Pollutants In Aquatic Environment Research Articles

Synergistic Photocatalysis of Bayerite/Zeolite Loaded TiO2 Nanocomposites for Highly Efficient Degradation of Organic Pollutants in Aqueous Environments

Synergistic Photocatalysis of Bayerite/Zeolite Loaded TiO2 Nanocomposites for Highly Efficient Degradation of Organic Pollutants in Aqueous Environments

Processing Banana Peel Organic Waste in Tourism Areas as an Effort to Control Aquatic Environmental Pollution

Processing Banana Peel Organic Waste in Tourism Areas as an Effort to Control Aquatic Environmental Pollution

Co-exposure to cadmium and triazophos induces variations at enzymatic and transcriptional levels in Opsariichthys bidens

Heavy metals and pesticides are significant pollutants in aquatic environments, often leading to combined pollution and exerting toxic effects on aquatic organisms. With the rapid growth of modern industry and agriculture, heavy metal cadmium (Cd) and pesticide triazophos (TRI) are frequently detected together in various water bodies, particularly in agricultural watersheds. However, the combined toxic mechanisms of these pollutants on fish remain poorly understood. This experiment involved a 21-day co-exposure of Cd and TRI to the hook snout carp Opsariichthys bidens to investigate the toxic effects on liver tissues at both enzymatic and transcriptional levels. Biochemical analysis revealed that both individual and combined exposures significantly increased the content or activity of caspase-3 (CASP-3) and malondialdehyde (MDA). Moreover, the impact on these parameters was greater in the combined exposure groups compared to the corresponding individual exposure groups. These findings suggested that both individual and combined exposures could induce mitochondrial dysfunction and lipid peroxidation damage, with combined exposure exacerbating the toxicological effects of each individual pollutant. Furthermore, at the molecular level, both individual and combined exposures upregulated the expression levels of cu-sod, cat, and erβ, while downregulating the expression of il-1. Similar to the patterns observed in the biochemical parameters, the combined exposure group exhibited a greater impact on the expression of these genes compared to the individual exposure groups. These results indicated that exposure to Cd, TRI, and their combination induced oxidative stress, endocrine disruption, and immunosuppression in fish livers, with more severe effects observed in the combined exposure group. Overall, the interaction between Cd and TRI appeared to be synergistic, shedding light on the toxic mechanisms by which fish livers responded to these pollutants. These findings contributed to the understanding of mixture risk assessment of pollutants and were valuable for the conservation of aquatic resources.

Protective effect of quercetin on carp cardiac damage caused by difenoconazole via alleviating oxidative damage, inflammatory responses, and apoptosis

Pollution of aquatic environment by difenoconazole (DFZ) significantly affects survival and safety of freshwater aquaculture. Due to its anti-inflammatory and antioxidant properties, plant-derived quercetin (QUE) is often used as a dietary supplement. The main purpose of this study was to explore the protective effect of QUE on heart damage caused by exposure to pesticide DFZ and the potential mechanisms of these effects. This study found that QUE could effectively reduce the myocardial enzyme spectrum index of carp after exposure to DFZ, increase the levels of total antioxidant capacity (T-AOC), glutathione (GSH), and catalase (CAT), inhibit the content of malondialdehyde (MDA), and increase the transcription levels of superoxide dismutase (sod), glutathione peroxidase (gsh-px), and cat. By reducing the expression of keap1, QUE increased the transcription levels of nrf2 and nqo-1, reduced the production of reactive oxygen species (ROS) in the heart after exposure to DFZ, and restored the redox homeostasis of the heart. QUE upregulated the expression of anti-inflammatory cytokines il-10 and tgf-β1 levels, downregulated the transcription levels of pro-inflammatory factor inos, il-1β, il-6 and tnf-α, and alleviated the in vivo redox imbalance caused by exposure to DFZ, leading to myocardial interstitial inflammatory cell infiltration. The results showed that QUE inhibited the apoptosis after exposure to DFZ by affecting the expression of apoptotic factors in the mitochondrial apoptotic pathway. In summary, QUE can effectively decrease myocardial injury caused by exposure to DFZ in aquatic environment.

Sources, Risks, and Remediation Technologies of Pollutants in Aquatic Environments

Sources, Risks, and Remediation Technologies of Pollutants in Aquatic Environments

Suspect and non-targeted screening of chemical pollutants in Botswana's aquatic environments

Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological importance. Here, we perform a study of water samples collected from 13 locations distributed across Botswana to obtain the first overview of the nature and distribution of chemical contaminants across the country's aquatic environment. High resolution mass spectrometry was applied using non-targeted and suspect screening methods to qualitatively analyse samples. A total of 114 contaminants of emerging concern (CECs) were identified including 68 (59.6 %) pharmaceuticals and pharmaceutical metabolites; 16 (14.2 %) pesticides; 13 (11.4 %) psychoactive compounds and metabolites; 11 (9.7 %) industrial chemicals and intermediates and lastly, 5 (4.4 %) personal care products. Allopurinol, 3,4-dimethylmethcathinone, and diazolidinyl urea represented the most commonly detected pharmaceutical, psychoactive drug and personal care product, respectively. The pesticide dodemorph and three industrial chemicals (stearamide, pthalic acid and bis(2-ethylhexyl) phthalate) were detected in all samples obtained. 90 CECs were detected in receiving water (from 7 sample locations), 75 in wastewater (from 3 sample locations) and 60 in surface water (from 9 sample locations). Of the compounds detected, only 8 had been identified in environmental samples acquired in Botswana previously. We discuss the variations in the nature and frequency of chemical pollutants detected in this work in a geographical context. The results indicate that Botswana's aquatic systems are subject to pollution, despite wastewater treatment and that in order to mitigate potentially harmful effects on both human and aquatic ecosystems, more investigations are required to correctly identify, track and tackle the sources of pollution.

Effects of 17β-Estradiol Pollution on Microbial Communities and Methane Emissions in Aerobic Water Bodies.

17β-Estradiol (E2) is a widely present trace pollutant in aquatic environments. However, its impact on microbial communities in aerobic lake waters, which are crucial for methane (CH4) production, remains unclear. This study conducted an E2 contamination experiment by constructing laboratory-simulated aerobic microecosystems. Using 16S rRNA high-throughput sequencing, the effects of E2 on bacterial and archaeal communities were systematically examined. Combined with gas chromatography, the patterns and mechanisms of E2's impact on CH4 emissions in aerobic aquatic systems were uncovered for the first time. Generally, E2 contamination increased the randomness of bacterial and archaeal community assemblies and weakened microbial interactions. Furthermore, changes occurred in the composition and ecological functions of bacterial and archaeal communities under E2 pollution. Specifically, two days after exposure to E2, the relative abundance of Proteobacteria in the low-concentration (L) and high-concentration (H) groups decreased by 6.99% and 4.01%, respectively, compared to the control group (C). Conversely, the relative abundance of Planctomycetota was 1.81% and 1.60% higher in the L and H groups, respectively. E2 contamination led to an increase in the relative abundance of the methanogenesis functional group and a decrease in that of the methanotrophy functional group. These changes led to an increase in CH4 emissions. This study comprehensively investigated the ecotoxicological effects of E2 pollution on microbial communities in aerobic water bodies and filled the knowledge gap regarding aerobic methane production under E2 contamination.

Recycling crayfish shell and waste activated sludge as biochar to in-situ enhance antibiotics removal from wastewater: Linking structure properties and reaction kinetics

Aquaculture water represents a substantial source of antibiotics in the environment, thereby implicating potential hazards to human health and ecological stability. Additionally, the cultivation of crayfish in such water exacerbates concerns regarding the management of shell waste. In this investigation, crayfish shells and waste activated sludge were repurposed as biochar for the in-situ mitigation of antibiotics elimination from aquaculture wastewater. Compared to crayfish biochar (C-BC) solely from crayfish shell, crayfish sludge biochar (CS-BC) significantly enhances the adsorption of typical antibiotics like tetracycline and ciprofloxacin by 50.3–77.1 %. Findings from kinetic and isotherm experiments suggest that antibiotics adsorption mainly involves physical pore filling, but sludge introduction shifts CS-BC towards chemical adsorption. Further analysis reveals that sludge introduction reduces biochar pore size, boosts specific surface area, and offers more active adsorption sites. Additionally, hydrogen bonding on hydroxyl groups and increased oxygen-containing functional groups enhanced antibiotic adsorption onto CS-BC surfaces. This research presents a promising strategy for addressing antibiotic pollution in aquatic environments while also improving the utilization of organic solid waste resources.

Green route to fabrication of Semal-ZnO nanoparticles for efficient solar-driven catalysis of noxious dyes in diverse aquatic environments.

This work successfully demonstrates a sustainable and environmentally friendly approach for synthesizing Semal-ZnO nanoparticles (NPs) using the aqueous leaf extract of Bombax ceiba L. These NPs exhibit an absorption peak at approximately 390nm in the UV-visible spectrum and an energy gap (Eg) of 3.11eV. Detailed analyses of the morphology and particle size using various spectroscopic and microscopic techniques, XRD, FE-SEM with EDS, and HR-TEM reveal crystallographic peaks attributable to the hexagonal phase, with an average crystal size of 17nm. The Semal-ZnO NPs also exhibit a notable photocatalytic efficiency for degrading methylene blue (MB) and methyl orange (MO) under sunlight in different water samples collected from diverse natural sources, indicating that they are promising photocatalysts for environmental remediation. The photocatalytic efficiency of the biofabricated Semal-ZnO NPs is impressive, exhibiting a photodegradation rate of up to 99% for MB and 79% for MO in different water samples under exposure to sunlight. The novel phytofabricated Semal-ZnO NPs are thus a beacon of hope for the environment, with their desirable photocatalytic efficiency, pseudo-first-order kinetics, and ability to break down noxious dye pollutants in various aquatic environments.

Heavy metals removal in a graphene engineered concrete-based filter column

In this study, crushed aggregate surfaces were coated with reduced graphene oxide (RGO) using a chitosan-derived solution and included in porous concrete-based filter column samples to improve heavy metal removal. The RGO coating strengthened the aggregate and cement interfaces, thus improving the compressive strength of these samples by up to 18 %. The removal of lead and copper in samples containing RGO coated aggregate (GCA) operated with a minimum hydraulic load was found to be 97 % and 92 %. Increasing the hydraulic load reduced this heavy metal removal, but the presence of GCA increased the active sites for heavy metal ions to immobilize, leading to improved copper removal under such operating conditions. Calcium ions from the cement hydrates were found to leach from the concrete matrices during such a wastewater passage. This leaching of calcium ions was determined to be relatively lesser in RGO decorated concrete samples, pointing out the positive effects of GCA on the resistance of the concrete matrices to aggressive chemicals. Clay particles containing highly turbid water were also passed through these concrete samples to examine the effects on the infiltration rate. Clay particles were found to clog pores, marginally reducing the infiltration rate. Concrete-based water filters are easy to operate and have low maintenance requirements, and industries responsible for heavy metal pollution in aquatic environments can widely adopt them instead of complex treatment methods.

Self-powered organic pollutants degradation in wastewater by photocatalytic ozonation based on triboelectric nanogenerator

It is of great significance to explore innovative ways to degrade organic pollutants in wastewater. Here, for the first time, we report a self-powered photocatalytic ozonation water purification system for removing organic pollutants in aquatic environment. A rabbit fur-based rotary triboelectric nanogenerator (RR-TENG) is designed as the power supply of water purification system. As a new TENG-based ozone generation method, spark-surface dielectric barrier discharge (Spark-SDBD) is proposed, which is composed of spark discharge device and surface dielectric barrier discharge (SDBD) device in series and can generate ozone to a maximum concentration of 36.4 mg/m3. Rhodamine B and ciprofloxacin, two typical organic compounds, are selected as simulated pollutants in wastewater, and P25 particles loaded on nickel foam are used as the photocatalyst. Ozone is continuously introduced into the polluted solution through an aeration device, coupled with photocatalysis. Within 80 minutes, it can be observed that Rhodamine B has 100% decolorization and ciprofloxacin is degraded to 99%. This work broadens the field of water purification and provides an effective way to create a cleaner and safer aquatic environment.

Bronze TiO2-MXene heterostructures for dramatic enhancement of photocatalytic degradation of tetracycline under visible light

Although TiO2 nanomaterials have been widely used for the photocatalytic degradation of antibiotic pollutants in aqueous environments under ultraviolet (UV)-light irradiation, their photocatalytic performances are still unsatisfactory under visible light because of the large band gap. Herein, the bronze TiO2-MXene (TiO2(B)-MXene) heterostructures are successfully prepared and serve as photocatalysts to degrade the tetracycline (TC) pollutants under visible light for the first time. As a result, the heterostructure photocatalysts (20 mg) realize almost ∼ 92 % degradation efficiency of TC (20 mg L-1, 100 mL) in 40 min under the irradiation of Xe lamp (300 W), attributing to the synergistic effect of MXene nanosheets and TiO2(B) nano-flowers.

Novel core-shell structural nZVI@Fe2P for sulfadiazine (SDZ) degradation: Accelerated Fe(III)/Fe(II) dynamic cycling, boosted Fenton performance and stability

Nano zero valent iron (nZVI) is widely used in traditional hydrogen peroxide (H2O2)-based Fenton reactions for the degradation of persistent organic pollutants in aqueous environments. How to restrain the blocked electron transfer aroused from thickening of the iron oxide passivation layer and reinforce the Fe(III)/Fe(II) dynamic cycling is essential for Fenton reactions. In this work, a novel core–shell structural nZVI@Fe2P was fabricated and employed for the degradation of sulfadiazine (SDZ). Compared to nZVI, the nZVI@Fe2P demonstrated a significant performance and stability in the degradation of SDZ. Completed SDZ removal is achieved in less than 15 min and the SDZ removal kept over 60% even in the ninth consecutive cycles. Although the SDZ removal decreased dramatically to only 27.4% in the tenth cycle, the value could be restored to 80.6% after a facile re-phosphorization process. Both experimental and density function theory (DFT) calculation revealed the dominant role of Fe2P in promoting H2O2 activation and strengthening the Fe(III)/Fe(II) dynamic cycling. In the nZVI@Fe2P/H2O2 system, the low impedance and high proton conductivity of the Fe2P shell layer played a dual function, i.e., accelerating electron transfer and donating electrons for the continuous Fenton reaction. This implication of these findings provides a novel strategy by integrating the state-of-the-art material science, advanced oxidation process, and mechanism elucidation for practical environmental wastewater remediation.

Comparative impact of pristine and aged microplastics with triclosan on lipid metabolism in larval zebrafish: Unveiling the regulatory role of miR-217

The prevalence of microplastics (MPs), especially aged particles, interacting with contaminants like triclosan (TCS), raises concerns about their toxicological effects on aquatic life. This study focused on the impact of aged polyamide (APA) MPs and TCS on zebrafish lipid metabolism. APA MPs, with rougher surfaces and lower hydrophobicity, exhibited reduced TCS adsorption than unaged polyamide (PA) MPs. Co-exposure to PA/APA MPs and TCS resulted in higher TCS accumulation in zebrafish larvae, notably more with PA than APA. Larvae exposed to PA + TCS exhibited greater oxidative stress, disrupted lipid metabolism, and altered insulin pathway genes than those exposed to TCS. However, these negative effects were lessened in the APA + TCS group. Through miRNA-seq and miR-217 microinjection, it was revealed that PA + TCS co-exposure upregulated miR-217, linked to lipid metabolic disorders in zebrafish. Moreover, molecular docking showed stable interactions formed between PA, TCS, and the insulin signaling protein Pik3r2. This study demonstrated that PA and TCS co-exposure significantly inhibited the insulin signaling in zebrafish, triggering lipid metabolism dysregulation mediated by miR-217 upregulation, while APA and TCS co-exposure alleviated these disruptions. This research underscored the ecological and toxicological risks of aged MPs and pollutants in aquatic environments, providing crucial insights into the wider implications of MPs pollution.

Development of diffusive gradients in thin-films technique for monitoring polycyclic aromatic hydrocarbons in coastal waters

Addressing the challenge of accurately monitoring polycyclic aromatic hydrocarbons (PAHs) in aquatic systems, this study employed diffusive gradients in thin-films (DGT) technique to achieve methods detection limits as low as 0.02 ng L−1 to 0.05 ng L−1 through in situ preconcentration and determination of time-integrated concentrations. The efficacy of the developed DGT samplers was validated under diverse environmental conditions, demonstrating independence from factors such as pH (5.03–9.01), dissolved organic matter (0–20 mg L−1), and ionic strength (0.0001–0.6 M). Notably, the introduction of a novel theoretical approach to calculate diffusion coefficients based on solvent-accessible volume tailored for PAHs significantly enhanced the method’s applicability, particularly for organic pollutants with low solubility. Field deployments in coastal zones validated the DGT method against traditional grab sampling, with findings advocating a 4 to 7-day optimal deployment duration for balancing sensitivity and mitigating lag time effects. These results provide a sophisticated, efficient solution to the persistent challenge of monitoring hydrophobic organic pollutants in aquatic environments, broadening the scope and applicability of DGT in environmental science and providing a robust tool for researchers.

Metagenomic investigations into the microbial consortia, degradation pathways, and enzyme systems involved in the biodegradation of plastics in a tropical lentic pond sediment.

The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments.

Microplastics alter the leaf litter breakdown rates and the decomposer community in subtropical lentic microhabitats

Microplastics, pervasive pollutants in aquatic environments, have been primarily studied for their impact on marine ecosystems. However, their effects on freshwater systems, particularly in forested phytotelmata habitats, remain understudied in Subtropical systems. This research examines the influence of varying microplastic concentrations (0.0, 200, 2,000, 20,000, and 200,000 ppm) on leaf litter breakdown of Inga vera (in bags of 10 and 0.05 mm mesh) and the naturally associated invertebrate community occurring in forested phytotelmata. The study employs an experimental design with microplastic concentration treatments in artificial microcosms (buckets with 800 mL of rainwater) arranged in an area of Atlantic Rain Forest native vegetation of Subtropical systems. The results indicate that elevated concentrations of microplastics may enhance leaf litter breakdown (6–8%), irrespective of the bag mesh, attributed to heightened decomposer activity and biofilm formation. Consequently, this contributes to increased invertebrate richness (33–37%) and greater shredder abundance (21–37%). Indicator analysis revealed that Culicidae, Stratiomyidae, Chironomidae, Empididae, Planorbidae, and Ceratopogonidae were indicative of some microplastic concentrations. These findings underscore the significance of accounting for microplastics when evaluating the taxonomic and trophic characteristics of invertebrate communities, as well as the leaf breakdown process in Subtropical systems.

Dipole moment regulation for enhancing internal electric field in covalent organic frameworks photocatalysts

Covalent organic frameworks (COFs) have recently emerged as a kind of promising photocatalytic platform in addressing the growing threat of trace pollutants in aquatic environments. Along this, we propose a strategy of constructing internal electric field (IEF) in COFs through the dipole moment regulation, which intrinsically facilitates the separation and transfer of photogenerated excitons. Two COFs of BTT-TZ-COF and BTT-TB-COF are developed by linking the electron-donor of benzotrithiophene (BTT) block and the electron-acceptor of triazine (TZ) or tribenzene (TB) block, respectively. DFT calculations demonstrate TZ block with larger dipole moment can achieve more efficient IEF due to the stronger electron-attractive force and hence narrower bandgap. Moreover, featuring the highly-order crystalline structure for accelerating photo-excitons transfer and rich porosity for facilitating the adsorption, BTT-TZ-COF exhibited an excellent universal performance of photocatalytic degradations of various dyes. Specifically, a superior photodegradation efficiency of 99% Rhodamine B (RhB) is achieved within 20 min under the simulated sunlight. Therefore, this convenient construction approach of enhanced IEF in COFs through rational regulation of the dipole moment can be a promising way to realize high photocatalytic activity.

Innovative ternary composite photocatalyst: BiOCl/Bi12O17Cl2/Bi2O3 for sustainable water remediation

The presence of pollutants in aquatic environments is causing severe health effects on both humans and animals. To address this issue, it has become crucial to develop more efficient and environmentally friendly photocatalysts for the removal of persistent pollutant mixtures from water. In this context, photocatalysts containing more than two bismuth-based materials have rarely been explored for water remediation. With this in mind, we propose an innovative ternary composite, BiOCl-1/Bi12O17Cl2/Bi2O3, as a potentially sustainable visible light-active photocatalyst. Firstly, bismuth oxychloride has been prepared in the presence of ionic liquid, leading to the formation of BiOCl-1 with highly reactive {110} facets. Subsequently, the construction of the ternary composite has been accomplished using a facile and soft hydrothermal approach. The as-prepared BiOCl-1/Bi12O17Cl2/Bi2O3 composite has been successfully used in degrading binary mixtures of contaminants (i.e. ciprofloxacin, methylparaben or methyl orange), achieving an improved visible-light photocatalytic activity compared to single BiOCl-1 and other previously reported bismuth-based photocatalysts. In addition, the photocatalytic mechanism and degradation pathways have been elucidated through scavenger and electrochemical experiments, as well as chromatography-mass spectrometry (LC-MS) analysis, respectively.

Synthesis and photocatalytic activity of BiOI particles: An efficient visible-light-driven degradation of organic pollutants in aqueous environments

Bismuth oxyiodide (BiOI) particles were successfully fabricated through solvothermal activation using bismuth (III) nitrate pentahydrate and potassium iodide as precursors. The photocatalytic activities of BiOI were investigated under the influence of synthesis temperature (120–200 °C) with a fixed duration of 12 h. The physical-chemical properties of the samples were systematically investigated using X-ray diffraction, scanning electron microscopy, N2-sorption isotherm techniques, and pH of the point of zero charge (pHpzc). The prepared BiOI exhibited a single phase with a non-uniform 2D morphology with different sizes, an average crystallite size of 30 nm, and a BET surface area of 20.71 m²g−1. The zero-point charge was determined to be 7.7. The photocatalytic performance under simulated solar light irradiation was investigated by examining the effects of dye initial concentration, catalyst dose, and dye pH. Remarkably, BiOI synthesized at 160 °C demonstrated an impressive 85% removal efficiency of 10 ppm MO (methyl orange) at normal pH levels (pH 6.8) within 120 min under visible light irradiation, along with the highest rate constant of 0.01418 min−1. The quenching effects of different scavengers indicate the significant role of reactive O2•– and a minor role of hVB+ and •OHads in the photocatalytic process. These findings underscore the potential of BiOI particles as efficient photocatalysts for environmental applications, particularly in the degradation of organic pollutants in water using solar light irradiation.