Grain size and concentrations of organic carbon (Corg) and particulate metals (PMs) As, Cd, Cr, Cu, Hg, Pb, Zn, Al, Fe, and Mn of 373 surface sediment samples, salinities in 67 surface water samples, were analyzed in various environments, including the upper delta plain wetlands (UDPW), its adjacent shallow sea wetland (SSW) in the Liaodong Bay, and river channels that are running through the Liaohe Delta, to evaluate the spatial distribution, transportation environmental dynamics of metals, and the provenance of metal pollution and assess the filtration functions of wetlands. The concentrations of PMs for UDPW were generally higher by a factor of ~ 10–22% compared with its analogues in SSW, suggesting the accumulation of PMs within the UDPW indicates that the UDPW systems are efficiently physical and chemical traps for PMs of anthropogenic sources by retaining and storing pollutants flowing into the sea. However, there was sever sewage irrigation-induced Cd pollution with a geo-accumulation index of 0.62–3.11 in an area of ~ 86 km² of the adjacent shallow sea wetland, where large amount wetlands were historically moved for agriculture in the UDPW. Remarkably, the distributions of PMs were controlled by salinity-induced desorption and re-adsorption mechanisms and significantly dispersed the contamination coverage by the three-dimensional hydrodynamic and sedimentation processes that dominated by inputs of freshwater and ocean dynamics including NE-SW tidal currents and NE-E longshore drifts in the SSW of the Liaodong Bay. A high agreement between the UDPW and the SSW datasets in principal component analysis essentially reflects that the characteristics of PM sources in the SSW were actually inherited from that in the UDPW, with a much closer relationship among metals, organic matter, and fine particulates in SSW than that of UDPW, which was judged by their correlation coefficient range of 0.406–0.919 in SSW against those of 0.042–0.654 in UDPW.

Long-range atmospheric transport is one of the most important ways in which persistent organic pollutants can be transported from their source to remote and pristine regions. Here, we report the results of the first Argentinian measurements of organochlorine pesticides in the Antarctic region. During a 9665-km track onboard OV ARA Puerto Deseado, within the framework of Argentinian Antarctic Expeditions, air samples were taken using high-volume samplers and analyzed using GC-μECD. HCB, HCHs, and endosulfans were the major organic pollutants found, and a north-south gradient in their concentrations was evident by comparing data from the Argentinian offshore zone to the South Scotia Sea.

In the process of creating eco-friendly environment and conserving fossil fuels for the future generations, biodiesel has been chosen as a good substitute for diesel. It is a proven fact that biodiesel operated diesel engine can deliver comparable results with diesel. The present work focuses on TSME20 (tamarind seed methyl ester 20% + diesel 80%) as a renewable fuel, and its performance and emission results are analyzed at different exhaust gas recirculation rates and various injection pressures. The process is done in two stages. Firstly, experiments are conducted on TSME20 operated diesel engine at three injection pressures (180, 200, and 220 bar), and the results are analyzed. From the experimental results, improved efficiency by 2.29% and reduced emissions, such as hydrocarbon, smoke, and carbon monoxide, by 53.84, 56.25, and 75.15% are observed at the peak load for the increased injection pressure (220 bar) over 200 bar except NOx levels, which are found high by 11% compared to 200-bar injection pressure. Secondly, tests are again performed at the optimal condition of 220-bar injection pressure with the exhaust gas re-circulation (EGR) rates at different levels, i.e., 10 and 20%. The test results reveal that the addition of 10% EGR to the engine operating at 220 bar counteracts the release of NOx levels, which are found reduced by 80.5% over standard conditions without much compromise in engine performance. Also, the combustion characteristics of diesel engine at 220-bar fuel injection pressure of tamarind biodiesel blend showed enhancement when compared to other fuel injection pressures.

The control measures for estrogens in the aquatic environment are topics of growing concern. It is a meaningful issue to finding optimal process parameters for efficient removal of estrogens with the purpose of efficient total nitrogen (TN) or total phosphorus (TP) removal in sewage treatment plants. The present paper is concerned with the relationships between the estrogen removal and TN or TP removal in a pilot-scale three-stage anoxic/oxic (A/O) system treating real municipal wastewater. The total removal efficiency for estrone (E1) and 17β-estradiol (E2) and their sulfate and glucuronide conjugates were on average 87% in the pilot-scale system. The concentrations of the sulfate and glucuronide conjugates of estrogens (E1 and E2) in the system were much lower than the estrogens, which might be caused by the rapid degradation of conjugates in the pilot-scale system. The average removal efficiencies of E1 and E2 and their sulfate and glucuronide conjugates were significantly lower under high TP removal conditions than those under high TN removal conditions that suggested that the ammonia oxidation promotes estrogen degradation. When the system achieved efficient TN removal, the concentrations of both E1 and E2 were generally lower in the aerobic zones than those in the anoxic zones. Instead, when the system achieved efficient TP removal conditions, the estrogen concentrations were higher in the aerobic zones than in the anoxic zones. However, it was thought that the variation of the concentrations of the estrogen conjugates had weak influence on concentrations of the free estrogens. The increase of the free estrogens in the aerobic zones could be attributed to the release of the estrogens adsorbed on the sludge. The variation of estrogens in a three-stage A/O system can be properly estimated and measured by a binary linear regression model with the variables of TP and TON (NO₂⁻-N and NO₃⁻-N), which is probably the important information for the improvement and optimization of wastewater treatment processes to obtain higher removal efficiency for estrogens.

Ecotoxicological studies have revealed the association between synthetic pyrethroid (SP) exposure and aquatic toxicity in fish; however, research on the toxic effects of SP metabolites is still limited. In this study, the toxicity of two SPs (permethrin (PM) and β-cypermethrin (β-CP)) and their three metabolites (3-phenoxybenzoic alcohol (PBCOH), 3-phenoxybenzaldehyde (PBCHO), and 3-phenoxybenzoic acid (PBCOOH)) towards zebrafish embryos and larvae was evaluated. Both SPs and their metabolites exhibited significant developmental toxicities, caused abnormal vascular development, and changed locomotor activities in larvae. The alteration of gene expression involved in the thyroid system and the innate immune system indicated that SPs and their three metabolites have the potency to induce thyroid disruption and trigger an immune response. The results from the present study suggest that SP metabolites could induce multiple toxic responses similar to parent compounds, and their toxicity should be considered for improving the understanding of environmental risks of SPs.

Using Fourier transform infrared spectroscopy (FT-IR) measurements and comparing the spectrum peaks (range 4000–600 cm⁻¹) with reference spectra database and instrument libraries, we observed new evidence of the ingestion of microplastic particles analyzing the digestive tracts of Talitrus saltator. Specimens, sampled in central Italy, probably ingested the particles with natural detritus. Since worldwide many species of invertebrates and vertebrates (e.g., birds) feed on Amphipoda along coastal ecosystems, we hypothesized that microplastic in these crustaceans can be accumulated along the food chain.

Heavy metal (HM) contamination in road dust is a potential environmental and human health threat. The sources, concentrations, spatial distribution, and ecological risk of As, Cd, Cu, Cr, Ni, Pb, and Zn in road dust in Rafsanjan City, Iran, were investigated. Pollution was assessed using the enrichment factor (EF). The potentially harmful effects of HMs were evaluated by calculating the potential ecological risk factor of individual metals (E ᵣ) and of multiple metals (RI) using the Hakanson method. Correlation and principal component analyses (PCA) were applied to identify HM pollution sources. The concentrations of HMs in road dust were higher (ca. 5–10 folds) than their natural background values. The EF and E ᵣ increased according to the following order Cu > Pb > As > Zn > Cd > Cr > Ni and Cu > Cd > Pb > As > Ni > Zn > Cr, respectively. Thus, Cu is regarded as the pollutant of highest concern. Based on potential ecological risk index (RI) spatial distribution, all parts of Rafsanjan are characterized by significantly high potential ecological risk. HM concentration heat maps, PCA, and correlation analysis suggest that Cu, Pb, As, Cd, and Zn may have originated from the same source and follow the same spatial distribution pattern. These metals originated mainly from anthropogenic sources like copper mining and smelting plants, industrial and chemical activities, inordinate application of chemical fertilizers and pesticides in farmlands, and heavy traffic. Ni and Cr are likely to origniate from the industrial activities and traffic load in Rafsanjan City.

This study was conducted to investigate the growth modulatory effects of dietary supplementation with silver nanoparticles (Ag NPs) and Ag nitrate on broiler chickens. Thirty 15-day-old chicks were equally divided into the control group (fed basal diets), the Ag-nano group (fed basal diets supplemented with 50 ppm/kg of Ag NPs for 12 d), and the Ag nitrate group (fed basal diets supplemented with 100 ppm/kg Ag nitrate for 12 days). Chicks fed Ag NPs showed increased body weight gain and muscle weight, improved feed efficiency, and increased ash digestibility, while Ag digestibility tend to increase but not significant. Plasma triiodothyronine contents, and muscle Ag and nitrogen contents as well as a significant increase in the following mRNA levels in muscle tissue: insulin-like growth factor-1 (IGF1), glucose transporters (Glut1, Glut3), citrate synthase (CS), and glutathione peroxidase (GPx), whereas the atrogin-1, fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), lactate dehydrogenase (LDH), and carnitine palmitoyl transferase 1A (CPT1A) mRNA levels were unchanged. However, these chicks exhibited decreased levels of plasma cholesterol, triglyceride, and glucose. Dietary supplementation with Ag NPs improved the growth performance of broiler chickens.

Cyanotoxins are a type of cyanobacteria that is poisonous and poses a health threat in waters that could be used for drinking or recreational purposes. Thus, it is necessary to predict their presence to avoid risks. This paper presents a nonparametric machine learning approach using a gradient boosted regression tree model (GBRT) for prediction of cyanotoxin contents from cyanobacterial concentrations determined experimentally in a reservoir located in the north of Spain. GBRT models seek and obtain good predictions in highly nonlinear problems, like the one treated here, where the studied variable presents low concentrations of cyanotoxins mixed with high concentration peaks. Two types of results have been obtained: firstly, the model allows the ranking or the dependent variables according to its importance in the model. Finally, the high performance and the simplicity of the model make the gradient boosted tree method attractive compared to conventional forecasting techniques.

This study aimed to evaluate the interface effect between five types of natural precipitated dust and two normal floras. Five kinds of natural dust (FC-1#, FC-2#, FC-15#, FC-18#, and FC-21#) were collected, and particle size and chemical components were detected by laser particle size analyzer and X-ray fluorescence (XRF). The elements, bacterial count, glucose (GLU) consumption, pH, and three biochemical indicators were measured after being co-cultured with Escherichia coli and Staphylococcus epidermidis in vitro. In addition, the changes of bacterial morphology were observed by scanning electron microscopy (SEM). Results showed that most particles contained a high level of SiO₂, which diameter ranged from 0.3 to 1.0 μm. The concentration of Ca showed s significant increase upon interaction with E. coli and S. epidermidis in all dusts (p < 0.01). Moreover, FC-1# and FC-21# induced obvious growth in bacterial count, glucose consumption, and pH after they reacted with two normal floras (p < 0.05). Besides, the results also showed an apparent increase in the concentration of pyruvate, β-galactosidase, and alkaline phosphatase (AKP) after being co-cultured with E. coli and S. epidermidis, in which FC-1# is enhanced in the most obvious. The E. coli interacted with dust made more indentations in surface, and the configuration became thin and long. Some broken bacteria were present, and bacterial wreckage was visible. Plenty of S. epidermidis interacted with dust gathered in the indentations of dust, particularly in pleated surfaces. Further, these findings demonstrated that the alkaline dust with higher Ca content stimulated the growth of bacteria, and irregularly shaped or thin dust would be easier to combine with bacteria and conduct interface effect.