Poultry manure is a reservoir for antibiotics and antibiotic resistance genes and composting is an effective biological treatment for manure. This study explored the effect of using two methods of adding a complex microbial agent to the composting of laying-hen manure on doxycycline degradation and tetracycline resistance genes elimination. The results showed that incorporating a complex microbial agent at 0.8% (w/w) on the 0ᵗʰ and 11th day (group MT2) effectively degraded doxycycline with a final degradation rate of 46.83 ± 0.55%. The half-life of doxycycline in this group was 21.90 ± 0.00 days and was significantly lower than that of group MT1 (1.6% (w/w) complex microbial agent added on the 0ᵗʰ day) and group DT (compost without complex microbial agent). But there was no significant difference in the final degradation rate of doxycycline between group DT and group MT1. The addictive with the complex microbial agent changed the microbial community structure. Bacteroidetes, Firmicutes and Proteobacteria were the dominant phyla during composting. Aerococcus, Desemzia, Facklamia, Lactobacillus, Streptococcus, and Trichococcus were the bacteria related to the degradation of doxycycline. Moreover, the incorporation of a complex microbial agent could decrease the risk on spreading tetracycline resistance genes. The single addition promoted the elimination of tetM, whose possible hosts were Enterococcus, Lactobacillus, Staphylococcus, and Trichococcus. Adding the complex microbial agent twice promoted the elimination of tetX, which was related to the low abundance of Chryseobacterium, Flavobacterium and Neptunomonas in group MT2. Redundancy analysis showed that the bacterial community, residual doxycycline and physiochemical properties have a potential effect on the variation in tetracycline resistance genes levels. Overall, adding the complex microbial agent twice is an effective measure to degrade doxycycline.

The ecological effects of wastewater treatment plant (WWTP) effluents on stream ecosystems cause growing concern. However, it is difficult to assess these effects as most streams receiving WWTP effluents are also affected by other stressors. We performed a whole-ecosystem manipulation experiment following a BACI design (Before-After/Control-Impact) in order to exclude the influence of other potentially confounding factors. We diverted part of the effluent of a large tertiary urban WWTP into a small, unpolluted stream, and studied its effects on ecosystem structure and functioning over two years (i.e., one year before and one year after the effluent diversion). Although highly diluted (final concentration in the receiving stream averaged 3%), the effluent promoted biofilm chlorophyll-a and biomass (2.3 and 2.1 times, respectively), exo-enzymatic activities (phosphatase 2.2 and glucosidase 4.2 times) and invertebrate-mediated organic matter decomposition (1.4 times), but reduced phosphorus uptake capacity of the epilithic biofilm down to 0.5 of the initial values. Biofilm metabolism, reach-scale nutrient uptake and microbially-mediated organic matter decomposition were not affected. Our results indicate that even well treated and highly diluted WWTP effluents can also affect the structure of the biofilm community and stream ecosystem functioning.

Microplastics (MPs) are new persistent organic pollutants derived from the degradation of plastics. They can accumulate along the food chain and enter the human body through oral administration, inhalation and dermal exposure. To identify the impact of Polystyrene (PS) MPs on the cardiovascular system and the underlying toxicological mechanism, 32 male Wister rats were divided into control group and three model groups, which were exposed to 0.5 μm PS MPs at 0.5, 5 and 50 mg/L for 90 days. Our results suggested that PS MPs exposure increased Troponin I and creatine kinase-MB (CK-MB) levels in serum, resulted in structure damage and apoptosis of myocardium, and led to collagen proliferation of heart. Moreover, PS MPs could induce oxidative stress and thus activate fibrosis-related Wnt/β-catenin signaling pathway. These results suggested that PS MPs could lead to cardiovascular toxicity by inducing cardiac fibrosis via activating Wnt/β-catenin pathway and myocardium apoptosis triggered by oxidative stress. The present study provided some novelty evidence to elucidate the potential mechanism of cardiovascular toxicity induced by PS MPs.

Concentrations of As, Cd, Cr, Cu, Hg, Pb, and Zn in sediment samples and muscle tissue of the European perch were analyzed using inductively-coupled plasma optical emission spectrometry (ICP-OES), with the aim to assess the potential ecological (RI) and human health risk, and the degree of contamination (Cd) of three types of reservoirs in Serbia, based on their purpose: electricity generation (Vlasina, Perućac, Zaovine, and Međuvršje), drinking water supply (Garaši), and recreation (Lake Sava). The concentrations of the studied elements were higher in sediments than in fish. However, the levels of Cd in fish caught in Vlasina, Zaovine, and Međuvršje, Hg in Perućac and Garaši, and Pb in Lake Sava exceeded the maximum allowed concentrations. The pollution load index (PLI) indicated that sediments in all six reservoirs were contaminated, but Cd was low; a moderate contamination with Cd was observed in Vlasina, Perućac, and Zaovine, Cr in Zaovine and Međuvršje, and Cu in Međuvršje. A low RI was recorded for all studied reservoirs. Cd was found to be the primary contamination and ecological risk factor. Total target hazard quotient (THQ) and target carcinogenic risk factor (TR) were higher for fishers operating in these reservoirs than for the general population. Higher values of PLI, Cd, RI, and TR were observed in electricity generation reservoirs. Results indicated that this type of reservoirs suffer from higher anthropogenic pressure and/or have a worse pollution management policy compared with other types of reservoirs included in this study, especially the drinking water supply reservoir.

Assessing the fate of both legacy and newer persistent organic pollutants (POPs) is an ongoing challenge. Top predators, including seabirds, are effective monitors of POPs because they forage over a range of marine habitats, integrating signals over space and time. However, migration patterns can make unravelling contaminant sources, and potentially assessments of the effectiveness of regulations, challenging if chemicals are acquired at distant sites. In 2014, we fitted geolocators on ancient murrelets (Synthliboramphus antiqueus) at four colonies on the Pacific Coast of Canada to obtain movement data throughout an annual cycle. All birds underwent a post-breeding moult in the Bering Sea. Around one-third then returned to overwinter on the British Columbia (BC) coast while the rest migrated to overwinter in waters along the north Asian coast. Such a stark difference in migration destination provided an opportunity to examine the influence of wintering location on contaminant signals. In summer 2015, we collected blood samples from returned geo-tagged birds and analyzed them for a suite of contaminants, including polybrominated diphenyl ethers (PBDEs), non-PBDE halogenated flame retardants, perfluoroalkyl substances (PFASs), organochlorines, and mercury. Feathers were also collected and analyzed for stable isotopes (δ¹³C, δ¹⁵N, and δ³⁴S). We found no significant differences in blood concentrations of any contaminant between murrelets from the two different overwinter areas, a result that indicates relatively rapid clearance of POPs accumulated during winter. Spatial variation in diet (i.e., δ¹³C) was associated with both BDE-47 and -99 concentrations. However, individual variation in trophic level had little influence on concentrations of any other examined contaminants. Thus, blood from these murrelets is a good indicator of recent, local contaminants, as most signals appear independent of overwintering location.

Fossil fuels still prevail over other energy sources in the world’s consumption energy matrix. Thus, oil transportation and operations over maritime routes have been in high demand for a long time. Although oil spill accidents caused by these activities have reduced significantly over the last few decades, they still cause great concern. From this perspective, this paper presents simulation analyses of oil spill case studies using TELEMAC-3D hydrodynamic model coupled with an oil model. Hence a location susceptible to such accidents was selected and three real oil spills were simulated, for each of which there were official technical monitoring reports available. The obtained results contribute to the knowledge of oil pollution susceptibility in environmentally sensitive areas, as well as provide information concerning oil slick behaviour. Additionally, similarities between the modelled results and the technical reports were confirmed. These findings are useful for contingency planning and responding to these probable accidents.

In this work, the electrochemical degradation of antibiotic ceftazidime has been studied using a novel rare earth metal Ce and carbon nanotubes codoped PbO₂ electrode. A competitively high oxygen evolution potential (2.4 V) and enhanced catalytic surface area were obtained, evidence by LSV and CV electrochemical characterization. The G/CNT-Ce/PbO₂–Ce electrode possessed a more compact structure and a smaller grain size than the other PbO₂ and Ce–PbO₂ electrodes, exhibiting a prolonged service lifetime, evidence by accelerated lifespan test and recycling degradation experiment. As electrolysis time reached 120 min, the removal efficiency of ceftazidime and TOC arrived at 100.0% and 54.2% respectively in 0.05 M Na₂SO₄ solution containing 50 mg⋅L⁻¹ ceftazidime. The effect of applied current density, pH value, initial ceftazidime concentration and chloride contents on the degradation performance were systematically evaluated. The results demonstrated that electrochemical oxidation of ceftazidime over the G/CNT-Ce/PbO₂–Ce electrode was highly effective, and the mineralization rate was greatly improved, compared with pristine PbO₂ electrode. Considering the toxicity was increased after 30 min electrolysis, the intermediates were quantitatively investigated through HPLC-MS, GC-MS and IC technology. According to the identified products, a reaction mechanism has been proposed and pyridine and aminothiazole were detected with concentration from approximately 1 to 3 mg⋅L⁻¹, which were regarded as toxic byproducts during electrooxidation. Further electrocatalyzing by ring cleavage reaction and complete mineralization to CO₂, NO₃⁻ and NH₄⁺ was proposed, which demonstrated the G/CNT-Ce/PbO₂–Ce electrode exhibited high efficiency for ceftazidime removal in mild conditions.

Uncertainty assessment of parameters associated with non-point source pollution mechanism modeling are crucial for improving the effectiveness of pollution controlling. In this study, an approach based on Bayesian inference and integrated Markov chain Monte Carlo and multilevel factorial analysis has been developed, and it can not only apply straightforward Bayesian inference to assess parameter uncertainties, but also quantitatively investigate the main and interactive effects of multiple parameters on the model response variables by measuring the specific variations of model outputs. Its applicability and advantages are presented through the application of the Soil and Water Assessment Tool to Shitoukoumen Reservoir Catchment in northeast China. This study investigated the uncertainties of a set of sensitive parameters and their multilevel effects on model response variables, including average annual runoff (AAR), average annual sediment (AAS) and average annual total nitrogen (AAN). Results revealed that (i) soil conservation service runoff curve number for moisture condition II (CN2) had a positive effect on all response variables; (ii) available water capacity of the soil layer (SOL_AWC) had a negative effect on all response variables; (iii) the universal soil loss equation support practice (USLE_P) had a positive effect on AAS and AAN, and little effect on AAR; while the nitrate percolation coefficient (NPERCO) had a positive effect on AAN, and little effect on AAS and AAR; and (iv) the interactions amongst parameters had obvious interdependent effects on the model response variables, for example, the interaction between CN2 and SOL_AWC had a major impact on AAR. The above findings can improve the simulating and predicting capabilities of non-point source pollution mechanism model. Overall, this study highlights that the proposed approach represents a promising solution for uncertainty assessment of model parameters in non-point source pollution mechanism modeling.

Dibutyl phthalate (DBP) is widely used as plasticizer and has been detected in the environment, posing a threat to animal health. However, the effects of DBP on agricultural microbiomes are not known. In this study, DBP levels in black soil were evaluated, and the impact of DBP contamination on the uptake and metabolism of sugars in microbes was assessed by glucose absorption tests, metaproteomics, metabolomics, enzyme activity assays and computational simulation analysis. The results indicated that DBP contamination accelerated glucose consumption and upregulated the expression of porins and periplasmic monosaccharide ATP-binding cassette (ABC) transporter solute-binding proteins (SBPs). DBP and its metabolic intermediates (carboxymuconate and butanol) may form a stable complex with sugar transporters and enhance the rigidity and stability of these proteins. Sugar metabolism resulting in the generation of ATP and reducing agent (NADPH), as well as the expression of some key enzymes (dehydrogenases) were also upregulated by DBP treatment. Moreover, a diverse bacterial community appears to utilize sugar, suggesting that there are widespread effects of DBP contamination on soil microbial ecosystems. The results of this study provide a theoretical basis for investigating the toxicological effects of DBP on microbes in black soil.

Monitoring studies have quantified microscopic plastic debris, so-called microplastics, in freshwater systems, including banks, surface waters and sediments. However, there is a lack of knowledge of freshwater and terrestrial environments.When microplastics are released in freshwater environments, they will be transported and will not remain stationary. Moreover, their transport from sink to source (land-based to river systems) may depend on several factors such as weather conditions and river hydrology.The present study aims to investigate the abundance and composition of microplastics in the most important river of Apulia Region (Southeast Italy) evaluating the main drivers and possible input sources of microplastic debris. The following work is the first study showing an Italian river context. For this research five sampling campaigns have been conducted west of the Ofanto river mouth. Microplastics were collected by three surface plankton nets fixed in the middle of the river in order to reduce the spatial and temporal variability. For each campaign, a total of six replicates were sampled during two time slots.Microplastic concentrations ranged from 0.9 ± 0.4 p/m³ to 13 ± 5 p/m³ showing comparable values to or greater than those ones reported in other studies. A statistically significant difference in the average microplastic concentrations in different campaigns of this study has been observed, suggesting thus a temporal variation in plastic abundances. These significant differences could be explained by the hydrology of the river that influences the particle concentration with its physical forces such as flow velocity, water level and seasonal variability. Microplastics were found at higher concentrations during wet periods indicating a land-based origin probably connected to waste produced by the surroundings agricultural areas. In fact, Spearman's correlation results show a strong positive statistically significant correlation between the concentration of microplastics and the water level (R = 0.8475, p < 0.0001).