Environmental Progress & Sustainable Energy最新文献

In order to solve a major environmental concern, this analysis highlights the potential of synthetic biodegradable polymers for wastewater color removal. Because of their biodegradability, environmental compatibility, and adjustable qualities, the study intends to investigate the effectiveness of polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHA), poly ε-caprolactone (PCL), polybutylene succinate (PBS), and poly (lactic-co-glycolic acid) (PLGA). Techniques for synthesis and modification are described in depth, including copolymerization, ring-opening polymerization, polycondensation, biomimetic synthesis, and surface modifications such as chemical functionalization and nanostructuring. Adsorption mechanisms, including physical interactions, chemical interactions, and ion exchange, are discovered, highlighting the effectiveness of polymers for adsorbent with different dyes such as Azo, Anthraquinone, reaction, acid, and basic color. Research shows the effectiveness of these polymers by adsorbent kinetics and balanced model. Future research guidelines include the development of new polymers, integrated advanced materials and nanotechnology, optimizing adsorption processes, and promoting long-term methods. These trends are aimed at improving performance, selection, and environmental sustainability of general biodegradation polymers, providing a promising and environmentally friendly solution to pollute dyes in wastewater, finally protecting the environment and human health.

Open-field burning of paddy straw and husk is a major environmental issue in India, driving efforts to use these residues as renewable co-firing feedstocks in thermal power plants. This review synthesizes recent findings on the combustion behavior, fly ash formation, and valorization potential of paddy straw and coal blends, focusing on their compositional variability and operational implications. The study examines how variations in feedstock composition (notably SiO₂, K₂O, CaO, and Cl contents), pelletization parameters, and blending ratios impact fly ash fusion characteristics, slagging and fouling tendencies, emission formation, and power plant efficiency. Strategies such as additive use (kaolin, dolomite), controlled blending, and selection of coal types rich in alumina or sulfur are analyzed for their role in mitigating corrosion and deposit formation. Furthermore, the review examines the agricultural and construction reuse of CFA (co-fired fly ash), highlighting its potential as a supplementary cementitious or soil amendment material when applied under controlled conditions. Additionally, operational aspects such as downstream impacts on electrostatic precipitator (ESP) performance and fly ash handling efficiency are evaluated to provide a comprehensive perspective on system-level implications. Furthermore, the review highlights key research priorities, including pellet quality control, regional straw variability, supply chain logistics, and fly ash conveying performance, that warrant further investigation. The review offers operational guidance for utilities and policymakers aiming to scale co-firing while maintaining boiler reliability and facilitating safe, value-added fly ash reuse. It also highlights the research priorities necessary to ensure the technical feasibility and long-term sustainability of integrating biomass into coal-fired systems.

In this paper, the heterostructure of Ag₃PO₄/BiOBr was synthesized by chemical deposition. The degradation rates of MO and MG in Ag₃PO₄/BiOBr-2 (B2AP) reached 93.33% and 89.16% within 35 and 6 min, and the degradation kinetic rate constants were 3.47 and 1.17 times higher than those of pure Ag₃PO₄, and B2AP still maintained good catalytic activity after 4 cycles. BiOBr nanosheets are attached to the surface of Ag₃PO₄ nanoparticles, which increases the reactive site and improves the light utilization efficiency. Through free radical trapping experiments, it was determined that the main active substances for the degradation of MO were ·O₂⁻ and h⁺. After a series of characterization and photoelectrochemical experiments, a new possible photocatalytic mechanism of Z-type heterojunction Ag₃PO₄/BiOBr photocatalyst was proposed.

This study investigates the synthesis and applications of magnesium oxide nanoparticles (MgO NPs) using the sol–gel method. X-ray diffraction (XRD) confirmed a cubic crystalline structure with an average crystallite size of 22.53 ± 3.42 nm. Scanning electron microscopy (SEM) showed spherical nanoparticles with sizes ranging from 40 to 60 nm, with a mean diameter of 56.52 nm. Optical analysis showed a direct bandgap of 3.12 eV and a UV absorption peak at 308 nm. Fluorescence spectra revealed emission peaks at 408, 445, and 478 nm, attributed to oxygen vacancies. The MgO NPs demonstrated excellent photocatalytic activity, degrading 99.82% of Malachite Green dye in 120 min under sunlight (k = 0.02763 min⁻¹). They also removed 98.75% of cadmium ions in 120 min (k = 0.01695 min⁻¹) and exhibited stable adsorption for copper and lead over five cycles. In CO₂ conversion, the NPs produced 63 μmol/g methane and 58 μmol/g hydrogen in 4 h, with a hydrogen production rate of 1034 μmol·g⁻¹·h⁻¹. Photoelectrochemical tests showed stable photocurrent response. These findings highlight MgO NPs' potential for wastewater treatment, heavy metal removal, CO₂ conversion, and hydrogen production, demonstrating their high effectiveness for environmental and energy applications.

The primary by-product of coal-burning industries and thermal power plants is flyash (FA). Heavy metals and trace elements present in the FA pose a significant disposal problem. Due to its enormous availability and favorable physicochemical properties, it has multiple applications, including environmental remediation, construction utilities and agricultural activities. The review elaborates on the origin, chemical composition, improper disposal methods, and ecological and environmental hazards of FA, focusing on the sustainable management of water pollution through adsorption. The major factors influencing adsorption and the most recent developments in FA modification techniques are also covered. Through the present application, one can deal with the concurrent problems of FA disposal and water pollution management, thereby addressing the concepts of the circular economy. Unmodified FA has adsorption capacities of 10–250 mg/g for different heavy metals and 2–100 mg/g for dyes, while modified and composite forms that contain magnetic nanoparticles, zeolites, and biochar have adsorption capacities of 1000–1500 mg/g. The adsorption efficiency increases three to six times as a result of modifications, demonstrating the potential of engineered FA-based adsorbents in wastewater treatment. Future advancements in novel surface modification methods of FA could improve its surface area, adsorption capacity, and selectivity for various contaminants, thereby enhancing its adsorption efficiency.

Despite its amazing properties, which include high purity (free from lignin and hemicellulose), excellent mechanical strength, a nanofibrillar 3D network with high crystallinity, high water-holding capacity, good thermochemical stability, biocompatibility, non-toxicity, and biodegradability, the commercial applications of bacterial nanocellulose (BNC) remain limited due to its higher production costs and limited productivity. To address this, the current study investigated rice straw hydrolysate (RSH) as a cost-effective substitute for an expensive carbon source. The rice straw was pretreated with 2% sodium hydroxide, followed by enzymatic hydrolysis, forming a hydrolysate containing reducing sugars (29.37 ± 0.4 g/L). The BNC production by utilizing RSH medium was later optimized by employing the BBD (Box–Behnken design). Under optimized conditions (such as pH 6, RSH: water (1:1), and 32.5°C incubation temperature), the BNC yield after 2 weeks of incubation reached 6.26 ± 0.05 g/L, which is considerably higher than yields reported from other lignocellulosic feedstocks by Acetobacter hansenii. The resulting BNC films were characterized by using SEM, XRD, and FTIR, and their structural and physicochemical characteristics were compared to BNC produced in standard Hestrin-Schramm (HS) medium. SEM study verified the characteristic nanocellulose fibrillar 3D network, XRD analysis exhibited peaks conforming to the cellulose I structure, and FTIR spectra discovered absorption bands representative of BNC-specific functional groups. Overall, the use of RSH medium did not substantially affect the fundamental properties of BNC, apart from minor alterations. These results suggest that rice straw hydrolysate holds promise as an economical and sustainable substrate for industrial-scale BNC production.

This study presents a satellite-based analytical framework that integrates Nitrogen Dioxide (NO₂) observations from Sentinel-5P/Tropospheric Monitoring Instrument (TROPOMI) with meteorological variables (temperature and humidity) from Moderate Resolution Imaging Spectroradiometer (MODIS) and wind speed data from Gridded Surface Meteorological Dataset (GRIDMET) to assess air pollution dispersion near bio refinery sites. The framework uses Long Short-Term Memory (LSTM) neural networks enhanced with Time2Vec temporal encoding to forecast NO₂ concentrations across three Saudi Arabian cities—Al Riyadh, Al Jubail, and Najran—using daily measurements collected between August 2018 and April 2023. Data preprocessing includes cloud masking through Google Earth Engine (GEE) quality-control filters, kriging-based interpolation for meteorological variable alignment, and min–max normalization. The Time2Vec-LSTM model achieves a mean absolute error of 41.57 μg/m³ for Al Riyadh, with a Root Mean Square Error (RMSE) of 54.44 μg/m³ and a Mean Absolute Percentage Error (MAPE) of 33.07%, representing a 2.8% improvement over the baseline LSTM. Spatiotemporal analysis indicates distinct seasonal variations, with peak NO₂ concentrations during winter (attributed to increased heating emissions) and minimum levels during summer (due to enhanced atmospheric dispersion). Overall, the proposed framework addresses monitoring gaps in regions with limited ground-based air quality networks and offers valuable decision-support capabilities for environmental policy development and sustainable urban planning.

The Wadi El-Rayan depression, a protected area in Egypt's Western Desert southwest of Cairo, contains two man-made lakes that serve as reservoirs for agricultural wastewater while supporting fisheries and irrigation. This study assessed their water quality, including heavy metals and microbiological parameters, using the Water quality index (WQI) and heavy metal pollution indices to evaluate suitability for aquatic life. Microbiological analysis found that total coliform, fecal coliform, and fecal streptococci levels at most sites were within acceptable limits for aquatic organisms. The Upper Lake demonstrated fair water quality (WQI = 52–78), while the Lower Lake was of medium quality (WQI = 50–66) and exhibited higher total dissolved solids. Heavy metal pollution was also more pronounced in the Lower Lake. The primary threat to the Upper Lake is effluent from the El-Wadi Drain, which degrades water quality through intensive agricultural discharge. The Lower Lake faces additional ecological stress from a shrinking surface area due to agricultural encroachment and sand dunes. To prevent further degradation, immediate actions, such as optimizing water allocation and establishing a robust water quality monitoring program for the lakes and the drain, are critical. This study underscores the potential for effective water resource conservation and calls for an integrated effort among policymakers, industries, and communities to ensure a sustainable water future.

With rapid industrialization, the environmental challenges of industrial solid waste demand urgent solutions. This study develops a novel composite environmental material (PSEM) via mechanochemical activation of phosphogypsum (PG) and slag. The influence of PSEM mix ratios on the solidification of hexavalent chromium [Cr(VI)]-contaminated soil was investigated through particle size analysis, unconfined compression tests, volume shrinkage, and toxicity leaching assessments, supported by Brunauer–Emmet–Teller (BET), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and x-ray photoelectron spectroscopy (XPS) characterizations. Mechanochemical activation significantly reduced PSEM particle size and enhanced reactivity. At a slag-to-PG ratio of 1:1.2, compressive strength reached 3.927 MPa, volume shrinkage stabilized at 0.388%–2.530%, and Cr(VI) leaching declined to 0.137 mg/L. The solidified matrix exhibited mesoporous structures with increased surface area, while Cr(VI) was immobilized through chemical substitution and physical encapsulation. These findings demonstrate the potential of PSEM for Cr(VI) stabilization and promote the sustainable utilization of PG.