Biomass is a dominant solid fuel type worldwide. Traditional biomass combustion leads to severe indoor and ambient environmental problems. Biomass pellet utilization in forced-draft gasifier stoves is regarded as an improved approach to these problems. Previous studies on forced-draft biomass stoves mainly considered average emission amounts and lacked details of the combustion properties and dynamic correlations between emissions and combustion. This study used a dynamic measurement system to test a typical forced-draft gasifier stove consuming wood pellets and maize straw pellets. Real-time fuel burning rate, that partly reflects the combustion performance, and CO, NOₓ and PM₂.₅ emission rates, over a whole combustion course, were monitored. In all tests, the burning rate rose to a high and stable level, and then sharply subsided. CO, NOₓ and PM₂.₅ emission rates varied across the combustion course. CO (NOₓ) emissions have a negative (positive) logarithmic linear relationship with burning rate, while no consistent relationship was observed for PM₂.₅ emission rate. The identified relationships between burning rate and pollutant emission rates suggest the possibility of estimating emission performance of forced-draft biomass pellet stoves based on combustion indicators, or vice versa.

The co-occurrence of aquatic contaminants, such as antibiotics and herbicides, has motivated investigations into their interactive effects on aquatic organisms. We examined the combined effects of environmental concentrations of the antibiotic Enrofloxacin (Enro; 0–2.25 μg l−1) and Roundup OriginalDI (Roundup®; 0–0.75 μg active ingredient l−1), a glyphosate based-herbicide, on Elodea canadensis. Enro alone was not toxic, but the plants were highly sensitive to Roundup® whose toxicity is related to the induction of oxidative stress. The metabolism of Enro by plants into Ciprofloxacin (Cipro) was observed, and although former is not phytotoxic, oxidative events associated with Cipro generation were observed. The activity of cytochrome P450 was shown to be involved in Enro degradation in E. canadensis. As a cytochrome P450 inhibitor, Roundup® decreases Enro metabolism in plants. Enro, in turn, increases glyphosate uptake and toxicity, so that Enro and Roundup® have synergistic effects, disrupting the physiological processes of E. canadensis. Our results suggest E. canadensis as a potential candidate for the reclamation of Enro in contaminated waters, but not for Roundup® due to its high sensitivity to that herbicide.

Electronic waste (e-waste) has emerged as a global environmental problem because of its massive production volume and un-structured management policy. Since the rate of e-waste accumulation is startling and the combinatorial effects of toxicants are complex, we have investigated six phthalic acid esters (PAEs), bis (2-ethylhexyl) adipate (DEHA)), bisphenol A (BPA), sixteen polycyclic aromatic hydrocarbons (PAHs) and eight heavy metals (HMs) in the surface soil of e-waste recycling workshops and nearby open dumpsites in four metropolitan cities of India viz., New Delhi (north), Kolkata (east), Mumbai (west) and Chennai (south). Average concentration of ∑₁₆PAHs (1259 ng/g), ∑₆PAEs (396 ng/g), BPA (140 ng/g) and ∑₈HM (1288 mg/kg) in the informal e-waste recycling sites were higher than ∑₁₆PAHs (1029 ng/g), ∑₆PAEs (93 ng/g), BPA (121 ng/g) and ∑₈HM (675 mg/kg) in dumpsites. Almost 50–90% of BPA, bis (2-ethylhexyl) phthalate (DEHP), ∑₇cₐᵣcPAHs and copper (Cu) were from e-waste sites predominantly from metal recovery sites (EWR). Extensive combustion of e-waste particularly in the EWR sites at New Moore market and Pudupet in Chennai and Wire Lane, Kurla of Mumbai can explain the segregation of diethyl phthalate (DEP), benzyl butyl phthalate (BBP) and carcinogenic PAHs in the first principal component (PC-1). Copper and lead along with highly abundant plasticizers like DEHP, dibutyl phthalate (DBP) and BPA were loaded in PC-2. Combined impact of burning the plastic cables in e-waste and acid leaching process especially at Mandoli in New Delhi might have driven this result. Loading of chrysene, DEHA and low molecular weight (LMW) PAHs mostly in dumpsite soil might have resulted from incomplete combustion of dumped e-waste. Copper was found to exhibit the highest pollution estimated by geo-accumulation index (Igeo). Maximum estimated carcinogenic risk for adults via dermal contact was due to copper, followed by chromium, lead and nickel.

The increase of CO₂ concentration in the atmosphere, water and soil environment can lead to the changes in microbial activities. However, the transformation of antibiotic resistance genes has not been investigated in the presence of higher levels of CO₂. This study demonstrated that CO₂ facilitated the transformation of pUC19 plasmid, carrying ampicillin resistance genes, into Escherichia coli. Mechanism studies revealed that the type Ⅱ secretion system, type Ⅳ pilus and some other secretion systems were enhanced by CO₂, leading to DNA capture by pilus, larger cell pore sizes and more cell membrane channels. CO₂ also increased reactive oxygen species production, leading to SOS response and cell membrane damage. Besides, changes in intracellular Fe²⁺ and Mg²⁺ concentrations induced by CO₂ caused greater damage to the cell membrane and enhanced secretion systems, respectively. Overall, increased CO₂ provided more cell membrane channels for plasmid uptake and led to higher transformation efficiencies. The potential risk of a natural factor on the transformation of ARGs was first studied in this study, which helps us understand the fate of ARGs in ecosystems. As the carbon emission will continue to grow and enhance the enrichment of CO₂ in water and soil, the findings revealed a more severe public health issue under the background of carbon emission and CO₂ leakage.

Recently, novel-nanomaterials with excellent sorption capacities, mild stability, and environmental-friendly performance, have enabled massive developments in capturing heavy metal ions. This review firstly introduces the preparation and modification of novel-nanomaterials (e.g., MOFs, nZVI, MXenes, and g-C₃N₄). Then, the heavy metal ions’ sorption properties and the impact of environmental conditions have been discussed. Subsequently, the sorption mechanisms are verified through batch experiments, spectral analysis, surface complexation models, and theoretical calculations. Finally, the applications prospects of novel-nanomaterials in removing heavy metal ion polluted water have also been discussed, which provide perspective for future in-depth research and practical applications.

Boscalid as one of the most widely used succinate dehydrogenase inhibitor (SDHI) fungicides has been frequently detected in both freshwater and estuarine environments. Its acute toxic effects on zebrafish and freshwater algae have been reported in our previous studies. To further investigate its chronic toxic effects to aquatic organisms, adult zebrafish were exposed for 28 days to a series of environmentally relevant boscalid concentrations in this study. Growth indicators and histopathology were determined in this study. Results indicated that boscalid inhibited the growth of zebrafish and induced damage in the kidneys and liver. Carbohydrate and lipid metabolism as the key pathways of energy metabolism in growth of zebrafish were also investigated. Results showed boscalid caused an increase in the activity of hexokinase (HK), the content of glycogen, glucose-6-phosphatase (G6Pase), and insulin (INS) in liver and a decrease in blood glucose content and succinate dehydrogenase (SDH) activity. Boscalid reduced the total content of triacylglyceride (TG) and cholesterol (TC) and the activity of fatty acid synthase (FAS) and acetyl coenzyme A carboxylase (ACC) in the liver. Correspondingly, expression of the genes related to carbohydrate and lipid metabolism in liver and intestine was affected by boscalid, especially in the significant upregulation of G6Pase and pparα and downregulation of SGLT-1 and AMY. Results suggested that boscalid could affect carbohydrate metabolism of adult zebrafish via regulation of gluconeogenesis and glycolysis at 0.1 mg/L. Moreover, boscalid might induce an increase in β-oxidation and a decrease in lipid synthesis at 0.01 mg/L. In conclusion, our study identified that carbohydrate and lipid metabolism are the possible biological pathways that mediate boscalid-induced developmental effects.

Freshwater contamination with mining waste can result with high concentrations of toxic metals in the water and in fish organs. In North-Eastern Macedonia, several rivers (e.g., Zletovska, Kriva) are exposed to acid mine drainage from active Pb/Zn mines. Previous studies confirmed high concentrations of dissolved metals in their water. This study was performed in liver and gills of Vardar chub (Squalius vardarensis Karaman, 1928) from three Macedonian rivers (Bregalnica, Kriva and Zletovska) in spring and autumn 2012. The aim was to establish if increased exposure to certain metals have resulted with their increased bioaccumulation. The concentrations of 19 elements were measured in cytosolic tissue fractions, to obtain information on metabolically available metal species. The following ranges of cytosolic concentrations of highly toxic elements were measured in the Vardar chub liver (in μg/L): Cd, 1.18–184; Cs, 0.25–25.4; Tl, 0.02–5.80; Pb, 0.70–61.1. Their ranges measured in the gills (in μg/L) were the following: Cd, 0.24–59.2; Cs, 0.39–24.4; Tl, 0.01–1.00; Pb, 0.65–87.2. Although the water of the mining impacted Zletovska River was highly contaminated with several essential metals, especially with Mn and Zn, the majority of essential elements (Na, K, Ca, Mg, Co, Cu, Fe, Mn, Mo, and Zn) did not reflect the exposure level. In contrast, seven nonessential elements reflected the level of exposure in the water. Significantly increased hepatic and gill concentrations of Cs, Rb, Sr, and Tl were detected in Vardar chub from the Zletovska River compared to the other two rivers, of Cd and Pb in the Zletovska and Kriva River compared to Bregalnica, and of V in the Bregalnica River compared to Zletovska and Kriva rivers. Observed significant metal bioaccumulation, in particular of highly toxic elements, as a consequence of exposure to water contaminated with mining waste points to necessity of intensified supervision of mining impacted rivers.

This paper investigated 10 carbapenemase genes and selected the hosts of these genes in the estuary of Bohai Bay. The results showed that the OXA-58 producer accounted for a large percentage of carbapenem resistant bacteria in the sampling points, whereas the VIM, KPC, NDM, IMP, GES, OXA-23, OXA-24, OXA-48 and OXA-51 producers were not detected in the study. In addition, 9 bacterial genera with 100% identical blaOXA₋₅₈ sequences, including Pseudomonas, Rheinheimera, Stenotrophomonas, Shewanella, Raoultella, Vibrio, Pseudoalteromonas, Algoriphagus, Bowmanella and Thalassospira, were isolated from seawater. It is suggested that the host of blaOXA₋₅₈ gene were varied and many kinds of them could survive in the seawater. Moreover, we preformed the quantitative RT-PCR and the result shown the abundance of blaOXA₋₅₈ fluctuated between 2.8×10⁻⁶ copies/16S and 2.46×10⁻⁴ copies/16S, which was of the same order of magnitude as some common antibiotic resistance genes in environment. Furthermore, the variation trend of blaOXA₋₅₈ gene suggested that pollution discharge and horizontal gene transfer could contribute to the increase of the gene in coastal area.

The widely usage of silver nanoparticles in a range of consumer products inevitably results in its being released to the wastewater. As a result, the potential negative effects associated with AgNPs on wastewater treatment systems need to be assessed to develop the regulatory guidelines. In this paper, the exposure experiment at environmentally relevant concentration (100 μg L⁻¹) were conducted to demonstrate the effects of AgNPs on the pollutant removals in constructed wetlands (CWs) with different plants and the spatial distribution of silver. Before adding AgNPs, the system with Arundo donax (VF2) had the better nitrogen removal than Cyperus alternifolius (VF1). After exposure for about 94 d, the average removal efficiencies of NH₄⁺-N significantly reduced by 32.43% and 23.92%, TN of 15.82% and 17.18% and TP of 22.74% and 20.46% in VF1 and VF2, respectively, while the COD removal had no difference. However, presence of 100 μg L⁻¹ AgNPs for about 450 d showed no inhibition effects on nutrient removals in two experimental CWs. Two wetlands showed high removal efficiencies of about 98% on AgNPs, indicating CWs could play a crucial role to control the AgNPs release to environment. It was found that AgNPs mainly accumulated in the soil layer with the Ag content of 0.45–5.96 μg g⁻¹ dry weight in lower soil and 2.84–11.37 μg g⁻¹ dry weight in upper soil. The roots of Cyperus alternifolius absorbed more AgNPs, with higher bioconcentration factors (1.32–1.44) than that of 0.59 in Arundo donax. The differences of translocation factors on leaves and stems in two test plants showed that AgNPs assimilated by roots in Cyperus alternifolius were more easily transferred to the leaves. The obtained results showed that the macrophyte Cyperus alternifolius could be better choice for immobilization of AgNPs.

Many cities in China are currently experiencing severe air pollution due to modernization. Previous studies investigating the effects of air pollutants exposure were particularly conducted in severe air polluted area and studies in low pollution areas were sparse.To quantitatively assess the short-term effects of ambient air pollutants (PM2.5, PM10, SO2, NO2, CO and O3) on outpatient visits in low pollution area, we conducted a time-series analysis from Jan 1, 2015 to Dec 31, 2016 in Shennongjia, China. Generalized additive model (GAM) was used to evaluate the influence of PM2.5 on daily hospital outpatient visits with different lag structures. We also conducted stratified analysis to explore the association between PM2.5 concentration and outpatient visits in different seasons.In the present study, per IQR increment of PM2.5, PM10, NO2, CO and O3 were related with 1.92% (0.76%–3.09%), 1.92% (0.77%–3.07%), 2.74% (95% CI: 1.65%–3.83%), 1.89% (95% CI: 0.68%–3.10%) and 2.30% (95% CI: 0.65%–3.95%) increase on respiratory outpatient visits. Significant associations were found between PM2.5, PM10, NO2 and respiratory outpatient visits at lag0:1, lag0:2 days. The effects of PM2.5 were more evident in the cool season than in the warm season.Our study showed that short-term exposures to PM2.5, PM10, NO2, CO and O3 were related with increased risk of outpatient visits of respiratory diseases, and highlighted the adverse effect of air pollutants exposure, especially PM2.5 exposure in cool season on health in low pollution area.