M (1:1, 2:1, 3:1, 5:1, and 1:2) were prepared and efficiently utilized as photocatalysts. To look at the structural and morphological properties of the prepared samples, X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), and elemental analysis were used to describe the composite fibers. SCB:M augmented with H2O2 as a Fenton reaction was used to eliminate Reactive blue 19 (RB19) from polluted water and was compared with pristine SCB and M. Additionally, the response surface methodology (RSM) statistically located and assessed the optimized parameters. The optimal operating conditions were recorded at pH 2.0 and 3:1 SCB: M with 40 mg/L and 100 mg/L of hydrogen peroxide. However, the temperature increase inhibits the oxidation reaction. The kinetic modeling fit showed the reaction following the second-order kinetic model with an energy barrier of 98.66 kJ/mol. The results show that such photocatalyst behavior is a promising candidate for treating textile effluent in practical applications. [ABSTRACT FROM AUTHOR]

Gd/Fe-SnO2 nanopowders as novel photocatalysts for the active removal of Rose Bengal dye and methyl parathion pesticide were synthesized with a low-cost coprecipitation route. The X-ray diffraction analysis of SnO2, Sn0.96Gd0.02Fe0.02O2 and Sn0.94Gd0.02Fe0.04O2 nanopowders proved the formation of a tetragonal phase of tin oxide with average crystallite sizes in the range of 13–18 nm. The Fourier transform infrared (FTIR) spectra of all samples displayed the characteristic absorption bands of SnO2. The nanopowder of the pure SnO2 sample, as seen in its transmission electron microscope (TEM) image, contains spherical-like particles of variable sizes. The TEM images of the Sn0.96Gd0.02Fe0.02O2 and Sn0.94Gd0.02Fe0.04O2 powders revealed the synthesis of fine spherical nanoparticles. Based on the TEM images, the average particle size of the pure, (Gd, 2 wt% Fe) and (Gd, 4 wt% Fe) codoped SnO2 nanopowders was estimated to be 14, 10 and 12 nm, respectively. After the addition of (Gd, 2 wt% Fe) and (Gd, 4 wt% Fe) to the SnO2 structure, the band gap energy of SnO2 was reduced from 3.4 eV to 2.88 and 2.82 eV, respectively. Significantly, the Sn0.96Gd0.02Fe0.02O2 nanocatalyst exhibited a high removal efficiency of 98 and 96% for Rose Bengal dye and methyl parathion pesticide after activation by sunlight for 35 and 48 min, respectively. Furthermore, this catalyst has shown perfect mineralization as well as high stability properties for the treatment of Rose Bengal dye and methyl parathion pesticide. These results suggest the suitability of the Sn0.96Gd0.02Fe0.02O2 nanocatalyst for the treatment of agriculture and industrial effluent under sunlight light energy. [ABSTRACT FROM AUTHOR]

Synthetic dyes, exceeding 100,000 types on the market and produced at a global scale of over 700,000 tons annually, are extensively used in the textile industry. This industry, a leading contributor to water contamination, relies on dyes like reactive, azo, anthraquinone, and triphenylmethane, resulting in substantial water usage and significant effluent generation. A significant modern challenge is the pollution caused by dye-mixed wastewater, releasing hazardous chemicals into water bodies and posing threats to ecosystems, plants, and human health. Traditionally, physicochemical techniques have addressed textile dye-containing wastewater, but their drawbacks, including cost, inefficiency, and potential secondary pollution, have steered attention towards biological alternatives. Utilizing microorganisms and enzymes, these biological methods, such as microbial cell enzyme immobilization, the biofilm technique, bioreactors, biofuel/bioelectricity production, and genetic engineering, have emerged as promising, cost-effective, and environmentally friendly solutions for efficient dye removal from wastewater. This review paper specifically highlights advanced biological techniques and emphasizes their efficacy in addressing the challenges posed by synthetic textile dyes. Through a systematic review of recent research papers, published results, and observations, this review paper provides insights into emerging biological treatment strategies for effectively removing synthetic textile dyes and contaminants from wastewater. [ABSTRACT FROM AUTHOR]

The high-temperature composite phase change materials (HCPCMs) were prepared from solid waste blast furnace slag (BFS) and NaCl-KCl binary eutectic salt to achieve efficient and cost-effective utilization. To ensure good chemical compatibility with chlorine salt, modifier fly ash (FA) was incorporated and subjected to high-temperature treatment for the processing of industrial solid waste BFS, which possesses a complex chemical composition. The HCPCMs were synthesized through a three-step process involving static melting, solid waste modification, and mixing–cold pressing–sintering. Then, the influence of the modification method and the amount of SiC thermal conductivity reinforced material on chemical compatibility and thermodynamic performance was explored. The results demonstrate that the predominant phase of the modified solid waste is Ca2Al2SiO7, which exhibits excellent chemical compatibility with chlorine salt. HCPCMs containing less than 50 wt.% chloride content exhibit good morphological stability without any cracks, with a melting temperature of 661.76 °C and an enthalpy value of 108.73 J/g. Even after undergoing 60 thermal cycles, they maintain good chemical compatibility, with leakage rates for melting and solidification enthalpies being only 6.3% and 0.23%, respectively. The equilibrium was achieved when 40 wt.% of chloride salt was encapsulated upon the addition of 10% of SiC, and the incorporation of SiC resulted in an enhancement of thermal conductivity for HCPCMs to 2.959 W/(m·K) at room temperature and 2.400 W/(m·K) at 200 °C, with an average increase of about 2 times. The cost of the prepared HCPCMs experienced a significant reduction of 81.3%, demonstrating favorable economic performance and promising prospects for application. The research findings presented in this article can offer significant insights into the efficient utilization of solid waste. [ABSTRACT FROM AUTHOR]

The use of economic instruments within environmental policy has become a challenging topic for policymakers, governments and scholars. Environmental taxes have emerged as a prevailing preference in developed countries to promote sustainability. Recently, a particular focus has been given to waste generation and disposal, shifting the attention from greenhouse gases to another important source of environmental pollution. This paper investigates the effect of national environmental taxes and policies on industrial waste. A fixed effects model is used for 34 countries across Europe from 2004 to 2022. The results suggest that environmental taxes and energy policies reduce industrial (hazardous and non-hazardous) waste. However, environmental tax reforms should take into consideration the deterioration in environmental quality, the increase in economic costs and undesirable social consequences. [ABSTRACT FROM AUTHOR]

Waste management is one of the many major challenges faced by all urban cities around the world. With the increase in population, the current mechanisms for waste collection and disposal are under strain. The waste management problem is a global challenge that requires a collaborative effort from different stakeholders. Moreover, there is a need to develop technology-based solutions besides engaging the communities and establishing novel policies. While there are several challenges in waste management, the collection of waste using the current infrastructure is among the top challenges. Waste management suffers from issues such as a limited number of collection trucks, different types of household and industrial waste, and a low number of dumping points. The focus of this paper is on utilizing the available waste collection transportation capacity to efficiently dispose of the waste in a time-efficient manner while maximizing toxic waste disposal. A novel knapsack-based technique is proposed that fills the collection trucks with waste bins from different geographic locations by taking into account the amount of waste and toxicity in the bins using IoT sensors. Using the Knapsack technique, the collection trucks are loaded with waste bins up to their carrying capacity while maximizing their toxicity. The proposed model was implemented in MATLAB, and detailed simulation results show that the proposed technique outperforms other waste collection approaches. In particular, the amount of high-priority toxic waste collection was improved up to 47% using the proposed technique. Furthermore, the number of waste collection visits is reduced in the proposed scheme as compared to the conventional method, resulting in the recovery of the equipment cost in less than a year. [ABSTRACT FROM AUTHOR]

Red mud (RM) is an industrial waste generated in the process of aluminum refinement. The recycling and reusing of RM have become urgent problems to be solved. To explore the feasibility of using RM in geotechnical engineering, this study combined magnesium oxide (MgO) (or calcium oxide (CaO)) with RM as an RM-based binder, which was then used to stabilize the soil. The physical, mechanical, and micro-structural properties of the stabilized soil were investigated. As the content of MgO or CaO in the mixture increased, the unconfined compressive strength (UCS) of the RM-based cementitious materials first increased and then decreased. For the soils stabilized with RM–MgO or RM–CaO, the UCS increased and then decreased, reaching a maximum at RM:MgO = 5:5 or RM:CaO = 8:2. The addition of sodium hydroxide (NaOH) promoted the hydration reaction. The UCS enhancement ranged from 8.09% to 66.67% for the RM–MgO stabilized soils and 204.6% to 346.6% for the RM–CaO stabilized soils. The optimum ratio of the RM–MgO stabilized soil (with NaOH) was 2:8, while that of the RM–CaO stabilized soil (with NaOH) was 4:6. Freeze–thaw cycles reduced the UCS of the stabilized soil, but the resistance of the stabilized soil to freeze–thaw erosion was significantly improved by the addition of RM–MgO or RM–CaO, and the soil stabilized with RM–MgO had better freeze–thaw resistance than that with RM–CaO. The hydrated magnesium silicate generated by the RM–MgO stabilized soil and the hydrated calcium silicate generated by the RM–CaO stabilized soil helped to improve the UCS of the stabilized soil. The freeze–thaw cycles did not weaken the formation of hydration products in the stabilized soil but could result in physical damage to the stabilized soils. The decrease in the UCS of the stabilized soil was mainly due to physical damage. [ABSTRACT FROM AUTHOR]

Some composite materials have been prepared, constituted by a cyclodextrin-bis-urethane-based nanosponge matrix in which a reduced graphene oxide/silver nanoparticles photocatalyst has been dispersed. Different chain extenders were employed for designing the nanosponge supports, in such a way as to decorate their hyper-cross-linked structure with diverse functionalities. Moreover, two different strategies were explored to accomplish the silver loading. The obtained systems were successfully tested as catalysts for the photodegradation of emerging pollutants such as model dyes and drugs. Enhancement of the photoactive species performance (up to nine times), due to the synergistic local concentration effect exerted by the nanosponge, could be assessed. Overall, the best performances were shown by polyamine-decorated materials, which were able to promote the degradation of some particularly resistant drugs. Some methodological issues pertaining to data collection are also addressed. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) is a type of polymer, which exists in various forms in the environment. Very few studies are available concerning the structure or enzymatic mechanism of the microbial community, which can degrade PU. Degradation of PU remains a difficult problem with respect to the environmental and biological disciplines. This study mainly focused on identifying the micro-organisms able to degrade polyurethane and confirming the degradation by performing a plate assay, Sturm test and scanning electron microscopy. Optimal culture conditions for maximum PU degradation were also analyzed through classical methods. A soil burial test was conducted by placing polyurethane films in the soil for one month, and the microbe growing on the surface of polyurethane films—with a maximum degradation of 55%—was isolated and identified as Aspergillus versicolor (ARF5). The culture medium was also optimized with different physical and chemical parameters for maximum PU degradation. The presence of CO2 as a by-product of PU biodegradation was confirmed through the Sturm test. [ABSTRACT FROM AUTHOR]

We have developed an innovative thin-film nanocomposite membrane that contains cellulose acetate (CA) with small amounts of TiO2-decorated graphene oxide (GO) (ranging from 0.5 wt.% to 2 wt.%) sandwiched between two polytetrafluoroethylene (PTFE)-like thin films. The PTFE-like films succeeded in maintaining the bulk porosity of the support while increasing the thermal and chemical robustness of the membrane and boosting the catalytic activity of TiO2 nanoparticles. The membranes exhibited a specific chemical composition and bonding, with predominant carbon–oxygen bonds from CA and GO in the bulk, and carbon–fluorine bonds on their PTFE-like coated sides. We have also tested the membranes' photocatalytic activities on azithromycin-containing wastewaters, demonstrating excellent efficiency with more than 80% degradation for 2 wt.% TiO2-decorated GO in the CA-GO-TiO2/PTFE-like membranes. The degradation of the azithromycin formulation occurs in two steps, with reaction rates being correlated to the amount of GO-TiO2 in the membranes. [ABSTRACT FROM AUTHOR]

The efficient utilization of waste heat from industrial processes can provide a significant source of energy savings for production plants, as well as be a driver of sustainable operations and the abatement of emissions. Industrial waste heat usually is contained in liquid or gaseous outlet streams. Although the possible ways to utilize waste heat are discussed in a wide variety of papers, these either provide only a general overview of utilization options and opportunities or focus on a narrow range of industrial processes. The aim of the present paper is to discuss the practical aspects of waste heat utilization in the European Union so that the reader can gain perspective on (i) the thermal classification of waste heat, (ii) liquid and gaseous waste streams and their typical temperatures for industrial use cases, (iii) the technical, economic, physical, and environmental aspects barring full utilization of the available waste heat, (iv) waste heat sources in various industries, and (v) standardized equipment and technologies applicable to industrial waste heat utilization, including their advantages, disadvantages, and weak points. [ABSTRACT FROM AUTHOR]

Sewage sludge and red mud, as common industrial waste, have become a research hotspot in the field of achieving carbon peaking and carbon neutrality, reducing carbon emissions, and solving environmental problems. However, their treatment and disposal have always been a difficult problem in the environmental field. Utilizing these two materials for thermal energy storage can not only improve energy utilization efficiency but also further reduce carbon emissions during their treatment process, providing a new approach for sustainable development in the industrial sector. This article summarizes the research progress for the resource recovery of sewage sludge and red mud for direct thermal energy recovery and composite phase change energy storage. After proper treatment, sludge and red mud can be directly used as energy storage materials. In addition, sludge and red mud can be combined with phase change materials to prepare composite materials with an excellent energy storage performance. This composite has broad application prospects in fields such as solar energy utilization and building energy efficiency. However, there are still some challenges and issues in this resource recovery and utilization, such as potential environmental pollution during the treatment process, the long-term stability of energy storage materials, and cost-effectiveness, which require further research and resolution. The purpose of this paper is to evaluate the potential of sewage sludge and red mud as energy storage materials, to explore their feasibility and advantages in practical applications, and to reveal the research progress, technical challenges, and future development directions of these two materials in the field of thermal energy storage. [ABSTRACT FROM AUTHOR]

The decarbonization and decentralization of district heating networks lead to the shared use of on-site resources by multiple stakeholders. The optimal design of prospective equipment in such contexts should take into account the preferences and objectives of each stakeholder. This article focuses on the adaptation of a 4E multicriteria model (the criteria being energy, exergy, economic, and exergoeconomic) to include and compare the stakeholders' performance criteria around the technical design. In addition, two graphical supports are proposed that represent and cross-analyze the different stakeholders' preferred optima. A preliminary implementation of the methodology is illustrated through a study case in France, which features waste heat recovery for district heating utilization. After presenting the results, a discussion is offered on how to complete the methodology with an iterative negotiation procedure to determine the most suitable design. It was concluded, among other considerations, that the relaxation of the stakeholders' optimality requirements can greatly enable the project's feasibility. Such a relaxation could be implemented in the form of a joint consortium. In addition, the results showed that stakeholder relaxations of requirements can lead to new solutions that may outperform the best solutions pre-relaxation. Lastly, perspectives are suggested toward verifying whether relaxed requirements from upstream stakeholders might be more impactful than those of downstream stakeholders. [ABSTRACT FROM AUTHOR]

Alkali-activated materials are gaining much interest due to their outstanding performance, including their great resistance to chemical corrosion, good thermal characteristics, and ability to valorise industrial waste materials. Reusing waste glasses in creating alkali-activated materials appears to be a viable option for more effective solid waste utilisation and lower-cost products. However, very little research has been conducted on the suitability of waste glass as a prime precursor for alkali activation. This study examines the reuse of seven different types of waste glasses in the creation of geopolymeric and cementitious concretes as sustainable building materials, focusing in particular on how using waste glasses as the raw material in alkali-activated materials affects the durability, microstructures, hydration products, and fresh and hardened properties in comparison with using traditional raw materials. The impacts of several vital parameters, including the employment of a chemical activator, gel formation, post-fabrication curing procedures, and the distribution of source materials, are carefully considered. This review will offer insight into an in-depth understanding of the manufacturing and performance in promising applications of alkali-activated waste glass in light of future uses. The current study aims to provide a contemporary review of the chemical and structural properties of glasses and the state of research on the utilisation of waste glasses in the creation of alkali-activated materials. [ABSTRACT FROM AUTHOR]

Metakaolin-based geopolymers have substantial potential as replacements for cement, but their relatively inferior mechanical properties restrict their application. This paper aims to enhance the mechanical properties of metakaolin-based geopolymers by incorporating appropriate amounts of calcium sources. CaCO3, Ca(OH)2, and CaSO4 are three types of calcium sources commonly found in nature and are widely present in various industrial wastes. Thus, the effects of these three calcium sources on the performance of metakaolin-based geopolymers were studied. Through the analysis of the mechanical properties, heat-release behavior during hydration, hydration products, and microstructure of geopolymers, the effectiveness of the aforementioned calcium sources in improving the performance of metakaolin-based geopolymer was evaluated, and the mechanisms of action were elucidated. The results indicate that the pozzolanic reaction between CH and MK could promote MK hydration and increase the proportion of CASH gel in the hydration products, thereby facilitating the setting of the geopolymer and enhancing its strength. CS could react with the active aluminates in MK to form ettringite, thus forming a higher early strength. CC had a lower reactivity with MK and does not improve the performance of MK-based geopolymers. [ABSTRACT FROM AUTHOR]

Biological wastewater treatment using trickle bed reactors is a commonly known and used solution. One of the key elements of the proper operation of the trickle bed bioreactor is the appropriate selection of biofilm support elements. The respective properties of the bioreactor packing media used can influence, among other things, the efficiency of the treatment process. In this study, the possibility of polyester waste material usage for the preparation of the biofilm support elements was tested. The following properties were checked: adsorption capacity, swelling, surface morphology, microbicidal properties, as well as the possibility of their use in biological wastewater treatment. The tested elements did not adsorb copper nor showed microbicidal properties for bacterial strains Escherichia coli and Staphylococcus aureus as well as fungal strains Aspergillus niger and Chaetomium globosum. The hydrophilic and rough nature of the element surface was found to provide a friendly support for biofilm formation. The durability of the elements before and after their application in the biological treatment process was confirmed by performing tests such as compressive strength, FTIR analysis, hardness analysis and specific surface area measurement. The research confirmed the applicability of the packing elements based on polyester textile waste to the treatment of textile wastewater. The treatment efficiency of the model wastewater stream was above 90%, while in the case of a stream containing 60% actual industrial wastewater it was above 80%. The proposed solution enables the simultaneous management of textile waste and wastewater treatment, which is consistent with the principles of a circular economy. The selected waste raw material is a cheap and easily available material, and the use of the developed packing elements will reduce the amount of polyester materials ending up in landfills. [ABSTRACT FROM AUTHOR]

To improve the in situ soil stabilization, different chemical additives are used (ion exchange compounds, additives based on H2SO4 or vinyl polymers, and organic additives using lignosulfonates). One interesting alternative is the production of additives from various waste materials. The extensive testing of waste-based blends with soil was performed; the mechanical (unconfined compressive strength (UCS)) and hydraulic (capillary rise, water absorption, and frost resistance (FR)) soil properties were measured. The optimization process led to obtaining additive compositions ensuring high strength and sealing properties: by-pass ash from the ceramics industry, waste H2SO4, pyrolytic waxes/oils from waste mixed plastics, waste tires and HDPE, and emulsion from chewing gum waste. For sandy soil, the following additives were the most promising: emulsion from pyrolytic wax (EPW) from waste PE foil (WPEF) with the addition of waste H2SO4, pyrolytic-oil emulsion from waste tires, EPW from waste mixed plastics with the addition of "by-pass" waste ash and NaOH, EPW from WPEF with the addition of NaOH, and EPW from WPEF reaching up to 93% FR, a 79.6% 7-day UCS increase, and a 27.6% of 28-day UCS increase. For clay: EPW from WPEF with the addition of NaOH, EPW from WPEF with the addition of waste H2SO4, and solely EPW from WPEF reaching up to 7.5% FR, an 80.7% 7-day UCS increase, and a 119.1% 28-day UCS increase. [ABSTRACT FROM AUTHOR]

In this paper, two flower-like magnesium silicate nanomaterials were prepared. These and another two commercial magnesium silicate materials were characterized using a scanning electron microscope, the N2 adsorption–desorption method, and other methods. The structure–activity relationship between the adsorption performance of these four magnesium silicate materials and their specific surface area, pore size distribution, and pore structure was compared. The results showed that the 3-FMS modified by sodium dodecyl sulfonate (SDS) had the largest specific surface area and pore size, the best adsorption performance, and the largest experimental equilibrium adsorption capacity (qe,exp) for Co2+, reaching 190.01 mg/g, and Cr3+, reaching 208.89 mg/g. The adsorption behavior of the four materials for Co2+ and Cr3+ both fitted the pseudo-second-order kinetic model and Langmuir adsorption model, indicating that chemical monolayer uniform adsorption was the dominant adsorption process. Among them, the theoretical adsorption capacity (qm) of 3-FMS was the highest, reaching 207.62 mg/g for Co2+ and 230.85 mg/g for Cr3+. Through further research, it was found that the four materials mainly removed Co2+ and Cr3+ through electrostatic adsorption, surface metal ions (Mg2+), and acidic groups (-OH and -SO3H) exchanging with ions in solution. The adsorption performance of two self-made flower-like magnesium silicate materials for Co2+ and Cr3+ was superior to that of two commercial magnesium silicates. [ABSTRACT FROM AUTHOR]

Low P-containing wastewaters (LPWs) exhibit huge P recovery potential, considering their larger volume. P recovery via CaP crystallization using apatite as seed is documented as being potentially well suited for LPWs. However, its responsible mechanisms remain a subject for debate. Taking hydroxyapatite (HAP) as the seed of LPWs, this paper conducted HAP adsorption/dissolution experiments, titration experiments, and P recovery experiments to distinguish the primary responsible mechanism. Results showed that it was HAP dissolution, not P adsorption, that occurred when the initial P concentration was no higher than 5 mg/L, ruling out adsorption mechanism of P recovery from LPWs using HAP as the seed. Significant OH− consumption and rapid P recovery occurred simultaneously within the first 60 s in titration experiments, suggesting CaP crystallization should be responsible for P recovery. Moreover, the continuous increase in P recovery efficiency with seed dosages observed in P recovery experiments seemed to follow well the mechanism of pre-nucleation ion clusters (PNCs) aggregation. During PNCs aggregation, P aggregates with Ca2+ quickly, generating CaP PNCs; then, CaP PNCs aggregate with seed particles, followed by CaP PNCs fusion, and ultimately transform into fines attached to the seed surface. PNCs' aggregation mechanism was further supported by a comparison of seed SEM images before and after P recovery, since denser and smaller rod-shaped fines were observed on the seed surface after P recovery. This study suggests that PNCs' aggregation is the dominant mechanism responsible for the recovery of P from LPWs via CaP crystallization using HAP as the seed. [ABSTRACT FROM AUTHOR]

The H 2 O 2 -assisted oxidation by a peroxidase enzyme takes place to help plants maintain the concentrations of organic compounds at physiological levels. Cells regulate the oxidation rate by inhibiting the action of this enzyme. The cells use two inhibitory processes to regulate the enzyme: a noncompetitive substrate inhibitory process and a competitive substrate inhibitory process. Numerous applications of peroxidase have been developed in clinical biochemistry, enzyme immunoassays, the treatment of waste water containing phenolic compounds, the synthesis of various aromatic chemicals, and the removal of peroxide from industrial wastes. The kinetic mechanism of the Spanish broom peroxidase enzyme is a Ping Pong Bi Bi mechanism with the presence of competitive inhibition by substrates. A mathematical model may help in identifying the key mechanism from amongst a set of competing mechanisms. In this study, we developed a fractional mathematical model to describe the H 2 O 2 -supported oxidation by the enzyme Spanish broom peroxidase. Numerical simulations of the model produced results that are consistent with the known behaviour of Spanish broom peroxidase. Finally, some future investigations of the study are briefly indicated as well. [ABSTRACT FROM AUTHOR]

A mixed metal oxide W-TiO2 nanopowder photocatalyst was prepared by using the sol–gel method with a broad range of elemental compositions x = CW/(CW + CTi), including TiO2 and WO3. The material was structurally characterized and evaluated in adsorption and photocatalytic processes by testing its removal capacity of a representative pollutant methylene blue (MB) in aqueous solutions and under UV-A and sunlight illuminations. The nanopowders appeared to be more effective adsorbents than pure TiO2 and WO3 materials, showing a maximum at 15 mol% W, which was set as the tungsten solubility limit in anatase titania. At the same time, the photocatalytic decomposition of MB peaked at 2 mol% W. The examination of different compositions showed that the most effective MB removal took place at 15 mol% W, which was attributed to the combined action of adsorption and heterogeneous photocatalysis. Moreover, MB decomposition under sunlight was stronger than under UV-A, suggesting photocatalyst activation by visible light. The pollutant removal efficiency of the material with 15 mol% W was enhanced by a factor of ~10 compared to pure TiO2 at the beginning of the process, which shows its high potential for use in depollution processes in emergency cases of a great pollutant leak. As a result, a Wx=0.15-TiO2 catalyst could be of high interest for wastewater purification in industrial plants. [ABSTRACT FROM AUTHOR]

The present work aimed to prepare novel bio-based composites by adding fillers coming from agro-wastes to an acrylate epoxidized soybean oil (AESO) resin, using liquid crystal display (LCD) 3D printing. Different photocurable formulations were prepared by varying the reactive diluents, iso-bornyl methacrylate (IBOMA) and tetrahydrofurfuryl acrylate (THFA). Then, two fillers derived from different industrial wastes, corn (GTF) and wine (WPL-CF) by-products, were added to the AESO-based formulations to develop polymer composites with improved properties. The printability by LCD of the photocurable formulations was widely studied. Bio-based objects with different geometries were realized, showing printing accuracy, layer adhesion, and accurate details. The thermo-mechanical and mechanical properties of the 3D-printed composites were tested by TGA, DMA, and tensile tests. The results revealed that the agro-wastes' addition led to a remarkable increase in the elastic modulus, tensile strength, and glass transition temperature in the glassy state for the systems containing IBOMA and for flexible structures in the rubbery region for systems containing THFA. AESO-based polymers demonstrated tunable properties, varying from rigid to flexible, in the presence of different diluents and biofillers. This finding paves the way for the use of this kind of composite in applications, such as biomedical for the realization of prostheses. [ABSTRACT FROM AUTHOR]

The mouth of the Tinto River is located on the southwest coast of the Iberian Peninsula in the northwest of the Gulf of Cadiz. The river flows into an estuarine system shared with the Odiel River, commonly known as the "Ría de Huelva". In the 1960s, a wide area of ancient salt marshes was transformed by a stockpile of industrial wastes of phosphogypsum, reaching a height of 35 m above the level of the salt marsh at its highest point. Two surveys using high-resolution seismic reflection in conjunction with a parametric profiler were carried out in 2016 and 2018. The purpose of these geophysical studies was the realization of a 3D model of the sedimentary units constituting the most recent filling of the estuary. The records present abundant extrusion structures located on the margins of the waste stockpiles, which break the visible stratification of the surficial units of the estuary. In some sectors, these structures have reached the estuarine surface and have, therefore, a morphological expression on the estuarine floor. The origin of these structures is interpreted as a vertical escape of fluidized sediments from lower units caused by overpressure from stacking. [ABSTRACT FROM AUTHOR]

To address the growing global water demand, it is imperative to implement advanced treatment systems and sustainable alternatives for managing the large amount of waste generated during the water purification process, known as water treatment sludge (WTS). Worldwide, researchers and companies are exploring alternatives and methods for the valorization of WTS as a raw material in other processes. It is urgent that all productive sectors, which contribute significantly to greenhouse gas emissions, adopt this management principle to ensure more sustainable production, contributing to the global goal of climate neutrality. Notably, in civil construction, incorporating WTS as a supplementary cementitious material (SCM) shows great promise, considering that the industrial waste currently used for this purpose is increasingly restricted. The use of WTS as a raw material in the cement industry not only contributes to the reduction of the carbon footprint, but also reduces the high waste load still disposed of in landfills. The emerging applications for WTP sludge are reviewed, with emphasis on its valorization in the civil construction as an SCM. The main characteristics of this waste and their impacts on the environment are also addressed. [ABSTRACT FROM AUTHOR]