https://aet.irost.ir/ Advances in Environmental Technology en daily 1 Wed, 01 Jul 2026 00:00:00 +0330 Wed, 01 Jul 2026 00:00:00 +0330 https://aet.irost.ir/article_1671.html Industrial effluents have emerged as a critical environmental challenge due to limited water resources, their toxic nature, and carcinogenic properties. Therefore, it is essential to treat industrial wastewater and eliminate toxic pollutants. This study focuses on synthesizing nanocrystals of zeolite imidazole frameworks (ZIF-8) by doping with iron to create a porous ZnFe/ZIF-8 (ZFZ) composite using a green method (water solvent) to enhance performance and synergistic effects. The morphology of ZFZ nanocrystals was analyzed using a variety of complementary characterization techniques (Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM)). The ZFZ and ZIF-8 were assessed for the removal of Direct Red 23 (DR-23) dye from wastewater by varying the effective variables (pH, dye dosage, initial concentration, an(d contact time). For comparative analysis, ZIF-8 was also synthesized and used in conjunction with ZFZ to remove the DR-23 dye. The results demonstrated that ZFZ possesses a significantly higher adsorption capacity (383 mg/g) for DR-23 than ZIF-8 (94.79 mg/g), representing a fourfold enhancement. At a contact time of 120 minutes, the ZFZ composite achieved a maximum removal efficiency of 92.3% with 0.006 g of adsorbent at pH 3. Analysis of the equilibrium adsorption data for anionic dyes confirmed a strong alignment with the Langmuir model (R² = 0.99), consistent with a homogeneous, monolayer adsorption process. Additionally, the adsorption mechanism on ZFZ and ZIF-8 composites followed second-order kinetics with R² = 0.99. These findings confirm that synthesized ZFZ is an efficient adsorbent for the remediation of dye-contaminated wastewater. https://aet.irost.ir/article_1676.html The treatment of high-strength wastewater generated from fermented rice noodle production poses significant environmental challenges due to its elevated organic load, acidity, and nitrogen content. This study investigated the optimization of wastewater treatment using Effective Microorganisms (EM), focusing on the effects of initial wastewater pH (6–8) and EM dosage (1–10% v/v) on Chemical Oxygen Demand (COD) and Total Kjeldahl Nitrogen (TKN) removal efficiency. A Central Composite Design (CCD) within the framework of Response Surface Methodology (RSM) was employed to model and analyze the interactive effects of these operating parameters. The results demonstrated that near-neutral pH (6.9) and a low EM dosage (1.2% v/v) yielded the highest COD removal efficiency (80.21%), whereas an alkaline pH (8.0) with a low EM dosage (1% v/v) resulted in the maximum TKN removal efficiency (75.18%). Statistical analysis revealed that EM dosage significantly impacted COD removal (p < 0.0001), while initial pH had a more pronounced effect on TKN removal (p < 0.0001). The quadratic regression model exhibited strong predictive performance for both COD (R² = 0.9827) and TKN (R² = 0.9326) removal. The findings further indicate that COD removal is predominantly governed by biologically regulated microbial metabolism, whereas TKN removal is controlled mainly by pH-driven physicochemical pathways. Overall, the EM application optimized through RSM represents a promising and sustainable strategy for enhancing the simultaneous removal of organic matter and nitrogen from wastewater generated by the fermented rice noodle industry. https://aet.irost.ir/article_1675.html This study explores the photocatalytic degradation of Rhodamine B (RhB) under sunlight irradiation using Cu2Cr-LDH/BiOCl and Cu2Cr-LDH/TiO2 nanocomposites. The structural, optical, and morphological properties of the materials were thoroughly examined by X-ray diffraction (XRD), Ultraviolet–visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The primary objective was to assess the photocatalytic efficiency of these nanocomposites in degrading RhB dye under sunlight. The Cu2Cr-LDH/BiOCl nanocomposite exhibited superior photocatalytic performance, achieving 90.29 % RhB degradation, significantly outperforming Cu2Cr-LDH/TiO2 (56.45%) and pure Cu2Cr-LDH (31.36%). This enhanced efficiency is attributed to the formation of a heterojunction between Cu2Cr-LDH and BiOCl, which facilitates effective separation and transfer of charge carriers. The improved photocatalytic activity is primarily attributed to the well-dispersed BiOCl phase on the Cu₂Cr-LDH surface, demonstrating that interfacial architecture plays a more critical role than simply increasing the Bi or Ti content. Hydroxyl radicals and holes were determined to be the primary active species responsible for the degradation process. Additionally, both nanocomposites demonstrated remarkable stability and reusability, retaining high catalytic efficiency over four consecutive cycles. A detailed photocatalytic mechanism was proposed to explain the enhanced activity of the nanocomposites, highlighting the synergistic effects of the heterojunction structure and efficient charge carrier dynamics. https://aet.irost.ir/article_1673.html This research explores the production of spherical activated carbon derived from glucose using the combination of a hydrothermal process followed by chemical impregnation with hydrogen peroxide (H2O2), citric acid (CA), and acrylic acid (AA), and pyrolysis. The adsorption performances, kinetics, and thermodynamics of the synthesized materials were compared with those of the material without chemical impregnation using batch experiments. Boehm titration and Fourier-transform infrared spectroscopy (FTIR) confirmed an increase in oxygen-containing functional groups (carboxyl, lactone, and phenol), facilitating adsorption through electrostatic interaction, reduction, and complexation. Adsorption kinetics and isotherm modeling confirmed that the process adhered to the Elovich model and the Redlich-Peterson or Langmuir isotherm, suggesting chemisorption dominance. Among the materials tested, AA-modified activated carbon (AC-AA) exhibited the highest adsorption capacity of 244 mg/g, outperforming previously studied biochar-based adsorbents. Kinetic and thermodynamic assessments demonstrated that Cr(VI) adsorption was spontaneous (ΔG<0), endothermic (ΔH>0), and entropy-favored (ΔS>0). Notably, the study elucidates the concurrent adsorption and reduction of Cr(VI) to Cr(III) at low pH, driven by electron transfer from surface functional groups. Moreover, NaOH was identified as the most effective desorption agent, underscoring the potential for material regeneration and reuse. This research highlights the potential application of glucose-based carbon spheres with functionalized surfaces as a sustainable, cost-effective solution for Cr(VI) removal in industrial wastewater treatment. https://aet.irost.ir/article_1681.html Nowadays, immobilized photocatalyst clay beads have attracted considerable research interest due to their outstanding properties, including enhanced stability, easy recovery and reuse, and reduced secondary pollution. In this study, novel titanium dioxide/zinc oxide composites were synthesized via the sol–gel method and immobilized on clay beads using the dip-coating process. Various titanium dioxide/zinc oxide ratios were used to obtain different composites. For the immobilization procedure, four titanium dioxide/zinc oxide layers were coated on clay beads, dried in the oven at 100°C for 30 min, and subsequently calcined at 2°C/min up to 500°C. The coated beads were characterized using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Photocatalytic degradation experiments were conducted to test their performance using methylene blue as a model pollutant. The highest methylene blue degradation efficiency was achieved with pure titanium dioxide-coated clay beads. All titanium dioxide/zinc oxide composites maintained their photocatalytic performance after five consecutive recyclability experiments. This work aims to demonstrate a reproducible, scalable, and economic immobilization procedure for single and composite photocatalysts on clay beads with outstanding photocatalytic performances for wastewater treatment. https://aet.irost.ir/article_1684.html This study investigated the complex relationships among environmental factors in coastal settings and identified potential sources of microplastics in tropical coastal and river sediments within a non-industrial urban area. The research was conducted along the northern coast of Aceh, Indonesia, encompassing two river estuaries: the Krueng Aceh and Krueng Lamnyong. The results indicate that land use, population density, and distance from the river estuary influence the distribution of microplastics in coastal sediments. The Krueng Aceh River, which is associated with a higher population density, exhibited greater levels of microplastic contamination than the Krueng Lamnyong River. The formation of estuarine turbidity maxima (ETM) is considered a key factor controlling microplastic distribution along the Krueng Aceh River, whereas distribution patterns in the Krueng Lamnyong River appear to be more strongly influenced by local anthropogenic activities and environmental conditions. The study area is distinctive because, despite the absence of major industrial sources, identifying microplastic origins remains complex. In coastal zones, tourist sites tend to exhibit lower microplastic abundances, likely due to stricter waste management practices, whereas non-tourist areas show higher levels of contamination. This study provides new insights into the distribution and potential sources of microplastics in tropical non-industrial urban environments and offers a foundation for developing more effective mitigation strategies for microplastic pollution. https://aet.irost.ir/article_1682.html Due to increasing environmental concerns and requirements, the adoption of modern heating methods is strongly recommended. The microwave-based system has attracted considerable attention due to its efficiency, low carbon footprint, low energy consumption, and short process timing. Our studies on microwave heating for synthesizing cobalt and various alloys showed a significant need for novel predictors to model microwave heating processes. This paper is novel in its evaluation of the performance of outstanding numerical methods for solving microwave-based reactions in both kinetic and environmental aspects. As a case study, the experimental results related to the reaction of cobalt metal oxide with syngas under microwave heating were compared to the orthogonal collocation outcomes, and outstanding results were reported with a mean error lower than 5%. The emissions from a microwave and an electrical furnace, based on kinetic values, were also compared. To evaluate numerical methods for different types of reactions in the mentioned microwave heating process, the governing equations from the modeling of gas-solid catalyzed reactions with different reaction orders were solved using the perturbation and orthogonal collocation methods. The environmental analysis demonstrated that the microwave process offered notable environmental and operational advantages over the furnace process, including significantly faster CO removal, more controllable CO₂ emissions, higher energy efficiency, and a reduced overall carbon footprint by possibly reducing energy consumption. https://aet.irost.ir/article_1686.html This study assesses the landfill gas (LFG) production potential in Saveh City, Iran, utilizing the Landfill Gas Emissions Model (LandGEM) to estimate methane and other emissions based on the area’s waste characteristics, environmental factors, and projected waste volumes. Saveh’s landfill is expected to see increasing waste production, driven by urban population growth and economic expansion, with waste quantities rising from 150 tons daily in 2014 to over 175 tons by 2030. Given the semi-arid climate, methane generation is influenced by limited moisture, with waste moisture content typically between 20-30%. Methane and overall landfill gas emissions are projected to peak by the year 2035, aligning with the landfill’s maximum waste capacity. Environmental impacts associated with methane’s high global warming potential, along with health risks from non-methane organic compounds (NMOCs) such as benzene, underscore the need for emission control measures. Recommended strategies include methane capture for energy recovery, enhanced waste diversion programs to reduce organic input, leachate recirculation to optimize moisture, and NMOC treatment to mitigate air quality concerns. This analysis provides a framework for managing Saveh’s landfill emissions effectively, contributing to climate and health protection goals. Additionally, sensitivity analyses highlight how parameter adjustments, such as increased moisture or waste composition changes, could enhance methane recovery. The study demonstrates the importance of localized data in refining LFG models like LandGEM for accurate emission forecasting in specific environments. https://aet.irost.ir/article_1689.html In the present research, a magnetic nanostructure based on graphene oxide and iron oxide modified by the amino acid tryptophan was synthesized. The properties of the adsorber were determined using a Fourier transform infrared spectrometer, elemental analysis, X-ray diffraction, scanning electron microscope, and vibrating-sample magnetometer. Optimum parameters such as pH, contact time, amount of used adsorbent, initial concentration of copper ions, and the effect of temperature were investigated. Adsorption isotherm studies were conducted using the Langmuir and the Freundlich models, in which the Langmuir isotherm model was more consistent in the adsorption process. The theoretical maximum adsorption capacity of the adsorbent is 125 mg of copper per gram of adsorbent, which is close to the maximum adsorption capacity of the adsorbent in the real state (118 mg of copper per gram of adsorbent). To investigate the thermodynamics of adsorption, the Van't Hoff Equations were used, the results of which indicate that the adsorption process is endothermic. Meanwhile, the removal rate of copper ions from the real wastewater sample in the presence of other ions was determined to be 46%.