Increasing the understanding of high mountain lake dynamics is essential to use these remote aquatic ecosystems as proxies of global environmental changes. With this aim, at Sabocos, a Pyrenean cirque glacial lake or tarn, this study shows the main results of a morphological and catchment characterization, along with statistical analyses of its hydrochemical trends and their concomitant driving factors from 2010 to 2013. Dissolved oxygen, water temperature stratification, and its snow and ice cover composition and dynamics have been also investigated. According to morphological analyses, Sabocos can be classified as a medium-large and deep lake, having a circular contour and a long water retention time as compared to Pyrenean glacial lake average values. Sabocos hydrochemistry is mainly determined by very high alkalinity, pH and conductivity levels, and high Ca²⁺, Mg²⁺, and SO₄²⁻ content, coming from the easily weatherable limestone-dolomite bedrock. Thus, lake water is well buffered, and therefore, Sabocos tarn is non-sensitive to acidification processes. On the other hand, the main source of K⁺, Na⁺, and Cl⁻ (sea salts) and nutrients (NH₄⁺, NO₃⁻, and phosphorous) to lake water appears to be atmospheric deposition. Primary production is phosphorous limited, and due to the N-saturation stage of the poorly developed soils of Sabocos catchment, NO₃⁻ is the chief component in the total nitrogen pool. External temperature seems to be the major driver regulating lake productivity, since warm temperatures boot primary production. Although precipitation might also play an important role in lake dynamics, especially regarding to those parameters influenced by the weathering of the bedrock, its influence cannot be easily assessed due to the seasonal isolation produced by the ice cover. Also, as occurs in the whole Pyrenean lake district, chemical composition of bulk deposition is highly variable due to the contribution of air masses with different origin.

Among metals, Ni has been indicated as one of the most dangerous for the environment, and plants exposed to this metal are frequently reported to undergo a severe stress condition. In this work, the tolerance responses to different Ni concentrations at physiological and biochemical levels were evaluated in Amaranthus paniculatus L., a plant species previously characterised for their ability to phytoremove Ni from metal-spiked water. Results indicated a good metal tolerance of this plant species at environmentally relevant Ni concentrations, while clear symptoms of oxidative damages were detected at higher Ni concentrations, both in roots and leaves, by measuring lipid peroxide content. At the photosynthetic level, pigment content determination, chlorophyll fluorescence image analysis and gas-exchange parameter measurements revealed a progressive impairment of the photosynthetic machinery at increasing Ni concentrations in the solution. Regarding biochemical mechanisms involved in antioxidative defence and metal binding, antioxidative enzyme (ascorbate peroxidase, APX; catalase, CAT; guaiacol peroxidase, GPX; superoxide dismutase, SOD) activity, polyamine (PA) content, polyamine oxidase (PAO) activity and organic acid (OA) content were differently affected by Ni concentration in the growth solution. A role for GPX, SOD, PAs, and oxalic and citric acid in Ni detoxification is suggested. These results can contribute to elucidate the tolerance mechanisms carried out by plants when facing environmentally relevant Ni concentrations and to identify some traits characterising the physiological and biochemical responses of Amaranthus plants to the presence and bioaccumulation of Ni.

Constructed wetlands (CWs) have been used as an alternative to conventional technologies for wastewater treatment for more than five decades. Recently, the use of various modified CWs to improve treatment performance has also been reported in the literature. However, the available knowledge on various CW technologies considering the intensified and reliable removal of pollutants is still limited. Hence, this paper aims to provide an overview of the current development of CW strategies and techniques for enhanced wastewater treatment. Basic information on configurations and characteristics of different innovations was summarized. Then, overall treatment performance of those systems and their shortcomings were further discussed. Lastly, future perspectives were also identified for specialists to design more effective and sustainable CWs. This information is used to inspire some novel intensifying methodologies, and benefit the successful applications of potential CW technologies.

With rapid response to environmental changes, phytoplankton communities have been used as a favorable bioindicator to evaluate environmental stress and anthropogenic impacts in aquatic ecosystems. The feasibility for their community-based bioassessment was studied in a mid-subtropical canal (Tiesha River), southern China, during a 1-year cycle (November 2009–December 2010). Samples were monthly collected at four sampling stations within a contamination gradient. Environmental variables, such as water temperature, dissolved oxygen (DO), chemical oxygen demand (COD), biological oxygen demand (BOD₅), total phosphorus (TP), and total nitrogen (TN), were measured synchronously for comparison with biotic parameters. The phytoplankton community structures showed a significant difference among four stations. The spatial variation in abundance was significantly correlated with the changes in environmental variables, especially TN, TP, and COD. Four dominant species (Aulacoseira granulata, Leptocylindrus danicus, Oscillatoria tenuis, and Radiococcus nimbatus) were significantly correlated with nutrients, while the species richness index represented a significant correlation with BOD₅. The phytoplankton-based Saprobien indices could not reveal the spatial variation in water quality status although may reflect water pollution levels (from β- to α-mesosaprobic zone) in the canal system. It is suggested that phytoplankton communities might be used as a potentially robust bioindicator for discriminating environmental quality status in mid-tropical canal systems.

Copper (Cu) is an essential micronutrient for normal plant growth and development, but in excess, it is also toxic to plants. The present study investigated the influence of ethylenediaminetetraacetic acid (EDTA) in enhancing Cu uptake and tolerance as well as the morphological and physiological responses of Brassica napus L. seedlings under Cu stress. Four-week-old seedlings were transferred to hydroponics containing Hoagland’s nutrient solution. After 2 weeks of transplanting, three levels (0, 50, and 100 μM) of Cu were applied with or without application of 2.5 mM EDTA and plants were further grown for 8 weeks in culture media. Results showed that Cu alone significantly decreased plant growth, biomass, photosynthetic pigments, and gas exchange characteristics. Cu stress also reduced the activities of antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) along with protein contents. Cu toxicity increased the concentration of reactive oxygen species (ROS) as indicated by the increased production of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in both leaves and roots. The application of EDTA significantly alleviated Cu-induced toxic effects in B. napus, showing remarkable improvement in all these parameters. EDTA amendment increased the activity of antioxidant enzymes by decreasing the concentrations of MDA and H₂O₂both in leaves and roots of B. napus. Although, EDTA amendment with Cu significantly increased Cu uptake in roots, stems, and leaves in decreasing order of concentration but increased the growth, photosynthetic parameters, and antioxidant enzymes. These results showed that the application of EDTA can be a useful strategy for phytoextraction of Cu by B. napus from contaminated soils.

Human exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs) in cigarette smoking might result in generation of reactive oxygen species (ROS) and induce formation of 8-hydroxy-2′-deoxyguanosine (8-OHdG). This study was designed to examine whether levels of 8-OHdG are associated with levels of urinary metabolites of PAHs. Two groups (smokers and non-smokers) were recruited from college students in Guangzhou, China. Their urine samples were collected and analyzed for ten urinary mono-hydroxylated PAHs (OH-PAHs) and 8-OHdG by liquid chromatography equipped with tandem mass spectrometer (LC/MS/MS). Multiple linear regression analysis was performed to examine correlations between urinary levels of 8-OHdG and OH-PAHs. No significant difference was observed for creatinine-adjusted OH-PAHs between smokers and non-smokers. The levels of 8-OHdG between smokers and non-smokers were comparative. OH-PAH levels in this study were 2–50 times higher than those in populations from other countries and areas. The estimated daily intake (EDI; μg/day) of PAHs ranged from 0.02 to 371.4, which were far lower than the reference doses (RfDs) specified by U.S. Environmental Protection Agency (EPA). Though smoking was a main factor, which affected the PAH exposure, it was not a dominant factor in the exposure to PAHs of Guangzhou college students. The environmental exposure could not be ignored. The sum concentrations of OH-PAHs (∑OH-PAHs) had a dose-increase relationship with 8-OHdG both for smokers and non-smokers, especially for smokers. Though people in Guangzhou bore higher PAH hazards, the estimated environmental risk was still under safe ranges.

Lakes along the Yangzte River are very important for inhabitants due to their ecosystem service values. In this study, the level of eight endocrine-disrupting compounds (EDCs) was studied in the Honghu Lake and East Dongting Lake. In each lake, 21 water samples and 21 sediment samples were collected. The total concentrations of eight EDCs in surface water (47.60–419.82 ng L⁻¹, mean value: 225.65 ng L⁻¹) and sediments (202.71–635.36 ng g⁻¹ dry weight (dw), mean value 371.90 ng g⁻¹ dw) of Honghu Lake were significantly higher than those in surface water (43.52–394.21 ng L⁻¹, mean value 153.03 ng L⁻¹) and sediment (70.01–464.63 ng g⁻¹ dw, mean value 238.42 ng g⁻¹ dw) in East Dongting Lake. 4-Nonylphenol (NP), 4-octylphenol (OP), and bisphenol A (BPA) in surface water and sediments were main EDCs in two lakes. No correlation relationships were found between concentrations of EDCs in water and sediment from two lakes. The concentrations of OP and 17α-ethinylestradiol (EE2) in sediments of Honghu Lake had significant positive correlation with the content of total organic carbon (TOC). The concentrations of EDCs in outlet of Honghu Lake were comparable to those in the main lake, whereas the EDCs in outlet of East Dongting Lake were lower than those in the main lake. The EDCs in Honghu Lake and East Dongting Lake may have a significant potential biological effect on fish based on the estimation of EDC estrogenicity.

Nonylphenol (NP) can accumulate in river sediment. Bioaugmentation is an attractive option to dissipate heavy NP pollution in river sediment. In this study, two NP degraders were isolated from crude oil-polluted soil and river sediment. Microcosms were constructed to test their ability to degrade NP in river sediment. The shift in the proportion of NP-degrading genes and bacterial community structure in sediment microcosms were characterized using quantitative PCR assay and terminal restriction fragment length polymorphism analysis, respectively. Phylogenetic analysis indicated that the soil isolate belonged to genus Stenotrophomonas, while the sediment isolate was a Sphingobium species. Both of them could almost completely clean up a high level of NP in river sediment (150 mg/kg NP) in 10 or 14 days after inoculation. An increase in the proportion of alkB and sMO genes was observed in sediment microcosms inoculated with Stenotrophomonas strain Y1 and Sphingobium strain Y2, respectively. Moreover, bioaugmentation using Sphingobium strain Y2 could have a strong impact on sediment bacterial community structure, while inoculation of Stenotrophomonas strain Y1 illustrated a weak impact. This study can provide some new insights towards NP biodegradation and bioremediation.

The registration of plant protection products (PPPs) in the EU is under Regulation 1107/2009, which recommends a tiered approach to assessing the risk to non-target terrestrial plants (NTTPs). However, little information is provided on how to perform and implement higher tier studies or how to use them to refine the risk assessments. Therefore, a stakeholder workshop was organized to consolidate current knowledge and expertise to aid the further development of testing and assessment procedures for NTTPs. This brief communication highlights the agreed recommendations of the workshop, which relate to the three main themes, i.e. specific protection goals, risk assessment and mitigation. The participants of the workshop adopted the European Food Safety Authority (EFSA) approach of using an ecosystem services framework for identifying specific protection goals. First, delivery and protection of ecosystem services were discussed for in-crop, in-field and off-crop, and off-field areas. Second, lower and higher tier risk assessment methods, including modelling approaches, were evaluated. Third, options for risk mitigation of spray drift and run-off were discussed and evaluated. Several important knowledge gaps were identified, and specific data collation and literature-based tasks were actioned to begin to address them. A full workshop report is planned for the fall of 2014.

In this study, simulated fly ash containing CuO/CuCl₂ was heated at 350 °C in a flow of N₂ and also in a nitrogen flow containing 10 vol% H₂, to evaluate the influence of hydrogen adding on dioxin formation. The total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) output derived from the CuO sample under N₂ and 10 % H₂ was 7.382 and 0.708 ng/g, respectively. As for CuCl₂, it was 589 and 46.1 ng/g, respectively. The results show that the hydrogen adding has a good inhibition effect on PCDD/F formation; the inhibition rate was higher than 90 % for PCDD/Fs. HCl and NH₃ were detected by Gasmet in the flue gas; the probable inhibition mechanism of hydrogen reaction was proposed, based on our measurements and others’ researches.