Carbazole in source water is a potential precursor for toxic chlorocarbazoles in drinking water when chlorine is used as a disinfection agent in drinking water treatment plants. However, the reactivity of carbazole and the specific structures and predominant analogues of chlorocarbazoles produced during aqueous chlorination remain unknown. In this study, the aqueous chlorination of carbazole was performed to characterize its reactivity and the chlorinated products. Chlorocarbazoles generated from carbazole were identified by a comprehensive two-dimensional gas chromatography-mass spectrometry method, and their molecular structures were predicted by the Fukui index of electrophilic attack, f−1(r). As a result, the comprehensive chlorination pathway of carbazole was extrapolated with a total of nine chlorocarbazoles identified, including two monochlorocarbazoles (3-chlorocarbazole and 1-chlorocarbazole), four dichlorocarbazoles (3,6-dichlorocarbazole, 1,6-dichlorocarbazole, 1,3-dichlorocarbazole and 1,8-dichlorocarbazole), two trichlorocarbazoles (1,3,6-trichlorocarbazole and 1,3,8-trichlorocarbazole) and one tetrachlorocarbazole (1,3,6,8-tetrachlorocarbazole). The f−1(r) value indicates that the C1, C3, C6 and C8 atoms of carbazole were the favored positions for electrophilic attack, with the C3 and C6 atoms being the predominant sites for chlorine substitution. 3-Chlorocarbazole, 3,6-dichlorocarbazole, 1,3,6-trichlorocarbazole and 1,3,6,8-tetrachlorocarbazole were the major analogues of each chlorocarbazole group; however, the production of minor analogues such as 1-chlorocarbazole and 1,6-dichlorocarbazole should not be overlooked. The chlorination of carbazole was a pseudo first order reaction with a reaction rate of 0.1836 nmol/(L· h) and half-life of 3.77 h (pH = 6.4, Cl2 = 4.7 mg/L), and the chlorination rate of carbazole was approximately 5 times faster than that of an known chlorination precursor pyrene. These results showed that Fukui index was efficacious to predict the chlorination sites of aromatic compounds, and that carbazole is readily transformed into toxic chlorocarbazoles in drinking water treatment plants that use chlorine as a disinfection agent.

Many heavy metals in sediments and water have potential adverse effects on aquatic organisms such as Corbicula fluminea (O.F. Müller, 1774), a bivalve species frequently used as a biomonitor for metal pollution. Studies over the past decades examining the heavy metal uptake by C. fluminea, very few has investigated the effect of hydrodynamic conditions on accumulation of heavy metal by C. fluminea. Therefore, in this study, to investigate the mechanism of intracellular and extracellular accumulation of metal, individuals of C. fluminea were exposed to cadmium (Cd)-treated water under three different hydrodynamic conditions. These included exposures in two set ups: three rates of rotation (500, 350, 200 r/min) in beakers for 10 days, and then exposure to Cd-treated sediment under two naturally turbulent water conditions (14 cm/s and 3.2 cm/s) in experimental flumes for 23 days. Hydrodynamic force increased the burrowing rate but decreased the activity of C. fluminea. After 10 days of exposure, the extracellular concentrations of Cd in the tissues of C. fluminea in the sand group were significantly higher than that in the gravel groups. The intracellular and extracellular concentrations of Cd in the tissues of C. fluminea dramatically increased in the Cd-treated sediment test. Moreover, the concentration of the extracellular Cd adsorbed on the tissues of C. fluminea in the 14 cm/s and 3.2 cm/s groups was significantly higher than that in the control group, whereas the effect of hydrodynamic force on absorption of Cd by C. fluminea was not obvious. These results suggest that hydrodynamic condition plays an important role in extracellular accumulation of Cd by C. fluminea. In future study, when using C. fluminea to assess Cd pollution in aquatic environment, extracellular Cd adsorbed on the tissue should be removed to avoid the influence of hydrodynamics.

Monoterpene emissions of Quercus coccifera L. were repeatedly measured during the two years following the spreading of a sewage sludge compost at rates of 50Mgha⁻¹ and 100Mgha⁻¹, in a twelve-year-old post-fire Mediterranean shrubland. We also monitored the patterns of change in soil and leaf nutrient content, plant water potential, chlorophyll fluorescence, and plant growth. Compost spreading resulted in weak changes in leaf nutrient content and plant water status, and therefore no significant effect on monoterpene emissions at leaf scale, except during one summer sampling, probably related to advanced leaf maturity with the highest compost rate. However, compost increased plant growth, particularly the leaf biomass. The results suggest that compost spreading in Mediterranean shrublands has no strong short-term effect on Q. coccifera monoterpene emissions at leaf level, but may indirectly increase volatile organic compound fluxes at the stand scale, which may contribute to regional ozone pollution.

Artificial light at night (ALAN) is a recognised disruptor of biological function and ecological communities. Despite increasing research effort, we know little regarding the effect of ALAN on woody plants, including trees, or its indirect effects on their colonising invertebrates. These effects have the potential to disrupt woodland food webs by decreasing the productivity of invertebrates and their secretions, including honeydew and lerps, with cascading effects on other fauna. Here, we cultivated juvenile river red gums (Eucalyptus camaldulensis) for 40 weeks under experimentally manipulated light (ALAN) or naturally dark (control) conditions. To assess direct impacts on tree growth, we took multiple measures of growth at four time periods, and also measured physiological function, biomass and investment in semi-mature trees. To assess experimentally the direct and indirect (tree-mediated) impacts of ALAN on invertebrates, from 19 weeks onwards, we matched and mismatched trees with their original ALAN environments. We colonised trees with a common herbivore of E. camaldulensis, the red gum lerp psyllid (Glycaspis nr. brimblecombei) and then measured the effects of current and historic tree lighting treatment on the psyllid life cycle. Our data revealed direct effects of ALAN on tree morphology: E. camaldulensis trees exposed to ALAN shifted biomass allocation away from roots and into leaves and increased specific leaf area. However, while the intensity of ALAN was sufficient to promote photosynthesis (net carbon gain) at night, this did not translate into variation in tree water status or photosystem adaptation to dim night-time light for ALAN-exposed trees. We found some evidence that ALAN had broad-scale community effects—psyllid nymphs colonising ALAN trees produced more lerps—but we found no other direct or indirect impacts of ALAN on the psyllid life cycle. Our results suggest that trees exposed to ALAN may share morphological responses with trees under dim daylight conditions. Further, ALAN may have significant ‘bottom-up’ effects on Eucalyptus woodland food webs through both trees and herbivores, which may impact higher trophic levels including woodland birds, mammals and invertebrates.

Institute for Development of Water Resources Jaroslav Černi and the Republc Hydrometeorological Service of Serbia carried out detailed processing and analysis of available hydrometeorological data within the amendments of the draft for Water Management Master Plan of Serbia in 2009. In this particular case, the most important characteristics of time series of hydrological and meteorological parameters on key sections of hydrological and meteorological stations, their conventional processing and analysis was completed and updated. The final goal of amendments of the draft of Water Management Master Plan is to provide elements to define the balance of available water resources in the territory of the Republic of Serbia, necessary for defining the strategy of water use and defining the conditions for integrated and rational management. This paper presents the most important elements of water balance using modern GIS technology.

The objective of this work was to test the effect of water limitation on Copaifera langsdorffii Desf. cultivated in mining tailings from the dam rupture in Mariana City, Brazil. Plants were grown in the mining tailing and under two conditions: field capacity (FC) and 50% FC for 60 days. The effects of water restriction on growth, gas exchange, water potential, and leaf anatomy of C. langsdorffii were evaluated. The experimental design was completely randomized with two treatments and 15 replicates, and data was submitted to one-way ANOVA to p < 0.05. Mining tailings showed adequate nutrient levels and the presence of Al, Cd, Pb, and Cr as well as very small particles of 1.19 μm in diameter. The reduction in water availability promoted no changes in the shoot fresh weight, however, increased this parameter for the roots. In addition, water limitation increased plant investment in the root system while reduced biomass allocation to shoots. Lower water levels also increased the root length, number of leaves, and leaf area. However, both water potential and content were not changed by reduced water availability. Lower water levels also increased gas exchange parameters and chlorophyll content. In addition, 50% FC increased the stomatal length/width ratio and their size though no effect in stomatal density was found. Thus, Copaifera langsdorffii grows and thrives in mining tailings even under reduced water availability up to 50% FC showing potential for reforestation systems.

The role of morpho-anatomical adaptations of six Kyllinga brevifolia populations in successfully invading hyper-saline environments was investigated. Physiological and anatomical characteristics showed a high degree of plasticity indicating its adaptability potential to a variety of environmental conditions. The population from hyper-saline saltmarsh Sahianwala was exposed to physiological drought for a long time and its survival relied on the prevention of water loss attained by decreased stomatal density and area, lignin deposition in the inner and outer cortical region, especially outside vascular tissue. Larger cells of cortical storage parenchyma aided in water storage and wide metaxylem vessels in better conduction of solutes. Higher accumulation of shoot Ca²⁺ in this habitat protected neutralized the impact of the enhanced shoot and root Na⁺ ion uptake. Organic osmoprotectants like total free amino acid, proline, soluble proteins, and sugars accumulated in a higher quantity that contributed towards an osmotic adjustment in Sahianwala population. Population from seasonal inundation (Treemu Headworks) showed larger root aerenchyma to supply sufficient oxygen for respiration, broader xylem vessels for better water and nutrient conduction, and greater density of leaf stomata for better transpiration. Maximum shoot and root length, total leaf area, and water potential were observed in the least saline Chinyot population indicating its best growth potential in a slightly saline aquatic environment. Each population showed specific physiological and anatomical modifications to colonize their respective habitats.

This study analyzed the nutrients and metals concentrations of the surrounding soils and sclerophyllous vegetation of a tailing at the CODELCO–El Teniente copper mine in Central Chile. The content of metal, macro-, and micronutrients were analyzed in the soils outward from the tailing till 60-m distance at depths of 30, 60, and 90 cm, and in the foliage and stems of the native vegetation associated to the tailing. At plant level, we measured height, diameter, level of damage, and physiological attributes. Cu, Ni, Cr, and As were higher in the tailing, whereas soil Mn and Fe were higher at 60 m from the tailing. Soil K was higher at 30-cm depth, whereas Na was higher at 90-cm depth. Foliar Cu was higher in Acacia caven (40.5 mg kg⁻¹), whereas the levels of Cu and Zn in stems were higher in Quillaja saponaria (6.5 mg kg⁻¹ for Cu and 13.1 mg kg⁻¹ for Zn). As the values of water potential and quantum efficiency of the photosystem II averaged − 1.1 MPa and 0.73, respectively, these two species exhibited no physiological stress. Only Q. saponaria tended to increase the level of damage at higher distances from the tailing. A. caven and Q. saponaria exhibited foliar contents of Cu and Fe considered toxic (Cu from 18.5 to 40.5 and Fe from 298 to 407 mg kg⁻¹); however, both species were able to prosper at the limit of the tailing.

Groundwater studies often involve using any one of geophysical, geological, geochemical, or chemical data in the assessment of its characteristics. An integrated method in using all the above had been carried out for more comprehensive and confirmative assessments along the Thandava River basin, India. The geophysical data included the recording of the vertical electrical soundings by Schlumberger array configuration in 50 stations along the basin. Thirty soil samples and rainfall data of 5 years included the geological data. Chemical characterizations for 117 groundwater water samples were carried for two seasons. This study proposes the advantages besides delineating the approach in carrying integrated rather than mere single parameter-based speculative study. This correlative and computer modeling aided study led to an in-depth along with confirmative assessments on various geological, geophysical, and chemical characteristics of the groundwater along with the pollution status. Comprehensive details of groundwater like geomorphology, potential water zones, flow pattern, soil types, geochemical evolution of ions, chemical status, and suitability can be accessed by applying this type of integrated study. Graphical Abstract ᅟ