DOM samples extracted from a wastewater effluent (EW) and from leachates collected from lysimeters in which Eucalyptus trees were deficit-irrigated with either EW (EL) or with water pumped from an aquifer recharged with the EW (TL) were studied. As ascertained by principal component analysis, DOM from both leachates displayed similar properties, different from those of the EW DOM. ¹H-NMR and FTIR spectra of the > 1-kDa DOM size fraction of the EW revealed less aromaticity than this fraction of either leachate. 3-D fluorescence maps indicated that the density of nitro, carboxyl, or phenol groups attached to aromatic structures was lowest in the EW DOM and only that DOM displayed protein-like fluorescence peaks. The leachates’ DOM > 1 kDa fraction complexed more Cu²⁺ per unit C than this fraction of the EW (Kd = ~ 10⁵ and ~ 10⁴ L kg⁻¹ DOC, respectively, at ~ 10⁻⁵ M free Cu²⁺). While Cu complexed preferentially with non-fluorescing sites in the EW DOM, in the leachates’ DOM, Cu bound primarily with fluorescing (aromatic) groups or with adjacent groups. The similar behavior displayed by DOM from leachates obtained under irrigation with either EW or reclaimed water suggests that processes occurring in the soil (e.g., by roots or microbiota) influenced the soil DOM’s properties to a larger extent than the nature of OM in the irrigation water. Thus, irrigation with good quality secondary effluent should not significantly enhance heavy metal mobility as compared to their mobility under irrigation with higher quality water.

Three sub-basins of the Seine River (France) under contrasted land uses (i.e., forested, agricultural, and urban) have been investigated in order to assess the origin and seasonal variation of trace metals, and evaluate their geochemical background and dynamics. Our results highlight a high anthropogenic impact on all elements for both the dissolved and particulate fractions. The main source for each element in the dissolved phase was determined and shows that transition and post-transition metals mainly originate from forested areas, while alkali and alkaline earth elements, metalloids, and halogens rather originate from agricultural land use. Conversely, for the particulate phase, most of the elements cannot be associated with a specific land use. Seasonal variation of elements was assessed according to the forested and agricultural land uses, and geochemical backgrounds were determined using average export rates, highlighting that the geochemical background for the forested land use is higher than the agricultural one for most of the elements. Finally, to confirm those results, Zn dynamics in the three characteristic sub-basins and between the different land uses was investigated using a combination of Zn speciation, Zn isotopic ratio, and Zn export rates.

Isopyrazam (IPZ) is a broad spectrum succinate dehydrogenase inhibitor fungicide. Little is known about its potential ecological risks of aquatic organisms recently. The present study examined the embryonic development effects of zebrafish exposed to IPZ under static condition using a fish embryo toxicity test. The lowest observed effect concentration of IPZ was 0.025 mg/L in 4-day exposure. Developmental abnormalities, including edema, small head deformity, body deformation and decreased pigmentation, and mortality were observed in zebrafish embryos of 0.05 mg/L and higher concentrations, which shown concentration dependency. The heart rate of zebrafish was disrupted by IPZ. Moreover, enzyme and gene experiments shown that IPZ exposure caused oxidative stress of zebrafish. Furthermore, it induced a decrease of succinate dehydrogenase (SDH) enzyme activity and gene transcription level in zebrafish larvae. It can be speculated that IPZ may have a lethal effect on zebrafish, which is accompanied by decreased SDH activity, oxidative stress, and abnormality. These results provide toxicological data about the IPZ on aquatic non-target organisms, which could be useful for further understanding potential environmental risks.

In recent years, ambient air has been severely contaminated by particulate matters (PMs) and some gas pollutants (nitrogen dioxide (NO₂) and sulfur dioxide (SO₂)) in China, and many studies have demonstrated that exposure to these pollutants can induce great adverse impacts on human health. The concentrations of the pollutants were much higher in winter than those in summer, and the average concentrations in this studied area were lower than those in northern China. In the comparison between high-resolution emission inventory and spatial distribution of PM₂.₅, significant positive linear correlation was found. Though the pollutants had similar trends, NO₂ and SO₂ delayed with 1 h to PM₂.₅. Besides, PM₂.₅ had a lag time of 1 h to temperature and relative humidity. Significant linear correlation was found among pollutants and meteorological conditions, suggesting the impact of meteorological conditions on ambient air pollution other than emission. For the 24-h trend, lowest concentrations of PM₂.₅, NO₂, and SO₂ were found around 15:00–18:00. In 2015, the population attributable fractions (PAFs) for ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), lung cancer (LC), and acute lower respiratory infection (ALRI) due to the exposure to PM₂.₅ in Zhejiang province were 25.82, 38.94, 17.73, 22.32, and 31.14%, respectively. The population-weighted mortality due to PM₂.₅ exposure in Zhejiang province was lower than the average level of the whole country—China.

This study investigates the influence of multilayer substrate configuration in horizontal subsurface flow constructed wetlands (HSCWs) on their treatment performance, biofilm development, and solids accumulation. Three pilot-scale HSCWs were built to treat campus sewage and have been operational for 3 years. The HSCWs included monolayer (CW1), three-layer (CW3), and six-layer (CW6) substrate configurations with hydraulic conductivity of the substrate increasing from the surface to bottom in the multilayer CWs. It was demonstrated the pollutant removal performance after a 3-year operation improved in the multilayer HSCWs (49–80%) compared to the monolayer HSCW (29–41%). Simultaneously, the multilayer HSCWs exhibited significant features that prevented clogging compared to the monolayer configuration. The amount of accumulated solids was notably higher in the monolayer CW compared to multilayer CWs. Further, multilayer HSCWs could delay clogging by providing higher biofilm development for organics removal and consequently, lesser solids accumulations. Principal component analysis strongly supported the visualization of the performance patterns in the present study and showed that multilayer substrate configuration, season, and sampling locations significantly influenced biofilm growth and solids accumulation. Finally, the present study provided important information to support the improved multilayer configured HSCW implication in the future.

Catalytic oxidation of benzene, toluene, and ethylbenzene (BTE) on virgin zeolite, nZnO-coated zeolite, with and without UV + O₃, at 300 °C bed temperature was investigated using laboratory experiments. The coating was done at three weight ratios of Zn (estimated Zn content in nZnO) to zeolite (0.2:1.0, 0.5:10, 1.0:1.0). The coated adsorbents were examined by scanning electron microscopy, wavelength dispersive X-ray spectroscopy, and Brunauer Emmett Teller analyses. In the catalytic oxidation experiments, the adsorbents were first saturated with BTE by purging an air stream containing a mixture of BTE at 5 ppm each for 28 min. Introduction of UV + O₃ on the coated 13X zeolite (0.5:1.0) bed improved the average removal efficiency (RE) of benzene, toluene, and ethylbenzene (with inlet concentration of 5 ppm each) to 68.7, 90.0, and 99.6%, respectively, from the corresponding values of 57.3, 79.9, and 98.5% when no UV + O₃ was used. An increase in the coating weight ratio from 0.2:1.0 to 0.5:1.0 had produced a higher RE for benzene only, while a further increase to 1.0:1.0 witnessed a decrease in RE for all three compounds, and more for benzene. Avg RE of BTE decreased with the increase in their inlet concentrations, more significantly for an increase from 5 to 50 ppm and less noticeable for a further increase to 100 ppm. The final oxidation products and intermediate products in the outlet streams from the oxidation and thermal desorption were analyzed which showed predominant compositions of CO₂ followed by BTE and some levels of CO and other volatile organic compounds.

Indirect nitrous oxide (N₂O) emissions account for the majority of uncertainty associated with the global N₂O budget. Agricultural streams with subsurface (tile) drainage are potential hotspots of indirect N₂O emissions from streams and groundwater. However, there are only a limited number of studies with direct measurements from stream surfaces. Research presented here represents the first study of N₂O emissions from agricultural streams in Illinois, USA. We measured water chemistry data from 10 sites in three watersheds in east-central Illinois. Additionally, floating chambers and gas transfer velocity models were used to measure N₂O fluxes from the stream surface at 4 of the 10 sites. Dissolved N₂O concentrations ranged from < 0.1 to 7.46 μg N₂O-N L⁻¹. Floating chamber N₂O fluxes ranged from 0 to 13.84 μg N₂O-N m⁻² min⁻¹. We found strikingly different patterns of nitrate (NO₃−) concentrations at sites downstream of a wastewater treatment plant (WWTP) effluent. Data from sites not affected by the WWTP expressed seasonal variations of NO₃− with elevated concentrations in winter and spring months when subsurface tile drains were flowing. Floating chamber N₂O fluxes were strongly correlated (p value 0.001) with NO₃− at sites not affected by the WWTP. All sites were correlated with flow (p value 0.01) and dissolved N₂O (p value 0.02). Our data suggest flow and dissolved N₂O are stronger indicators of N₂O flux from stream surfaces than NO₃− concentrations in agricultural watersheds. Furthermore, this study supports growing concerns of estimating N₂O emissions using linear relationships between N₂O and NO₃−, such as those used in IPCC estimates.

Breast cancer is the second most common fatal cancer in women. Developing a breast cancer is a multi-factorial and hormonal-dependent process, which may be triggered by many risk factors. An endocrine disrupting substance known as bisphenol A (BPA), that is used greatly in the manufacture of plastic products, was suggested as a possible risk factor for developing breast cancer. BPA has a strong binding affinity to non-classical membrane estrogen receptors like estrogen-related and G protein-coupled (GPER) receptors. Based on animal and in vitro studies, results showed a link between BPA exposure and increased incidence of breast cancer. BPA has the ability to alter multiple molecular pathways in cells namely, G protein-coupled receptor (GPER) pathway, estrogen-related receptor gamma (ERRγ) pathway, HOXB9 (homeobox-containing gene) pathway, bone morphogenetic protein 2 (BMP2) and (BMP4), immunoregulatory cytokine disturbance in the mammary gland, EGFR-STAT3 pathway, FOXA1 in ER-breast cancer cells, enhancer of zeste homolog 2 (EZH2), and epigenetic changes. Thus, the aforementioned alterations cause undesired gene stimulation or repression that increase risk of developing breast cancer. So, restricting exposure to BPA should be considered to aid in lowering the risk of developing breast cancer.

In this study, the adsorption behavior of waste boiler fly ash has been explored for purification of nickel heavy metal ion bearing water. The raw boiler fly ash (RBFA) was alkali modified to improve the adsorption characteristics. The modified boiler fly ash (MBFA) was characterized using the SEM, XRF, XRD, BET, and TGA analyzers to confirm the improved textural, mineralogical, porosity and thermal characteristics of the adsorbent. The adsorption studies were conducted in a batch mode by varying different operational parameters like pH, contact time, heavy metal ion concentration, and time. The MBFA showed higher adsorption capacity (~ 86 mg/g) as compared to RBFA (~ 64.8 mg/g) at optimized conditions. The equilibrium data for Ni(II) sorption were analyzed using Langmuir, Sips, and Freundlich isotherm models. Sips model proves to be superior with R² = 0.99. Thermodynamics of Ni(II) removal showed that the process of adsorption is endothermic and spontaneous in nature. Enthalpy calculated was 2.95 and 18.65 kJ/mol for RBFA and MBFA, respectively. The adsorption kinetics of Ni(II) by both RBFA and MBFA were modeled using pseudo-first-order, fractional order, and intra-particle diffusion equations. The results indicate that the fractional order kinetic equation and intra-particle diffusion model were suitable to describe the nickel adsorption.

Glyphosate (N-(phosphonomethyl) glycine) is one of the most widely used herbicides in the world. Experiments using distilled water or CaCl₂ extractor resulted in as much as 60% of glyphosate being desorbed from goethite. When Mehlich 1 extractor was used, desorption could reach up to 73%. At pHs 2.0, 4.0, 6.0, and 8.0, an increase in salt content decreased the adsorption of glyphosate onto goethite. This indicates that most of the glyphosate is bound weakly to goethite through an outer-sphere complex. Thus, in soils with a high goethite content, glyphosate will contaminate groundwaters or rivers easily. FT-IR spectra showed that glyphosate interacts with goethite through the phosphate group and, at high pH, the amine group could be involved. Evidences of the interaction of the amine group of glyphosate with goethite were also obtained from the EPR spectra that showed, at high pH, a distortion in the octahedral symmetry of iron. In addition to the adsorption decrease with an increase in pH, a decrease of desorption at high pH occurs. This probably occurs because, at high pH, glyphosate interacts with goethite as a monodentate complex and through the amine group. The adsorption results fit best to a Freundlich isotherm model. This is in good agreement with the desorption results, indicating the presence of at least two adsorption sites—one for outer-sphere complexes and the other of inner-sphere complexes. The experimental results fit well with both pseudo-second-order and diffusion-limited models. The experimental results also fit well with a diffusion-limited model; however, the C value was different from zero. Therefore, the adsorption process was not controlled by diffusion only. Adsorption of glyphosate onto goethite is a complex process that could involve intra-particle diffusion. After adsorption of glyphosate onto goethite, a large decrease of pHₚzc was observed. The surface area and pore volume of goethite did not change with the adsorption of glyphosate.