Pollutants In Water Systems Research Articles

Environmental fluoxetine promotes skin cell proliferation and wound healing

This study investigates the effects of environmentally-relevant concentrations of fluoxetine (FLX, commercial name: Prozac) on wound healing. Pollution of water systems with pharmaceutical and personal care products, including antidepressants such as FLX and other selective serotonin reuptake inhibitors, is a growing environmental concern. Environmentally-relevant FLX concentrations are known to impact physiological functions and behaviour of aquatic animals, however, the effects of exposure on humans are currently unknown. Using a combination of human skin biopsies and a human keratinocyte cell line, we show that exposure to environmental FLX promotes wound closure. We show dose-dependent increases in wound closure with FLX concentrations from 125 ng/l. Using several –omics and pharmaceutical approaches, we demonstrate that the mechanisms underlying enhanced wound closure are increased cell proliferation and serotonin signalling. Transcriptomic analysis revealed 350 differentially expressed genes after exposure. Downregulated genes were enriched in pathways related to mitochondrial function and metabolism, while upregulated genes were associated with cell proliferation and tissue morphogenesis. Kinase profiling showed altered phosphorylation of kinases linked to the MAPK pathway. Consistent with this, phosphoproteomic analyses identified 235 differentially phosphorylated proteins after exposure, with enriched GO terms related to cell cycle, division, and protein biosynthesis. Treatment of skin biopsies and keratinocytes with ketanserin, a serotonin receptor antagonist, reversed the increase in wound closure observed upon exposure. These findings collectively show that exposure to environmental FLX promotes wound healing through modulating serotonin signalling, gene expression and protein phosphorylation, leading to enhanced cell proliferation. Our results justify a transition from the study of behavioural effects of environmental FLX in aquatic animals to the investigation of effects of exposure on wound healing in aquatic and terrestrial animals, including direct impacts on human health.

Elemental Profiling with Reference to Metal Index to Study Pollutant Load in Northern River of India

Present light was to determine elemental load in Sirsa river ecosystem to know the concentration of toxicants in this Sutlej river’s tributary that act as a gutter for industrial effluents of Baddi region. The inductively coupled plasma mass spectroscopy was used to detect concentration of elements in the department of biochemical engineering and biotechnology at IIT Delhi and the collected data was further analyzed statistically using one way ANOVA at (p≤0.05) followed by post hoc Duncan’s test to predict degree of variations and comparative profile in Table 1. The application of metal index was also performed to estimate water quality and co-related it with health hazards. Variations in concentration of elements was reported near common effluent treatment plant on pollutant Nallah (S2) in deceasing order read as Mg>Na>Ca>B>Zn>Cu>Mn>Fe>Mo>Al>Tl>Se in ppb. The concentration of elements reported at S1, S2, S3 were within permissible limit of WHO and Bureau of Indian Standards, except the value of Boron, Magnesium and Thallium were exceeded these guidelines constantly at site S2 of study area.The metal index values at S1, S2 and S3 were 1.55, 5.80 and 2.57 respectively. The site S2 was affected strongly due to presence of elemental dust and un-treated waste water discharged by chemical industrial units of Baddi region. This site (S2) was nearer to common effluent treatment plant on the bank of Sirsa river and found to be unsuitable at all with more value of metal index. It was also viewed to adopt such scale indices to estimate drinking water quality with respect to concentration of elements after equal interval of time; as there may be seasonal change in the load of debris due to rate of pollutants dumping in the riverine ecosystem which is directly proportional to the content of elements. The load of pollutants in water system was underlined to know the impact of inorganic waste discharges on water quality of river in this region of Himachal Pradesh along industrial belt.

Shopping around: Comparing Cd(II) sorption performance of disparate functional groups-modified microcrystalline cellulose composites

The structure-function relationship of functionalized microcrystalline cellulose (MCC) composites as adsorbents remains unclear. Herein, the orange peel-derived MCC (i.e., OP-OH-H-25) was treated by different functional agents to prepare adsorbents for cadmium (Cd(II)) removal. Mercaptoacetic acid and orthophosphoric acid did not apparently impact MCC's surface site types and contents. Alternatively, they efficiently purified OP-OH-H-25 and generated OP-OH-SH and OP-OH-P samples with increased cellulose amounts. In contrast, the glycine modification produced OP-OH-NH2 with fewer sulfhydryl/carboxyl functional groups and more amide/amino sites. The pH-dependent Cd(II) removal trends by the MCC-related materials showed three successive stages with disparate sorption modes. The Cd(II) sorption kinetics processes on OP-OH-SH, OP-OH-P, and OP-OH-NH2 reached equilibrium after 0.25 h, faster than 0.5 h on OP-OH-H-25. The maximum Cd(II) sorption capacities of MCC-related adsorbents were OP-OH-P (151.81 mg/g) > OP-OH-SH (150.80 mg/g) > OP-OH-H-25 (124.90 mg/g) > > OP-OH-NH2 (55.23 mg/g). OP-OH-P exhibited the strongest Cd(II) sorption ability under the interference of mixed aquatic components. The intrinsic Cd(II) sorption mechanisms were identified as inner-sphere complexation and cation-π bond interaction. Overall, the select priority of modifying agents is orthophosphoric acid > mercaptoacetic acid > > glycine when preparing functionalized MCC adsorbents for purifying Cd(II)-polluted water systems.

Fecal coliform assessment and detection of blaTEM, blaSHV, and tetA in Escherichia coli isolated from selected river waters of Tacloban City, Leyte, Philippines

Fecal coliforms (FCs) are generally used as indicators of fecal pollution in water systems. High levels of FC pollution in water bodies may also be associated with antibiotic resistance. Escherichia coli, a member of the FC group, is generally commensal and harmless. However, some strains can cause various diseases in humans. The prevalence of antibiotic-resistant E. coli has been reported in several river systems worldwide. Herein, we report the most probable number (MPN) of FC and E. coli and the first detection of blaTEM, blaSHV, and i>blaSHVetA antibiotic resistance genes (ARGs) as well as ARG combinations (i.e. blaTEM + tetA and blaSHV + tetA) in E. coli isolates from river waters with high levels of FC in Tacloban City. MPN was determined using a multiple-tube fermentation technique, and ARG was detected using polymerase chain reaction (PCR). Results show that the Bagacay River had the highest MPN of FC and E. coli (both >160,000 MPN/100 mL), followed by the Burayan Creek (>160,000 MPN/100 mL; 160,000 MPN/100 mL), the Mangonbangon River (92,000 MPN/100 mL; 54,000 MPN/100 mL), and the Tigbao River (35,000 MPN/100 mL; 24,000 MPN/100 mL). Among the 113 uidA gene-confirmed E. coli isolates, blaTEM, blaSHV, and tetA were detected in 39 (34.5%), 7 (6.2%), and 83 (73.5%) E. coli isolates, respectively. Moreover, 34 (30%) of the isolates possess both blaTEM and tetA, and five (4.4%) of the isolates have both i>blaSHV and tetA. These results imply that the rivers are unsafe for anthropogenic use and the presence of ARGs in E. coli isolates pose a threat for locals. Hence, the public is urged to ensure safety and awareness in relation to these water environments. Further monitoring and source tracking are recommended to enhance environmental and public health safety among locals.

Preparation of β-cyclodextrin-reduced graphene oxide aerogel and its application for adsorption of herbicides

Herbicides are the primary pesticides that can easily pollute water bodies, attracting significant attention from researchers regarding the effective removal of herbicide residues from the water environment. In this study, a β-cyclodextrin-reduced graphene oxide (β-CD-BTCA-rGO) aerogel was prepared following the self-assembly hydrothermal method using 1,2,3,4-butane tetracarboxylic acid (BTCA) as crosslinkers. The self-assembly process involved the cross-linking of “soft” β-cyclodextrin (β-CD) with “hard” graphene oxide (GO) nanosheets, forming a stable β-CD-BTCA-rGO aerogel. The prepared β-CD-BTCA-rGO aerogel demonstrated excellent adsorption performance. The adsorption capacities were 62.3 and 46.8 mg/g for sulfentrazone and quinclorac, respectively, surpassing the traditional reduced graphene oxide (rGO) aerogel and citric acid cross-linked (β-CD-CA-rGO) aerogel. Correspondingly, its adsorption capacity for quinclorac was 1.8 times and 12 times that of rGO aerogel and β-CD-CA-rGO aerogel, respectively. Quantum chemical calculations at the density functional theory (DFT) level, utilizing the Fukui function to predict chemical reaction sites, indicated that BTCA, as crosslinkers, formed stable chemical bonds (ester bonds) with GO through hydroxyl and carboxyl surface functional groups, leading to the formation of stable porous aerogels. Furthermore, the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gap was quantitatively measured for various adsorption mechanisms, revealing that electrostatic adsorption was the main force of the adsorption on the aerogels. The β-CD-BTCA-rGO aerogels prepared in this study demonstrated economic feasibility as adsorbents and exhibited good reproducibility. Consequently, β-CD-BTCA-rGO aerogels hold promising application prospects in the remediation of pesticide pollution in water systems.

Collaborative adsorption and photocatalytic degradation of high concentration pharmaceutical pollutants in water using a novel dendritic fibrous nano-silica modified with chitosan and UiO-66

This study presents a novel hybrid mesoporous material for degrading drug pollutants in water. The hybrid materials, derived from UiO-66 metal-organic framework and chitosan, coated on nano-silica, showed excellent drug adsorption through hydrogen-bonding interactions and efficient photodegradation of antibiotics. The hybrid material's enhanced conductivity and reduced band gap significantly improved pollution reduction by minimising electron-hole recombination. This allows for more efficient charge transport and better light absorption, boosting the material's ability to break down pollutants. Structural and morphological analyses were conducted using various techniques, including scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Optimising the adsorption-photodegradation process involved investigating pH, catalyst dose, and radiation time. Non-linear optimisation revealed an efficiency exceeding 85 % for 400 mg/L tetracycline and doxycycline, the model antibiotics. The optimal parameters for maximal elimination were determined as pH = 4.3, hybrid mesosphere dose = 4.0 mg/mL, and radiation time = 10 min. Kinetic studies favored pseudo-second-order diffusion models over pseudo-first-order models. The hybrid mesosphere showed sustained efficiency after three cycles and performed well in real aqueous samples, removing over 80 % of each antibiotic. This study demonstrates the potential of the hybrid mesoporous material for removing pharmaceutical pollutants in water systems.

Electrochemical reduction of nitrate to Ammonia: Recent progress and future directions

Ammonia (NH3) is essential for global food production as a key agricultural fertilizer and is increasingly recognized as a renewable energy carrier. The electrochemical nitrate reduction (eNO3RR) method stands out as a promising alternative to the traditional, energy-intensive and CO2-emitting Haber-Bosch process, capable of converting residual NO3– pollutants in water systems into valuable NH3 under ambient conditions. Advancing this process toward commercialization relies on the development of electrocatalysts that are highly active, durable, and cost-effective. This article reviews recent progress in electrocatalyst design aimed at improving the efficiency and selectivity of the NO3– to NH3 conversion. Through an exploration of innovative strategies, including doping, alloying, defect engineering, hybridization and single/dual-atom catalysts, this review details how these methods have markedly enhanced catalyst performance, offering avenues to surmount the challenges posed by traditional pure material-based electrocatalysts. Furthermore, the potential for scaling up these technologies for industrial applications is explored. The objective is to provide a comprehensive overview that not only addresses the scientific and technical challenges but also suggests future directions in the development of sustainable and efficient ammonia synthesis technologies, contributing to global efforts in sustainable energy and agricultural practices.

Biodegradation of Pharmaceutical Pollutants Using Fungal Enzyme

Abstract: The potential of filamentous fungi and their enzymes are investigated for bioremediating pharmaceutical pollutants from wastewater thereby addressing the growing concern of emerging pollutants in water resources. Among the various microorganisms, the current abstract discusses the role of fungi in degrading antibiotics and persistent pharmaceutical compounds. These fungi allow the biodegradation via the formation of highly oxidative hydroxyl radicals. It summarizes the role of both intra (cytochrome P450) and extracellular (laccase) enzyme systems for the bioremediation of emerging clinical pollutants. It emphasizes the importance of both biosorption and biodegradation for effective pollutant removal by breaking down pharmaceuticals (e.g. antibiotics) and other hazardous compounds (e.g. endocrine-disrupting compounds, polycyclic aromatic hydrocarbons). Although the enzymes CYP450 are not directly engaged, their metabolic pathways execute mechanisms such as oxidation, the formation of reactive intermediates, and chemical modification, all of which result in the degradation of clinical pollutants. Amongst all enzyme systems in the case of laccase which oxidise a wide spectrum of substrates, converts them to free radicals. Additionally, the role of recombinant enzyme production and transgenic strains for pollutant degradation has also been elaborated. These considerations emphasise the need for ongoing research and biotechnological advancements to address the growing concern of pharmaceuticals and personal care product pollutants in water systems.

Tandem photocatalysis of nitrate to nitrogen on Cu@CN/TiOx S-scheme heterojunction

The persistent challenge of nitrate (NO3–) pollution in water systems, profoundly impacting ecosystems and human health, demands effective remediation strategies. Here, we present an innovative S-scheme Cu@CN/TiOx heterojunction for high-efficiency photocatalytic denitrification (PCDN). Evaluation of its performance demonstrates exceptional NO3– removal efficiency (99.5%) and remarkable N2 selectivity (95.5%), with 13.7 and 4.1 times higher rate constants of NO3– removal than the individual Cu@CN and TiOx components. Notably, this catalyst exhibits impressive stability across multiple cycles, maintaining consistent high conversion rates and selectivity. Mechanistic insights unveiled a tandem reaction pathway where Cu@CN selectively reduced NO3– to NO2–, followed by the TiOx-mediated CO2•– generation, enabling highly selective NO2– to N2 conversion. This unique catalytic system, featuring spatially separated redox-active sites, presents a promising avenue for efficient, selective, and stable denitrification processes, offering significant potential in addressing water pollution challenges and advancing tandem catalytic systems.

Experimental and ab initio studies of enhance photocatalytic efficiency of La-doped ZnO/g-C3N4 nanocomposites for bromothymol blue dye degradation

The ability of photocatalysis to clean up environmental contamination, notably in the treatment of water and air, has received extensive research. The composite materials synthesized by the coprecipitation method were made of ZnO and graphitic carbon nitride (g-C3N4) with various concentrations of lanthanum doping (La-ZnO). It was discovered that La metal ions were evenly distributed throughout the layered stacking structures of ZnO nanosheet, which had an impact on the band structure and increased the rate of electron-hole separation and visible light absorption. First-principles calculations show that La-doped ZnO-gC3N4 possesses a direct band gap and a type-II band structure with the conduction band minimum and the valence band maximum located in separate layers. A built-in electric field from the gC3N4 to the La-doped ZnO has been established through an analysis of charge density difference, Bader charge, work function, and band alignment. The electron-hole pair becomes spatially separated as a result, which increases the photodegradation activity. High interfacial charge transfer, efficient charge separation and migration, and high visible light optical absorbance were caused by the direct coating of ZnO on an ultra-thin g-C3N4 layer. The 0.6 % La-doped ZnO-gC3N4 degraded 97 % of the bromothymol blue (BB) dye, which was four times higher than the bulk ZnO, which could remove only about 21 % of the dye at the same time. The combined effects of lower photo corrosion, higher solar light usage owing to a hollow structure and heterostructured semiconductor photocatalysis contribute to this increased photocatalytic activity. The capacity of La-doped ZnO/g-C3N4 nanocomposite to effectively break down BB dye via photocatalysis suggests that it has the potential to address the problems associated with dye pollution in water systems.

Light harvesting enhancement through band structure engineering in graphite carbon nitride / polydopamine nanocomposite photocatalyst: Addressing persistent organophosphorus pesticide pollution in water systems

Organophosphorus pesticides, particularly profenofos (PF), pose a significant threat to the food supply and human health due to their persistence, toxicity, and resistance to natural breakdown processes. An urgent need exists for an environmentally friendly solution, and photocatalysis emerges as a practical, cost-effective option. However, challenges like poor light responsiveness and difficulties in material separation and reusability persist. To address these issues, we developed a nanocomposite consisting of graphite carbon nitride (g-C3N4) doped with polydopamine (pDA) through a hydrothermal synthesis method. This innovative nanocomposite was employed as a photocatalyst to degrade PF. Various analytical techniques, including UV-DRS, FT-IR, XRD, HR-TEM, and EDAX, were utilized to characterize the synthesized nanocomposite. The strategically modulated band gaps of the nanocomposite enable efficient absorption of UV light, facilitating the robust photocatalytic degradation of PF (96.4%). Our study explored photodegradation using different g-C3N4/pDA catalyst dosages, varied PF concentrations, and pH levels (3, 5, 9, and 11) under UV light. Our findings promise applications in wastewater management, offering an efficient catalyst for PF degradation. This marks a significant stride in addressing challenges related to pesticide pollution in the environment.

Nuclear gene introgressions in hybrid populations of water frog Pelophylax esculentus complex: geographical analysis of the phenomenon and its interpretation.

Reproduction of water frog hybrids Pelophylax esculentus (Pelophylax ridibundus x Pelophylax lessonae) is associated with hemiclonal reproduction and backcrossing. The hemiclonal mode of reproduction occurs within P. esculentus allodiploids. In this case, the unrecombined genome of one parental species is transmitted to the offspring after premeiotic elimination of the chromosome set of the second parental species. Usually, the chromosome set of P. lessonae is eliminated, and the altered genome of P. ridibundus is passed on to the progeny. The hemiclonal inheritance within diploid Pelophylax esculentus hybrids may be accompanied by certain aberrations of premeiotic elimination. As a result, the formation of P. ridibundus specimens with introgressions of the P. lessonae genetic material, or the formation of recombinant hybrids occurs, depending on which of the parental species backcrossing takes place. The aim of our study is to describe the aberration of premeiotic elimination within the water frog P. esculentus complex detected by the nuclear gene Ldh-B inheritance, with an attempt to find out the causes of this phenomenon. It has been established that aberrations of premeiotic elimination are widespread, but only within populations of water frog from the river system of Upper Dnieper within Ukraine. The highest level of introgression takes place in the water frog populations within Kiev metropolis under conditions of expressed anthropogenization, while the maximum frequency of recombinants was detected within populations from the basin of Desna River, that has preserved native ecosystems. It was demonstrated that the frequency of premeiotic aberrations does not correlate with the intensity of interspecific water frog hybridization. Populations with introgressions are more common than populations with recombinants, however, within the latter, the frequency of recombination events is higher. The primary factor of gametogenesis aberrations, most likely, is the genetic characteristics of the local populations of parental species, since unambiguous explanations of this phenomenon based on the action of environmental stress (pollution of water systems) are not obvious.

Microplastic Pollution in Water Systems: Characteristics and Control Methods

Microplastics have been widely detected in the natural water environment, which brings inevitable risks to the water ecosystem and human health. However, the understanding of the potential impact of microplastics on aquatic animals, plants, and human health is still limited, and technical methods to control microplastic pollution in natural water are still rare. Hence, this paper summarizes the progress of research on microplastic pollution in water systems in terms of microplastic source, attributes, distribution characteristics, environmental effects, and prevention and control methods according to the relevant research reports on water microplastic pollution. It also expounds the basic ways for the prevention, control, and treatment of water microplastics, and looks forward to the research direction of water microplastic pollution in the future. The results show that the abundance of fresh water microplastics in China is higher than that in other regions, but the pollution level of marine microplastics is at the middle level. Compared with other countries, the pollution degree of microplastics in aquatic organisms in China is at the middle and lower level, but the spatial heterogeneity is more obvious. Through hydraulic control and the substitution of degradable plastic products, water microplastic pollution can be greatly reduced. This paper can provide a reference basis for the formulation of microplastic pollution prevention and control in China.

Ubiquitous occurrence of p-Phenylenediamine (PPD) antioxidants and PPD-quinones in fresh atmospheric snow and their amplification effects on associated aqueous contamination

p-Phenylenediamine (PPD) antioxidants are heavily used for protection of commercial rubber products (e.g., vehicle tire), resulting in their widespread contamination in ecosystem. PPD-quinones (PPDQs), the toxic quinone derivatives of PPDs, are also discovered as novel environmental pollutants. However, the contamination characteristics of PPDs/PPDQs in fresh atmospheric snow (without deposition on the Earth surface) have seldom been studied. This work first reports the broad distributions of PPDs and PPDQs in fresh atmospheric snow collected from seven Chinese urban areas. Individual median values of detected concentrations were in the ranges of 0.4 to 260 pg g−1 (PPDs) and 0.7 to 104 pg g−1 (PPDQs). The concentration deviation by long-term deposition on the ground was eliminated. In most sampling regions, wearing of vehicle rubber tires was possibly responsible for spatial-dependent PPDs’ pollution level variations, and high concentrations of PPDs promoted PPDQs’ formation in snow from atmosphere. Yet, excessive O3 may further oxidize and reduce PPDQs in atmospheric fresh snow from Zhengzhou, which is different from previous research. Furthermore, snowfall was noticed might amplify concentrations of three PPDs and PPDQs in an inland lake, which possibly worsen corresponding pollution in water system. Current study elucidates the potential impacts of snow-bound PPDs/PPDQs on ecosystems should not be underestimated.

High-efficient charge separation in novel Zn0.5Cd0.5S/Bi4V2O11 heterostructure for boosting photocatalytic Cr (VI) reduction and degradation of tetracycline hydrochloride

Photocatalysis is a green and sustainable technology for the efficient removal of harmful pollutants in water, however, due to the coexistence of multiple pollutants in water system, it is a great challenge to develop multi-functional and efficient photocatalytic systems. Herein, a novel bifunctional Zn0.5Cd0.5S/Bi4V2O11 (ZCS/BVO) heterostructrue photocatalyst was designed and prepared by growing Zn0.5Cd0.5S nanospheres on the surfaces of Bi4V2O11 disc-like nanoflowers through a facial in-situ hydrothermal method. The as-prepared ZCS/BVO heterostructure showed much more enhanced bifunctional visible-light catalytic activity for Cr (VI) reduction and TCH degradation compared with pure Zn0.5Cd0.5S and Bi4V2O11. Among ZCS/BVO samples, ZCS/BVO-10 possessed the best Cr (VI) reduction performance of 86.7 % in 60 min, which was 1.38 and 9.96 times of Zn0.5Cd0.5S and Bi4V2O11. Moreover, ZCS/BVO-10 heterostructure also showed excellent TCH degradation ability of 80.3 % in 48 min, about 2.38 and 3.20 times as high as those of Zn0.5Cd0.5S and Bi4V2O11. The synergistic effect between Zn0.5Cd0.5S and Bi4V2O11 and the close contacted ZCS/BVO heterostructure greatly favored TCH degradation and Cr (VI) reduction reactions due to the increased surface area, enhanced light absorption and boosted charge separation. From the cyclic experiment, ZCS/BVO exhibited high stability and reusability. This work undoubtedly provided a multi-functional and effective photocatalyst for treating various pollutants in water bodies.

MICROPLASTIC POLLUTION IN FRESH WATER

Water bodies are being slowly but inevitably suffocated by microplastics. Different routes, such as atmospheric deposition, runoff from contaminated soil, or municipal wastewater, allow microplastics to reach water bodies. The movement of plastic debris was significantly aided by storm-water runoff. Microplastics comprise fibres, shreds, particles, flakes, sheets, or foams and occur in a wide range of shapes, colours, and chemical compositions. Environmentalists, organisations, and governments are now aware of the contamination caused by microplastics in both the marine and terrestrial environments. The available literature on microplastic pollution in water systems was obtained for this review. It was noted that freshwater ecosystems and oceans might be comparable. The existence of microplastics as a stressor in freshwater habitats around the world, given that research on microplastics has just recently begun, our knowledge of their appearance, dispersion, and methods for reliable identification and quantification is still limited. Furthermore, it is unclear how microplastics could affect human health. Considering that extensively human populations rely on water supplies for food and drinking water, raising awareness in these areas is critical if we are to develop appropriate policies and management tools to address this emerging issue. Keywords: Water bodies, microplastics, storm-water runoff, plastic debris, human health

A Review on Pulsed Laser Fabrication of Nanomaterials in Liquids for (Photo)catalytic Degradation of Organic Pollutants in the Water System.

The water pollution caused by the release of organic pollutants has attracted remarkable attention, and solutions for wastewater treatment are being developed. In particular, the photocatalytic removal of organic pollutants in water systems is a promising strategy to realize the self-cleaning of ecosystems under solar light irradiation. However, at present the semiconductor-based nanocatalysts can barely satisfy the industrial requirements because their wide bandgaps restrict the effective absorption of solar light, which needs an energy band modification to boost the visible light harvesting via surface engineering. As an innovative approach, pulsed laser heating in liquids has been utilized to fabricate the nanomaterials in catalysis; it demonstrates multi-controllable features, such as size, morphology, crystal structure, and even optical or electrical properties, with which photocatalytic performances can be precisely optimized. In this review, focusing on the powerful heating effect of pulsed laser irradiation in liquids, the functional nanomaterials fabricated by laser technology and their applications in the catalytic degradation of various organic pollutants are summarized. This review not only highlights the innovative works of pulsed laser-prepared nanomaterials for organic pollutant removal in water systems, such as the photocatalytic degradation of organic dyes and the catalytic reduction of toxic nitrophenol and nitrobenzene, it also critically discusses the specific challenges and outlooks of this field, including the weakness of the produced yields and the relevant automatic strategies for massive production.

Recent Advances in Metal-Organic Framework (MOF)-Based Photocatalysts: Design Strategies and Applications in Heavy Metal Control.

The heavy metal contamination of water systems has become a major environmental concern worldwide. Photocatalysis using metal-organic frameworks (MOFs) has emerged as a promising approach for heavy metal remediation, owing to the ability of MOFs to fully degrade contaminants through redox reactions that are driven by photogenerated charge carriers. This review provides a comprehensive analysis of recent developments in MOF-based photocatalysts for removing and decontaminating heavy metals from water. The tunable nature of MOFs allows the rational design of composition and features to enhance light harvesting, charge separation, pollutant absorptivity, and photocatalytic activities. Key strategies employed include metal coordination tuning, organic ligand functionalization, heteroatom doping, plasmonic nanoparticle incorporation, defect engineering, and morphology control. The mechanisms involved in the interactions between MOF photocatalysts and heavy metal contaminants are discussed, including light absorption, charge carrier separation, metal ion adsorption, and photocatalytic redox reactions. The review highlights diverse applications of MOF photocatalysts in treating heavy metals such as lead, mercury, chromium, cadmium, silver, arsenic, nickel, etc. in water remediation. Kinetic modeling provides vital insights into the complex interplay between coupled processes such as adsorption and photocatalytic degradation that influence treatment efficiency. Life cycle assessment (LCA) is also crucial for evaluating the sustainability of MOF-based technologies. By elucidating the latest advances, current challenges, and future opportunities, this review provides insights into the potential of MOF-based photocatalysts as a sustainable technology for addressing the critical issue of heavy metal pollution in water systems. Ongoing efforts are needed to address the issues of stability, recyclability, scalable synthesis, and practical reactor engineering.

New activated carbon derived from Gundelia tournefortii seeds for effective removal of acetaminophen from aqueous solutions: Adsorption performance

Pharmaceuticals as one of the emerging pollutants in water systems are a global environmental concern. This study aims to synthesize a new activated carbon from Gundelia tournefortii seeds (ACGT) for effective removal of acetaminophen (ACT) from aqueous solutions. The synthesized adsorbent was characterized by different techniques, namely FESEM, EDX, XRD, FTIR, BET, TGA, and pHpzc. The effects of experimental parameters such as pH, adsorbent dosage, initial concentration, contact time and ionic strength on the ACT adsorption were investigated. Optimization studies revealed that the maximum removal (98.31%) of ACT was obtained at 30 min of contact time, 0.25 g/L adsorbent, 20 mg/L Ca2+, pH 4.0 and temperature 25˚C. For predicting ACT adsorption on synthetized adsorbent, isotherm, kinetic, and thermodynamic characteristics were determined. The equilibrium data were well represented by Freundlich model (R2 = 0.97) and kinetics data were well fitted by the pseudo-second order model. The thermodynamic analysis discovered that the adsorption process was endothermic and spontaneous. Overall, the development of the ACGT can be a promising adsorbent for ACT removing from aqueous solutions.

A novel 3-dimensional graphene-based cobalt-manganese bimetallic layered double hydroxide:Formation mechanism and performance in photo-assisted permonosulfate-activated degradation of sulfamethoxazole in aqueous solution

Sulfamethoxazole (SMX) is a common antibiotic used mainly for bacterial treatment. In this study, a novel three-dimensional cobalt-manganese bimetallic layered double hydroxide graphene hydrogel (CoMn-LDHs/rGO) has been prepared for photo-assisted permonosulfate (PMS)-activated degradation of SMX in water. Compared with the CoMn-LDHs/rGO + PMS and CoMn-LDHs/rGO + Vis systems, the degradation effect of CoMn-LDHs/rGO + PMS + Vis system is the best, and the degradation effect of CoMn-LDHs/rGO system could reach more than 98% under the optimal conditions. After 10 cycles, the catalytic degradation performance of CoMn-LDHs/rGO system remained good, while effectively preventing the leaching of metal ions. Based on the synergistic effect of photocatalysis and PMS oxidation, electron spin resonance spectroscopy and quenching experiments showed that three active substances (•OH, •SO4− and O2•−) were involved in the degradation of SMX. Density functional theory and liquid chromatography-mass spectrometry (LC-MS) results further proposed the SMX degradation transformation calculation. As expected, the study of the reaction mechanism of 3D CoMn-LDHs/rGO assisted PMS activation under visible light provides an efficient and rapid method for the sustainable degradation of pollutants in water system.