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Microbial fuel cells (MFCs) use the metabolic actions of microorganisms in an anode chamber to convert the chemical energy from wastewater into electrical energy. To improve the MFC power generation performance and chemical oxygen demand (COD) removal efficiency, Stenotrophomonas acidaminiphila was added to the anode chamber of a dual-compartment MFC. In this process, Stenotrophomonas acidaminiphila promotes the degradation of macromolecules such as bis(2-ethylhexyl) phthalate in food waste oil. Additionally, the generated electrical energy reduced Cu 2+ in the copper-containing wastewater in the cathode chamber to Cu monomers. The maximum power density of the MFC was 49.5 ± 3.5 mW/m 2 , the maximum removal efficiencies of COD and Cu 2+ were 63.5 ± 5.8% and 96.5 ± 1.0%, respectively, and Cu 2+ was reduced to brick-red Cu monomers. This study provides insights into the simultaneous implementation of food waste oil treatment and metal resource recovery.

This study proposes an efficient ex situ remediation method combining leaching with electrochemical treatment for Pb(II)-contaminated fine-grained soil. During the leaching stage, citric acid (CA) was identified as the optimal leaching agent, with the optimal washing conditions determined as: 0.1 mol/L CA (pH 3), liquid-to-solid ratio of 10, and a duration of 3 h. Under these conditions, the Pb(II) removal rate of 17.21% was achieved. Crucially, electrochemical enhancement was implemented during the filtration phase using a custom-designed vertical apparatus operated under constant current mode (2–4 mA/cm²), significantly improving remediation efficacy. Orthogonal experiments revealed current density as the dominant factor influencing Pb(II) removal. The optimal parameters (P 3 T 20 I 3 ) were: pressure of 0.57 MPa, electric field initiation at 20% before the filtration-threshold time point (36 min), and current density of 3 mA/cm². This integrated approach achieved a remarkable Pb(II) removal rate of 70.1% within 3 h, representing a fourfold increase compared to single-stage leaching. Morphological analysis of Pb(II) in soil samples post leaching and electrochemical remediation, conducted using the BCR sequential extraction method, revealed that the Pb(II) fractions removed in the regions near both the cathode and anode were predominantly in the exchangeable (F1) and reducible (F2) states, with a smaller proportion in the oxidizable (F3) state. This indicates that the remediation treatment successfully reduced the mobility and bioavailability of the heavy metal, thereby diminishing its environmental impact. This combined remediation technology offers advantages of short duration and operational simplicity, enabling the deep removal of pollutants exceeding environmental standards in soil.

Depending on the end of use, the quality of biogas must be upgraded in order to utilize the maximum amount of energy necessary for proper applications. Upgrading biogas refers to the increase of methane concentration in product gas by removal of CO 2 , which increases its heating power. Several treatment technologies are available for biogas upgrading: high pressure water scrubbing (HPWS), pressure swing adsorption, membrane separation, chemical absorption, and gas permeation. Water absorption based on the physical effect of dissolving gases in liquids (HPWS) is a well-known technology and the most effective upgrading process, since provides a simultaneous removal of CO 2 and H 2 S. This could ensure an increasing methane concentration and energy content per unit volume of biogas. In spite of this, few studies are published on biogas upgrading using pressurized water technology. In order to elucidate the performance of HPWS technology at industrial scale with the possibility of water regeneration and recirculation, effects of different operating parameters on the removal of undesired components from biogas were examined, based on modeling and simulation tools. For simulation, the commercial software tool Aspen Plus was applied. Equilibrium model was applied for simulating the absorption process. The simulation results were validated with experimental data from the literature. The results are summarized in terms of system efficiency, expressed as CH 4 enrichment, methane loss, and CO 2 removal. Finally, new data which can be further applied for scale-up calculations and techno-economic analysis of the HPWS process are provided.

A membrane composed of polyethylene terephthalate nanofiber and multi-walled carbon nanotubes (PET NF-MWCNTs) composite is used to adsorb methylene blue (MB) dye from an aqueous solution. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction techniques are employed to study the surface properties of the adsorbent. Several parameters affecting dye adsorption (pH, MB dye initial concentration, PET NF-MWCNTs dose, and contact time) are optimized for optimal removal efficiency (R, %) by using the Taguchi L25 (54) Orthogonal Array approach. According to the ANOVA results, pH has the highest contributing percentage at 71.01%, suggesting it has the most significant impact on removal efficiency. The adsorbent dose is the second most affected (12.08%), followed by the MB dye initial concentration of 5.91%, and the least affected is the contact time (1.81%). In addition, experimental findings confirm that the Langmuir isotherm is well-fitted, suggesting a monolayer capping of MB dye on the PET-NF-MWCNT surface with a maximum adsorption capacity of 7.047 mg g−1. Also, the kinetic results are well-suited to the pseudo-second-order model. There is a good agreement between the calculated (qe) and experimental values for the pseudo-second-order kinetic model.

Floating treatment wetlands are new ecological infrastructures for stormwater treatment. Despite a recent proliferation in their usage, their contaminant removal efficiency e continues to draw research attention. Here, the e from idealized FTWs is numerically computed across a wide range of flow and geometric conditions while accommodating joint contributions of advection, turbulent dispersion, and vegetation removal. The emerging mathematical structure describing e bears resemblance to a simplified plug flow model and supports an empirical shallow-basin model from long-term field measurements. The present model indicates that e remains significantly influenced by a Dämkohler number that quantifies the effects of both vegetation and flow properties. The impacts on e of the underflow region and contaminant blockage on the removal mechanisms are also investigated.

Plant species diversity could enhance plant productivity and pollutant removal efficiency in constructed wetlands (CWs). However, the potential importance of plant density for ecosystem functioning has largely been neglected. In this study, we conducted a factorial experiment in which three common plant species were planted in a gradient of species richness (one, two, and three) and seven species compositions at two densities (six and twelve individuals per microcosm). Plant total biomass and total organic carbon (TOC) and total inorganic nitrogen (TIN) removal efficiency were measured to explore the effect of plant species diversity and density on the ecosystem functioning of CWs. Results showed that (1) plant species richness had no significant effect on plant total biomass and TOC and TIN removal efficiency under high and low plant density. (2) There were significant differences in TIN removal efficiency among seven species compositions under low plant density; especially, the presence of Canna indica reduced the TIN removal efficiency. In contrast, species composition and species identity had no significant effect on ecosystem functioning under high plant density. (3) High plant density increased plant total biomass of C. indica monocultures, and also enhanced TIN removal efficiency in mixtures of two species. These results indicated C. indica alone may not be an ideal species for enhancing pollutant removal in constructed wetlands but planting at high density could mitigate its negative effect on ecosystem functioning.

The dye effluents released from the textile and printing industries contain strong colorants, inorganic salts, and other toxic compounds. The conventional coagulation technique of dye effluent treatment is plagued with issues of low removal rate of color, generation of large quantities of sludge, and toxic end-products. Recently electrocoagulation technique gained immense attention due to its high efficiency. This technique involves the dissolution of the sacrificial anodes to provide an active metal hydroxide as a strong coagulant that destabilizes the pollutants and removes them by precipitation or flocculation. This study is about the efficiency of the electrocoagulation process using titanium coated - aluminum and mild steel electrodes to treat industrial dye wastewater. Effects of parameters such as current density & initial dye concentration were investigated. It was observed that, for the same current density, electrode consumption was higher with TiO2/Al electrode than with mild steel electrode, resulting in more color removal efficiency (CRE) using TiO2/Al electrode. The settling rate of the flocs was higher in the rector having TiO2/Al electrode at the 100 mL with current density (2.5 mL.min-1 to 5.3 mL.min-1), while in the reactor with mild steel electrode, the settling rate was very less. The results showed that dye removal was 95.11% and 92.1% for mild steel and titanium-coated electrodes, respectively. It was observed that 50 % of Aluminum was removed from the treated effluent after the final stage of filtration. Based on the multicriteria analysis to identify the optimum operational parameters to be applied at the field level, it was observed that maximum CRE may be obtained with TiO2/Al electrode and the applied current of 1 Amps with a flow rate of 100 mL.min-1. It can be concluded that electrocoagulation is a highly efficient and the fastest method to treat dye effluents from industries.

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.

Due to a lack of water treatment technology, developing and emerging nations have become significant polluters and water shortage is exacerbated by pollution. Ammonium toxicity is a huge global environmental concern with no clear solution. Population growth and industrialization destroy the ecosystem. Common and industrial products contain ammonium ions. Water pollution damages fish and other aquatic life. An inexpensive and green wastewater treatment method is adsorption. Adsorbent polymers that remove ammonium ions from wastewater have been explored. Ammonium ions are very hazardous when deposited into surface waters. Surfaces of bentonite and montmorillonite clay may attach sodium ammonium ions. They are cheap and abundant, therefore used to treat drain water. Bentonite outperformed montmorillonite in eliminating ammonium ions from water. Bentonite and montmorillonite clays were used to remove residual ammonium ions. These are utilized for bentonitic and montmorillonitic clays. Both clays were absorbed in a neutral pH, and it was free of sulfuric acid, ammonium ions, and phosphorus ions. Montmorillonitic clay boosted TDS by nearly 10% whereas bentonitic clay only raised TDS by 1%. Adsorption may inexpensively filter water and the surface charge of adsorbents affect their adsorption capacity. Ammonium ions may be recycled, and several bioreactors can remove ammonium ions from liquid and solid phases. Iterate over several models and the Freundlich isotherm model outperforms the Langmuir model by 5%. And bentonite clay adsorbs better due to iron oxide content.

Constructed wetlands are viable alternatives for the removal of multiple pollutants. The performance of Sagittaria latifolia in free flowing and subsurface wetlands in removing pollutants from domestic waters was evaluated. 12 wetlands will be followed, three free with species and three without species, three subsurface with species and three without species, with retention times of 6.7 days for the free and 3.5 days for the subsurface. The subsurface with species presented an effluent with turbidity of 4.4±0.8 NTU, color of 143.9±27.4 UC and 33.9±25.7 mgL-1 of COD. The free samples with species presented turbidity of 10.1±2.8 NTU, color of 346.3±87.0 UC and 74.7±30.0 mgL-1 of COD. The wetland with the best performance was the subsurface with species, eliminating turbidity, color, and COD in 95.9, 89.4, 95.7% respectively, obtaining a COD kinetic coefficient of 0.34 (free flow) and 0.89 days-1 (subsurface).