Fares Almomani

The increasing global energy demand, driven by industrialization, population growth, and technological advancements, has led to unprecedented energy consumption levels and significant environmental...

Reliable evaluation of membranes for hypersaline desalination requires an integrated assessment of selectivity, transport behaviour and operational stability. This study develops a four-test diagnostic framework combining water-activity calculations, permeate ionic ratios, final-period flux analysis, and hydraulic and thermal characterisation. The framework is applied to electrospun polystyrene (PS), PS membranes containing polytetrafluoroethylene (PTFE) particles, and commercial PTFE and polyethylene membranes in direct contact membrane distillation of synthetic brines containing 37.8 and 75.7 g L⁻¹ total dissolved solids. Water-activity calculations establish a predicted salinity-related flux reduction of 2.5–5% under the assumed membrane-surface conditions, providing a baseline for interpreting measured flux ratios and temporal behaviour. Final-period analysis resolves start-up effects, yielding commercial PTFE C1/C2 flux ratios of 0.47–0.84. Most PS specimens exhibit low permeate ionic concentrations and chloride-based apparent rejection of 99.987–99.9975%, whereas feed-like ionic ratios in commercial PTFE permeates indicate liquid-feed carryover. Flux–flow exponents of 0.33–0.35 highlight the contribution of external heat transfer. Water-breakthrough pressures of 1.7–7.0 psi and a storage-modulus decrease at 35–55 °C identify priorities for reinforcement and thermal stabilisation. The framework connects separation performance with operating constraints, supports meaningful membrane comparisons, and guides the development of reproducible PS membranes with high selectivity and improved operational robustness.

Decarbonizing the petroleum and hydrogen industries is essential to climate goals, yet conventional amine scrubbing faces high energy consumption, degradation, and toxicity. This critical review evaluates deep eutectic solvents (DESs) as a next-generation capture platform, offering generally lower toxicity, negligible vapor pressure, and tunable properties; however, these environmental and economic benefits remain uncertain given inconsistent life cycle assessment boundaries and limited pilot-scale data (Sections 8, 10). We bridge molecular design to process-scale engineering, providing a roadmap for implementation. Amine-functionalized DESs achieve CO2 capacities of 0.5–1.35 mol/mol, with life cycle assessments showing 40–60% lower eutrophication and toxicity impacts than MEA. However, high viscosity impedes industrial adoption, keeping DESs at low Technology Readiness Levels (TRL 2–4). Future work should prioritize viscosity reduction (<50 mPa·s), standardized benchmarking, and pilot-scale demonstrations to translate DES technology from a laboratory concept toward industrial decarbonization.

Polymeric membranes are key materials for environmental separation processes because their chemistry, porosity, wettability, and processability can be tailored for wastewater reclamation and brine concentration. In hypersaline direct contact membrane distillation (DCMD), however, membrane performance cannot be assessed reliably from initial flux or salt rejection alone. Long-term operation is controlled by coupled effects of brine concentration, water recovery, organic fouling, surfactant exposure, crystallization, pore wetting, and cleaning resistance. This study develops a quantitative descriptor-based framework for benchmarking polymeric membranes under hypersaline DCMD conditions. We aim to convert complex membrane performance into clear measurable indicators so different membranes can be compared on the same basis. Electrospun polystyrene, commercial polyethylene, and porosity-dependent polystyrene datasets are analyzed together with recent studies on PTFE, PVDF, Janus, omniphobic, slippery-coated, and embedded-interface polymer membranes. Four operational descriptors—Brine Severity Index, Normalized Flux Retention, Apparent Flux Decline Rate, and Recovery-Weighted Stability Factor—are combined with mechanistic indicators, including liquid entry pressure and XDLVO interfacial free energy, to relate polymer membrane architecture to stability under brine-stress conditions. The analysis shows that high initial flux, high salt rejection, and static contact angle are insufficient predictors of long-term membrane durability. Conventional single-layer hydrophobic membranes may perform well initially, but their stability decreases sharply under high recovery, mixed organic–inorganic fouling, surfactant exposure, and crystallization. Engineered polymer interfaces improve recovery-weighted stability by limiting scale intrusion, low-surface-tension wetting, foulant adhesion, and irreversible flux decline. The results also show that operating temperature, hydrodynamics, scale-mitigation cycling, and clean-in-place reusability must be evaluated together with membrane structure. The proposed framework provides a quantitative basis for comparing polymeric membranes beyond isolated flux values and supports descriptor-guided design of durable porous polymer membranes for hypersaline wastewater reclamation, brine concentration, and zero-liquid-discharge applications.

Food waste valorization through Anaerobic Digestion (AD) represents a sustainable and circular approach to managing organic residues by converting them into valuable bioenergy and biobased products. Despite a growing body of literature on food waste AD, a critical methodological gap persists in which existing reviews largely treat reactor-level performance, life cycle assessment (LCA), and techno-economic analysis (TEA) as discrete fields, leaving the spreading of high-rate reactor uncertainties into integrated LCA/TEA scaling decisions largely unresolved. This review directly bridges that gap by systematically linking process-level performance metrics to sustainability and economic outcomes within a cohesive analytical framework. The biochemical composition of food waste is examined first, emphasizing carbohydrate, protein, and lipid content influence digestion efficiency and methane yields. Recent technological advancements in high-rate digestion systems are critically analyzed, including Upflow Anaerobic Sludge Blanket (UASB), Expanded Granular Sludge Bed (EGSB), and Internal Circulation (IC) reactors with particular attention to operational bottlenecks such as granule stability, inhibitory compound accumulation, and scale-up constraints that limit real-world performance relative to laboratory benchmarks. Two-stage AD (TSAD) configurations and membrane bioreactor (MBR) innovations are assessed for their capacity to enhance CH₄ yields and improve biomass retention, though at the cost of increased capital expenditure and process complexity. Substrate pretreatment strategies are assessed for their effectiveness in enhancing biodegradability and biogas production by 25–80%, combined with the energy penalties and reagent costs that frequently offset these gains on a commercial scale. These process-level trade-offs are carried forward into a structured synthesis of co-digestion approaches are examined for synergistic benefits. Whereas LCA studies confirm that AD reduces environmental impacts across multiple impact categories relative to landfilling and incineration. Critically, TEA findings reveal that economic viability remains sensitive to feedstock heterogeneity. The integration of AD within sustainable food systems supports nutrient recovery, decentralized waste management, and renewable energy generation. However, realizing these co-benefits at scale requires resolving constant uncertainties in digestate quality standards, gate fee structures, and carbon accounting methodologies from most TEA framework. Thus, these findings advance the transition toward a circular bioeconomy by providing a coherent, critically grounded framework that connects high-rate reactor design to real-world sustainability performance.

Sulfur dioxide (SO₂), hydrogen sulfide (H₂S), ammonia (NH₃), and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), all IARC-classified or WHO-priority hazardous air contaminants, are generated by medical waste incineration under environmentally relevant field conditions. This study presents the first AERMOD-based comparative dispersion assessment of these pollutants from three operational incinerators in Qatar (multi-chambered, controlled air, rotary kiln) at Al Wakrah Municipality (25.17°N, 51.60°E), using 10 years of site-specific AERMET meteorological data. Pre-operational baseline monitoring confirmed PM₁₀ exceedances of WHO 2021 guidelines (193–259 µg/m³; factor 4.3–5.8×) due to regional aeolian dust, with PCDD/Fs below detection limits at all six receptor stations. AERMOD simulations across 18 receptors, three stack configurations (15–30 m height; 1–3 m diameter) and four capacity levels (150–500 kg/h) revealed a consistent emission hierarchy: rotary kiln > controlled air > multi-chambered. Rotary kiln 1-hour SO₂ peaked at 67.2 µg/m³ at the 15 m stack, exceeding the WHO 2021 24-hour guideline of 40 µg/m³. Increasing stack height to 30 m reduced peak SO₂ by 82%, restoring compliance across all incinerator types. Spatial hotspot analysis identified schools and a hospital within the primary downwind exposure corridor driven by Qatar's prevailing northwest shamal winds. Qatar's regulatory framework currently prescribes no minimum stack height for medical waste incinerators; this study provides the quantitative basis for a mandatory 30 m minimum.