Search Results (358)

Pharmaceuticals are emerging contaminants of global concern, but their occurrence and removal in semi-arid regions such as Algeria remain poorly documented. This study provides the first systematic evaluation of pharmaceutical and physicochemical parameters in two wastewater treatment plants (WWTPs) in Mascara: an activated sludge system (WWTP-1) and an aerated lagoon system (WWTP-2). Ten pharmaceuticals of different therapeutic classes were quantified using UPLC-HR-QTOF-MS in influent, effluent, and sludge samples, and removal efficiencies were compared using ANOVA and Principal Component Analysis (PCA). WWTP-1 showed higher efficiency, with >90% removal of COD, BOD₅, and ammonium, and near-complete elimination of sulfamethoxazole (99.9%) and atenolol (94%). In contrast, WWTP-2 achieved only moderate reductions (69% COD, 51% BOD₅) and low pharmaceutical removal, with negative efficiencies for persistent compounds such as carbamazepine, diclofenac, and ibuprofen. Weak correlations between macro- and micropollutants indicated that traditional indicators cannot predict pharmaceutical behavior. This work is the first to integrate physicochemical monitoring, pharmaceutical profiling, and multivariate analysis in Algerian WWTPs. The findings highlight the limitations of conventional treatment in semi-arid conditions and provide a critical baseline for adopting advanced technologies to mitigate pharmaceutical pollution in North Africa. Full article

Electronic nose (e-nose) systems have emerged as transformative tools for odor and gas analysis, leveraging advances in nanomaterials, sensor arrays, and machine learning (ML) to mimic biological olfaction. This review synthesizes recent developments in e-nose technology, focusing on innovations in sensor design (e.g., graphene-based nanomaterials, MEMS, and optical sensors), drift compensation techniques, and AI-driven data processing. We highlight key applications across healthcare (e.g., non-invasive disease diagnostics via breath analysis), food quality monitoring (e.g., spoilage detection and authenticity verification), and environmental management (e.g., pollution tracking and wastewater treatment). Despite progress, challenges such as sensor selectivity, long-term stability, and standardization persist. The paper underscores the potential of e-noses to replace conventional analytical methods, offering portability, real-time operation, and cost-effectiveness. Future directions include scalable fabrication, robust ML models, and IoT integration to expand their practical adoption. Full article

Second-, third-, and fourth-generation biofuels represent an important response to the challenges of clean energy supply and climate change. In this context, the Horizon 2020 “TO-SYN-FUEL” project aimed to produce advanced biofuels together with phosphorus from municipal wastewater sludge through a combination of technologies including a Thermo-Catalytic Reforming system, Pressure Swing Adsorption for hydrogen separation, Hydrodeoxygenation, and biochar gasification for phosphorous recovery. This article presents the environmental performance results of the demonstrator installed in Hohenberg (Germany), with a capacity of 500 kg per hour of dried sewage sludge. In addition, four alternative scenarios are assessed, differing in the source of additional thermal energy used for sludge drying: natural gas, biogas, heat pump, and a hybrid solar greenhouse. The environmental performance of these scenarios is then compared with that of conventional fuel. The comparative study of these scenarios demonstrates that the biofuel obtained through wood gasification complies with the Renewable Energy Directive, while natural gas remains the least sustainable option. Heat pumps, biogas, and greenhouse drying emerge as promising alternatives to align biofuel production with EU sustainability targets. Phosphorus recovery from sewage sludge ash proves essential for compliance, offering clear environmental benefits. Although sewage sludge is challenging due to its high water content, it represents a valuable feedstock whose sustainable management can enhance both energy recovery and nutrient recycling. Full article

Dye-contaminated wastewater has become one of the most severe environmental challenges due to the non-biodegradability and toxicity of synthetic dyes. While photocatalytic degradation is considered a green and efficient technology for wastewater purification, conventional TiO₂ suffers from limited light utilization and rapid electron–hole recombination. In this exploration, Ag-TiO₂-RGO nanocomposites were successfully fabricated and systematically investigated by XRD, SEM, TEM, XPS, Raman, and PL spectroscopy. The incorporation of Ag nanoparticles and reduced graphene oxide (RGO) synergistically improved charge separation and transfer efficiency. Photocatalytic activity was evaluated using different dyes as pollutants under visible light irradiation. Among the samples, Ag-TiO₂-RGO-3% exhibited the highest RhB degradation efficiency of 99.5% within 75 min, with a rate constant (K) of 0.05420 min⁻¹, which was nearly three times higher than that of pure TiO₂. The photocatalyst also showed excellent reusability with only minor efficiency loss after five cycles, and its activity remained stable across a wide pH range. Radical trapping experiments revealed that •O₂⁻ served as the dominant reactive species, with additional contributions from •OH and photogenerated holes (h⁺). A possible photocatalytic mechanism was proposed, in which Ag nanoparticles and RGO effectively suppressed electron–hole recombination and accelerated the formation of reactive oxygen species for efficient dye mineralization. These findings demonstrate that Ag-TiO₂-RGO-3% is a promising photocatalyst with high activity, stability, and environmental adaptability for wastewater remediation. Full article

Microbial electrosynthesis (MES) has emerged as a promising bio-electrochemical technology for sustainable CO₂ conversion into valuable organic compounds since it uses living electroactive microbes to directly convert CO₂ into value-added products. This review synthesizes advancements in MES from 2010 to 2025, focusing on the electrode materials, microbial communities, reactor engineering, performance trends, techno-economic evaluations, and future challenges, especially on the results reported between 2020 and 2025, thus highlighting that MES technology is now a technology to be reckoned with in the spectrum of biofuel technology production. While the current productivity and scalability of microbial electrochemical systems (MESs) remain limited compared to conventional CO₂ conversion technologies, MES offers distinct advantages, including process simplicity, as it operates under ambient conditions without the need for high pressures or temperatures; modularity, allowing reactors to be stacked or scaled incrementally to match varying throughput requirements; and seamless integration with circular economy strategies, enabling the direct valorization of waste streams, wastewater, or renewable electricity into valuable multi-carbon products. These features position MES as a promising platform for sustainable and adaptable CO₂ utilization, particularly in decentralized or resource-constrained settings. Recent innovations in electrode materials, such as conductive polymers and metal–organic frameworks, have enhanced electron transfer efficiency and microbial attachment, leading to improved MES performance. The development of diverse microbial consortia has expanded the range of products achievable through MES, with studies highlighting the importance of microbial interactions and metabolic pathways in product formation. Advancements in reactor design, including continuous-flow systems and membrane-less configurations, have addressed scalability issues, enhancing mass transfer and system stability. Performance metrics, such as the current densities and product yields, have improved due to exceptionally high product selectivity and surface-area-normalized production compared to abiotic systems, demonstrating the potential of MES for industrial applications. Techno-economic analyses indicate that while MES offers promising economic prospects, challenges related to cost-effective electrode materials and system integration remain. Future research should focus on optimizing microbial communities, developing advanced electrode materials, and designing scalable reactors to overcome the existing limitations. Addressing these challenges will be crucial for the commercialization of MES as a viable technology for sustainable chemical production. Microbial electrosynthesis (MES) offers a novel route to biofuels by directly converting CO₂ and renewable electricity into energy carriers, bypassing the costly biomass feedstocks required in conventional pathways. With advances in electrode materials, reactor engineering, and microbial performance, MES could achieve cost-competitive, carbon-neutral fuels, positioning it as a critical complement to future biofuel technologies. Full article

The galvanic industry requires considerable amounts of water and produces significant quantities of wastewater. Two types of wastewater are created in the processes of the galvanic application of metal coatings: used galvanic baths and wastewater generated while rinsing coated elements. The composition and amount of wastewater depend on the type of process, the plant’s operational system, and the quantity of water utilised to rinse the coated elements. In this article, the possibilities of using different techniques, such as chemical precipitation, coagulation and flocculation, ion exchange, adsorption, and membrane filtration, to remove heavy metals from galvanic wastewater were analysed and assessed. It was determined that the use of physicochemical methods (i.e., chemical precipitation, coagulation, and flocculation) to remove heavy metals has significant disadvantages, including operational costs connected with the purchase of chemical reagents and the emergence of metal complexes requiring management/utilisation. On the other hand, the processes of ion exchange and adsorption can be used only for wastewater characterised by a low heavy metal concentration, with organic matter preliminarily removed. In addition, waste polluted with heavy metals in the form of used regenerative baths and used sorbents is generated during these processes. In turn, the advanced techniques of membrane filtration allow for the removal of different types of organic pollutants and heavy metals. The processes of membrane wastewater treatment exhibit a range of advantages compared to traditional technologies, including the complete, environmentally friendly removal of permanent organic pollution, easy integration into conventional technologies, a limited amount of residue, a high level of separation, and a shorter process time. The efficiency of membrane wastewater treatment depends on many parameters, including, most of all, the composition, pH, and type of membrane, as well as process conditions. The possibility of using new types of membranes to remove heavy metals from spent galvanic baths was analysed, and the possibility of using the processes in wastewater treatment systems according to the circular economy model was assessed. The assessment of the efficiency of heavy metal removal in hybrid systems combining specific individual processes and the development of state-of-the-art material solutions to realise these processes may be an interesting direction of research in this field. Full article

Shale gas wastewater from hydraulic fracturing poses significant environmental risks due to its high salinity and complex inorganic composition. This study investigates the behavior of major and trace inorganic constituents across a full-scale treatment train in the Sichuan Basin, China. Despite multi-stage processes including equalization, flocculation, flotation, biological reactors, membrane filtration, and clarification, key inorganic species such as Cl, Na, Br, Sr, Li, and B remained largely persistent in the final effluent with values of 13,760, 8811, 70, 95.9, 26.6, and 60.2 mg/L, respectively. Geochemical tracers including Br/Cl (average: 0.0022 mM/mM), Na/Br (average: 125 mg/mg), and Sr/Ca (average: 0.15 mM/mM) ratios, combined with halide endmember mixing models, revealed that salinity primarily originated from highly evaporated formation brines, with limited evidence for halite dissolution or external contamination. Elevated Sr (average: 89.3 mg/L) and Ca (average: 274 mg/L) levels relative to Mg (average: 32 mg/L) suggest significant water–rock interaction. Environmental risk assessments showed that concentrations of several elements in treated effluent greatly exceeded national and international discharge or reuse standards. These findings underscore the limitations of conventional treatment technologies and highlight the urgent need for advanced processes and regulatory frameworks that address the unique challenges of high-TDS (total dissolved solids) unconventional wastewater. Full article

Conventional wastewater treatment plants (WWTPs) have limited efficiency in removing emerging pollutants (EPs), meaning these pollutants persist and lead to widespread ecological contamination. In this study, real effluents from a WWTP were characterized using TOC and Py-GC/MS, which indicated the presence of various organic compounds that could be indicative of micro-nanoplastics (MNPs) or plastics additives. To address this challenge, we propose the use of a photocatalytic membrane reactor (PMR) as an advanced treatment system capable of achieving high degradation efficiency under mild operating conditions. Preliminary experimental tests were conducted using various commercial photocatalysts (TiO₂, WO₃, Nb₂O₅), four UV lamps, and oxidants (air, O₂) using added Gemfibrozil (GEM) as a drug model compound. Real effluent samples collected from WWTP were tested with and without pretreatment to remove coarse particles prior to photocatalysis. Mineralization was achieved in both cases, but it occurred at a higher rate for the pretreated effluent. The mineralization of GEM and EPs in real effluent was achieved within five hours under UV irradiation using titanium dioxide (TiO₂) as a low-cost photocatalyst in a PMR. The results highlight the potential of photocatalytic systems, and particularly PMRs, as a promising technology for removing recalcitrant pollutants in real effluents offering a viable solution for improved environmental protection. Full article

This review concentrates on the bioactive potential of two significant agri-food by-products: coffee by-products (coffee pulp and husk, spent coffee grounds, and silverskin) and olive by-products (olive mill wastewater, pomace, stones, and leaves). These residues are produced in substantial quantities, and despite their considerable application potential, they remain predominantly underutilized, thereby contributing to environmental burdens and economic losses. Their richness in bioactive compounds is unequivocal. Specifically, coffee by-products are abundant in caffeine and chlorogenic acids, whereas olive by-products serve as excellent sources of oleuropein, hydroxytyrosol, and tyrosol. Such compounds possess health-promoting properties and are promising active ingredients for cosmetic formulations, owing to their antioxidant, anti-aging, UV protective, antimicrobial, emollient, and moisturizing effects. This review not only compiles the bioactive compounds present in these by-products and explores their potential applications but also examines the extraction methods employed for their recovery. Both conventional techniques (solvent extraction) and green extraction technologies (ultrasound-assisted extraction, microwave-assisted extraction, and supercritical fluid extraction) are discussed. These innovative and environmentally friendly approaches enhance extraction efficiency and are aligned with sustainability objectives. In this context, the importance of incorporating natural ingredients into cosmetic products is emphasized, both to meet regulatory and environmental standards and to satisfy the increasing consumer demand for safer, more effective, and environmentally sustainable formulations. Full article

The widespread presence of estrogens in aquatic environments represents a One Health concern, as it simultaneously threatens environmental integrity, wildlife health, and human well-being. These compounds, widely used in human and veterinary medicine, are excreted in partially or unmetabolized forms and persist in the environment due to the inefficiency of conventional water treatment systems in removing them. This systematic review provides a global overview of the occurrence of estrogens in water resources. We synthesized data on study characteristics, estrogen compounds detected, their concentrations, types of water bodies, and geographic locations. In total, 39 estrogens, including natural, synthetic, and metabolite forms, were reported at concentrations ranging from 0.002 to 10,380,000.0 ng/L across 40 water body types in 59 countries on all continents. The most frequently detected compounds were estrone, estradiol, and ethinylestradiol. Estrogens were predominantly identified in wastewater treatment plant effluents, rivers, lakes, surface waters, and even drinking water sources. These findings underscore the estrogen contamination and its potential to disrupt endocrine functions across species, posing serious implications for ecosystems. Within the One Health framework, this review highlights the urgent need for integrated strategies to improve water quality monitoring, develop advanced treatment technologies, and update regulatory standards to address the multifaceted risks posed by estrogenic contaminants. Full article

The persistence of antibiotics and antibiotic-resistant bacteria (ARB) in aquatic environments poses a significant risk to both the environment and public health. Conventional wastewater treatment systems are often inefficient in completely removing these emerging contaminants, highlighting the need for advanced and integrative treatment approaches. Electrocoagulation (EC) has emerged as a promising electrochemical method due to its operational simplicity, low chemical demand, and versatility in treating a wide range of wastewater types. This review critically analyzes the efficiency of EC, both as a standalone process and in combination with complementary technologies such as electrooxidation, membrane filtration, advanced oxidation processes (AOPs), and biological treatments. Emphasis is placed on the removal mechanisms, influencing parameters (pH, current density, electrode material), and the synergistic effects that enhance the degradation of antibiotics and the inactivation of ARB. Additionally, the review discusses the limitations of EC, including electrode passivation and energy consumption. The integration of EC with other technologies demonstrates improved pollutant removal and process robustness, offering a viable alternative for treating complex wastewater streams. This work provides a perspective on the current state and future potential of EC-based hybrid systems in mitigating the environmental impact of antibiotic pollutants and antimicrobial resistance. Full article

Sludge dewatering remains a resource-intensive process, often constrained by high residual moisture content and inefficient chemical conditioning. Conventional systems typically rely on fixed polymer dosages and predetermined filtration pressures, which are unable to respond to variations in sludge characteristics, resulting in inconsistent and suboptimal performance. In this study, a real-time control system for municipal wastewater sludge dewatering was developed to dynamically regulate coagulant dosing and filtration pressure based on continuous monitoring of critical sludge parameters, including total solids (TS), viscosity, sludge temperature, and pH change following coagulant addition. The control logic, derived from empirical correlations between sludge dewaterability metrics such as time-to-filter (TTF) and capillary suction time (CST) and operational variables, enables adaptive adjustment of polyoxyethylene alkyl ether (POAE) injection and pressing conditions. Implementation of this system achieved a final cake moisture content of approximately 63% after 60 min of filtration, substantially lower than the ~84% moisture observed under static conditions. Real-time flux feedback facilitated timely pressure escalation (from 15 to 20 bar to 25–30 bar), improving water removal efficiency while avoiding premature cake blinding. The pH drop (~0.7 units) post-polymer addition served as a practical indicator of adequate flocculation, supporting dose optimization and minimizing chemical waste. The proposed system demonstrated enhanced dewatering performance, reduced polymer consumption, and greater operational robustness compared to conventional approaches. These findings highlight the potential of integrated sensor-based control to advance sludge treatment technologies by promoting smarter, adaptive, and resource-efficient dewatering operations. Full article

Arsenic-containing wastewater and soil systems are a serious hazard to public health and the environment, particularly in areas where agriculture and drinking water depend on groundwater. Therefore, the removal of arsenic contamination from soil, water, and the environment is of great importance for human welfare. Most of the conventional methods are inefficient and have very high operational costs, especially for metals at low concentrations or in large solution volumes. This review delivers a comprehensive approach to arsenic remediation, including microbiological processes, phytoremediation, biochar technologies, bio-based adsorbents, and nanomaterial-assisted techniques. All of these methods are thoroughly examined in terms of removal competence, their mechanisms, environmental impact, cost-effectiveness, and scalability. Phytoremediation and microbial remediation techniques are self-regenerating and eco-friendly, whereas fruit-waste-derived materials and biochar provide abundant adsorbents, and are therefore low-cost. On the other hand, nanotechnology-based approaches show remarkable effectiveness but raise concerns regarding economic feasibility and environmental safety. Additionally, this review represents a comparative analysis and discusses synergistic and hybrid systems that combine multiple technologies for enhancing the remediation performance. Future research directions are emphasized along with challenges such as material stability, regeneration, and policy integration. This review aims to guide decision-makers, research scholars, and industry stakeholders toward affordable, sustainable, and high-performance arsenic remediation techniques for practical use. Full article

This review provides a critical and technically grounded assessment of continuous electrocoagulation processes (CEPs) for the treatment of industrial inorganic pollutants, emphasizing recent innovations, methodological developments, and practical outcomes. A comprehensive literature survey indicates that 53 studies published over the past 25 years have investigated CEPs for inorganic contaminant removal, with 36 focusing on standalone electrocoagulation systems and 17 exploring integrated CEPs approaches. Recent advancements in reactor design, such as enhanced internal mixing, optimized electrode geometry, and modular configurations, have significantly improved treatment efficiency, scalability, and operational stability. Evidence indicates that CEPs can achieve high removal efficiencies for a wide range of inorganic contaminants, including fluoride, arsenic, heavy metals (e.g., chromium, lead, nickel, iron), nitrates, and phosphates, particularly under optimized operating conditions. Compared to conventional treatment methods, CEPs offer several advantages, such as simplified operation, reduced chemical consumption, lower sludge generation, and compatibility with renewable energy sources and complementary processes like membrane filtration, flotation, and advanced oxidation. Despite these promising outcomes, industrial-scale implementation remains constrained by non-standardized reactor designs, variable operational parameters, electrode passivation, high energy requirements, and limited long-term field data. Furthermore, few studies have addressed the modeling and optimization of integrated CEPs systems, highlighting critical research gaps for process enhancement and reliable scale-up. In conclusion, CEPs emerge as a novel, adaptable, and potentially sustainable approach to industrial inorganic wastewater treatment. Its future deployment will rely on continued technological refinement, standardization, validation under real-world conditions, and alignment with regulatory and economic frameworks. Full article

This study presents a comprehensive analysis aimed at validating the use of an innovative nanosensor based on graphitic nanomembranes for the smart monitoring of industrial wastewater. The validation of the potential of the nanosensor was carried out through the development of advanced analytical methodologies, a direct experimental comparison with commercially available electrode sensors commonly used for the detection of chemical species, and the evaluation of performance under conditions very similar to real-world field applications. The investigation involved a series of controlled experiments using an organic pollutant—benzoquinone—at varying concentrations. Initially, data analysis was performed using classical linear regression models, representing a conventional approach in chemical analysis. Subsequently, a more advanced methodology was implemented, incorporating machine-learning techniques to train a classifier capable of detecting the presence of pollutants in water samples. The study builds upon an experimental protocol previously developed by the authors for the nanomembranes, based on electrochemical impedance spectroscopy. The results clearly demonstrate that integrating the nanosensor with machine-learning algorithms yields significant performance. The intrinsic properties of the nanosensor make it well-suited for potential integration into field-deployable platforms, offering a real-time, cost-effective, and high-performance solution for the detection and quantification of contaminants in wastewater. These features position the nanomembrane-based sensor as a promising alternative to overcome current technological limitations in this domain. Full article