This study presents levels of ¹³⁷Cs and ⁴⁰K concentrations in the placentas of seals gathered in the period 2007–2015. The mean activity of ¹³⁷Cs and ⁴⁰K was 5.49 Bq kg⁻¹w.w. and 136.6 Bq kg⁻¹ ww respectively. Statistically significant correlation was observed between the ¹³⁷Cs activities in placenta and in herring—the staple food for seals. The concentrations of ¹³⁷Cs and ⁴⁰K were also determined in other tissues (muscle, liver, lung, and brain) of wild seals. The concentrations of ¹³⁷Cs were from 2.59 Bq⁻¹ ww (lungs) to 24.3 Bq kg⁻¹ ww (muscles). The transfer factor values for ¹³⁷Cs (seal tissue/fish) ranged from 0.89 to 2.42 in the case of the placentas and from 1.35 to 8.17 in the case of the muscle. For adults seal, the effective dose from ¹³⁷Cs was 2.98 nGy h⁻¹. The mean external radiation dose to pup was 0.77 nGy h⁻¹ from ¹³⁷Cs and 6.69 nGy h⁻¹ from ⁴⁰K.

In this study, the novel adsorbent PVA-TA-βCD was synthesized via thermal cross-linking between polyvinyl alcohol and β-cyclodextrin. The characterization methods SEM-EDS, FTIR, and XPS were adopted to characterize the adsorbent. The effect of pH, contact time, initial concentrations, and temperature during the adsorption of Pb(II), Cd(II), and Mn(II) onto the PVA-TA-βCD was also investigated. In a single-component system, the data fitted well to pseudo-second-order, and film diffusion and intra-particle diffusion both played important roles in the adsorption process. As for isotherm study, it showed a heterogeneous adsorption capacity of 199.11, 116.52, and 90.28 mg g⁻¹ for the Pb(II), Cd(II), and Mn(II), respectively. Competition between the ions existed in a multi-component system; however, owing to the stronger affinity of the PVA-TA-βCD for Pb(II) relative to Cd(II) and Mn(II), the Pb(II) adsorption onto the PVA-TA-βCD was less affected by the addition of the other metals, which could be effectively explained by the hard and soft acid and base theory (HSAB). Furthermore, PVA-TA-βCD showed good reusability throughout regeneration experiments.

N₂O is a GHG of environmental concern. It is generated from the nitrous material contained in wastewater and is the sixth most important contributor to N₂O emissions. There is a great variety of methods to quantify the emission of N₂O in a wastewater treatment plant (WWTP), which present variants among them, such as predetermined values and operational data of the plants. In this paper, we compared three different methods to quantify the N₂O emission in 2015 from WWTP in two metropolitan areas with high population density: Mexico City and the Metropolitan Area of Barcelona (MAB). MAB has advanced treatment plants that remove nutrients from wastewater, and Mexico City has only traditional treatment plants. The N₂O emission/inhabitant from WWTPs in MAB (3,214,211 inhabitants served) was 40% lower than the plants in Mexico City (1,806,440 inhabitants served). The MAB emission was 0.009 tCO₂e/inhabitant and 0.013 tCO₂e/inhabitant in Mexico City; these emission values could be considered statistically different with a risk error of 5%. This difference could be due to the fact that MAB has nutrient removal (42% of inhabitants served), and Mexico City has only traditional treatment plants. The results obtained may be influenced by the default emission factors of each methodology. In addition, per capita protein consumption and water consumption per inhabitant are different parameters that must be considered between these zones to quantify and compare the emission of N₂O. The integral methods are closer to the reality of the N₂O emission when the operating parameters of each plant and wastewater are considered. There should be more research on the reduction of this GHG in wastewater treatment for a correct quantification of these emissions, and more especially in the estimation of N₂O emission factors suitable for each treatment plant and study area.

Evaluation of 50 nm zinc oxide nanoparticles’ (ZnO-NPs) effects on the microalgae Chlorococcum sp. growing in high salt growth medium (HSM) was investigated by using flow cytometry parameters (cell size (FSC), granularity (SSC), chlorophyll a fluorescence (FL3), and formation of reactive oxygen species (ROS)). Algal cells in exponential growth were exposed to 0–100 mg/L of ZnO-NPs and their physiological responses were measured after 24 and 96 h of treatment. Behavior of ZnO-NPs was analyzed in HSM and results indicated that ZnO-NPs formed agglomeration with a large distribution. Total soluble Zn concentration increased when initial ZnO-NP concentration increased. Significant negative effect on algal cells was observed after 96 h exposition and at high ZnO-NP concentration. This negative impact was evaluated by the significant increase in ROS production, inhibition in the photosynthetic electron transport, and reduction in cell growth. In this study, using flow cytometry multi-parameters might help to prevent and evaluate inhibitory effect of oxide nanoparticles on aquatic photosynthetic microorganisms.

This research project explores the performance of soils intended to support ornamental plants serving an ecological benefit within bioremediating rain gardens. Three plots of identical plantings were installed in autumn of 2015 into three different planting media in Northeast Ohio, USA. A control soil blend was tested against two experimental soil blends in the field under natural conditions for 3 years to explore any potential differences in overall plant performance. The control planting soil was created following current Ohio Department of Natural Resources specifications for rain garden planting soils which consist of no less than 80% sand and no more than 10% clay by volume. Test soil blends incorporated lightweight expanded shale to combat the potential negative effects of high sand soils for plants (i.e., high matric potential) while maintaining required engineering benefits (i.e., fast infiltration rate coupled with good physical, chemical, and biological filtration). Our analysis suggests that incorporating expanded shales into bioremediating gardens as a replacement to high sand content can maintain all engineering specifications and may increase survival rates of plant life beyond rates currently found in high sand content rain gardens. Survival rate for plants in the control plot was at 48.3% while experimental plots one and two were 96.5% and 75.8% respectively. The research team suggests that these increased survival rates could contribute to more widespread adoption and implementation of stormwater management practices, especially small-scale, interconnected rain gardens in the urban environment as designated by low-impact development standards.

Phosphorus-rich sludge is one of most suitable raw materials for phosphorus recovery as slow release fertilizers by struvite crystallization. However, alginic acid as a surrogate for extracellular polymeric substances in the sludge has been proved to adversely inhibit struvite crystallization. To quantitatively evaluate the inhibitory effect, the study aimed to investigate the influence of the concentration of alginic acid (0–250 mg/L), reactant concentration (2.5–3.5 mmol/L), pH (8.0–9.5), and ionic strength (0.01–0.2 mol/L NaCl), on the inhibition of the growth rate of struvite crystals, which was accurately determined by constant composition technique. The results indicated that the growth rate of struvite crystals substantially decreased with increasing the concentration of alginic acid, thereby adversely affecting the quantity and quality of struvite crystals. Moreover, as reactant concentration or pH increased, the growth rate of struvite crystals showed a considerable increase, whereas the weaker inhibitory effect of alginic acid was observed. Conversely, the increase of ionic strength drastically reduced the growth rate of struvite crystals, but moderately enhanced the inhibitory effect. Our study provides an effective theoretical foundation for deriving high-quality struvite crystals as slow release fertilizers from the phosphorus-rich sludge commonly containing a considerable number of organic pollutants.

An acquisition of metal tolerance in cladocerans related to the historical exposure has been well documented for the genera Daphnia and Ceriodaphnia, which are frequently used in ecotoxicological studies. However, small-sized cladocerans are rarely investigated for the inter-clonal variation in metal sensitivity, whereas they often dominate zooplankton community in many lakes and ponds, and even in eutrophicated rivers. We investigated the influence of historical copper exposure on the copper sensitivity of Bosmina longirostris. Copper sensitivity was compared among three clones originating from a site (Lake Yanaka), which located at downstream of historically contaminated river (Watarase River) and clones from five different reservoirs. For reference, the background copper concentration (as Cu²⁺ activity) at each site and its toxicity to Daphnia magna were estimated by metal speciation and the biotic ligand model (BLM), respectively. Less copper-sensitive Bosmina clones were obtained only from Lake Yanaka, although the background copper concentrations were far below the lethal levels. The results suggested the variability in copper-sensitivity in B. longirostris and its association with historical copper contamination.

Numerous uncertainty factors in dispersion models should be taken into account in order to improve the reliability of predictions. The ability of a mesoscale meteorological model to assimilate observational data is an efficient way to improve operational air quality model forecasts. In this study, local weather data assimilation based on a flux-adjusting surface data assimilation system (FASDAS) is introduced to a Gaussian atmospheric dispersion model for a period with reported stable meteorological conditions. After evaluating the vulnerabilities of FASDAS, a combined data assimilation method is proposed to simultaneously improve the model weather prediction and retrieve the representation of accurate concentration distributions for short-range dispersion modeling against a control run. The two main uncertainty parameters considered are the wind speed and direction. A twin experiment demonstrates that the combined technique effectively improves the distribution of simulated concentrations. Comparison between results before and after the implement of data assimilation demonstrates that discrepancies between the reference simulation and the model forecast are mitigated after introducing the combined method, with more than 70 % of the predictions within a factor of two of the measurements. The errors in wind predictions in the FASDAS influenced the dispersion calculations, and the implementation of wind data assimilation in conjunction with the FASDAS has an indirect effect on further alleviating pollutant transport modeling errors.

Mine waste contaminated soils are classified as degraded soils with poor conditions such as low soil pH, low organic matter and high metal concentrations. This study evaluated the potential of fly ash enriched vermicompost in improving poor soil conditions in mine waste affected soils. The soils were amended with the vermicompost to supply 0, 10, 20, 40 and 80 mg of phosphorus per kg and incubated for 8 weeks. The soil pH increased from the original acidic range of 3.7–5.3 to 6.8–7.6. Available P significantly improved (P < 0.001) to yield the target P levels; however, at the end of incubation period, 80 mg-P/kg treatment had lower Olsen P relative to the 40 mg-P/kg treatment. Nitrogen mineralisation was enhanced with addition of the vermicompost as reflected by an average increase of 51% in NO₂/NO₃⁻-N while NH₄⁺-N decreased over time. The Mn, Zn and Pb solubility was reduced with addition of the vermicompost, with 20 mg-P/kg resulting in the most reduced solubility. However, concentrations at 20 mg-P/kg treatment were generally not different to 40 mg-P/kg. Solubility of Cu significantly increased in proportion to increase in amendment rate but did not exceed maximum permissible limits. Solubility of Cd and Cr also increased during the incubation study; however, this could not be attributed to the different vermicompost treatments but the soil properties. Therefore, in conclusion, application of fly ash enriched vermicompost at 40 mg-P/kg was found to be optimum for a balanced supply of essential nutrients and reduced metal solubility.

Nanomaterial applications are a fast-developing field. In spite of their powerful advantages, many open questions regarding how these small-sized chemicals may influence the environment and human health. However, scarce reports are available on the potential hazards of combined nanoparticles, taken into consideration that nickel oxide (NiO) and cobalt (II, III) oxide (Co₃O₄) nanoparticles (NPs) are already used together in many applications. Hence, the present work was designed to study the probable changes in some biological, hematological, and serum biochemical variables throughout 2 weeks following an oral administration of 0.5 g and 1.0 g of NiO-NPs or/and Co₃O₄-NPs per kilogram body weight of rats. As compared with the controls, the exposure to NiO-NPs or Co₃O₄-NPs solely caused significant elevations in the relative weights of brain (RBW), kidney (RKW) and liver (RLW), water consumption (WC), red blood cells (RBCs) count, hemoglobin (Hb) content, packed cell volume (PCV), and serum levels of low-density lipoprotein cholesterol (LDL-C), glucose, creatinine, urea, and uric acid as well as serum activities of aspartate and alanine aminotransferases (ASAT and ALAT). In addition, remarkable declines in the total body weight (TBW), feed consumption (FC), white blood cells (WBCs) count, serum levels of total protein (TP), albumin, albumin/globulin ratio, total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) were caused by administration of NiO-NPs or Co₃O₄-NPs, separately. On contrary, the co-administration of NiO-NPs and Co₃O₄-NPs together caused less noticeable changes in most of studied variables as compared with those administered NiO-NPs or Co₃O₄-NPs, individually. In conclusion, the exposure to a combination of NiO-NPs and Co₃O₄-NPs suppressed the adverse effects of the individual NPs on the studied variables.