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Fate of household and personal care chemicals in typical urban wastewater treatment plants indicate different seasonal patterns and removal mechanisms
2022
Li, Wen-Long | Zhang, Zi-Feng | Kilgallon, John | Sparham, Chris | Li, Yi-Fan | Yuan, Yi-Xing
Studies on the presence and fate of household and personal care chemicals (HPCCs) in wastewater treatment plants (WWTPs) are important due to their increasing consumption worldwide. The seasonal patterns and removal mechanisms of HPCCs are not well understood for WWTPs that apply different treatment technologies. To answer these questions, the sewage and sludge samples were taken from 10 typical WWTPs in Northeast China. Levels of UV filters in the influents in the warm season were significantly greater than that of the cold season (p < 0.05). Significant seasonal differences were found for the removals of many HPCCs. Results revealed that the highest removal efficiencies were found for linear alkylbenzene sulphonates with values ranging from 97.2% to 99.7%, and the values were 50.0%–99.9% for other HPCCs. The SimpleTreat model demonstrated that the studied WWTPs were operating with high efficiency at the time of sampling. The sorption of HPCCs to sludge can be strongly associated with their physicochemical parameters. Mass balance calculation suggested that sorption was the dominant mechanism for the removal of antimicrobials, while degradation and/or biotransformation were the other mechanisms for removing the most HPCCs in the WWTPs. This study real the factors influencing the seasonal patterns and removal mechanisms which imply the need for further studies to fully understands the plant and human health implications as sludge could be used in the municipal land application of biosolids.
Show more [+] Less [-]Synthesis and characterization of lanthanum-based metal organic framework decorated polyaniline for effective adsorption of lead ions from aqueous solutions
2022
Govarthanan, M. | Jeon, Chang-Hyun | Kim, Woong
The novel La-MOF@x%PANI composite was synthesized via a two-step procedure with ultra-sonication, and the adsorption mechanism of Pb²⁺ ions from synthetic aqueous solutions was systematically studied. The Pb²⁺ adsorption on the La-MOF@x%PANI was evaluated by the Fourier transform infrared spectroscopy, powder X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray analysis, Brunauer–Emmett–Teller analysis, X-ray photoelectron spectroscopy, and elemental mapping analyses. The effects of the adsorption-influencing parameters, including contact time, solution pH, and co-existing cations on the maximum adsorption capacity of Pb²⁺ onto the prepared composite material were investigated. Moreover, the adsorption of Pb²⁺ ions could be eliminated with rapid adsorption kinetics using the water-stable La-MOF@x%PANI composite. The as-synthesized La-MOF@50%PANI exhibited excellent adsorption performance toward Pb²⁺ ions with an extraordinary adsorption capacity of 185.19 mg/g at pH 6. The Pb²⁺ adsorption onto the La-MOF@x%PANI composite follows the pseudo-second-order kinetics and fits well with the Langmuir isotherm model, indicating the Pb²⁺ adsorption depended on the solution pH as the adsorption mechanism was mainly governed by the electrostatic attraction. Notably, La-MOF@x%PANI composite possesses outstanding regeneration ability and stability after up to four successive cycles. The satisfactory findings reflect that the La-MOF@50%PANI hybrid composite holds a great promise for remediating Pb²⁺ ions from aqueous environments.
Show more [+] Less [-]Does liming grasslands increase biomass productivity without causing detrimental impacts on net greenhouse gas emissions?
2022
Abdalla, Mohamed | Espenberg, Mikk | Zavattaro, Laura | Lellei-Kovacs, Eszter | Mander, Ulo | Smith, Kate | Thorman, Rachel | Damatirca, Claudia | Schils, Rene | ten-Berge, Hein | Newell-Price, Paul | Smith, Pete
Soil acidification has negative impacts on grass biomass production and the potential of grasslands to mitigate greenhouse gas (GHG) emissions. Through a global review of research on liming of grasslands, the objective of this paper was to assess the impacts of liming on soil pH, grass biomass production and total net GHG exchange (nitrous oxide (N2O), methane (CH4) and net carbon dioxide (CO2)). We collected 57 studies carried out at 88 sites and covering different countries and climatic zones. All of the studies examined showed that liming either reduced or had no effects on the emissions of two potent greenhouse gases (N2O and CH4). Though liming of grasslands can increase net CO2 emissions, the impact on total net GHG emission is minimal due to the higher global warming potential, over a 100-year period, of N2O and CH4 compared to that of CO2. Liming grassland delivers many potential advantages, which justify its wider adoption. It significantly ameliorates soil acidity, increases grass productivity, reduces fertiliser requirement and increases species richness. To realise the maximum benefit of liming grassland, we suggest that acidic soils should be moderately limed within the context of specific climates, soils and management.
Show more [+] Less [-]Pesticides in doormat and floor dust from homes close to treated fields : Spatio-temporal variance and determinants of occurrence and concentrations
2022
M. Figueiredo, Daniel | Nijssen, Rosalie | J.M. Krop, Esmeralda | Buijtenhuijs, Daan | Gooijer, Yvonne | Lageschaar, Luuk | Duyzer, Jan | Huss, Anke | Mol, Hans | C.H. Vermeulen, Roel
Indoor dust has been postulated as an important matrix for residential pesticide exposure. However, there is a lack of information on presence, concentrations and determinants of multiple pesticides in dust in residential homes close to treated fields. Our objective was to characterize the spatial and temporal variance of pesticides in house dust, study the use of doormats and floors as proxies for pesticides in indoor dust and identify determinants of occurrence and concentrations. Homes within 250 m from selected bulb fields were invited to participate. Homes within 20 km from these fields but not having agricultural fields within 500 m were selected as controls. House dust was vacuumed in all homes from floors (VFD) and from newly placed clean doormats (DDM). Sampling was done during two periods, when pesticides are used and not-used. For determination of 46 prioritized pesticides, a multi-residue extraction method was used. Most statistical analyses are focused on the 12 and 14 pesticides that were detected in >40% of DDM and VFD samples, respectively. Mixed models were used to evaluate relationships between possible determinants and pesticides occurrence and concentrations in DDM and VFD. 17 pesticides were detected in more than 50% of the homes in both matrixes. Concentrations differed by about a factor five between use and non-use periods among homes within 250 m of fields and between these homes and controls. For 7 pesticides there was a moderate to strong correlation (Spearman rho 0.30–0.75) between concentrations in DDM and VFD. Distance to agricultural fields and air concentrations were among the most relevant predictors for occurrence and levels of a given pesticide in DDM. Concentrations in dust are overall higher during application periods and closer to fields (<250 m) than further away. The omnipresence of pesticides in dust lead to residents being exposed all year round.
Show more [+] Less [-]Significant impact of seasonality, verticality and biofilm on element accumulation of aquatic macrophytes
2022
Engloner, Attila I. | Németh, Kitti | Óvári, Mihály
Submersed macrophytes accumulate large amounts of macro- and trace elements from the environment and, therefore, are frequently used as indicators of water pollution and tools to remove pollutants from contaminated waters. This study provides evidences that the quantity of macro- and trace elements accumulated in the macrophyte Ceratophyllum demersum depends strongly on the seasonality, on the vertical position of the plant material and on the biofilm cover. Element contents of macrophytes with and without biofilm cover and that of vertical plant sections were investigated by an ICP-MS technique in three different habitats, at the beginning and at the end of the vegetation period. Results demonstrated that the element concentrations of Ceratophyllum demersum dropped to one-half and one-eighth by the end of the summer; and the amount of certain elements in the lower part of plants were up to six times higher than in the upper and in plants with well-developed epiphytic microbial community 2-5-fold higher than in plants without biofilm.These results help in phytoremediation practice and in setting up future biomonitoring studies. When it is necessary to calculate the exact amount of elements which can be accumulated by plants in a polluted environment or should be removed from a contaminated water by harvesting macrophytes, it is of high importance to consider the month of the study, the plant parts harvested and the biofilm cover.
Show more [+] Less [-]Materials, surfaces, and interfacial phenomena in nanoplastics toxicology research
2022
Martin, Leisha M.A. | Gan, Nin | Wang, Erica | Merrill, Mackenzie | Xu, Wei
In response to the growing worldwide plastic pollution problem, the field of nanoplastics research is attempting to determine the risk of exposure to nanoparticles amidst their ever-increasing presence in the environment. Since little is known about the attributes of environmental nanoplastics (concentration, composition, morphology, and size) due to fundamental limitations in detection and quantification of smaller plastic particles, researchers often improvise by engineering nanoplastic particles with various surface modifications as models for laboratory toxicological testing. Polystyrene and other commercially available or easily synthesized polymer materials functionalized with surfactants or fluorophores are typically used for these studies. How surfactants, additives, fluorophores, the addition of surface functional groups for conjugation, or other changes to surface attributes alter toxicological profiles remains unclear. Additionally, the limited polymers used in laboratory models do not mimic the vast range of polymer types comprising environmental pollutants. Nanomaterials are tricky materials to investigate due to their high surface area, high surface energies, and their propensity to interact with molecules, proteins, and biological probes. These unique properties can often invalidate common laboratory assays. Extreme care must be taken to ensure that results are not artefactual. We have gathered zeta potential values for various polystyrene nanoparticles with different functionalization, in different solvents, from the reported literature. We also discuss the effects of surface engineering and solvent properties on interparticle interactions, agglomeration, particle-protein interactions, corona formation, nano-bio interfaces, and contemplate how these parameters might confound results. Various toxicological exemplars are critically reviewed, and the relevance and shortfalls of the most popular models used in nanoplastics toxicity studies published in the current literature are considered.
Show more [+] Less [-]The association between bisphenol A exposure and oxidative damage in rats/mice: A systematic review and meta-analysis
2022
Zhang, Huan | Yang, Rui-fu | Shi, Wanying | Zhou, Xin | Sun, Suju
Numerous studies reported that BPA could cause oxidative damage to different tissues in rats/mice. This study aimed to perform a systematic review and meta-analysis of BPA exposure on oxidative damage in rats/mice. A comprehensive literature search was conducted using PubMed, Embase, and Web of Science databases from their inception date until July 18, 2020. 20 eligible articles were included in this study. The results showed that BPA could significantly increase the level of MDA (SMD, 16.88; 95%CI, 12.06–21.71), but there was a significant reduction in the contents of antioxidants, such as GR (−10.46, −13.91 ∼ −7.02), CAT (−8.48, −11.66 ∼ −5.30), GPx (−9.37, −11.95 ∼ −6.80), GST (−7.59, −14.51 ∼ −0.67), GSH (−10.64, −13.96 ~ −7.33), and SOD (−6.48, −8.37 ∼ −4.58) in rats/mice. Our study provided clear evidence that BPA exposure could significantly induce oxidative damage in rats/mice. And we also found that the degree of oxidative damage was related to BPA dose, target tissue, intervention means, and exposure duration of BPA.
Show more [+] Less [-]RNA metabarcoding helps reveal zooplankton community response to environmental stressors
2022
Ankley, Phillip J. | Xie, Yuwei | Havens, Sonya | Peters, Lisa | Timlick, Lauren | Rodriguez-Gil, Jose Luis | Giesy, John P. | Palace, Vince P.
DNA metabarcoding can provide a high-throughput and rapid method for characterizing responses of communities to environmental stressors. However, within bulk samples, DNA metabarcoding hardly distinguishes live from the dead organisms. Here, both DNA and RNA metabarcoding were applied and compared in experimental freshwater mesocosms conducted for assessment of ecotoxicological responses of zooplankton communities to remediation treatment until 38 days post oil-spill. Furthermore, a novel indicator of normalized vitality (NV), sequence counts of RNA metabarcoding normalized by that of DNA metabarcoding, was developed for assessment of ecological responses. DNA and RNA metabarcoding detected similar taxa richness and rank of relative abundances. Both DNA and RNA metabarcoding demonstrated slight shifts in measured α-diversities in response to treatments. NV presented relatively greater magnitudes of differential responses of community compositions to treatments compared to DNA or RNA metabarcoding. NV declined from the start of the experiment (3 days pre-spill) to the end (38 days post-spill). NV also differed between Rotifer and Arthropoda, possibly due to differential life histories and sizes of organisms. NV could be a useful indicator for characterizing ecological responses to anthropogenic influence; however, the biology of target organisms and subsequent RNA production need to be considered.
Show more [+] Less [-]Microbial community composition and glyphosate degraders of two soils under the influence of temperature, total organic carbon and pH
2022
Muskus, Angelica M. | Miltner, Anja | Hamer, Ute | Nowak, Karolina M.
Glyphosate can be degraded by soil microorganisms rapidly and is impacted by temperature and soil properties. Enhanced temperature and total organic carbon (TOC) as well as reduced pH increased the rate of ¹³C₃¹⁵N-glyphosate conversion to CO₂ and biogenic non-extractable residues (bioNERs) in a Haplic Chernozem (Muskus et al., 2019) and in a Humic Cambisol (Muskus et al., 2020). To date; however, the combined effect of temperature and TOC or pH on microbial community composition and glyphosate degraders in these two soils has not been investigated. Phospholipid fatty acid [PLFA] biomarker analysis combined with ¹³C labeling was employed to investigate the effect of two soil properties (pH, TOC) and of three temperatures (10 °C, 20 °C, 30 °C) on soil microorganisms. Before incubation, the properties of a Haplic Chernozem and a Humic Cambisol were adjusted to obtain five treatments: (a) Control (Haplic Chernozem: 2.1% TOC and pH 6.6; Humic Cambisol: 3% TOC and pH 7.0), (b) 3% TOC (Haplic Chernozem) or 4% TOC (Humic Cambisol), (c) 4% TOC (Haplic Chernozem) or 5% TOC (Humic Cambisol), (d) pH 6.0 (Haplic Chernozem) or pH 6.5 (Humic Cambisol), and (e) pH 5.5 for both soils. All treatments were amended with 50 mg kg⁻¹ glyphosate and incubated at 10 °C, 20 °C or 30 °C. We observed an increase in respiration, microbial biomass and glyphosate mineralization with incubation temperature. Although respiration and microbial biomass in the Humic Cambisol was higher, the microorganisms in the Haplic Chernozem were more active in glyphosate degradation. Increased TOC shifted the microbiome and the ¹³C-glyphosate degraders towards Gram-positive bacteria in both soils. However, the abundance of ¹³C-PLFAs indicative for the starvation of Gram-negative bacteria increased with increasing TOC or decreasing pH at higher temperatures. Gram-negative bacteria thus may have been involved in earlier stages of glyphosate degradation.
Show more [+] Less [-]The relationship between greenspace and personal exposure to PM2.5 during walking trips in Delhi, India
2022
Mueller, William | Wilkinson, Paul | Milner, James | Loh, Miranda | Vardoulakis, Sotiris | Petard, Zoë | Cherrie, Mark | Puttaswamy, Naveen | Balakrishnan, Kalpana | Arvind, D.K.
The presence of urban greenspace may lead to reduced personal exposure to air pollution via several mechanisms, for example, increased dispersion of airborne particulates; however, there is a lack of real-time evidence across different urban contexts. Study participants were 79 adolescents with asthma who lived in Delhi, India and were recruited to the Delhi Air Pollution and Health Effects (DAPHNE) study. Participants were monitored continuously for exposure to PM₂.₅ (particulate matter with an aerodynamic diameter of less than 2.5 μm) for 48 h. We isolated normal day-to-day walking journeys (n = 199) from the personal monitoring dataset and assessed the relationship between greenspace and personal PM₂.₅ using different spatial scales of the mean Normalised Difference Vegetation Index (NDVI), mean tree cover (TC), and proportion of surrounding green land use (GLU) and parks or forests (PF). The journeys had a mean duration of 12.7 (range 5, 53) min and mean PM₂.₅ personal exposure of 133.9 (standard deviation = 114.8) μg/m³. The within-trip analysis showed weak inverse associations between greenspace markers and PM₂.₅ concentrations only in the spring/summer/monsoon season, with statistically significant associations for TC at the 25 and 50 m buffers in adjusted models. Between-trip analysis also indicated inverse associations for NDVI and TC, but suggested positive associations for GLU and PF in the spring/summer/monsoon season; no overall patterns of association were evident in the autumn/winter season. Associations between greenspace and personal PM₂.₅ during walking trips in Delhi varied across metrics, spatial scales, and season, but were most consistent for TC. These mixed findings may partly relate to journeys being dominated by walking along roads and small effects on PM₂.₅ of small pockets of greenspace. Larger areas of greenspace may, however, give rise to observable spatial effects on PM₂.₅, which vary by season.
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