Bowerstorp9450

Based on the correlation analyses of Cd and Fe in amorphous-bound state and Fe-manganese (Mn) oxidation state in simulation experiments, it is demonstrated that Fe-Mn oxides control the behavior of Cd in soil clay, and SRB-mediated Fe-bearing minerals promote the transformation of Cd from activated to stable state.In this study, the nano-scale spatial distribution of natural organic matter (NOM) on the surface of iron (hydr)oxides and its relevance to oxyanion (PO43-) and metal cation (Cd2+ and Cu2+) adsorption to the assemblage of oxide (goethite) and NOM (humic acids (HA) or fulvic acids (FA)) was investigated with experiments and advanced surface complexation modeling. Both the linear additive Multi-Surface model (MSM) and the more sophisticated Natural Organic Matter-Charge Distribution (NOM-CD) model were used. The MSM model ignores the effects of NOM-mineral interaction on ion adsorption, whereas the NOM-CD model considers this effect. The results showed that with the increase of NOM loading on oxides, deviation between the MSM and NOM-CD model became bigger for PO43-, but smaller for Cd2+ and Cu2+. Oxyanions bind mainly to oxides and therefore the competitive effect of NOM cannot be neglected, which explains the large difference between these two models for PO43-. On the contrary, at a relatively high NOM loading, a large fraction of NOM extends further away from the surface of oxides. Thus for metal cations that bind mainly to NOM, the influence of NOM-mineral interaction on their adsorption is small and the results of the MSM and NOM-CD model are similar. In top soils, the NOM loading on oxides is often high, therefore the linear additive MSM is applicable for metal cation speciation calculations as reported in many literatures. An approach based on the NOM-CD model was proposed, which can not only calculate the macroscopic solid-solution distribution of both cations and anions, but can also provide information regarding their microscopic surface speciation.Upon release into the aquatic environment, the surface of microplastics (MPs) can be readily colonized by biofilms, which may enhance the adsorption of contaminants. In this study, industrial-grade polystyrene (PS) of about 4 mm in size (MP4000-1), food-grade PS of about 4 mm in size (MP4000-2), and Powder PS of about 75 μm in size (MP75) were co-cultured with a model freshwater fungus, namely Acremonium strictum strain KR21-2, for seven days to form biofilms on their surface. We also determined the changes in surface physicochemical properties of the biofilm-covered MPs (BMPs) and the heavy metal adsorption capacity of the original MPs and BMPs. The results revealed that the biofilms improve the adsorption of heavy metals on MPs, and the particle size of MPs plays a crucial role in biofilm colonization and adsorption of heavy metals by BMPs. MP75 can carry more biofilm on its surface than that of the two MP4000s and form heteroaggregates with biofilms. In addition, there were more functional groups on the surface of BMP75 than on the surface of the two BMP4000s, which could promote the electrostatic interaction and chemical association of heavy metals. Moreover, BMP75 exhibited a higher capacity to adsorb Cu and reduce Cr (VI), which may be related to the functional groups in its biofilm. Overall, this study showed that after biofilms colonization, BMPs of smaller size have more significant potential as a metal vector, and the particle size deserves more scientific attention during the risk assessment.This study investigates authigenic metal (Zn, Cd, and Pb) sulfides formed in the upper (4-20 cm) layer of severely degraded soil close to ZnPb smelter in CE Europe (southern Poland). The soil layer is circumneutral (pH 6.0-6.8), organic, occasionally water-logged, and contains on average 26,400 mg kg-1 Zn, 18,800 mg kg-1 Pb, 1300 mg kg-1 Cd, and 2500 mg kg-1 of sulfur. The distribution of the authigenic sulfide mineralization is uneven, showing close association with the remains of vascular plants (Equisetaceae, Carex, and herbs). A combination of focused ion beam (FIB) technology with scanning (SEM) and transmission electron microscopy (TEM) is used to reveal the structure and organization of the metal sulfides at micro- and nanoscale resolution. The sulfides form spheroidal and botryoidal porous aggregates composed of nanocrystalline ( less then 5 nm) ZnCd sulfide solid solution and minor discrete PbS (galena) crystals up to 15 nm. The solid solution exists in a cubic (sphalerite) polytype over a whole Zn/Cils rich in organic matter that address the mobility of toxic metals and their transfer into living organisms.Dissolved organic matter (DOM) is composed of numerous fluorescent components. It is an indispensable parameter to affect the environmental fate of antibiotics in various ways. To assess the migration of antibiotics in environment compartments, it is crucial to understand the binding mechanism between DOM and antibiotics. How a particular component in DOM interacts with coexistence antibiotics is not still fully understood. Therefore, in the present study, interactions of two antibiotics oxytetracycline (OTC) and sulfadiazine (SD) with humic acid (HA) and L-tryptophan (L-Trp) which were representative DOM components, were investigated by multispectral techniques and density functional theory (DFT) calculations. The fluorescence quenching mechanism was static quenching. In the binding process, the quenching ability of OTC was stronger than that of SD in HA, which was the same as in L-Trp. DFT calculations were applied to confirm a stronger interaction between OTC and HA or L-Trp than SD. Meanwhile, analyzing the binding sequence by two-dimensional correlation spectroscopy (2D-COS), a humic-like substance bound antibiotics was earlier than a protein-like substance. In HA system, the combination of two antibiotics had a synergistic effect on HA quenching. In L-Trp system, the quenching relationship between the two antibiotics and L-Trp was antagonistic. The FTIR spectra showed that hydroxyl and amide were involved in the binding process of individual DOM components with OTC and SD. The work will help to further understand the behavior of coexistence antibiotics in the environment.Personal protective equipment (PPE) pollution has become one of the most pending environmental challenges resulting from the pandemic. While various studies investigated PPE pollution in the marine environment, freshwater bodies have been largely overlooked. In the present study, PPE monitoring was carried out in the vicinity of Lake Tana, the largest lake in Ethiopia. PPE density, types, and chemical composition (FTIR spectroscopy) were reported. A total of 221 PPEs were identified with a density ranging from 1.22 × 10-5 PPE m-2 (control site S1) to 2.88× 10-4 PPE m-2 with a mean density of 1.54 × 10-4 ± 2.58 × 10-5 PPE m-2. Colivelin ic50 Mismanaged PPE waste was found in all the sampling sites, mostly consisting of surgical face masks (93.7%). Statistical analyzes revealed significantly higher PPE densities in sites where several recreational, touristic, and commercial activities take place, thus, revealing the main sources of PPE pollution. Furthermore, polypropylene and polyester fabrics were identified as the main components of surgical and reusable cloth masks, respectively. Given the hazard that PPEs represent to aquatic biota (e.g., entanglement, ingestion) and their ability to release microplastics (MPs), it is necessary to implement sufficient solid waste management plans and infrastructure where lake activities take place. Additionally, local authorities must promote and ensure sustainable tourism in order to maintain the ecosystems in Lake Tana. Prospective research priorities regarding the colonization and degradation of PPE, as well as the release of toxic chemicals, were identified and discussed.Lakes are critical for biogeochemical and ecological processes and are sensitive and vulnerable to anthropogenic disturbances, but how and to what extent human activities disturb the biodiversity in lakes remain unknown. Here, we showed the microbial diversity in 46 lakes and assessed the influence of 27 anthropogenic factors. We found that the economic level (e.g., per capita gross domestic product) was strongly negatively correlated (r = -0.97) with bacterial diversity but positively correlated (r = 0.17) with fungal diversity in lakes. The composition of the microbial community significantly changed with increasing economic level. Bacteria are more sensitive than fungi to anthropogenic impacts. Expanding the population size and increasing the economic level may promote the development of fungal diversity but inhibit bacterial diversity. Air quality, urbanization and ozone were negatively correlated with bacterial diversity, and fisheries had a negative correlation with fungal diversity. The anti-interference ability of lake microorganisms in the middle economic level zones (45,000-90,000 yuan/person) was stronger than that in high-level (> 90,000 yuan/person) and low-level (> 45,000 yuan/person) economic zones. Overall, our investigation provides national-scale evidence that changes in the microbial diversity in lakes were related to economic levels.Beijing-Tianjin-Hebei and the surrounding area (BTHSA) shows the poorest air quality in China, reflected in sub-standard PM2.5 and increasingly pronounced O3 pollution, stressing the urgency for regional cooperation and collaborative control of PM2.5 and O3. With the aim to explore the cooperative regions and response mechanisms of PM2.5 and O3 in BTHSA, this study applied multiple mathematical models and analytical indicators to multiple data sources, including applying self-organizing map (SOM), response surface model (RSM), random forest (RF), distributed lag nonlinear models (DLNMs), and meta-analysis, on ground observations of air quality and meteorology, ozone monitoring instrument (OMI) observations, and air pollutant emission inventory. The results revealed that BTHSA exhibited clear regional characteristics of air pollution and can be divided into four clusters for enhanced intercity cooperation. Over 2015-2020, anthropogenic factors played more important roles than meteorological ones on the alleviation of PM2.5 and the deterioration of O3. RSM based on observations and RF based on emissions both suggested that, in the near future, strengthened abatement of SO2, PM2.5 and VOC can be beneficial for controlling PM2.5 and O3 pollution, while intensive NOx reduction in PM2.5-dominant months and mitigatory NOx reduction in O3-dominant months should be formulated before certifying an obvious transition of O3-NOx-VOC sensitivity. This study, with multi-model and multi-data fusion, can be expected to provide synthesized fact- and science-based guidance for the next-stage collaborative control of PM2.5 and O3 in BTHSA.Size is a key factor controlling the rate of dissolution of nanoparticles, such property can be explored for producing controlled release fertilizers. Hence, one can expect the increasing discharge of nanoparticles closer to water streams in the near future. In this study, we employed the model fresh water organism Daphnia magna to investigate the uptake, acute toxicity and depuration of ZnO nanoparticles. The present study shows that the median lethal concentration (LC50) depended on particle size and the presence of surfactant. The LC50 for positive control ZnSO4 (2.15 mg L-1), 20 nm ZnO (1.68 mg L-1), and 40 nm ZnO (1.71 mg L-1) were statistically the same. However, the addition of surfactant increased the LC50 of 40 nm and 60 nm to 2.93 and 3.24 mg L-1, respectively. The 300 nm ZnO was the least toxic nanoparticle presenting LC50 of 6.35 mg L-1. X-ray fluorescence chemical imaging revealed that Zn accumulated along the digestive system regardless the particle size. Finally, contrary to what have been reported by several papers, the present study did not detect any depuration of ZnO nanoparticles in the next 24 h past the exposure assays.