Pollutants In Aquatic Environment Research Articles

Geochemical characteristics and migration patterns of rare earth elements in coal mining subsidence lakes under the influence of multiple factors

Mining activities cause surface subsidence and the formation of subsidence lakes, which dynamically change with the continuous coal mining activities. Under the combined influence of various human activities such as agriculture, aquaculture, and floating photovoltaic (FPV), the lake environment undergoes continuous changes, thereby altering the geochemical characteristics of rare earth elements (REEs) in the sediment. This study focused on the subsidence lakes in the Huainan coalfield in eastern China to examine the REEs content in the sediment, elucidated the temporal variations and geochemical characteristics of REEs distribution, explored the main controlling factors of REEs in the sediment, and revealed the migration and transformation behavior of REEs during dynamic subsidence processes. The study revealed that the migration pattern of REEs in the sediment was closely related to the duration of subsidence. The average content of REEs in lake sediments with subsidence duration <5 years increased from 219 μg·g−1 to 248 μg·g−1 compared to the soil, showing an enrichment model primarily driven by rainwater runoff, groundwater input retention, and mineral dissolution. With further subsidence, the processes of reduction dissolution of Fe–Mn oxides/hydroxides, organic colloid adsorption, and hydraulic disturbance gradually replaced the aforementioned enrichment behavior as the main migration pathways, resulting in a decrease in the average REEs content in the sediment to 179 μg·g−1 for subsidence durations exceeding 10 years. There was no strong correlation between REEs fractionation and subsidence duration. Artificial activities, such as FPV, are important factors causing Cerium and Erbium anomalies in some subsidence lake sediments. This study was not only of significant importance for understanding the migration, distribution, and environmental behavior of pollutants in aquatic environments under the interference of human activities but also provided a solid theoretical foundation for the future management of coal mining subsidence lakes.

Advancements in Biomonitoring and Remediation Treatments of Pollutants in Aquatic Environments, 2nd Edition

Worldwide anthropogenic activities continuously produce and release hundreds of potentially toxic chemicals that contaminate ecosystems, leaving devastating effects on the environment and living beings, humans included [...]

Dissolved Oxygen Inversion Based on Himawari-8 Imagery and Machine Learning: A Case Study of Lake Chaohu

Dissolved oxygen (DO) concentration is a widely used and effective indicator for assessing water quality and pollution in aquatic environments. Continuous and large-scale inversion of water environments using remote sensing imagery has become a hot topic in water environmental research. Remote sensing technology has been extensively applied in water quality monitoring, but its limited sampling frequency necessitates the development of a high-frequency dynamic water quality monitoring model. In this study, we utilized Lake Chaohu as a case study. Firstly, we constructed a dynamic water quality inversion model for monitoring DO concentrations using machine learning methods, with Himawari-8 (H8) satellite imagery as input data and DO concentrations in Lake Chaohu as output data. Secondly, the developed DO concentration inversion model was employed to estimate the overall grid-based DO concentration in the Lake Chaohu region for the years 2019 to 2021. Lastly, Pearson correlation analysis and significance tests were performed to examine the correlation and significance between the estimated grid-based DO concentration and the ERA5 reanalysis dataset. The results demonstrate that the Random Forest (RF) model performs best in DO concentration inversion, with a high R2 score of 0.84, and low RMSE and MAE values of 0.69 and 0.54, respectively. Compared to other models, the RF model improves average performance with a 38% increase in R2, 13% decrease in RMSE, and 33% decrease in MAE. The model accurately predicts DO concentrations. Furthermore, the inversion results reveal seasonal differences in DO concentrations in Lake Chaohu from 2019 to 2021, with higher concentrations in spring and winter, and lower concentrations in summer and autumn. The average DO concentrations in the northwest, central-south, and northeast regions of Lake Chaohu are 10.12 mg/L, 9.98 mg/L, and 9.96 mg/L, respectively, with higher concentrations in the northwest region. Pearson correlation analysis indicates a significant correlation (p &lt; 0.01) between DO concentrations and temperature, surface pressure, latent heat flux from the atmosphere to the surface, and latent heat flux from the surface to the atmosphere, with correlation coefficients of −0.615, 0.583, −0.480, and 0.444, respectively. The results verify the feasibility of using synchronous satellites for real-time inversion of DO concentrations, providing a more efficient, economical, and accurate means for real-time monitoring of DO concentrations. This study has practical value in improving the efficiency and accuracy of water environmental monitoring.

Preparation of magnetic Janus microparticles for the rapid removal of microplastics from water

The continuous spread of microplastics in aquatic environments poses a growing concern and a potential risk to human health. To address this concern, this paper presents a novel approach using magnetic Janus microparticles (MJMs) synthesized via a modified Pickering emulsion method with aminated Fe3O4@SiO2 as the raw material. The effectiveness of these MJMs in removing polystyrene (PS) and polyethylene (PE) microplastics from water was investigated. Paraffin was employed as the masking agent, while N-Octadecylphosphosphonic acid (PAC18) was used as the graft material for MJM preparation. The resulting particles exhibited a distinctive asymmetric flower-shaped structure on the surface, which was confirmed through various analytical techniques including FTIR, TGA, SEM, and water phase contact angle analysis. The MJMs demonstrated exceptional efficiency in adsorbing microplastics. With a microplastic suspension concentration of 2 mg/mL and an adsorbent dosage of 1 mg/mL, the MJMs can attain removal efficiencies of 92.08 % for PS and 60.67 % for PE in just 20 min of contact time. The effectiveness of the adsorption process was attributed to several factors, including hydrophobic interactions, cation-π interactions, electrostatic attraction, and the efficient dispersion of particles in water, as revealed by size distribution and zeta potential analysis. Additionally, kinetic and thermodynamic studies confirmed the remarkable adsorption rate and capacity of the MJMs (0.759 min−1 and 2.72 mg/mg for PS, 0.539 min−1 and 2.42 mg/mg for PE), highlighting their potential as a promising method for rapidly removing microplastics from water. This work provides valuable insights into the development of effective strategies for addressing microplastic pollution in aquatic environments.

Impacts of the steel industry on sediment pollution by heavy metals in urban water system

The impact of the steel industry on sediment heavy metal (HM) pollution in urban aquatic environments was investigated in a major iron ore-producing area (Ma'anshan) in China. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 9.68 ± 3.56, 170.31 ± 82.40, 90.62 ± 19.54, 30.61 ± 6.72, 125.43 ± 63.60, and 1276.59 ± 701.90 mg/kg in the steel industry intruded upon sediments and 4.63 ± 1.41, 87.60 ± 10.96, 52.67 ± 19.99, 37.49 ± 6.17, 35.84 ± 11.41, and 189.02 ± 95.57 mg/kg in the control area, respectively. Comparing with the local soil background (0.08 mg/kg for Cd, 62.6 mg/kg for Cr, 19.3 mg/kg for Cu, 28.1 mg/kg for Ni, 26.0 mg/kg for Pb, and 58.0 mg/kg for Zn), significantly higher levels of Cd, Cr, Cu, Pb, and Zn were detected in the steel industry affected sediments. The enrichment factor and principal component analysis indicated that the heavy metals (HMs), except for Ni, were primarily derived from anthropogenic inputs, particularly from steel industrial activities. Multiple risk assessment models suggested that the sediments affected by industrial activities showed significant toxic effects for Cd, Cr, Pb, and Zn, with Cd being the main contributor to sediment toxicity. However, the alkaline nature of the sediments (pH = 7.85 ± 0.57) and the high proportion of residual fraction Cd (61.09% ± 26.64%) may help to reduce the toxic risks in the sediments. Effective measures to eliminate tinuous thethe continous input of Cd and Zn via surface runoff are crucial.

Flower-like imide covalent organic framework as an electrochemical platform catcher for simultaneous sensitive detection of trace Pb(II) and Cd(II)

Heavy metal pollution in aquatic environment poses an enormous risk to ecosystems and human health. In this study, a flowerlike covalent organic framework (TpTa-COF) was synthesized by one-step solvothermal method with 2,4,6-triformylphloroglucinol (Tp) and 4, 4-diamino-tribiphenyl (Ta) as building elements. Then it was used as an effective trap to establish an electrochemical sensing platform for simultaneously sensitive detection of trace Pb(II) and Cd(II) in water. This three-dimensional flower-shaped structure exhibited exceptional adsorption capacity, large surface area, high stability, and all of which enhanced the detection sensitivity of the sensor and facilitated full contact between ions and substrate. The high oxygen content in the structure provided abundant active sites for Pb(II) and Cd(II), further enhancing its electrochemical response. The constructed sensor exhibited a linear response to Pb(II) within the concentration range of 3–60 µg/L under the optimal conditions, with a detection limit of 0.16 µg/L. Similarly, a linear response was observed for Cd(II) in the concentration range of 5–60 µg/L, with a detection limit of 0.29 µg/L. Low detection limits, excellent sensitivity, and strong stability were all features of the suggested approach. It has been successfully employed in determining Pb(II) and Cd(II) concentrations in two actual water samples. XPS, SEM-EDS mapping, and density functional theory calculations confirmed that TpTa-COF interacted with metal ions mainly via coordination with carbonyl oxygen atoms in the structure. Overall, these findings will broaden the applications of COF in the field of chemical analysis.

Temporary noise-induced underwater hearing loss in an aquatic turtle (Trachemys scripta elegans).

Noise pollution in aquatic environments can cause hearing loss in noise-exposed animals. We investigated whether exposure to continuous underwater white noise (50-1000 Hz) affects the auditory sensitivity of an aquatic turtle Trachemys scripta elegans (red-eared slider) across 16 noise conditions of differing durations and amplitudes. Sound exposure levels (SELs) ranged between 155 and 193 dB re 1 μPa2 s, and auditory sensitivity was measured at 400 Hz using auditory evoked potential methods. Comparing control and post-exposure thresholds revealed temporary threshold shifts (TTS) in all three individuals, with at least two of the three turtles experiencing TTS at all but the two lowest SELs tested, and shifts up to 40 dB. There were significant positive relationships between shift magnitude and exposure duration, amplitude, and SEL. The mean predicted TTS onset was 160 dB re 1 μPa2 s. There was individual variation in susceptibility to TTS, threshold shift magnitude, and recovery rate, which was non-monotonic and occurred on time scales ranging from < 1 h to > 2 days post-exposure. Recovery rates were generally greater after higher magnitude shifts. Sound levels inducing hearing loss were comparatively low, suggesting aquatic turtles may be more sensitive to underwater noise than previously considered.

Mechanism of iron salt impregnated biowaste biochar with a prevailing free radical initiator for effective removal of toxic thallium from solution

Thallium is an emerging metallic pollutant with extremely high toxicity which resulted in worldwide water pollution in the past decades. It is critical to develop multiple alternative methods for Tl removal to enrich control strategy towards Tl pollution in aquatic environment. It is proposed herein a highly effective and environmental-friendly Tl removal method by applying iron salt-impregnated biochar (BC) combined with persulfate (PS), using two most common iron salts (FeCl3 and Fe(NO3)3). It was found that FeCl3@BC-PS system achieved higher Tl removal capacity (164.42 mg/g), which exhibited a comparative preponderance relative to the reported iron based adsorbent composites, partially owing to significantly enhanced specific surface area (854.48 m2/g). The dominant Tl removal mechanisms include free radical based oxidation and chemical adsorption. Radical quenching experiments confirmed that SO4− and OH served as vital radicals for FeCl3@BC-PS and Fe(NO3)3@BC-PS, respectively. The study provides a reliable alternative for Tl-wastewater treatment with PS activation by catalyst based on the synergistic effect of biochar and iron salts.

Enhanced removal efficiency of bensulfuron-methyl by a novel boron doping biochar-based Acinetobacter YH0317 at a lower temperature

Biochar-based bacteria are regarded as an efficient strategy for remediating organic pollutants in aquatic environments. Herein, a strain named Acinetobacter YH0317 that could degrade bensulfuron-methyl (BSM) at a lower temperature (15 °C) was isolated from a paddy rice field with long-term BSM application. Then Acinetobacter YH0317 was loaded on unmodified biochar (BC) and boron doping biochar (BBC). Results showed that BBC-based YH0317 significantly enhanced the removal efficiency of BSM (71.8–99.1%) compared with BC-based YH0317 (41.9–44.0%) and YH0317 alone (18.1–20.7%) in 24 h. BBC promoted the growth of YH0317 and secretion of extracellular secretions by providing a carrier and shelter for YH0317. The electrochemical analysis suggested BBC improved the electron transfer rate, which ultimately facilitated the removal of BSM. Hydroponic experiments indicated that BBC-based YH0317 effectively improved the growth of soybean. This work reports a novel BBC-based Acinetobacter YH0317 that could effectively remediate BSM contamination in the water environment.

Occurrence and dynamics of microplastics and emerging concern microparticles in coastal sediments: Impact of stormwater upgrade and port-associated facilities

Urban runoff is a significant source of microplastic pollution in aquatic environments, especially in coastal areas. Despite urban stormwater runoff being considered a major pathway of anthropogenic particles there's no studies about the impact of stormwater upgrades on microparticle transport. Moreover, due to the influence of anthropogenic activities, including maritime traffic and maintenance, on coastal environments, it is crucial to identify plastic debris from both inland and in-shore sources. This study evaluates characteristics, abundance, and distribution of microplastics in subtidal sediments from the southwestern Atlantic region, influenced by a recently upgraded stormwater outfall and port facilities. Herein, we have analyzed temporal trends, including seasonal dynamics and their relation with the pre- and post-upgrade of the stormwater outfall. Three main types of anthropogenic microparticles were observed: common plastic (MPs), paints (Pps), and tire wear particles (TWPs). Microparticle groups varied in morphology, color, and size distribution, including uncommon microparticle debris. Analysis by FTIR and Raman spectroscopies allows the identification of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polyamide, and polyacrylonitrile polymers for MPs mainly. Pigments such as Naphthol AS, phthalocyanine, and quinacridone have been identified in Pps. SEM-EDS and FTIR analysis of collected TWPs revealed similar trace metals constituents and infrared signals to those observed in tire road samples. Spatial and temporal abundances of microparticle groups were significantly different (p < 0.05), mainly related to the distance from the stormwater outfall and seasons. TWPs showed the most significant seasonal increment rate among pre and post-upgrade periods. Furthermore, the upgrades made to the stormwater system have been observed to intensify the transport and increase the presence of specific anthropogenic microparticles in subtidal sediments. Based on these findings, the occurrence of TWPs emerges as a reliable urban runoff indicator to differentiate ex and in-situ sources in multipolluted coastal environments.

Microplastic abundance, distribution, and diversity in water and sediments along a subtropical river system.

Microplastic pollution in aquatic environments has been a ubiquitous concern in recent years, owing to their rapid production combined with poor waste management practices. However, information on freshwater microplastics in the Global South is still scarce, despite growing research on freshwater microplastics in recent years, particularly within the Global North. To help address this knowledge gap, we studied water and sediment microplastic dynamics along a subtropical river system, i.e. Crocodile River around the Nelspruit City area (South Africa), across three different seasons (i.e. cool-dry, hot-dry, hot-wet) using a combination of diversity indices and multivariate analyses. Microplastics were more abundant during the cool-dry season in the surface water samples (mean 1058 particles m-3) and high during the hot-dry season (mean 568 particles kg-1 dwt) in the sediment samples. The hot-wet season had a low particle density in both surface water (mean 625 particles m-3) and sediments (mean 86 particles kg-1 dwt) samples. Microplastic shapes were dominated by fibres and fragments, with the colour scheme dominated by transparent, blue, and black. The abundance of microplastics was positively correlated with pH and resistivity, and negatively with river flow. Wastewater was attributed as a primary source of microplastics, particularly because of the observed dominant fibre microplastics, usually released during laundry. Our results suggest that Crocodile River and its tributaries are temporary sinks of microplastics during periods of low rainfall. Implications of this pollution are far-reaching, including effects on residents who are dependent on the Crocodile River as a source of drinking water and aquatic biota which may be exposed to these pollutants.

Photocatalytic Degradation of Ciprofloxacin with Supramolecular Materials Consisting of Nitrogenous Organic Cations and Metal Salts

The design and synthesis of composite materials with new structures/properties have important practical significance for the degradation of organic pollutants in aquatic environments. On this basis, five new supramolecular materials {[L1]2·[Cu4I8]}(1), {[L1]2·[Ag4I8]}(2), {[L2]·[ZnBr4]}(3), {[L3]2·[AgI5]}(4), {[L3]·[CdBr3Cl]}(5) were synthesized by introducing an amino group into a series of nitrogen-containing cationic ligands (L1–L3) through the reaction of polybromomethylbenzene with 4-aminopyridine. The degradation effect of catalysts 1–5 on ciprofloxacin (CIP) under visible light was studied using their potential catalytic properties. The results showed that compounds 1 and 4 had better degradation effects compared to other compounds. Moreover, compounds 1 and 4 were proved to be excellent catalysts for the photocatalytic degradation of CIP with cyclic experiments. Through further exploration, it was found that neutral conditions and 20 mg compound dosage were more conducive to the photodegradation of CIP by the compound. Through free radical capture experiments, it was found that ·OH played a major role in the photodegradation of CIP.

Addition of graphene oxide to ZIF-8/HKUST-1 composite for enhanced adsorptive and photocatalytic removal of congo red in wastewater

Ternary composites comprised of graphene oxide (GO), ZIF-8, and HKUST-1 with varying amounts of GO were successfully synthesized via the solvothermal method. Based on the photoluminescence characterization, the GO/ZIF-8/HKUST-1 composite presents a more efficient charge carrier separation and transfer compared to pristine HKUST-1 and ZIF-8. As a result, electron-hole recombination was hindered due to the presence of GO as an electron mediator in the heterojunction. The dark adsorption kinetics data for the removal of Congo Red (CR) dye fit well with the pseudo-second order model. The photocatalytic degradation performance of the GO/ZIF-8/HKUST-1 composite was investigated by means of degrading CR dye under UV-LED irradiation. The photodegradation efficiency of the GO(10)/ZIF-8/HKUST-1 composite for the removal of CR dye was 91.81% within 60 min of irradiation. The trapping experiments showed that hydroxyl and superoxide radicals are the main reactive species. The results of this study indicate that ternary composites comprised of MOFs as photocatalysts have great potential for degrading pollutants in aquatic environments.

The potential of Lecane rotifers in microplastics removal

Dealing with hard-to-degrade plastics pollution of terrestrial and aquatic environments is one of the most urgent problems of the modern world. The smallest fraction (<5 mm) called micro-plastics (MP) has been found everywhere from ice in Greenland, streams, rivers, soil and even in the human placenta. The goal of our research was to assess the ability of rotifers Lecane inermis to remove micro-plastics suspended in the water column. In the experiments we investigated specific interactions between MP, biofilm and rotifers specialized in feeding on biofilm. We hypothesized that MP adhere to the biofilm and after ingestion by rotifers could be extracted from the water in the form of compact conglomerates excreted with fecal pellets. In these experiments, we demonstrated that: (i) the rotifers preferentially ingest microplastics embedded in biofilm, (ii) the presence of microplastics does not affect growth and fecundity of rotifers, and (iii) that MP aggregation is significantly improved by the presence of biofilm, additionally enhanced in the presence of rotifers. Our findings will help to understand the role of micro-grazers, such as L. inermis feeding on biofilm, in the fate of MP in nature. In the longer term, our results could help to develop biotechnological tools for MP removal from the aquatic environment.

Effect of aggregation behavior on microplastic removal by magnetic Fe3O4 nanoparticles

Magnetic nanotechnologies have been shown to be an efficient approach to the reduction of microplastic (MP) pollution in aquatic environments. However, uncertainties remain regarding the relationship between particle stability and MP removal under varying water conditions, hindering the practical application of magnetic nanotechnologies for MP removal. Herein, the influence of particle aggregation behavior on nano-scale MP removal by Fe3O4 nanoparticles (FNPs) was investigated, by monitoring dynamic light scattering parameters and analyzing the microstructures of particle aggregates. Results showed that 83.1 %–92.9 % of MPs could be removed by FNPs within 1 h, and MP removal exhibited a high degree of Pearson correlation (R = 0.95; P = 0.04) with particle aggregation behavior mediated by the FNPs dosage. Furthermore, pH-dependent electrostatic interactions significantly influenced particle aggregation behavior and the removal of MPs. Under pH <6.7 conditions, electrostatic attraction between electropositive FNPs and electronegative MPs led to charge neutralization-induced aggregation and efficient removal MP performance. Under increasingly saline conditions, compression of the electrical double layer enhanced the self-aggregation behavior of MPs, weakening the electrostatic repulsion between FNPs and MPs under alkaline conditions. Therefore, salinity improved the MP removal efficiency, especially under alkaline conditions, with MP removal increasing from 4.47 % to 55.1 % when the mass fraction of NaCl was increased from 0 % to 1 %. These findings further our understanding of the effect of aggregation behavior on MP removal by FNPs and highlight the potential for magnetic nanotechnology application in the removal of nano-scale MPs from aquatic environments, while also providing valuable insights for the design of FNP-based materials.

Occurrence and abundance of macro, meso and microplastics along the coasts of the Persian Gulf (case study: Bushehr Province coast)

One of the most critical emerging pollutants in aquatic environments is plastic waste. During this study, the presence and abundance of macro, meso, and microplastics at 17 stations on the coast of Bushehr province were investigated. The average abundances of macro-plastics and meso-plastics in coastal sediment were 41.0 and 121.8 items/m2, respectively. The mean abundance of microplastics at depths of 0–5 cm, 5–15 cm, 0–15 cm and the mean of two depth abundance were 226.2 ± 76.7 and 47.1 ± 16.1, 273.4 ± 78.8, and 136.7 ± 39.4 particles/kgd.w., respectively. Fibers with 55 %, black microplastics with 40 %, and microplastic size of <500 μm with 48 % had the highest abundance, respectively. According to the FTIR spectra, polyethylene, polystyrene, polyethylene terephthalate, and nylon were the most common types of polymers in plastics. Although plastics were observed at all stations, a comparison of our results, with other studies around the world shows that the region is moderately contaminated with plastics.

Microplastics (≤ 10 μm) bioaccumulation in marine sponges along the Moroccan Mediterranean coast: Insights into species-specific distribution and potential bioindication

Microplastics (MPs) are pervasive in marine environments and widely recognized as emerging environmental pollutants due to the multifaceted risks they exert on living organisms and ecosystems. Sponges (Phylum Porifera) are essential suspension-feeding organisms that may be highly susceptible to MPs uptake due to their global distribution, unique feeding behavior, and sedentary lifestyle. However, the role of sponges in MP research remains largely underexplored. In the present study, we investigate the presence and abundance of MPs (≤10 μm size) in four sponge species, namely Chondrosia reniformis, Ircinia variabilis, Petrosia ficiformis, and Sarcotragus spinosulus collected from four sites along the Mediterranean coast of Morocco, as well as their spatial distribution. MPs analysis was conducted using an innovative Italian patented extraction methodology coupled with SEM-EDX detection. Our findings reveal the presence of MPs in all collected sponge specimens, indicating a pollution rate of 100%. The abundance of MPs in the four sponge species ranged from 3.95×105 to 1.05×106 particles per gram dry weight of sponge tissue, with significant differences observed among sampling sites but no species-specific differences. These results imply that the uptake of MPs by sponges is likely influenced by aquatic environmental pollution rather than the sponge species themselves. The smallest and largest MPs were identified in C. reniformis and P. ficiformis, with median diameters of 1.84 μm and 2.57 μm, respectively. Overall, this study provides the first evidence and an important baseline for the ingestion of small MP particles in Mediterranean sponges, introducing the hypothesis that they may serve as valuable bioindicators of MP pollution in the near future.

Integrating culture-based and molecular methods provides an improved assessment of microbial quality in a coastal lagoon

Faecal pollution in aquatic environments is a worldwide public health concern, yet the reliability and comprehensiveness of the methods used to assess faecal contamination are still debated. We compared three approaches, namely a culture-based method to enumerate Faecal Indicator Bacteria (FIB), a FIB-targeting qPCR assay, and High-Throughput Sequencing (HTS) to detect faeces- and sewage-associated taxa in water and sediment samples of an impacted model lagoon and its adjacent sea across one year. Despite at different levels, all approaches agreed in showing a higher contamination in the lagoon than in the sea, and higher in sediments than water. FIB significantly correlated when considering separately sediment and water, and when using both cultivation and qPCR. Similarly, FIB correlated between cultivation and qPCR, but qPCR provided consistently higher estimates of FIB. Faeces-associated bacteria positively correlated with cultivated FIB in both compartments, whereas sewage-associated bacteria did only in water. Considering their benefits and limitations, we conclude that, in our study site, improved quali-quantitative information on contamination is provided when at least two approaches are combined (e.g., cultivation and qPCR or HTS data). Our results provide insights to move beyond the use of FIB to improve faecal pollution management in aquatic environments and to incorporate HTS analysis into routine monitoring.

Characteristics of a Novel Decomposed Corn Straw-Sludge Biochar and Its Mechanism of Removing Cadmium from Water.

The utilization of high-efficiency adsorption materials to reduce cadmium pollution in aquatic environments is the focus of current environmental remediation research. Straw waste and sludge, which are available in huge amounts, can be best utilized in the preparation of environmental remediation materials. In this study, six types of biochar (SBC, CBC, DBC, SD1BC, SRDBC, and SCDBC) were prepared from straw and sludge by co-pyrolysis, and their cadmium adsorption mechanisms were explored. Cd(II) adsorption isotherms and kinetics on the biochar were determined and fitted to different models. Kinetic modeling was used to characterize the Cd(II) adsorption of biochar, and findings revealed the process of sorption followed pseudo-second-order kinetics (R2 > 0.96). The Langmuir model accurately represented the isotherms of adsorption, indicating that the process was monolayer and controlled by chemical adsorption. SCDBC had the highest capacity for Cd(II) adsorption (72.2 mg g-1), 1.5 times greater than that of sludge biochar, and 3 times greater than that of corn straw biochar. As the pH level rose within the range of pH 5.0 to 7.0 and the ionic strength decreased, the adsorption capacity experienced an increase. SCDBC contained CaCO3 mineral crystals before Cd(II) adsorption, and CdCO3 was found in SCDBC after adsorbing Cd(II) via X-ray diffraction analysis; the peak of Cd could be observed by Fourier transform infrared spectroscopy after the adsorption of Cd(II). The possible adsorption of Cd(II) by SCDBC occurred primarily via surface complexation with active sorption sites, precipitation with inorganic anions, and coordination with π electrons. Collectively, the study suggested that the six types of biochar, particularly SCDBC, could be used as highly efficient adsorbents for Cd(II) removal from aquatic environments.

The dark side of artificial greening: Plastic turfs as widespread pollutants of aquatic environments

Artificial turf (AT) is a surfacing material that simulates natural grass by using synthetic, mainly plastic, fibers in different shapes, sizes and properties. AT has spread beyond sports facilities and today shapes many urban landscapes, from private lawns to rooftops and public venues. Despite concerns regarding the impacts of AT, little is known about the release of AT fibers into natural environment. Here, for the first time, we specifically investigate the presence of AT fibers in river and ocean waters as major conduits and final destination of plastic debris transported by water runoff. Our sampling survey showed that, AT fibers – composed mainly of polyethylene and polypropylene – can constitute over 15% of the mesoplastics and macroplastics content, suggesting that AT fibers may contribute significantly to plastic pollution. Up to 20,000 fibers a day flowed down through the river, and up to 213,200 fibers per km2 were found floating on the sea surface of nearshore areas. AT, apart from impacting on urban biodiversity, urban runoff, heat island formation, and hazardous chemical leaching, is a major source of plastic pollution to natural aquatic environments.