This study aims to investigate the preparation of zeolite-based geopolymer composites incorporating blast furnace slag at various temperatures and varying amounts of blast furnace slag as potential sustainable building and construction materials. The primary objectives were to use mining waste streams for geopolymer production and assess the mechanical behavior of these hybrid geopolymers, along with performing a life cycle assessment (LCA) to compare their environmental impact with conventional concrete. It was observed that the hybrid geopolymers attained a maximum mechanical strength of 40 MPa. Remarkably, substituting just 20% of the material with blast furnace slag resulted in a 92% improvement in compressive strength. To assess environmental impacts, a cradle-to-gate LCA was performed on different geopolymer mix designs, focusing particularly on the global warming potential (GWP). The results indicated that geopolymer concrete generated a maximum of 240 kg CO₂-e/m³, which was 40% lower than the emissions from ordinary cement, highlighting the environmental advantages of geopolymer materials. Further, X-ray diffraction was used to determine the mineral composition of both raw and developed composites. Solid-state nuclear magnetic resonance (NMR) was applied to study the molecular structure changes upon incorporating blast furnace slag. The initial setting time and shrinkage of the geopolymers were also investigated. Morphological characteristics were analyzed by scanning electron microscopy (SEM). Thermal analyses confirmed the stability of the geopolymers up to 800 °C. Geopolymer composites with high thermal stability can be used in construction materials that require fire resistance. This study not only enhances the understanding of geopolymer composite properties but also confirms the substantial environmental advantages of utilizing geopolymerization in sustainable construction.

Ardabil Plain, which holds significant political and economic importance in agricultural production in Iran, has faced various challenges including climate change, economic sanctions, and limited access to global trade. Ensuring food security has become a key priority for the region. The main objective of this research is to identify a suitable crop for this critical region with regard to future climate change conditions. This study employs a new framework of the system dynamics model (SDM) and the Hybrid Weighted Averaging (HWA) method to assess the Water–Energy–Food (WEF) nexus and resource sustainability in the Ardabil Plain under different climate change scenarios (RCP 2.6, RCP 4.5, and RCP 8.5). The research addresses current and future water challenges, emphasizing the need for additional energy and selecting optimal crops. Using the SDM, the study analyzes the impact of water supply fluctuations on agriculture, economic gain, and energy consumption from 2021 to 2050. The results indicate that barley is the most suitable crop for the Ardabil Plain in the near future, based on the overall ranking derived from the HWA method, which is as follows: barley > wheat > soybeans > potatoes > pears. The study highlights the significant challenges in energy supply for agriculture due to declining water levels and the increased force required by pumps to supply water to farms. These findings provide valuable insights for policymakers and stakeholders to make informed decisions in addressing water scarcity and rising energy demands in the Ardabil Plain.

Water scarcity is a growing global issue, especially in arid regions like Iran. Global food trade complicates water and food resource management by moving virtual water (the water used to produce goods) between regions. This study uses circular economy principles and life cycle assessment (LCA) to analyze virtual water use across income groups in Iran, focusing on food consumption. This study divided households into three groups: economically vulnerable, middle-class, and affluent. Lower-income households are more water-efficient, using 3.33 L per USD, compared with 0.81 L for middle-class and 0.41 L for affluent households. The per capita virtual water consumption was 3916.7 L for vulnerable groups, 3481.6 L for middle-class, and 3418 L for affluent groups—all higher than the global average. This is because they rely on low-water foods like bread and legumes. Additionally, affluent households consume 80% more red meat, which has a high water footprint. The study calls for policies to promote water-conscious diets, optimize virtual water trade, and integrate sustainability into LCA frameworks. Aligning resource management with circular economy goals can help Iran improve water security and sustainable development.

This study explores the fabrication, structural characteristics, and performance of an innovative porous geopolymer membrane made from waste natural zeolite powder for Pb(II) removal, with potential applications in wastewater treatment. A hybrid geopolymer membrane incorporating polyvinyl acetate (PVAc) (10, 20, and 30 wt.%) was synthesized and thermally treated at 300 °C to achieve a controlled porous architecture. Characterization techniques, including Fourier-transform infrared spectroscopy (FTIR), revealed the disappearance of characteristic C=O and C-H stretching bands (~1730 cm⁻¹ and ~2900 cm⁻¹, respectively), confirming the full degradation of PVAc. Thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) indicated a total mass loss of approximately 14.5% for the sample with PVAc 20 wt.%, corresponding to PVAc decomposition and water loss. Energy-dispersive spectroscopy (EDS) elemental mapping showed the absence of carbon residues post-annealing, further validating complete PVAc removal. X-ray diffraction (XRD) provided insight into the crystalline phases of the raw zeolite and geopolymer structure. Once PVAc removal was confirmed, the second phase of characterization assessed the membrane’s mechanical properties and filtration performance. The thermally treated membrane, with a thickness of 2.27 mm, exhibited enhanced mechanical properties, measured with a nano-indenter, showing a hardness of 1.8 GPa and an elastic modulus of 46.7 GPa, indicating improved structural integrity. Scanning electron microscopy (SEM) revealed a well-defined porous network. Filtration performance was evaluated using a laboratory-scale dead-end setup for Pb(II) removal. The optimal PVAc concentration was determined to be 20 wt.%, resulting in a permeation rate of 78.5 L/(m²·h) and an 87% rejection rate at an initial Pb(II) concentration of 50 ppm. With increasing Pb(II) concentrations, the flux rates declined across all membranes, while maximum rejection was achieved at 200 ppm. FTIR and EDS analyses confirmed Pb(II) adsorption onto the zeolite-based geopolymer matrix, with elemental mapping showing a uniform Pb(II) distribution across the membrane surface. The next step is to evaluate the membrane’s performance in a multi-cation water treatment environment, assessing the sorption kinetics and its selectivity and efficiency in removing various heavy metal contaminants from complex wastewater systems.

Per- and polyfluoroalkyl substances (PFASs) are persistent and mobile contaminants of global concern, and, while granular activated carbon (GAC) is widely used for their removal, it is limited by the high regeneration and disposal costs. This study investigates surface-modified clinoptilolite zeolites as low-cost and thermally regenerable alternatives to GAC for PFAS removal from water. Natural clinoptilolite was modified through acid washing, ion exchange with Fe³⁺ or La³⁺, grafting with aminosilane (APTES) or hydrophobic silane (DTMS), dual APTES + DTMS grafting, and graphene oxide coating. The adsorption performance was evaluated for perfluorooctanoic acid (PFOA, C8) and perfluorobutanoic acid (PFBA, C4) at 100 µg L⁻¹ in single- and mixed-solute systems, with an additional high-concentration PFOA test (1 mg L⁻¹). PFAS concentrations were quantified by liquid chromatography–tandem mass spectrometry (LC–MS/MS) using a SCIEX 7500 QTRAP system coupled to a Waters ACQUITY UPLC I-Class. Raw zeolite showed limited PFOA removal (4%), whereas dual-functionalized APTES + DTMS zeolites achieved up to 93% removal, comparable to GAC (97%) and superior to single-silane or metal-exchanged variants. At lower concentrations, modified zeolites effectively removed PFOA but showed limited PFBA removal (<25%), highlighting ongoing challenges for short-chain PFASs. Overall, the results demonstrate that dual-functionalized clinoptilolite zeolites represent a promising and scalable platform for PFAS remediation, particularly for mid- to long-chain compounds, provided that strategies for enhancing short-chain PFAS binding are further developed.