Applied Water Science最新文献

Recovery/extracting of a combination of lead (Pb(II)) and vanadium (V(V)) ions from wastewater has been enhanced by an emulsion liquid membrane with the presence of magnesium oxide (MgO) or aluminum oxide (Al₂O₃) nanoparticles (20–50 nm size range) in the internal/stripping phase (W1) and ionic liquid ([OMIM] PF6) in the organic/oil phase (O). The study found that the recovery/extraction batch time was shortened, enhancing emulsion extraction efficiency and stability. Furthermore, the study outcomes extend the ELM separation techniques to industrial-scale pollutant recovery/extraction applications, especially heavy metal ions, from industrial effluent. The percentage of Pb(II) recovery/extraction was increased significantly within three minutes when adding 0.01% (w/w) of MgO or Al₂O₃ nanoparticles separately with 5% (v/v) ([OMIM]PF6) ionic liquid achieving 95.8 and 94.6%, respectively. The recovery/extraction percentage of V(V) significantly improved to 98.6% within three minutes by adding 0.01% (w/w) of MgO nanoparticles. The percentage extraction reached 97.7% when adding 0.01% (w/w) of Al₂O₃ nanoparticles in the presence of 5% (v/v) ([OMIM]PF6) in both cases. The emulsion stability was noticeably enhanced, resulting in a 16% leakage after more than three days.

In response to increasing global water scarcity, reclaimed water, which is treated wastewater intended for reuse, has become a sustainable alternative for various applications. However, the presence of pharmaceutical residues that persist through conventional treatment processes raises concerns for environmental and human health. In this study, a direct injection liquid chromatography tandem mass spectrometry (DI-LC–MS/MS) method was developed and applied to quantify 75 pharmaceutical compounds in secondary and tertiary effluents from 14 wastewater treatment plants in Costa Brava, Catalonia. Among the compounds analyzed, metformin, tramadol, and azithromycin were the most abundant, with median concentrations above 1000 ng L⁻¹. The method demonstrated acceptable sensitivity, recovery, and matrix effect values for most analytes. Comparison of concentrations in secondary and tertiary effluents showed that tertiary treatment significantly improved removal for only 13 out of 31 evaluated compounds. These findings underscore the limitations of current wastewater treatment technologies and highlight the need for improved strategies to ensure the safety of water reuse.

Magnetically retrievable nanocatalysts are the most sustainable materials that have efficient photocatalytic ability due to large surface area, selectivity, and good recyclability without losing its activity. The use of such materials in the photocatalysis enhances the recoverability of photocatalyst which can be separated using external magnetic field that makes the recovery much easier and reduces the loss of photocatalyst associated with the traditional filtration and centrifugation methods. This concept aligns with green chemistry protocols in terms of environmental and economic requirements for sustainability. In this review, we aim to provide insight in the recent research done on TiO₂ loaded on the ferrite nanocomposites TiO₂/MFe₂O₄ (M = Co, Zn) in environmental remediation. When doped with metals, spinel ferrite nanocomposites demonstrate outstanding photocatalytic activity for the dye degradation. Dye degradation and removal of other organic pollutants are an environmental benign process when using a magnetically retrievable photocatalyst. Magnetic retrievable property helps in separating the photocatalyst from the reaction mixture and eliminating the need for filtration. Most organic pollutants can be removed using magnetic spinel ferrite composites, and their efficiency can be further enhanced through various strategies.

Aranda Mastin technology (AMT) is an emerging industry focused on the extracting aluminum from secondary sources, amid the decline of traditional bauxite resources. However, the cost-effectiveness of AMT operations remains challenged by the limited added value of its by-products. This study investigates the potential of utilizing acid-leached residues from Egyptian kaolin as low-cost adsorbents for removing methylene blue (MB) from aqueous solutions. Four mineral acids—HCl, HNO₃, H₂SO₄, and H₃PO₄—were evaluated for their effectiveness in direct kaolin dealumination under varying experimental conditions, including concentration, temperature, stirring time, and solid/liquid ratio. Optimal conditions were found to be: 7 mol L⁻¹ acid concentration, 100 °C, > 240 min of reaction time, and a 1/20 solid/liquid ratio. The leaching efficiency followed the order: H₃PO₄ > H₂SO₄ > HCl > HNO₃. X-ray diffraction (XRD) analysis confirmed amorphization due to dealumination in the residues from H₃PO₄ and H₂SO₄. The specific surface area (S_BET) of the residues increased in the order: H₂SO₄ > HCl > H₃PO₄ residues. Despite this, the highest dye removal efficiency (84.1%) was observed with residue treated using H₃PO₄, followed by HCl then with H₂SO₄ was the lowest efficiency. Adsorption kinetic studies followed the pseudo-second-order model for both H₃PO₄ and HCl residues, with high correlation coefficients (0.997–0.999), suggesting a heterogeneous adsorption mechanism. Additionally, the adsorption data for H₃PO₄-treated residue fit both the Langmuir and Freundlich isotherm models, indicating the coexistence of monolayer and multilayer adsorptions. When the removal efficiency was tested in MB-spiked seawater samples across various salinities and pH values (7.84–8.5), it remained consistently high (89.4–91.8%). These results highlight that while both H₃PO₄ and H₂SO₄ leaching effectively promote dealumination, only H₃PO₄-derived residues exhibit significant adsorption potential—making them suitable for cost-effective water treatment applications in addition to their role in aluminum recovery.

Green-synthesized magnetic nanocomposite adsorbents can remove heavy metals, like Mn(II), from drinking water. This study aimed to investigate the equilibrium, kinetic, and thermodynamic analysis of the green-synthesized magnetite-maghemite nanocomposite adsorbents (GSMMNs). UV–vis, FT-IR, XRD, TEM, SEM, EDS, TGA, DLS, BET, XPS, zeta potential, and VSM studies have been employed to characterize the nanocomposite. The average particle size of the GSMMN was 14.34 nm, according to the results of the TEM investigation. The highest removal efficiency and adsorption capacity have been determined to be 93% and 79.36 mg/g, respectively, at an optimal initial pH of 6.5, Mn(II) ion concentration of 10 mg/L, and adsorbent dose of 1.5 g/L. Adsorption kinetics better fit the pseudo-second-order model, and the Langmuir model was associated more closely than the Freundlich model. The thermodynamic parameters, such as enthalpy (ΔH⁰), entropy changes (ΔS0), and free energy changes (ΔG⁰), validated the adsorption nature. The Mn(II) ion adsorption process is endothermic, spontaneous, and physisorption-controlled, as evidenced by the thermodynamic parameters ΔH⁰ (36.5 kJ/mol), (Delta) S⁰ (127 J/mol K), and ΔG⁰ (− 1.3 to − 4.5 kJ/mol). Incorporating organic moieties into GSMMN enhanced Mn(II) adsorption capacity due to additional functional groups. GSMMNs nanocomposite showed strong Mn(II) selectivity over other divalent cations. The wastes from regeneration cycles can be safely disposed of by precipitating as solid waste. The study demonstrated the potential of the GSMMNs adsorbent to eliminate Mn(II) ions from contaminated aqueous solutions because of its stability, reusability, and high adsorption capacity.

Constructed wetland (CW) offers a long-term solution for wastewater treatment due to its high nutrient removal efficiencies, ecological benefits and low costs. Similarly, biochar, a carbon-rich organic material, offers a cost-effective solution for enhancing water treatment in CWs while also contributing to carbon footprint reduction. This study was aimed to assess the nitrogen (N) removal performances of Acorus calamus and Cyperus alternifolius in vertical flow constructed wetlands (VFCWs) treating simulated up-flow anaerobic sludge blanket (UASB) reactor effluent, focusing on the role of specific plant species. Rice husk biochar (RHBC) as a substrate material was amended to intensify further organic and N removal efficiencies of VFCWs. Five sets of VFCWs microcosms both planted and unplanted with biochar were developed to investigate the combined effect of biochar and plants on N removal. Results showed that CW1 (C. alternifolius + RHBC) demonstrated the highest total nitrogen (TN) and chemical oxygen demand (COD) removal efficiencies of 83.93 ± 4.70 and 86.70 ± 8.43%, respectively, outperforming the Control and other VFCWs. Nitrogen mass balance showed that, compared to CW3 (A. calamus + RHBC) CW1 achieved ~ 7% higher TN removal, primarily through plant uptake and biochar adsorption. Plant uptake and substrate adsorption were responsible for 30 and 26% of TN removal in CW2 (C. alternifolius) and CW4 (A. calamus), respectively. Furthermore, sequencing of the V3–V4 region of the 16S rRNA gene from sand revealed the highest phyla diversity in CW1, with Nitrosospira detected exclusively in CW1 (0.02%) and CW2 (0.01%), while being undetectable in Control, CW3 and CW4, suggesting a comparatively enhanced microbial richness and potential nitrifying activity in CW1 and CW2. These findings provide insights into the N removal mechanism of different plants and their interaction with biochar for improved N and organic removal in CWs.

The dye removal properties of Penicillium funiculosum mold were investigated in live and inactive forms. Acid Violet 90 and Direct Blue 86 textile dyes were used as target pollutant molecules. Bioaccumulation occurred when live mold was used. The dyes were gathered by living cells metabolically. The experiments were performed by adding mold spores and dyes to the nutrient medium in an orbital shaker with varied conditions. 100% removal efficiencies were achieved using 100 mg/L dye concentrations at the natural pH of the growth medium (pH 6.7), agitation speed of 160 rpm, 28 °C, and 4 days. The mold was killed in an autoclave for biosorption. The uptake occurred through the interaction of the dye molecules with the functional groups in the cell wall of dead mold. The biosorption experiments were done in batch mode at different pH, time, mixing speed, temperature, dead mold amount, and initial dye concentrations. The removal rates reached ~ 99% for AV90 and ~ 98% for DB86 using 0.1 g of mold at pH 4, 200 rpm shaking speed, 60 min reaction time, and 40 °C with 100 mg/L dye concentrations. The removal percentages were 100% when 0.25 g of mold was used in the same conditions. The kinetic, isotherm, and thermodynamic parameters of the biosorption were calculated. The biosorption is well fitted to the pseudo-second-order kinetic model and Langmuir isotherm. The used mold efficiently removed textile dyes in both live and inactive forms. The uptaken dyes can be seen in the microscope images of the treated molds.

This study proposes a piezoelectric sensor-based method for detecting membrane unit damage to enhance the effectiveness of integrity monitoring. The sensor can identify changes in the dynamic stiffness of the host structure and estimating internal pressure variations within the air injection pipe by measuring the electro-mechanical impedance of an air injection pipe. During the pressure decay test (PDT), resistance differences were observed in damaged regions during the gas–liquid conversion phase. However, these differences were subtle, with the rate of pressure rise to the preset PDT value ranging from a minimum of 0.015 to a maximum of 0.059 kPa/sec. As a result, conventional pressure gauges failed to accurately detect such changes. To validate the proposed method, both a pilot-scale single membrane test and a full-scale membrane unit test were conducted. The signal output from the piezoelectric sensor varied according to pipe pressure and demonstrated higher sensitivity in detecting pressure changes compared to traditional pressure gauges. This allowed for the detection of minute pressure changes caused by air leakage in damaged membranes. The use of the Cross-correlation coefficient index in relation to pressure variations reduced the diagnostic time and improved sensitivity in comparison with conventional PDT. Furthermore, the amount of leakage was reduced by up to 48% through turbidity monitoring of the permeate water. These findings indicate that the proposed method offers an efficient and reliable approach for membrane integrity testing of unit membrane systems.

Membrane fouling remains a major challenge in water and wastewater treatment. Membrane surface patterning offers a chemical-free approach to effectively control this issue. Previous research has focused on various surface pattern designs to mitigate membrane fouling, but has largely overlooked the combined effects of pattern dimensions and Reynolds number. In this study, we numerically investigate the filtration performance of four different membrane patterns—flat, triangular, mixed triangular-rectangular, and rectangular—by systematically varying pattern dimensions (100–800 μm), Reynolds number (200–1600), and salt (NaCl) concentration (14–70 mol/m³). This comprehensive approach allows us to assess the critical roles, these parameters play in enhancing the reverse osmosis filtration efficiency. For this purpose, the present study utilizes Computational Fluid Dynamics to simulate fluid flow and transport of diluted species in the vicinity of patterned membranes. In this study, the key parameters were evaluated, including the velocity streamline profile, wall shear stress, concentration polarization, permeate flux, and boundary layer thickness. Results reveal that the pattern dimensions and flow strength significantly affect the membrane’s antifouling performance and permeate flux, with parametric optimization being key to unlocking superior membrane performance. Remarkably, higher inlet flow velocities also help to reduce the boundary layer thickness across all patterned surfaces to even below that for flat surfaces, helping overcome an existing challenge in the literature. Overall, this work paves the way for further innovation in patterned membrane technology and supports its real-world application in enhancing water/wastewater treatment and reuse processes.