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Semiconductor-based photocatalysts have become increasingly used in the removal of pollutants from wastewater, especially antibiotics. A series of composite-based cuprous oxide and bismuth vanadate (Cu2O/BiVO4) composite-based photocatalysts were synthesized by using the chemical method. The structure of the Cu2O/BiVO4 composite was verified by using x-ray diffraction, scanning electron microscopy, photoluminescence, Fourier transform infrared spectroscopy, and UV–visible spectra. The degradation of methylene blue (MB) and tetracycline (TC) was investigated to check the photocatalytic activity of the Cu2O/BiVO4 composite series. The quantity of Cu2O was varied from 1% to 7% by weight to prepare the series of Cu2O/BiVO4 composites. The analysis of results verified that 5% Cu2O/BiVO4 exhibits an outstanding photocatalytic activity as compared to 1%, 3%, and 7% Cu2O/BiVO4, pure Cu2O, and pure BiVO4 under visible light irradiation. The optimum value of photocatalytic degradation achieved with 5% Cu2O/BiVO4 was 97% for MB dye and 95% for TC in 120 min, which is greater than the photocatalytic degradation of pure BiVO4 (MB 45% and TC 72%), pure Cu2O (MB 57% and TC 80%), 1% Cu2O/BiVO4 (MB 72% and TC 85%), 3% Cu2O/BiVO4 (MB 83% and TC 88%), and 7% Cu2O/BiVO4 (MB 87% and TC 91%). The stability and reusability of Cu2O/BiVO4 were also investigated. To check the major role of trapping in degradation, a trapping experiment was also performed by using three trapping agents: BQ, EDTA, and tBuOH. The results showed that Cu2O/BiVO4 exhibits an improved photocatalytic activity in the degradation of antibiotics in polluted water because the recombination rate of the electron–hole pair decreased and the surface area increased, which increased the active sites for redox reactions. Such a photocatalytic composite with high efficiency has various applications, such as energy production, environmental remediation, and water remediation. [ABSTRACT FROM AUTHOR]

Modelling of many real-world processes, such as drug delivery, wastewater treatment, and pharmaceutical production, requires accurate descriptions of the dynamics of hard particles confined in complicated domains. In particular, when modelling sedimentation processes or systems with driven flows, it is important to accurately capture volume exclusion effects. This work applies Dynamic Density Functional Theory to the evolution of a particle density under diffusion, external forces, particle–particle interaction, and volume exclusion. Using a spectral element framework, for the first time it is possible to include all of these effects in dynamic simulations on complex domains. Moreover, this allows one to apply complicated no-flux, and other non-local, non-linear, boundary conditions. The methodology is also extended to control problems, addressing questions of how to enhance production set-up in industrially-motivated processes. In this work the relevant models are introduced, numerical methods are discussed, and several example problems are solved to demonstrate the methods' versatility. It is shown that incorporating volume exclusion is crucial for simulation accuracy and we illustrate that the choice of boundary conditions significantly impacts the dynamics. [ABSTRACT FROM AUTHOR]

Defects in nanostructures play a pivotal role in determining their properties and performance in the desired applications. Herein, the defect states and structural properties of the bi-metal oxide composite of ZnO and α-Fe2O3 (ZF-W) are varied by annealing the composite at different temperatures. The changes in defects, structures, and phase are evaluated thoroughly using transmission electron microscopy, x-ray diffraction, photoluminescence, and Mössbauer spectroscopy techniques. The defect-rich ZF-W composite is found to be composed of defect-deficient ZnFe2O4 attaining the equilibrium state when as-synthesized ZF-W is annealed at 500 °C [ZF-W(500)]. Further annealing at 1000 °C, ZF-W(1000), a non-stoichiometric and highly defected ZnFe2O4 is evidenced in the composite. The changes in the composite with the annealing temperature are correlated with the cationic migration and evolution of defect states. Moreover, the transition associated with the vacancy defects, which trapped the excited electron and dispel the free electrons, thereby inhibiting fast electron–hole pair recombination, is corroborated from the photoluminescence spectra. When implemented for methyl blue adsorption/degradation without the assistance of any external sources, the degradation efficiency of ZF-W, ZF-W(300), ZF-W(500), and ZF-W(1000) is found to be 86%, 84%, 68%, and 82%, respectively. The prepared samples are highly stable and can be used repeatedly without losing effectiveness. The simultaneous evolution of defects and structural properties of the composite are attributed for the variation in methyl blue adsorption/degradation. The present study reveals the importance of defects present in the mixed metal oxide composite in obtaining high-performance dye degradation/adsorption properties for sustainable wastewater treatment. [ABSTRACT FROM AUTHOR]

Electrochemical advanced oxidation processes (EAOPs) offer several advantages over conventional Advanced Oxidation Processes (AOPs) such as UV/H 2 O 2 and H 2 O 2 /O 3. This includes the absence of chemical additives and ease of control. However, high energy consumption hampers the industrial application of EAOPs. Currently, the hydrogen generated at the cathode is vented and wasted, because of its low gas purity and difficulty in collecting it. But it also underscores an opportunity where the reactor design can be improved to facilitate the collection of high-purity hydrogen for energy savings. In our study, The EAOPs reactor was designed with a proton exchange membrane (PEM) for hydrogen generation. The hydrogen at the cathode chamber is then supplied to a fuel cell to generate electricity. The energy efficiency of the EAOPs-fuel cell system is evaluated through the wastewater treatment performance and energy saving that fuel cells achieve. To optimize the EAOPs-fuel cell system, various operational conditions, including different anode types, salt concentrations, and target organic compounds, were examined to optimize the system. Our experimental results indicate that the EAOPs-fuel cell system exhibits energy-efficient performance across various operational conditions. Notably, the highest energy efficiency and recovery ratio were achieved when operating at 3 V with boron-doped diamond (BDD) as the anode. Furthermore, we investigated the impact of mass transfer on the system's energy efficiency, considering both the initial organic concentration and flow velocity. This study provided valuable insights into combining the effect of EAOPs and hydrogen fuel cells, contributing to the understanding and optimizing the oxidation performance. It also contributes to developing sustainable and cost-effective advanced oxidation technologies with wide-ranging water treatment applications. • Collecting high-purity hydrogen during wastewater treatment. • Energy recovery is achieved with hydrogen fuel cells in the design of EAOPs system. • Comparison of four common anodes' oxidation performance for energy recovery purposes. • Analysis of the relationship between the current efficiency and energy efficiency. • Gave a direction for the future development of the EAOPs system. [ABSTRACT FROM AUTHOR]

This research explores the feasibility of using date seeds (DS), an agricultural waste, for the adsorption of malachite green (MG) dye from synthesized wastewater. The characterization of the DS before and after adsorption was accomplished by FTIR, SEM, BET, and EDX measurements. Batch adsorption experiments were investigated for MG dye adsorption from aqueous solution onto the DS. The effect of different parameters such as solution pH, adsorbent dose, contact time, temperature, and the initial dye concentration were studied. The optimum pH, adsorbent dose, temperature, and contact time for the dye removal were found to be 5, 0.1 g, 25 °C, and 30 min, respectively. The equilibrium studies for the data with Langmuir, Freundlich, and Temkin isotherms showed that Freundlich isotherm is the best model to describe the adsorption of MG onto the DS particles which has a heterogeneous surface. It was found that the adsorption process follows a pseudo-second-order kinetic model which revealed that the intra-particle diffusion stage is the rate-controlling stage for the process. The thermodynamic parameters ΔG, ΔS, and ΔH suggest the possibility of chemisorption and physisorption simultaneously and indicate the exothermic and spontaneous characters of the adsorption of MG dye on DS with negative values of ΔH and ΔG. This study used agriculture waste (date seeds) which is proved to be an environmentally friendly and low-cost adsorbent. The date seeds were shown to be a promising adsorbent, demonstrating high surface area and well-developed porosity. The prepared adsorbent will have a great impact on wastewater treatment technology and possible applications at a large scale. Thus, widespread and great progress in this area can be expected in the future. [ABSTRACT FROM AUTHOR]

In this work, green method to synthesize chromium-doped zinc oxide (ZnO) nanorods (NRs) using an aqueous flower extract from Rhododendron arboretum is explored. Herein, chromium-doped ZnO NRs were prepared with different amount of chromium doping, varied as 2–10%. The green synthesized products underwent substantial analysis through X-ray diffraction (XRD), spectroscopic such as ultraviolet spectroscopy(UV-Vis) and scanning electron microscopy (SEM) methods. All samples were found to have hexagonal wurtzite ZnO, with average particle sizes of 52.41, 56.6, 54.44, 53.05, and 56.99 nm, respectively, for 2, 4, 6, 8, and 10% chromium doping in ZnO NRs. The Cr-doped ZnO NRs exhibited remarkable photocatalytic degradation activity of cationic dyes under UV-light, i.e., Malachite Green and Fuchsin Basic with degradation of 99.604 and 99.881%, respectively in 90 min. The reusability tests for these green synthesized Cr-doped ZnO NRs have also been carried out, showed 9–11 cycles with 85% of degradation efficiency. In addition, the Cr-doped ZnO NRs exhibited high selectivity for cationic dyes when experiments against mixture of dyes were performed. Photodegradation kinetics followed the pseudo-first-order model. The flower-extract-stabilized chromium-doped ZnO NRs demonstrated high photocatalytic activity toward malachite green and fuchsin basic dyes, potential material for pollution remediation. Cr-doped ZnO NRs by green method using flower extract of Rhododendon arboretum were prepared for the first time under ambient reaction conditions. Effect of Dopant i.e. Cr on Photocatalytic activity have been exploited. Selective photocatalytic degradation of cationic dyes i.e. MG, and FB has been achieved in 60–90 minutes. Optimization of reaction condition and various parameters has also been carried out. Recyclability of Cr-doped ZnO NRs was also evaluated and were found to be reusable for 11 cycles for degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A "Turning waste into treasure" strategy was proposed. • An efficient ARM/NiOOH adsorbent has been successfully prepared. • The adsorption kinetics model has been reasonably established. • 348.0 mg g−1 congo red was adsorbed with a ∼ 100 % adsorption efficiency within 5 min. Extracting functional materials from industrial waste residues to absorb organic dyes can maximize waste reuse and minimize water pollution. However, the extraordinarily low purification efficiency still limits the practical application of this strategy. Herein, the lamellar NiOOH is in-situ anchored on the industrial waste red mud surface (ARM/NiOOH) as an adsorbent to purify organic dyes in wastewater. ARM/NiOOH adsorbent with high specific surface area and porosity provides considerable active sites for the congo red (CR), thereby significantly enhancing the removal efficiency of CR. Besides, we fit a reasonable adsorption model for ARM/NiOOH adsorbent and investigate its adsorption kinetics. Resultantly, ARM/NiOOH adsorbent can remarkably adsorb 348.0 mg g−1 CR within 5 min, which is 7.91 times that of raw RM. Our work provides a strategy for reusing industrial waste and purifying sewage pollution, which advances wastewater treatment engineering. [ABSTRACT FROM AUTHOR]

As the demand for clean water sources increases, it is crucial to identify the best wastewater treatment technology that is cost-effective and energy efficient. Despite their separation performance and durability limitations due to the membrane materials and chemicals used in current production techniques, membranes are useful for recovering water from contaminated water sources. This review focuses on nanocellulose-based membranes that utilize various methods, as biodegradable and inexpensive nanocellulose has been used widely in membrane research in recent years. The research regarding nanocellulose-based membranes is growing widely as incorporating nanocellulose enhances the hydrophilic properties and mechanical strength and increases the membrane adsorption capacities, which is ideal for future commercialization. The material high aspect ratio explains this potential, large specific surface area, good capacity retention, and environmental inertness. In addition to the benefits already described, active sites include chemical moieties that might improve the efficacy of pollutants attaching to surfaces. Besides that, nanocellulose could be chemically modified to increase the surface affinity and reactivity of membranes to remove specific contaminants efficiently. Future research directions for lignocellulosic nanocellulose for wastewater treatment and the difficulties and possibilities of nanocellulose-based membranes in these fields are also discussed. Lastly, the application of nanocelluloses in water treatment with an emphasis on membranes and filters fabricated primarily of nanocellulose. Hence, nanocellulose for these membrane applications provides tremendous potential for the wastewater treatment industry. [ABSTRACT FROM AUTHOR]

Catalytic wet air oxidation (CWAO) is a very promising technology for the elimination of various refractory pollutants, but to activate dioxygen under mild conditions is a great challenge. In this research, we report a series of Cux/CNy@SBA catalysts to activate dioxygen for CWAO of phenols and antibiotics under mild conditions. The catalysts were prepared by in situ growth and dispersion of g-C3N4 and Cu species over the SBA-15 surface. Characterization by HRTEM, EDS, XRD, FT-IR, and XPS showed that the formed ultrathin g-C3N4 coating over the surface of SBA-15 provided abundant locations to embed the Cu species and thus more active sites were generated. UV-vis DRS characterization proved that the synergetic effect between Cu species and the SBA-15-dispersed g-C3N4 greatly enhanced the ability to activate dioxygen. It was found interestingly that superoxide radicals (•O2−) were the dominating active species at low temperature, while both •O2− and hydroxyl radicals (•OH) became the active species at high temperature during the CWAO of phenol. Among the catalysts tested, Cu1/CN3.3@SBA-N demonstrated the highest activity, affording 100% phenol removal and more than 90% chemical oxygen demand (COD) removal, even at 90 °C and atmospheric dioxygen pressure. Modification of the SBA-15 surface with KH-550 could remarkably improve the recycling stability of the catalyst. These findings provide new insights for the development of highly effective catalysts for the activation of dioxygen, particularly in the field of CWAO wastewater treatment. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) have emerged as an efficient and easily prepared class of anion adsorbents, showcasing remarkable potential in the adsorption and recovery of phosphate from wastewater, notably due to their unique "memory effect" post-calcination. This study focuses on the enhancement of phosphate adsorption capabilities of ZnAl layered double hydroxides (ZnAl-LDHs), which are particularly known for their high phosphate affinity, through the incorporation of copper and subsequent modification with ethylenediamine. The resultant ZnAlCu layered trimetallic oxide (ZnAlCu-1%-LDO), post-calcination, was modified with ethylenediamine to produce a novel inorganic metal/organic amine composite adsorbent, designated as ZACen-0.5. Characterization of ZACen-0.5 demonstrated an improvement in surface hydrophilicity, alongside a notable alteration in the adsorbent's skeletal structure, which manifested as degraded granular layers, an increased pore volume, and an enhanced specific surface area. The specific surface area of ZACen-0.5 was found to be 104.61 m2 g-1, marking a 51% increase compared to ZnAlCu-1%-LDO (69.27 m2 g-1). The adsorption capacity of ZACen-0.5 for phosphate was significantly elevated to 271.00 mg P g-1, maintaining an efficiency of 88.2% over four regeneration cycles. The study elucidated the adsorption mechanism of ZACen-0.5, attributing it to monolayer and chemical adsorption processes, which involve electrostatic attraction, ligand exchange, and surface precipitation. In practical wastewater treatment, ZACen-0.5 achieved a phosphate removal efficiency of over 98% from wastewater with an initial phosphate concentration of 3.43 mg P L-1, reducing the phosphate level to 0.0531 mg P L-1, thereby surpassing the stringent firstlevel standard of GB 8978-1996 (0.5 mg P L-1). The findings of this research underscore the effectiveness of ethylenediamine modification of ZnAlCu-1%-LDO in significantly enhancing the phosphate adsorption efficiency of LDH-based materials, presenting a promising avenue for the development of advanced wastewater treatment technologies. [ABSTRACT FROM AUTHOR]

The increasing awareness of the importance of a clean and sustainable environment, coupled with the rapid growth of both population and technology, has instilled in people a strong inclination to address the issue of wastewater treatment. This global concern has prompted individuals to prioritize the proper management and purification of wastewater. Organic pollutants are very persistent and due to their destructive effects, it is necessary to remove them from wastewater. In the last decade, porous organic polymers (POPs) have garnered interest among researchers due to their effectiveness in removing various types of pollutants. Porous biopolymers seem to be suitable candidates among POPs. Sustainable consumption and environmental protection, as well as reducing the consumption of toxic chemicals, are the advantages of using biopolymers in the preparation of effective composites to remove pollutants. Composites containing porous biopolymers, like other POPs, can remove various pollutants through absorption, membrane filtration, or oxidative and photocatalytic effects. Although composites based on porous biopolymers shown relatively good performance in removing pollutants, their insufficient strength limits their performance. On the other hand, in comparison with other POPs, including covalent organic frameworks, they have weaker performance. Therefore, porous organic biopolymers are generally used in composites with other compounds. Therefore, it seems necessary to research the performance of these composites and investigate the reasons for using composite components. This review exhaustively investigates the recent progress in the use of composites containing porous biopolymers in the removal of organic pollutants in the form of adsorbents, membranes, catalysts, etc. Information regarding the mechanism, composite functionality, and the reasons for using each component in the construction of composites are discussed. The following provides a vision of future opportunities for the preparation of porous composites from biopolymers. [ABSTRACT FROM AUTHOR]

Driven by concerns over polluted industrial wastewater, particularly heavy metals and dyes, this study explores biosorption using chemically cross-link chitosan derivatives as a sustainable and cost-effective depollution method. Chitosan cross-linking employs either water-soluble polymers and agents like glutaraldehyde or copolymerization of hydrophilic monomers with a cross-linker. Chemical cross-linking of polymers has emerged as a promising approach to enhance the wet-strength properties of materials. The chitosan thus extracted, as powder or gel, was used to adsorb heavy metals (lead (Pb2+) and copper (Cu2+)) and dyes (methylene blue (MB) and crystal violet (CV)). Extensive analysis of the physicochemical properties of both the powder and hydrogel adsorbents was conducted using a range of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM), as well as 1H and 13C nuclear magnetic resonance (NMR). To gain a comprehensive understanding of the sorption process, the effect of contact time, pH, concentration, and temperature was investigated. The adsorption capacity of chitosan powder for Cu(II), Pb(II), methylene blue (MB), and crystal violet (CV) was subsequently determined as follows: 99, 75, 98, and 80%, respectively. In addition, the adsorption capacity of chitosan hydrogel for Cu(II), Pb(II), MB, and CV was as follows: 85, 95, 85, and 98%, respectively. The experimental data obtained were analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. The isotherm study revealed that the adsorption equilibrium is well fitted to the Freundlich isotherm (R2 = 0.998), and the sorption capacity of both chitosan powder and hydrogel was found to be exceptionally high (approximately 98%) with the adsorbent favoring multilayer adsorption. Besides, Dubinin has given an indication that the sorption process was dominated by Van der Waals physical forces at all studied temperatures. [ABSTRACT FROM AUTHOR]

The amount of anthropogenic activity in the environment has significantly increased due to urbanization and industrialization. Toxic metals and other contaminants have become more concentrated as a result, appearing in wastewater released by many sectors. Aquatic animals suffer as a result of tainted wastewater entering water bodies. As a result, damage also occurs in the crops contaminating the agricultural ecology. Although several techniques have been used to detoxify contaminants in wastewater, the current situation necessitates environmentally acceptable and economically viable techniques for wastewater treatment. To fulfill this objective, this review is aimed at exploring the major sources of metals in wastewater. The traditional techniques for treating wastewater take a lot of time and are not environmentally or financially sustainable. Utilizing microorganisms, plants, and biomass leftovers to break down metal poisons is a proven biotechnology strategy that is environmentally friendly. Hence, the review highlights the drawbacks of conventional techniques with importance of bioremediation for sustainable ecosystem. Also, phytoremediation—the process of removing metals from the environment using plants is discussed as a successful strategy. Plants are thought to be the most effective option for wastewater remediation because they contain a variety of microorganisms and enzymes that aid in the detoxification of metals from wastewater. Overall, to gain a better understanding of environmentally friendly and sustainable ways, the buildup and detoxification of metals through the use of plants, microorganisms, and biomass residues in environmental remediation is highlighted. [ABSTRACT FROM AUTHOR]

Recovery of carbon, nitrogen, and phosphorus resources can be accomplished through treatment of the anaerobic fermentation supernatant from waste activated sludge (WAS). However, the anaerobic fermentation process is significantly influenced by pH values. In this article, thickened sludge from a secondary sedimentation tank of a wastewater treatment facility in Zhengzhou was used to conduct a batch test to examine the effect of pH values between 5.0 and 11.0 on the recovery efficiency of carbon, nitrogen, and phosphorus in sludge fermentation liquid. The results showed that the production of volatile fatty acids and the total suspended solids degradation rate of sludge reached the highest levels at pH 10.0, with 2481.35 mg/L and 54.11%, respectively, which was 1.45 times higher than the results of the unadjusted pH group. The highest efficiency of nitrogen and phosphorus recovery in the supernatant of anaerobic fermentation was achieved at pH 10.0, with the mole ratio of Mg2+/NH4+-N of 1.5 and the mole ratio of PO43−/ NH4+-N of 1.0, yielding 96.55%. The actualization of sludge resource usage and the recovery of carbon, nitrogen, and phosphorus resources from WAS could be achieved simultaneously in this study. [ABSTRACT FROM AUTHOR]

Cultivation of microalgae has gained significant interest as an alternative protein source, potentially becoming a target commodity recovered from microalgae-based wastewater treatment. This study examined a semi-continuous cultivation strategy to optimize protein accumulation of the indigenous freshwater chlorophytes, Lobochlamys segnis and Klebsormidium flaccidum, and simultaneously remove nutrients from wastewater efficiently. A strain-specific regime was made based on a fixed biomass concentration at the start of 24-h cultivation cycle, i.e., a constant initial cell density, which regulated harvesting and fresh medium supply volume according to the dilution rate. Six cultivation cycles were conducted in lab-scale 1L reactors with a synthetic municipal wastewater. Lobochlamys segnis and K. flaccidum grew exponentially in all cycles. The biomass productivity was 573 and 580 mg L–1 day–1, in which the total protein consisted of 62 and 45% of dry cell weight (dw), respectively. When a culture medium deficient in nitrogen and phosphorus was used, protein level was significantly reduced. L. segnis consumed all NH4+ and PO43– supplied by the medium replacement, giving the removal rate of 9.2 and 5.2 mg L–1 day–1. Whereas K. flaccidum removed 13.8 mg L–1 day–1 NH4+ without completing PO43– removal. The amino acid profile of both strains was characterized by glutamic acids content (4–5% dw). We concluded that the designed cultivation regime would support a constant biomass production with stable and high protein content, along with an efficient removal of nutrient from the wastewater. [ABSTRACT FROM AUTHOR]

Microalgal biomass has proven to be highly effective in the removal of heavy metals such as Pb2+ and Cd2+. Moreover, there are treatments available to enhance the heavy metal removal capabilities. This study investigates the impact of alkaline pretreatment on Nannochloropsis oculata biomass on the biosorption of Pb2+ and Cd2+. Nannochloropsis oculata was cultured in fed-batch reactors at 25 °C, with 166 μmol photons m-2 s-1 light intensity, in f/2 Guillard medium for 21 days. The biomass was treated with 0.2 M CaCl2 and 0.2 M NaOH for 24 h with slow stirring. FTIR studies indicated that carboxyl functional groups were mainly responsible for binding Pb2+ and Cd2+ during biosorption. The maximum biosorption capacity of Pb2+ was 227.86 mg g-1 and 57.17 mg g-1 for Cd2+ in the untreated biomass. The treatment with CaCl2 (Bs1) was more effective in the removal of Pb2+ than NaOH treatment (Bs2), otherwise NaOH treatment (Bs2) was better in the absorption of Cd2+ than CaCl2 treatment (Bs1). The experimental results and biosorption isotherms suggest that the microalgae showed a greater affinity for the removal of Pb2+ than for Cd2+ in all of the experiments. Both biomass treatments had a negative effect on Pb2+ and Cd2+ biosorption. Furthermore, the equilibrium data align well with the Sips isotherm model in the Langmuir derivation, suggesting a complex monolayer biosorption process. [ABSTRACT FROM AUTHOR]

High volume and water content makes anaerobic digestate management difficult. Environmental drawbacks and limited resource recovery are associated with traditional polymer conditioning methods. The method of polymer conditioning incurs high operating costs, affects the environment, and pollutes water. Therefore, modifying traditional polymer conditioning of mesophilic digestate (MD) is necessary to address environmental concerns and promote resource recovery. This study explored alternative chemical conditioning agents, including metal coagulant ferric chloride (FeCl3) and oxidant hydrogen peroxide (H2O2), to enhance the dewatering efficiency of MD with pH adjustment while comparing the corresponding results without pH adjustments. The goal was to determine the best chemical dose combination that minimizes polymer consumption while maximizing volume reduction. After adjusting MD's pH [ Ca(OH)2 ] to 8.0 and treating it with 2.1 kg/t dry solids (DS) polymer, 2.1 kg/t DS FeCl3 , and 600 mg/L H2O2 , significant improvements in MD dewaterability were observed, including a 96% increase in capillary suction time and 40% increase in cake solid. In addition to dewatering, improving phosphorus recovery in the digestate was investigated. The same chemical conditioning resulted in 98% elimination of P from centrate and recovered in the sludge cake. The study emphasizes the necessity of pH adjustment and choosing suitable conditioning chemicals to improve dewatering performance while considering P release implications. By reducing polymer usage and incorporating FeCl3 and H2O2 , significant improvements can be achieved in dewatering performance and P removal from MD centrate while better managing digestate. The conditioning process consists of a novel chemical combination of cationic polymer, FeCl3 , and H2O2 at an adjusted pH that would enhance the post-treatment efficiency of municipal anaerobic digestates with improved dewatering efficiency, reduced odor, improved pathogen elimination, and resource recovery. The research suggested that switching toward a two-staged temperature phased anaerobic digestion process would significantly enhance resource recovery and yield class A biosolids. Complying with class A biosolids regulations allows for broadening its practical application and increasing its market value. Contributing to the economic viability of the wastewater treatment plants (WWTPs). Research findings suggest that WWTPs can reduce polymer consumption by 40%, substantially reducing their operational costs and improving their efficiency. Improved cake solid content and reduced volume result in lowered storage and transportation costs. As a result of nutrient and resource recovery from digestate, biosolids are more economically valuable and align with sustainability goals by minimizing waste and conserving resources. In this research, odor reduction is improved by 91%, improving the quality of WWTP environments. This research provides cost-effective and environmentally friendly wastewater treatment solutions that address nutrient imbalance, pathogen contamination, and odors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Edge surface exposure CoOOH vertically rotted into commercial activated carbon. • The optimized CoOOH@AC/PMS can degrade 100 % ciprofloxacin within 10 min. • This activity is ascribed to Co-contained edge surface forcing PMS decomposition for CIP degradation. Peroxymonosulfate (PMS) is widely employed to generate oxygen-containing reactive species for ciprofloxacin (CIP) degradation. Herein, cobalt oxyhydroxide @activated carbon (CoOOH@AC) was synthesized via a wet chemical sedimentation method to activate PMS for degradation of CIP. The result suggested AC can support the vertical growth of CoOOH nanosheets to expose high-activity Co-contained edges, possessing efficient PMS activation and degradation activity and catalytic stability. In the presence of 3.0 mg of optimal CoOOH@AC and 2 mM PMS, 96.8 % of CIP was degraded within 10 min, approximately 11.6 and 9.97 times greater than those of CoOOH/PMS and AC/PMS systems. Notably, it was disclosed that the optimal CoOOH@AC/PMS system still exhibited efficient catalytic performance in a wide pH range, different organics and common co-existing ions. Quenching experiments and electron paramagnetic resonance indicated that both radical and non-radical processes contributed to the degradation of CIP, with 1O 2 and direct electron transfer accounting for the non-radical pathway and SO 4 •− and •OH serving as the main radical active species. Finally, possible CIP degradation pathways were proposed based on high-performance liquid chromatography-mass spectrometry. This study provided an alternate method for wastewater treatment based on PMS catalyzed by cobalt-based hydroxide. [ABSTRACT FROM AUTHOR]

[Display omitted] The treatment of wastewater containing hypophosphite [P(I)] and phosphite [P(III)] is challenged by limitations of traditional Fenton oxidation such as low efficiency, secondary pollution and high costs. This study introduced a facile solvent-thermal method to synthesize Cu-Co 3 O 4 nanoparticles uniformly loaded on graphene (Cu-Co 3 O 4 /U-rGO) through the reduction and coordination effects of urushiol (U). As prepared Cu-Co 3 O 4 /U-rGO exhibited excellent activity in activating peroxymonosulfate (PMS) for the oxidation of P(I)/P(III) to phosphate [P(V)] (0.229 min−1), along with high stability and reusability (91.5 % after 6 cycles), low metal leaching rate (Co: 0.2 mg/L, Cu: 0.05 mg/L), insensitivity to common anions in water and a wide pH range (3–11). The activation mechanism involved the synergistic effects from both urushiol and graphene, which promoted redox of Cu+/Cu2+ and Co2+/Co3+ and induced abundant oxygen vacancies for PMS activation to produce singlet oxygen. Furthermore, the Cu-Co 3 O 4 /U-rGO/PMS was also excellent in the oxidative removal of organic phosphorus. This study is expected to advance strategies for the treatment of P(I)/P(III)-rich wastewater and provide new insights for the development of low-cost, highly efficient heterogeneous catalysts with abundant oxygen vacancies. [ABSTRACT FROM AUTHOR]

Exploring efficient adsorbents still remains an important challenge due to the poor efficiency of the reported adsorbents for the adsorption of antibiotics. Herein, we design and prepare a novel nanosheets-like hollow TiO 2 (NHT) adsorbent by using hollow TiO 2 as a precursor through alkaline hydrothermal treatment. Adsorption results show that NHT exhibits a high adsorption percentage (98.05%) within 20 min and a maximum adsorption uptake of 24.51 mg/g for Levofloxacin (LVOF) pollutant (10 mg/L, 50 mL), which is 17 times higher than that (1.4 mg/g) of pristine hollow TiO 2 (HT). Notably, NHT realizes >91% of the adsorption percentage for LVOF pollutant after the tenth run only through photo-regeneration without extra post-treatments, effectively overcoming the disadvantages of harsh regeneration procedures for most of the existed adsorbents. Adsorption data and the performance characterizations present deep insights into adsorption mechanism, which reveals that pore filling effect, hydrogen-bond interactions, and electrostatic attraction are the key parameters for the excellent adsorption of LVOF by NHT. Therefore, the present study can provide a promising direction for the fabrication of efficient adsorptive photocatalyst by using low-cost TiO 2 as a precursor. [Display omitted] • Novel nanosheets-like hollow TiO 2 (NHT) adsorbent was prepared via a facile alkaline hydrothermal treatment. • NHT adsorbent exhibited higher adsorption capacity of LVOF and faster adsorption kinetics than the present materials. • NHT manifested efficient adsorption of LVOF in ambient factors and real water matrices. • Exceptional levofloxacin adsorption/photo-regeneration cycles were realized by NHT adsorptive photocatalyst. • The efficient adsorption mechanism was ascribed to pore-filling effect, hydrogen bonding, and electrostatic interactions. [ABSTRACT FROM AUTHOR]

Graphene (GR) has considered to be a promising material to build proficient graphene-doped composites photocatalyst with superior catalytic activities for wastewater treatment. During the past decade, different graphene-doped composites have been constructed and applied in numerous solar and photocatalyst fields. GR-based composites have a sufficient surface area with numerous photocatalytic sites for wastewater treatment applications. In the present study the effect of hetero-atoms Aluminum, Nitrogen, and Boron on bandgap engineering and tuning of electronic and optical properties of GR-doped-composites by density functional quantum computing calculation. Our computed results demonstrate that hetero-atoms-doped-GR composites having direct energy band (Eg) semiconductor nature with an increment from 0.0 to 1.75 eV by the inclusion of hetero-atoms in GR, maybe some extra strong sites are formed in p state into the lifting of the energy bandgap (Eg). An extensive investigation of optical conductivity illustrates that increment in peaks from 2.5 to 4.0. Due to hetero-atoms dopant the absorbance peaks are increased and moved toward higher energy absorption. Our findings reveal that as compared to pure, Al, N,B hetero-atoms, the B-doped-GR surface has a large surface area with strong active sites for wastewater treatment. These theoretical findings can be useful in practical applications for wastewater remediation through hetero-atom-doped graphene composites. [ABSTRACT FROM AUTHOR]

The heterogeneous Fenton process is a promising technology for the removal of persistent pollutants in aqueous media. However, the development of solid catalysts that do not leach iron particles from the structure, that can be easily recovered and used in multiple reaction cycles is still a challenge. Therefore, the objective of this study was to propose the design of a new heterogeneous Fenton catalyst supported on pre-treated clinoptilolite nanoparticles with HNO3, with magnetic recovery. The zeolite was reduced to nanoparticles using a ball mill and then pre-treated with nitric acid in a reflux system. Iron particles were fixed on the support through the wet impregnation method, and the material was subjected to physicochemical characterization. The catalytic activity was tested in the degradation of the textile dye Reactive Blue (RB250) under batch conditions, and different effects were evaluated. The results showed that the modifications on the clinoptilolite support enhanced its specific surface area and pore volume, while Mössbauer results confirmed that the applied synthesis process resulted in excellent magnetic catalysts that can be easily recovered. The 15Fe/CPGT catalyst completely degraded the contaminant in 60 min, following pseudo-second-order kinetics (k = 1.14 L g−1.min−1). The reuse tests indicated the ease of removing the catalyst particles through magnetism and high catalytic performance even after eleven consecutive runs. Toxicological tests and chemical parameters such as TOC and COD confirmed the reduction of effluent toxicity. Finally, the developed magnetic Fenton catalyst is a material with high catalytic potential for application in the Fenton-like process. [ABSTRACT FROM AUTHOR]

Membrane distillation (MD) is a promising technology for desalination of different water streams. However, treating wastewater with complex compositions remains a challenge. In this study, we adopted the MD process to treat complex and harmful methylene blue (MB) dye-containing textile wastewater. The effect of relevant operating parameters on the MD process performance was investigated. Additionally, the membrane wettability during the MD process was evaluated. The results showed that increasing the temperature difference and feed flow velocity led to an increase in permeate flux (Jp) and a decrease in specific energy consumption (SEC). The Jp and SEC models exhibited good agreement between predicted and experimental values, with an R2 of 98.50% and 86.18%, respectively. During the 22 h of operation, the MD process applied for the treatment of dye wastewater demonstrated a decline of Jp by 71.8% and a slight decrease in dye rejection to attain 95.9%. The decline of the surface contact angle and the liquid entry pressure values and an increase in the permeate water conductivity detected the membrane wettability. The obtained results suggest that the MD process could present an efficient solution for the treatment of MB-dye wastewater. However, upscaling the MD technology requires further improvements on real wastewater treatment for a longer run time. [ABSTRACT FROM AUTHOR]

In this work, we explored the adsorptive detoxification potential of titania–bentonite clay composite for removing a cationic dye (crystal violet) from aqueous medium. Fresh clay composite sample were prepared by impregnated method, followed by spectroscopic characterization by SEM, FTIR, and EDX. After that, in batch studies dye removal were examined. The results under optimum conditions showed that this composite material has a 96% elimination capacity. Maximum removal of crystal violet was 49.26 mg/g, following Pseudo-second order kinetic model occurred at pH 8, at 125 rpm and 25 ppm initial concentration at 45 °C. Kinetics of reactions and isotherm models were investigated. Adsorption data showing the presence of monolayer adsorption were fitted using the Langmuir isotherm model. Chemisorption was shown to prevail according to Temkin isotherm criteria. Pseudo-second-order kinetics was followed in this case. For removing dye from industrial effluents, this titania–bentonite composite serves as a nonbiodegradable, low-cost, reliable, and ecologically safe adsorbent. [ABSTRACT FROM AUTHOR]

Lanthanum-modified mesoporous graphite nitride carbon composites (La-g-C3N4) were synthesized using a thermal shrinkage polymerization method. The samples underwent characterization through X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmet–Teller (BET) analysis. The results revealed that the La30-g-C3N4 sample displayed a more porous layered morphology with a uniform pore structure. The BET surface area of the sample was found to be 38.6 m2 g−1, which is 5.8 times higher than that of the undoped sample g-C3N4. The sample exhibited a type IV isotherm, indicating its mesoporous nature with a pore size distribution ranging from 3 to 20 nm. The application of these materials was investigated for the degradation of tetracycline (TC) and acidic fuchsin (AF) in simulated wastewater. The results demonstrated that the La30-g-C3N4 sample exhibited rapid and efficient degradation, along with excellent adsorption capacity for both TC and AF. Within 5 minutes, the degradation efficiency of the La30-g-C3N4 sample for TC and AF was measured to be 83.1% and 74.1%, respectively, with corresponding adsorption capacities of 63.9 mg g−1 and 129.4 mg g−1. The kinetic and thermodynamic analysis of the adsorption process revealed that the adsorption of TC and AF by La30-g-C3N4 followed the quasi-second-order kinetics and Langmuir adsorption isotherm model, indicating a predominantly single-layer chemical adsorption process. Furthermore, the composite material exhibited good cycling stability and maintained excellent adsorption performance even after six repeated uses. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) are a point source of nutrients, emit greenhouse gases (GHGs), and produce large volumes of excess sludge. The use of aquatic organisms may be an alternative to the technical post-treatment of WWTP effluent, as they play an important role in nutrient dynamics and carbon balance in natural ecosystems. The aim of this study was therefore to assess the performance of an experimental wastewater-treatment cascade of bioturbating macroinvertebrates and floating plants in terms of sludge degradation, nutrient removal and lowering GHG emission. To this end, a full-factorial experiment was designed, using a recirculating cascade with a WWTP sludge compartment with or without bioturbating Chironomus riparius larvae, and an effluent container with or without the floating plant Azolla filiculoides, resulting in four treatments. To calculate the nitrogen (N), phosphorus (P) and carbon (C) mass balance of this system, the N, P and C concentrations in the effluent, biomass production, and sludge degradation, as well as the N, P and C content of all compartments in the cascade were measured during the 26-day experiment. The presence of Chironomus led to an increased sludge degradation of 44% compared to 25% in the control, a 1.4 times decreased transport of P from the sludge and a 2.4 times increased transport of N out of the sludge, either into Chironomus biomass or into the water column. Furthermore, Chironomus activity decreased methane emissions by 92%. The presence of Azolla resulted in a 15% lower P concentration in the effluent than in the control treatment, and a CO2 uptake of 1.13 kg ha-1 day-1. These additive effects of Chironomus and Azolla resulted in an almost two times higher sludge degradation, and an almost two times lower P concentration in the effluent. This is the first study that shows that a bio-based cascade can strongly reduce GHG and P emissions simultaneously during the combined polishing of wastewater sludge and effluent, benefitting from the additive effects of the presence of both macrophytes and invertebrates. In addition to the microbial based treatment steps already employed on WWTPs, the integration of higher organisms in the treatment process expands the WWTP based ecosystem and allows for the inclusion of macroinvertebrate and macrophyte mediated processes. Applying macroinvertebrate-plant cascades may therefore be a promising tool to tackle the present and future challenges of WWTPs. [ABSTRACT FROM AUTHOR]

The coupled water electrolysis is a promising strategy for green hydrogen production. Pollutants are attractive feedstocks for the fungible anode reactions of the sluggish oxygen evolution reaction, with the advantages of trash-to-treasure and cost reduction. There is an urgent need for real waste sample tests from the view of both contaminant abatement and electrochemical hydrogen production. This work offers a systematic evaluation of the coupled water electrolysis with real wastewater, where four real wastewater with sulfur element compounds in different states are taken as examples. The technical and economic potentials are evaluated particularly based on the coupled water electrolysis performances, including cell voltage, current density, hydrogen production rate, hydrogen electricity consumption, and pollution abatement. The coupled water electrolysis with the refractory wastewater, e.g. the desulfurization wastewater from coal-fired power plants and the H acid wastewater, does not show advantages from the view of hydrogen production, due to the high overpotential and limited current density. Nevertheless, hydrogen is a high-value-added byproduct for operation cost reduction from the view of wastewater treatment. The readily oxidizable pollutants, e.g. sulfite and sulfide, exhibit notable potentials for anodic depolarization and electricity consumption reduction of hydrogen production. However, the coupled water electrolysis adopting the sulfide spent caustic stream may suffer a low hydrogen production rate for sulfide to sulfur. The coupled water electrolysis adopting sulfite wastewater indicates excellent potential for both space-time yield and electricity consumption for hydrogen production. This work may offer a reference for the systematic evaluation and selection of coupled water electrolysis with real wastewater. • An evaluation of coupled water electrolysis with real wastewater is presented. • Pollutants are attractive feedstocks for the coupled water electrolysis. • The readily oxidizable pollutants exhibit excellent potential for the coupled water electrolysis. • Hydrogen is a high-value-added byproduct for cost reduction of wastewater treatment. [ABSTRACT FROM AUTHOR]

Ni‐Sb‐SnO2(Ni‐ATO) can generate ozone electrochemically which compensates the energy efficiency. However, the selectivity of electrochemical ozone production (EOP) on Ni‐ATO surface is yet insufficient for practical application. In this study, ATO with Cu and Ni co‐doped (CuNi‐ATO) is prepared to enhance the electrochemical performance and stability of ozone generation. CuNi‐ATO achieves the highest known current efficiency of 71% for EOP under acidic conditions, which is 2.4 times higher than that of Ni‐ATO. Efficient EOP is maintained with diverse pH, temperature, and electrolytes. Notably, the service lifetime of CuNi‐ATO is 2.7 times longer than that of Ni‐ATO. DFT calculations further reveal that ATO with Cu and Ni co‐doped presents weakened adsorption toward O*, O2*, and O3*. The spontaneous combination of O* and O2* is the main reason for enhanced EOP capacity on CuNi‐ATO. This work provides a novel insight into designing materials for efficient ozone production. [ABSTRACT FROM AUTHOR]

Microalgae are photosynthetic microorganisms that have been extensively studied for their ability to produce biofuels, including hydrogen (H 2). While microalgae immobilization techniques have been extensively researched for wastewater treatment, their application for H 2 photoproduction is a relatively new area of study. In this review, we evaluate microalgae immobilization as a promising technology to improve the commercial maturity of green H 2 production by microalgae, as it offers multiple advantages over traditional suspended growth systems. It facilitates cell harvesting, reduces contamination risk, and improves control of cultivation conditions, biomass retention, and efficiency of H 2 production. However, the effectiveness of immobilization largely depends on the technical parameters, including the type of immobilization method used, the choice of immobilization materials, and the operational conditions. Here we provide a comparative review on different parameters and conditions suggested in the literature for microalgae immobilization, and propose a protocol optimized to achieve an efficient H 2 production. • Microalgae immobilization procedure should be tailored for the aim of efficient H 2 production. • Optimal choice of immobilization material includes 12 % alginate and 4 % SrCl 2. • Microalgae immobilization in thin layers like biofilms is highly preferred over beads. • Anaerobic dark incubation followed by continuous high light exposure are recommended. • Optimal pH of the medium is 7.7 and the recommended incubation temperature is 30 °C. [ABSTRACT FROM AUTHOR]

AbstractIn this study, palladium impregnated graphene oxide quantum dots (Pd-GOQD) have been synthesized by biogenic carbonization. The formation of Pd-GOQD and GOQD was confirmed by physicochemical techniques such as Brunauer–Emmett–Teller (BET), photoluminescence spectroscopy, XRD, Raman spectroscopy, XPS analysis, and HAADF-STEM analysis. TEM analysis revealed that GOQD and Pd-GOQD are spherical, with a mean size of around 2.9 and 3.7 nm, respectively. The photocatalytic activities of Pd-GOQD and GOQD using methylene blue (MB) and methyl orange (MO) dye under visible light were investigated using spectroscopic analysis. Pd-GOQD showed nearly better dye degradation efficiency as 90% dye was reduced within 75 min compared to 50% efficiency of GOQD. Kinetic of the reduction process of MB and MO was well correlated with first-order kinetics. Besides, the Pd-GOQD exhibited its regeneration and reusability as its photo-degradation performance remained unaffected after five successive reuses. Hence GO-Pd nanocomposite was a promising option for removing synthetic dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

Crop residue-based biochar (CRB) has shown great potential for removing trace elements (TEs) from aquatic matrices. Despite the increasing interest in this area, no review has focused specifically on the efficacy of CRB for TEs removal in aquatic environments. This comprehensive review examines the global TEs water contamination status with an emphasis on their sources, compositional metrics for crop residue feedstock (proximate, ultimate, and lignocellulosic properties), and the potential use of CRB for TEs removal in aquatic media. It also evaluates the factors that affect the ability of CRB to remove TEs, such as feedstock type, production conditions, water pH, background electrolytes, water temperature, CRB/water ratio, and underlying pollutant sorption mechanisms. This review also discusses the practical applications of CRB in real water samples and engineering considerations for designing CRB with improved physicochemical properties, treatment efficiencies, and regeneration abilities. Additionally, the cost–benefit and economic assessment of CRB, challenges, and future research directions related to CRB are highlighted to promote research on this sustainable source of biochar. By elucidating the prospects of CRB as an adsorbent, this review emphasizes the need for continued research on its practical implications for environmentally relevant pollutant concentrations. Highlights: Crop residue-based biochar (CRB) emerged as a top-notch adsorbent for TEs in aquatic systems. The CRB adsorption potential depended on the experimental conditions. The application of CRB to real water samples highlights its potential on a larger scale. Engineer-designed CRB exhibits high treatment efficiencies and regeneration abilities. [ABSTRACT FROM AUTHOR]

We have developed an innovative thin-film nanocomposite membrane that contains cellulose acetate (CA) with small amounts of TiO2-decorated graphene oxide (GO) (ranging from 0.5 wt.% to 2 wt.%) sandwiched between two polytetrafluoroethylene (PTFE)-like thin films. The PTFE-like films succeeded in maintaining the bulk porosity of the support while increasing the thermal and chemical robustness of the membrane and boosting the catalytic activity of TiO2 nanoparticles. The membranes exhibited a specific chemical composition and bonding, with predominant carbon–oxygen bonds from CA and GO in the bulk, and carbon–fluorine bonds on their PTFE-like coated sides. We have also tested the membranes' photocatalytic activities on azithromycin-containing wastewaters, demonstrating excellent efficiency with more than 80% degradation for 2 wt.% TiO2-decorated GO in the CA-GO-TiO2/PTFE-like membranes. The degradation of the azithromycin formulation occurs in two steps, with reaction rates being correlated to the amount of GO-TiO2 in the membranes. [ABSTRACT FROM AUTHOR]

A novel Cr-doped BaTiO3 aerogel was successfully synthesized using a co-gelation technique that involves two metallic alkoxides and a supercritical drying method. This freshly prepared aerogel has a high specific surface area of over 100 m2/g and exhibits improved responsiveness to the simulated sunlight spectrum. Methyl orange (MO) was chosen as the simulated pollutant, and the results reveal that the Cr-doped BaTiO3 aerogel, when modified with the noble metal silver (Ag), achieves a pollutant removal rate approximately 3.2 times higher than that of the commercially available P25, reaching up to 92% within 60 min. The excellent photocatalytic performance of the Ag-modified Cr-doped BaTiO3 aerogel can be primarily attributed to its extensive specific surface area and three-dimensional porous architecture. Furthermore, the incorporation of Ag nanoparticles effectively suppresses the recombination of photo-generated electrons and holes. Stability and reusability tests have confirmed the reliability of the Ag-modified Cr-doped BaTiO3 aerogel. Therefore, this material emerges as a highly promising candidate for the treatment of textile wastewater. [ABSTRACT FROM AUTHOR]

Colombia's continuous contamination of water resources and the low alternatives to produce biofuels have affected the fulfillment of the objectives of sustainable development, deteriorating the environment and affecting the economic productivity of this country. Due to this reality, projects on environmental and economic sustainability, phytoremediation, and the production of biofuels such as ethanol and hydrogen were combined. The objective of this article was to design and develop a sustainable system for wastewater treatment and the generation of biofuels based on the biomass of the aquatic plant Eichhornia crassipes. A system that simulates an artificial wetland with live E. crassipes plants was designed and developed, removing organic matter contaminants; subsequently, and continuing the sustainability project, bioreactors were designed, adapted, and started up to produce bioethanol and biohydrogen with the hydrolyzed biomass used in the phytoremediation process, generating around 12 g/L of bioethanol and around 81 ml H2/g. The proposed research strategy suggests combining two sustainable methods, bioremediation and biofuel production, to preserve the natural beauty of water systems and their surroundings. [ABSTRACT FROM AUTHOR]

Despite the many articles about activated carbon with different precursors in adsorption process, no in-depth research has been carried out to understand the causes of the difference in surface adsorption characteristics of activated carbon with different precursors and different activation processes. In this work, the ability of two active carbon adsorbents made of walnut shell and peach kernel by two chemical and physical methods (totally 4 different types of activated carbon) in treatment of oily wastewater including diesel, gasoline, used oil or engine lubricant has been compared. The results show that the chemical activated peach carbon active with 97% hardness has provided the highest hardness and physical activated walnut carbon active has obtained the lowest hardness value (87%). It is also found that peach activated carbon has a higher iodine number than walnut activated carbon, and this amount can be increased using chemical methods; Therefore, the highest amount of Iodine Number is related to Peach activated carbon that is made by chemical method (1230 mg/g), and the lowest amount of iodine number is seen in walnut activated carbon that is made by physical method (1020 mg/g). moreover, the pore diameter of physical activated carbon is lower than chemical activated carbon in all cases. So that the pore diameter of chemical activated peach carbon active is equal to 22.08 μm and the measured pore diameter of physical activated peach carbon active is equal to 20.42 μm. These values for walnut are obtained as 22.74 μm and 21.86 μm, respectively. Furthermore, the temperature and pH effects on the adsorption of different synthesized oily wastewater was studied and it was found that a decrease in adsorption can be seen with an increase in temperature or decreasing the pH value, which can be referred to this fact that the process of adsorption is an exothermic process. Finally, to analyze the compatibility of adsorption isotherms with experimental data and to predict the adsorption process, three different isotherms named Langmuir, Temkin, and Freundlich isotherms were applied and their parameters were correlated. The correlation results show that the Langmuir isotherm had the best correlation in all cases compared to the Freundlich and Temkin isotherms, based on the correlation coefficient, and the calculated R2 values which was greater than 0.99 in all the studied cases. [ABSTRACT FROM AUTHOR]

Anaerobic membrane bioreactors (AnMBRs) are seen as a promising technology for application in water reuse schemes. However, the evidence base for their potential and efficacy in this regard is fragmented. We draw together this disparate knowledge base to offer a state of the art review of municipal wastewater treatment with AnMBRs and evaluate the technology's potential application for water reuse. Water quality regulations and standards from different regions of the world are used as performance metrics to compare and contrast the treatment performance of pilot and laboratory scale AnMBR systems reported in the literature (n = 50). Findings indicate that under stable operation, AnMBRs have the potential to produce water for agricultural reuse. However, without post-treatment, AnMBRs are incapable of delivering water that meets other non-potable reuse standards across a range of important parameters such as COD, BOD5, NH3-N and TP. Analysis of key operational parameters determine the operation of AnMBR for non-potable reuse purpose cover influent water matrix, pH, temperature, hydraulic retention time, system and membrane configuration. An assessment of candidate post-treatment technologies suggests a tradeoff between the cost and effluent quality based on the reuse application requirement. We conclude by discussing a number of challenges and limitations to the use of AnMBRs for reuse applications in order to outline a pathway to maturity for effective treatment trains. [ABSTRACT FROM AUTHOR]

The high prevalence of antibiotic resistant bacteria (ARB) in several environments is a great concern threatening human health. Particularly, wastewater treatment plants (WWTP) become important contributors to the dissemination of ARB to receiving water bodies, due to the inefficient management or treatment of highly antibiotic-concentrated wastewaters. Hence, it is vital to develop molecular tools that allow proper monitoring of the genes encoding resistances to these important therapeutic compounds (antibiotic resistant genes, ARGs). For an accurate quantification of ARGs, there is a need for sensitive and robust qPCR assays supported by a good design of primers and validated protocols. In this study, eleven relevant ARGs were selected as targets, including aadA and aadB (conferring resistance to aminoglycosides); ampC, blaTEM, blaSHV, and mecA (resistance to beta-lactams); dfrA1 (resistance to trimethoprim); ermB (resistance to macrolides); fosA (resistance to fosfomycin); qnrS (resistance to quinolones); and tetA(A) (resistance to tetracyclines). The in silico design of the new primer sets was performed based on the alignment of all the sequences of the target ARGs (orthology grade > 70%) deposited in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, allowing higher coverages of the ARGs' biodiversity than those of several primers described to date. The adequate design and performance of the new molecular tools were validated in six samples, retrieved from both natural and engineered environments related to wastewater treatment. The hallmarks of the optimized qPCR assays were high amplification efficiency (> 90%), good linearity of the standard curve (R2 > 0.980), repeatability and reproducibility across experiments, and a wide linear dynamic range. The new primer sets and methodology described here are valuable tools to upgrade the monitorization of the abundance and emergence of the targeted ARGs by qPCR in WWTPs and related environments. [ABSTRACT FROM AUTHOR]

Treatment methods for high-salt wastewater mainly consist of physical methods, chemical methods and biological methods. However, there are some problems, such as slow treatment speed, high investment costs and low treatment efficiency. To address NaCl solutions, in this study, a circulatory flash system was designed based on gas–liquid equilibrium, mass conservation equation and energy conservation equation. A circulatory flash evaporation simulation and a static flash evaporation experiment were conducted on NaCl solutions under various operating conditions to investigate the effects of heating temperature, flash pressure and initial NaCl concentration on the circulatory flash evaporation system. The significance of each factor's influence on the evaporation fraction and energy consumption was examined through static flash experiments. The simulation results demonstrated that increasing the heating temperature, decreasing the flash pressure and having a higher initial NaCl concentration could enhance the treatment capacity of high-salt wastewater. The flow rate of vapor outlets increased with higher heating temperature but decreased as the flash pressure rose. The experimental results demonstrated that flash evaporation pressure was the primary factor influencing both the evaporation fraction and the energy consumption per unit mass of vapor produced. It was observed that with an increase in heating temperature, the flash pressure decreased and there was a corresponding decrease in energy consumption per unit mass of vapor produced. The optimal experimental conditions were achieved at a heating temperature of 99 °C, a flash pressure of 15 kPa, and an initial NaCl concentration of 20%. [ABSTRACT FROM AUTHOR]

Photosynthetic microbial fuel cells (pMFCs) are hybrid systems that enable simultaneous wastewater treatment under anaerobic conditions and the generation of electricity by utilizing the potential difference in the anaerobic anode chamber and the oxygenated cathode chamber. Dairy wastewater with a concentration of 2000 mg COD/L was treated in the anode of a batch pMFC. In the cathode chamber, Chlorella vulgaris or Arthrospira platensis was cultivated in synthetic medium, and next in diluted effluent from the anode chamber. The highest power density of 91 mW/m2 was generated by the pMFC with the cultivation of Arthrospira platensis. Higher values of dissolved oxygen remained during the dark phase in the cathodic medium with Arthrospira platensis cultivation than with Chlorella vulgaris. This depletion of oxygen significantly decreased voltage generation, which during the light phase increased again to the maximum values. The COD removal achieved in the anodic chamber was 87%. The efficiency of nitrogen removal in the cathode chamber during the cultivation of Arthrospira platensis and Chlorella vulgaris was about 78% and 69%, respectively. The efficiency of phosphorus removal in the cathode chamber with the cultivation of Arthrospira plantensis and Chlorella vulgaris was 58% and 43%, respectively. This study has shown that the introduction of Arthrospira platensis into the cathode chamber is more effective than that of Chlorella vulgaris. [ABSTRACT FROM AUTHOR]

Despite the significant Progression in nanocomposites (NCs) tailoring for ecological purposes, optimizing NCs for water treatment is still a challenge. Moreover, organic coloring (dyes) agents like Congo red (CR) and methylene blue (MB) were included which have carcinogenic effects. In this regard, photo-catalytic activity utilizing NCs for organic pollutants (dyes) removal is a great concern due to its viability and low cost. In this regard, a combination of nanocomposites including cerium Oxide (CeO 2), gadolinium oxide (Gd 2 O 3), and graphene oxide (GO) could be suggested. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were utilized for characterization in addition to EDX, and electron microscopes (TEM, and FESEM). TEM micrograph exhibits TNC as scattered lanthanides oxides (CeO 2 , and Gd 2 O 3) grains upon GO sheets. It shows a clear decline in the average size to reach 25 nm for CeO 2 , and 40 nm for Gd 2 O 3. Also, FESEM reports that GO reduces the lanthanide oxides aggregation tendency in TNC, besides forming shallow pores within its rough surface. Regarding the thermal study, It is clear that activation energy (E*) is the almost equal enthalpy of activation (ΔH). It could refer to the presence of the tested composition at a higher degree of temperature (thermally stable). Nano-composite powders exhibited improvement in photo-catalytic efficiency and inhibition of photo-corrosion as compared with pure lanthanide oxides. The MB degradation potential of CeO 2 /Gd 2 O 3 /GO drops from 94.4 % in the first usage to 82.1 % in the fifth. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrochemical oxidation of ammonia is an attractive process for wastewater treatment, hydrogen production, and ammonia fuel cells. However, the sluggish kinetics of the anode reaction has limited its applications, leading to a high demand for novel electrocatalysts. Herein, the electrode with the in situ growth of NiCu(OH)2 was partially transformed into the NiCuOOH phase by a pre-treatment using highly oxidative solutions. As revealed by SEM, XPS, and electrochemical analysis, such a strategy maintained the 3D structure, while inducing more active sites before the in situ generation of oxyhydroxide sites during the electrochemical reaction. The optimized NiCuOOH-1 sample exhibited the current density of 6.06 mA cm−2 at 0.5 V, which is 1.67 times higher than that of NiCu(OH)2 (3.63 mA cm−2). Moreover, the sample with a higher crystalline degree of the NiCuOOH phase exhibited lower performance, demonstrating the importance of a moderate treatment condition. In addition, the NiCuOOH-1 sample presented low selectivity (<20%) towards NO2− and stable activity during the long-term operation. The findings of this study would provide valuable insights into the development of transition metal electrocatalysts for ammonia oxidation. [ABSTRACT FROM AUTHOR]

Materials based on polymer hydrogels have demonstrated potential as innovative Fenton catalysts for treating water. However, developing these polymer-supported catalysts with robust stability presents a significant challenge. This paper explores the development and application of polymer-supported heterogeneous Fenton catalysts for the environmental remediation of wastewater, emphasizing the enhancement of metal incorporation into catalysts for improved efficiency. The study begins with an introduction to the heterogeneous Fenton process and its relevance to wastewater treatment. It further delves into the specifics of polymer-supported heterogeneous Fenton catalysts, focusing on iron oxide, copper complexes/nanoparticles, and ruthenium as key components. The synthesis methods employed to prepare these catalysts are discussed, highlighting the innovative approaches to achieve substantial metal incorporation. Operational parameters such as catalyst dosage, pollutant concentration, and the effect of pH on the process efficiency are thoroughly examined. The catalytic performance is evaluated, providing insights into the effectiveness of these catalysts in degrading pollutants. Recent developments in the field are reviewed, showcasing advancements in catalyst design and application. The study also addresses the stability and reusability of polymer-supported heterogeneous Fenton catalysts, critical factors for their practical application in environmental remediation. Environmental applications are explored, demonstrating the potential of these catalysts in addressing various pollutants. The Conclusions offers future perspectives, underlining the ongoing challenges and opportunities in the field, and the importance of further research to enhance the efficacy and sustainability of polymer-supported heterogeneous Fenton catalysts for wastewater treatment. [ABSTRACT FROM AUTHOR]

Aerobic granular sludge (AGS) and conventional activated sludge (CAS) are two different biological wastewater treatment processes. AGS consists of self-immobilised microorganisms that are transformed into spherical biofilms, whereas CAS has floccular sludge of lower density. In this study, we investigated the treatment performance and microbiome dynamics of two full-scale AGS reactors and a parallel CAS system at a municipal WWTP in Sweden. Both systems produced low effluent concentrations, with some fluctuations in phosphate and nitrate mainly due to variations in organic substrate availability. The microbial diversity was slightly higher in the AGS, with different dynamics in the microbiome over time. Seasonal periodicity was observed in both sludge types, with a larger shift in the CAS microbiome compared to the AGS. Groups important for reactor function, such as ammonia-oxidising bacteria (AOB), nitrite-oxidising bacteria (NOB), polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs), followed similar trends in both systems, with higher relative abundances of PAOs and GAOs in the AGS. However, microbial composition and dynamics differed between the two systems at the genus level. For instance, among PAOs, Tetrasphaera was more prevalent in the AGS, while Dechloromonas was more common in the CAS. Among NOB, Ca. Nitrotoga had a higher relative abundance in the AGS, while Nitrospira was the main nitrifier in the CAS. Furthermore, network analysis revealed the clustering of the various genera within the guilds to modules with different temporal patterns, suggesting functional redundancy in both AGS and CAS. Key points: • Microbial community succession in parallel full-scale aerobic granular sludge (AGS) and conventional activated sludge (CAS) processes. • Higher periodicity in microbial community structure in CAS compared to in AGS. • Similar functional groups between AGS and CAS but different composition and dynamics at genus level. [ABSTRACT FROM AUTHOR]

This study addresses water pollution challenges by employing photocatalysis as an effective solution. Titanium dioxide (TiO2) with unique characteristics is widely utilized in this approach. However, the design of nanosized TiO2 particles is crucial for enhancing photocatalytic performance during diazinon's photodegradation. As such, the TiO2 nanoparticles (NPs) were synthesized via the green sol‐gel method in this study, exhibit a mixed anatase‐brookite phase, a small particle size of 11.17 nm, and lower bandgap energy (3.00 eV) than pure anatase TiO2 of 3.20 eV, rendering them active under visible light. DFTB calculation was deployed to investigate the role of oxygen vacancies in reducing the bandgap energy. Experimentally measured (3.00 eV) and computationally (2.812 eV) determined bandgap energies align well. The TiO2 NPs demonstrate significant photocatalytic efficacy, degrading 73.3 % of diazinon within 210 min under sunlight, with a mineralization degree of 43.50 %, and 2‐isopropyl‐6‐methylpyrimidin‐4‐ol (IMP) was detected as the intermediate product. The photodegradation follows first‐order kinetics, and adsorption isotherm analysis fits the Langmuir model. ⋅O2− is identified as the predominant reactive oxygen species in the diazinon's photodegradation. Hence, the synthesized TiO2 NPs offer good reusability, maintaining a degradation efficiency of 67.4 % even after five cycles, showing good potential for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

The presence of poisonous Pb(II) ions in water resources has raised global health concerns. Herein, the adsorption performance of accordion‐like Ti3CN MXene for Pb(II) ions was investigated for the first time. Batch experiments were carried out by varying modifications, pH values, initial Pb(II) concentrations, adsorption time and temperatures. The results prove that the alkalized‐Ti3CN shows enhanced adsorption performance. Although the temperature effect is insignificant, the Pb(II) adsorption is strongly pH‐dependent. The maximum Pb(II) adsorption capacity of alkalized −Ti3CN is about 2.5 times higher than that of activated carbon. The adsorption ratio of Pb(II) is up to 96.6 %. The adsorption capacity increases with increasing the initial concentration of Pb(II). The alkalized‐Ti3CN adsorbs Pb(II) very quickly and the adsorption equilibrium is nearly achieved within 70 minutes. The adsorption follows the quasi‐second‐order kinetic model as well as the Langmuir model, and is mainly controlled by chemical adsorption. It is preliminarily concluded that Pb(II) replaces Na(I) of the −ONa functional groups on the alkalized‐Ti3CN surfaces. This study proves the alkalized‐Ti3CN MXene has potential application for the purification treatment of wastewater contaminated with Pb(II) ions. [ABSTRACT FROM AUTHOR]

This research investigates the efficacy of a high-performance pilot-scale Internal Circulation Anaerobic Reactor inoculated with Granular Sludge (ICAGSR) for treating cattle slaughterhouse wastewater while concurrently generating biogas. The primary objective is to assess the efficiency and performance of ICAGSR in terms of organic pollutant removal and biogas production using granular anaerobic sludge. The research methodology entails operating the ICAGSR system under ambient conditions and systematically varying key parameters, including different Hydraulic Retention Times (HRTs) (24, 12, and 8 h) and Organic Loading Rates (OLRs) (3.3, 6.14, and 12.83 kg COD/m³. d). The study focuses on evaluating pollutants' removal and biogas production rates. Results reveal that the ICAGSR system achieves exceptional removal efficiency for organic pollutants, with Chemical Oxygen Demand (COD) removal exceeding 74%, 67%, and 68% at HRTs of 24, 12, and 8 h, respectively. Furthermore, the system demonstrates stable and sustainable biogas production, maintaining average methane contents of 80%, 76%, and 72% throughout the experimental period. The successful operation of the ICAGSR system underscores its potential as a viable technology for treating cattle slaughterhouse wastewater and generating renewable biogas. In conclusion, this study contributes to wastewater treatment and renewable energy production by providing a comprehensive analysis of the ICAGSR system's hydrodynamic properties. The research enhances our understanding of the system's performance optimization under varying conditions, emphasizing the benefits of utilizing ICAGSR reactors with granular sludge as an effective and sustainable approach. Identifying current gaps, future research directions aim to further refine and broaden the application of ICAGSR technology in wastewater treatment and renewable energy initiatives. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) is a non-metallic semiconductor photocatalyst which is widely used in water treatment. Improving the charge separation and transfer efficiency of g-C3N4 has been a hot research topic. In this work, a sulfur-doped algal graphitic carbon nitride (SCN) was synthesized by microwave using thioacetamide as an elemental sulfur dopant. The alga-like structure endowed g-C3N4 with a higher specific surface area and visible light absorption. Combined with experiments and density functional theory (DFT) calculations, the introduction of S further changed the orbital structure and increased the charge density, leading to a shift of energy level positions as well as enhanced photogenerated electron transport. The combination of morphology adjustment and suitable elemental doping allowed the materials to achieve a significant improvement in the photocatalytic degradation performance of organics and the antibacterial activity. The degradation rate of rhodamine B (RhB) by SCN-60mg reached 0.21873 min−1, which was 12 times higher than that of bulk g-C3N4 (BCN). Similarly, SCN-60mg degraded malachite green (MG), neutral red (NR), methyl orange (MO), methylene blue (MB), tetracycline (TC), and ciprofloxacin (CIP) by 100%, 93%, 90%, 97%, 79%, and 86%, respectively, within 30 min. Meanwhile, SCN-60mg still exhibited excellent photocatalytic performance over four degradation cycles. In addition, SCN-60mg showed nearly 100% antibacterial efficiency of Staphylococcus aureus (S. aureus) within 1 hour. This study provides a new idea for fabricating effective photocatalysts for complex wastewater treatment. [ABSTRACT FROM AUTHOR]