Notable releases of nitrate, nitrite, and ammonia are often observed in contaminated sediment treatment works implementing in situ calcium nitrate injection. In order to provide extended information for making best decision of employing this in situ sediment remediation technology, in this study the releases of nitrate, nitrite, and ammonia from the sediment after the calcium nitrate addition operation was investigated in column setups designed to simulate the scenarios of a stagnant water (e.g., a pound or small lake) and a tidal-influenced water (e.g., a river mouth), respectively. Comparison with published aquatic toxicity data or authorized criteria was conducted to assess if there is any toxic effect that might be induced. Along with the vigorous N₂emission due to the denitrification reactions which occurred in the treated sediment, external loaded nitrate, intermediately produced nitrite, and indigenous ammonia in the sediment showed being mobilized and released out. Their promoted release and fast buildup in the overlying water to an excessive level probably cause toxic effects to sensitive freshwater living species. Among them, the potential ecological risk induced by the promoted sediment ammonia release is the greatest, and cautions shall be raised for applying the calcium nitrate injection in ammonia-rich sediments. The caused impacts shall be less violent in a tidal-influenced water body, and comparatively, the continuous and fast accumulation of the released inorganic nitrogen compounds in a stagnant water body might impose severer influences to the ecosystem until being further transferred to less harmful forms.

Activity concentration of ²³⁸U, ²³⁴U, ²²⁶Ra, ²²⁸Ra, ²¹⁰Pb and ²¹⁰Po in tap water from selected springs and private wells in the area of the former uranium mine at Žirovski Vrh were determined. A total of 22 tap water samples were collected at consumer’s houses. The results show that the activity concentrations of uranium in water samples are in range (0.17–372) and (0.22–362) mBq L⁻¹ for ²³⁸U and ²³⁴U, respectively. Radium activity concentrations are in range (0.14–16.7) and (0.9–11.7) mBq L⁻¹ for ²²⁶Ra and ²²⁸Ra, respectively. ²¹⁰Po activity concentration is in range (0.28–8.0) mBq L⁻¹ and can be regarded as the lowest amongst all analysed radionuclides. The range for ²¹⁰Pb is (0.5–24.6) mBq L⁻¹. Based on the results obtained for activity concentrations of six radionuclides, the committed effective dose for three different age groups of population were estimated. It was found that the committed effective dose was well below the recommended value of 100 μSv year⁻¹, ranging from 2.3 to 34.3 μSv year⁻¹ for adults, from 3.5 to 32.0 μSv year⁻¹ for children (7–12 years) and from 3.0 to 23.3 μSv year⁻¹ for infants.

This study demonstrates that under abiotic dark conditions in aquatic system, humic substances are not only capable of converting Hg(II) to Hg⁰ but also able to bind Hg(II) ion. The degree of Hg(II) reduction is significantly influenced by the ratio of –COOH/–OH groups and the sulfur content in the HS, revealing a strong competition between complexation and reduction of Hg(II). This study suggests that abiotic and dark Hg(II) reduction depends on the pH and salinity of aqueous medium. At lower pH (∼4.0) and lower salinity (≤5.0 PSU), the reduction of Hg(II) to elemental mercury (Hg⁰) was comparatively rapid. Higher –COOH/–OH ratios in HS, favors dark abiotic reduction of Hg(II) as did a lower sulfur (S) content of HS. This study provided a rigorously controlled experimental design that showed that dark abiotic Hg(II) reduction by HS can potentially be important in the aquatic environment and is independent of the photochemical reduction observed in both fresh water and sea water.

After the industrial revolution, urban growth has been increasing, especially with technological advances. Urbanization is accelerating environmental pollution and also affects climate significantly because of land use or land cover changes. In this study, the Hydrological Simulation Program-Fortran (HSPF) model developed by the United States Environment Protection Agency (USEPA) is used for modeling the impervious areas of Eskişehir which is located in the Porsuk Stream Watershed in Inner Anatolia, Turkey. Effects of impervious areas of Eskisehir on the Porsuk Stream pollution between 1975 and 2010 have been investigated. Important water quality parameters like nitrate, orthophosphate, sediment, chloride, and total coliform are modeled. Impervious land segments have been found to be affecting all parameter concentrations and also surface flows significantly as determined using the t test with a confidence level of 95 %.

Gamma radiation-induced genetic perturbations in aquatic vertebrates is largely unknown at low-dose rate, especially in the wake of a nuclear disaster and/or other environmental outbreaks. Freshwater fish, Oreochromis mossambicus subjected to low-dose rate (2 mGy/min) at 2.5-, 5-, and 10-Gy doses, were analyzed for “exposure signatures” in blood samples drawn on days 3, 6, 12, 18, and 30, respectively. Significant dose-dependent increments in micronuclei frequency and other anomalies such as nucleoplasmic bridges and tailed nuclei were observed and exhibit a strong positive correlation, suggesting that they could be used as prospective signatures of radiation exposure. Similarly increased incidence of apoptosis and DNA repair machinery circuits at high and low doses were noted. This work highlighted “cytogenetic signatures” in fish and the sensitivity of these endpoints toward low-dose rate of radiation exposure.

Coal fires are a serious threat to the workers’ security and safe production in open pit mines. The coal fire source is hidden and innumerable, and the large-area cavity is prevalent in the coal seam after the coal burned, causing the conventional extinguishment technology difficult to work. Foams are considered as an efficient means of fire extinguishment in these large-scale workplaces. A noble foam preparation method is introduced, and an original design of cavitation jet device is proposed to add foaming agent stably. The jet cavitation occurs when the water flow rate and pressure ratio reach specified values. Through self-building foaming system, the high performance foams are produced and then infused into the blast drilling holes at a large flow. Without complicated operation, this system is found to be very suitable for extinguishing large-scale coal fires. Field application shows that foam generation adopting the proposed key technology makes a good fire extinguishment effect. The temperature reduction using foams is 6–7 times higher than water, and CO concentration is reduced from 9.43 to 0.092 ‰ in the drilling hole. The coal fires are controlled successfully in open pit mines, ensuring the normal production as well as the security of personnel and equipment.

Plants growing on polluted soils need to control the bioavailability of pollutants to reduce their toxicity. This study aims to reveal processes occurring at the soil-root interface of Pistacia lentiscus L. growing on the highly Zn-contaminated tailings of Campo Pisano mine (SW Sardinia, Italy), in order to shed light on possible mechanisms allowing for plant adaptation. The study combines conventional X-ray diffraction (XRD) and scanning electron microscopy (SEM) with advanced synchrotron-based techniques, micro-X-ray fluorescence mapping (μ-XRF) and X-ray absorption spectroscopy (XAS). Data analysis elucidates a mechanism used by P. lentiscus L. as response to high Zn concentration in soil. In particular, P. lentiscus roots take up Al, Si and Zn from the rhizosphere minerals in order to build biomineralizations that are part of survival strategy of the species, leading to formation of a Si-Al biomineralization coating the root epidermis. XAS analysis rules out Zn binding to organic molecules and indicates that Zn coordinates Si atoms stored in root epidermis leading to the precipitation of an amorphous Zn-silicate. These findings represent a step forward in understanding biological mechanisms and the resulting behaviour of minor and trace elements during plant-soil interaction and will have significant implications for development of phytoremediation techniques.

Exposure to environmental estrogens and other endocrine-active chemicals can impact reproduction of freshwater fishes. While extensive data exists regarding the effect of estrogens on standard laboratory species, little is known about the sensitivity of freshwater fishes native to North America to these compounds. Current testing strategies for the toxicological assessment of contaminants still rely heavily on studies with live animals, which poses increasing concerns from an economical and ethical perspective. Therefore, the aim of the present study was to investigate the sensitivity of four native species, namely, northern pike (Esox lucius), walleye (Sander vitreus), white sucker (Catostomus commersoni), and juvenile white sturgeon (Acipenser transmontanus), to an environmental estrogen, 17α-ethinylestradiol (EE2), using an in vitro tissue explant approach. Transcript abundances of vitellogenin (VTG) as well as the estrogen receptors (ER) α and β were used as the measuring endpoints as they represent well established biomarkers previously used to assess exposure to estrogens. Transcript abundance of VTG was upregulated in a concentration-dependent manner in each species. Liver explants of male walleye were found to have the greatest sensitivity to EE2, with a lowest observable effect concentration of 300 ng/L (1.0 nM) for VTG transcript abundance, with juvenile white sturgeon having the greatest magnitude of VTG transcript upregulation in exposed tissue (15-fold relative to control). Exposure of liver explants to EE2 resulted in no alteration in transcript abundance of ERβ, whereas upregulation of ERα was observed in northern pike only. Based on in vitro expression of VTG, the species tested were among the species with greatest sensitivity to environmental estrogens tested to date.

Analysis of diurnal patterns of surface ozone (O₃) at multiple urban sites in the UK shows the occurrence of prominent nocturnal enhancements during the winter months (November–March). Whilst nocturnal surface ozone (NSO) enhancement events have been observed at other locations, this is the first time that such features have been demonstrated to occur in the UK and the second location globally. The observed NSO enhancement events in the UK were found to be so prevalent that they are clearly discernible in monthly diurnal cycles averaged over several years of data. Long-term (2000–2010) analysis of hourly surface ozone data from 18 urban background stations shows a bimodal diurnal variation during the winter months with a secondary nighttime peak around 0300 hours along with the primary daytime peak. For all but one site, the daily maxima NSO concentrations during the winter months exceeded 60 μg/m³ on >20 % of the nights. The highest NSO value recorded was 118 μg/m³. During the months of November, December, and January, the monthly averaged O₃ concentrations observed at night (0300 h) even exceeded those observed in the daytime (1300 h). The analysis also shows that these NSO enhancements can last for several hours and were regional in scale, extending across several stations simultaneously. Interestingly, the urban sites in the north of the UK exhibited higher NSO than the sites in the south of the UK, despite their daily maxima being similar. In part, this seems to be related to the sites in the north typically having lower concentrations of nitrogen oxides.

Two examples of the creation of naturalized areas in the littoral zone of the Three Gorges Reservoir in the urban core of Chongqing City, China, are described. The areas were created for the purpose of restoring ecological functions and services. Plants were selected based on surveys of natural wetland vegetation in the region, and experiments were conducted to discover the capacity of species of interest to survive the sometimes extreme hydrological regimes at the sites. Novel methods were developed to stabilize the plants against the rigors of extreme summer floods and constant swash, notably zigzag berms of rocks wrapped in iron mesh. The areas include native reeds, grasses, shrubs, and trees. Plant communities in the areas are zoned according to flooding stress, and their structure is less stable at lower elevations that are subjected to greater stress. The tall grass Saccharum spontaneum (widespread in Southern Asia) and the tree Pterocarya stenoptera (native to Southwest China) are notable for their utility at these sites in the center of a large city. Communities of tall reeds and grasses have become so dense and stable that they now provide the ecosystem services of capturing river sediments and resisting erosion of the river banks. It is recommended that extensive greening of the riparian zones in urban areas of the Three Gorges Reservoir be conducted for the purpose of providing ecosystem services, based in part on the experiences described here.