Tailings are frequently a source of pollution in mining areas due to the spread of metals from their bare surfaces via wind or runoff water. Phytostabilization is an interesting and low-cost option to decrease environmental risks in these sites. In this study, an acidic mine tailing (pH 3–4) located in a semiarid area in Southeast Spain and the spontaneous vegetation which grow on were investigated. Soil samples were taken to characterize metal contamination, and three plant species, Lygeum spartum, Piptatherum miliaceum, and Helichrysum decumbens, were sampled in order to determine plant uptake of metals. The rhizosphere pH of H. decumbens was measured to be 6.7, which was significantly higher than the bulk soil (pH 3). The electrical conductivity values were around 2–5 dS m−1. Total metal concentrations in soil were high (9,800 mg kg−1 for Pb and 7,200 mg kg−1 for Zn). DTPA-extractable Zn and Pb were 16% and 19% of the total amount, respectively. The three selected plant species accumulated around 2–5 mg kg−1 Cu in both shoots and roots. Zn concentration was 100 mg kg−1 in P. miliaceum roots. DTPA-extractable Zn was positively correlated with Zn plant uptake. These plant species demonstrated to grow well in acid tailings taking up only low concentrations of metals and therefore are good candidates to perform further phytostabilization works.

Atmospheric polychlorinated bihenyls (PCBs) deposit by dry and wet deposition mechanisms, and therefore they constitute a significant polluting source for lands and surface waters. Various samplers have been used to determine the PCB pollution level resulting from deposition. In the presented study, a modified wet deposition sampler (WDS) was used for sampling both wet and dry deposition samples with the same instrument by which wet deposition reservoir of the WDS is opened and dry deposition reservoir is closed when rain starts. Wet and dry deposition samples were collected between June 2008 and June 2009. In the samples taken from BUTAL which is known as an urban area with heavy traffic, ∑PCB dry deposition fluxes were determined as 18 ±â€‰10 ng/m2 −day, and wet deposition fluxes for dissolved and particle phase were measured as 480 ±â€‰1,185 and 475 ±â€‰1,000 ng/m2 −day, respectively. The dissolved and particle-phase PCB concentrations in rain were 10 ±â€‰13 and 13 ±â€‰14 ng/l, respectively. The contribution of wet deposition to total PCB deposition was determined as 52%. PCB concentrations in the ambient air were measured to be 370 ±â€‰200 and 20 ±â€‰20 pg/m3 for gas and particle phases, respectively. Washout ratio was determined by proportioning rain concentration to concentration in air. The washout ratios of the samples were between 1,675–311,800 and 12,775–2,511,120 for dissolved and particulate phases, respectively.

Concentrations of chromium, copper, and lead were determined in soil and plant specimens collected from the area of coal power plant (CPP), A. Dimitrios, the largest CPP in Greece located on the eastern part of Ptolemais basin, Macedonia. Two cultivated plants (Brassica oleracea var. capitata L. and Zea mays L.) and two non-cultivated plants (Rumex acetosa L. and Verbascum phlomoides L.) were chosen. The mean heavy metal content in the soil is described in the descending order of Cr>Pb>Cu, while for the plant material, the order was Cr>Cu>Pb. Stations in the vicinity of the CPP showed a distinctly high load of Cr in the soil, whereas for the other metals, no such correlation has been noted. Unexpectedly, high levels of chromium and copper have been found in plant samples of the control station (Grevena) where there is no significant point source of air pollution by particulate matter. In general, roots revealed a higher metal concentration than that of the other plant organs. This is more obvious in B. oleracea var. capitata for all metals studied. Thus, B. oleracea var. capitata possesses the potential for phytoremediation of soils contaminated by metals since this plant is removable together with its roots from the contaminated soil. The most contaminated leaves showed a variation in surface roughness. In V. phlomoides the non-glandular, branched candelabrum-like trichomes on the leaf epidermis effectively trapped and retained a considerable number of particles. In contrast, the waxy cuticle of R. acetosa, which forms a smooth sheet over the epidermal cells, enabled the fast removal of particles by rain or wind. In the case of Z. mays, seeds accumulated the lowest amount of all metals.

The Nyabugogo natural wetland (Kigali City, Rwanda) receives all kinds of untreated wastewaters, including those from industrial areas. This study monitored heavy metal concentrations (Cd, Cr, Cu, Pb, and Zn) in all environmental compartments of the swamp: water and sediment, the dominant plant species Cyperus papyrus, and fish (Clarias sp. and Oreochromis sp.) and Oligochaetes. Cr, Cu, and Zn concentrations in the water were generally below the WHO (2008) drinking water standards, whereas Cd and Pb were consistently above these limits. Except Cd, all metal concentrations were below the threshold levels for irrigation. The highest metal accumulation occurred in the sediment with up to 4.2 mg/kg for Cd, 68 mg/kg for Cu, 58.3 mg/kg for Pb, and 188.0 mg/kg for Zn, followed by accumulation in the roots of C. papyrus with up to 4.2 mg/kg for Cd, 45.8 mg/kg for Cr, 29.7 mg/kg for Cu, and 56.1 mg/kg for Pb. Except Cu and Zn, other heavy metal (Cd, Cr, and Pb) concentrations were high in Clarias sp., Oreochromis sp., and Oligochaetes. Therefore, there is a human health concern for people using water and products from the swamp.

Among various remediation factors, dissolved organic matter including humic substances (HS) has substantial effect on environmental contamination significantly changing the contaminant’s degradation, bioavailability, reactivity, and immobilization. However, the effects strongly depend on HS concentrations and their aromaticity index (AI). To understand underlying phenomena of remediation action of HS, which is revealed to occur within a definite interval of HS concentrations in water solution, a quantum statistical approach is supposed. Developing this approach, a model of protons as Fermi particles in humic substances was advanced for the first time and applied to describe transformations of HS molecules, i.e., multipoles into micelle structures, which in turn provide for mediating effects in water. Sufficiently high concentration of micelle granules in water solution exists if the concentration of HS lies within a definite interval. It was demonstrated applying a grand canonical Gibbs distribution method to a statistical ensemble of HS particles. Our approach allows for understanding and quantifying some biological and physiological processes connected with mediating action of HS, as for example the reversible red cell aggregation influenced by HS, adsorption of HS particles by cancer cells, and effect of HS on human resistibility to inflammatory processes of different kinds. Application of our results to water systems may be helpful to optimize waste processing and disposal.

Contamination of metal ions in soil and water represents more pressing threats to resources as well as human health. The present research was carried out to screen the phytosequester plants growing in industrial waste- and wastewater-affected industrial areas of Okhla, New Delhi, India. Accumulation trend of metal Fe, Zn, Cu, Cr, Pb, Cd, Hg, and As from soil and wastewater by plants were collected for study. Among aquatic plants Hydrilla verticillata, Marsilea quadrifolia, and Ipomea aquatica were found to be highest metals accumulator, Eclipta alba and Sesbania cannabina among terrestrial plant were highest accumulator of metals. Among the algal spp. Spirulina platensis and Phormidium papyraceum were the most efficient in accumulating Cd and Hg. The maximum bioconcentration factor (BCF) was recorded in Hygroryza aristata for the metals (Hg, Cd) in M. quadrifolia (Cd, Cr), in E. alba (Cr, Cu), and in S. platensis (Hg, Pb). However, the translocation factor (TF) of metals was found more in M. quadrifolia followed by I. aquatica than other plants. Among all the plants, H. verticillata showed high TF and low BCF values for toxic metals (Pb, Cr) and was suitable for phytostabilization of these metals. Our study showed that native plant species growing on contaminated sites may have a potential of phytosequestration of these metals.

Poly(acrylamide-acrylic acid-dimethylaminoethyl methacrylate) P(AAm-AA-DMAEMA) resin was prepared by the template copolymerization. PAAm was used as a template for the copolymerization of DMAEMA and AA in aqueous solution using gamma rays. The adsorption of indigo carmine and eriochrome black-T anionic dyes from aqueous media on P(AAm-AA-DMAEMA) has been investigated. The adsorption behavior of this resin has been studied under different adsorption conditions: dye concentrations (50–500 mg l−1), contact times, temperature (30–55°C), and pH values (2–7). The amount of dye adsorbed increased with increasing resin content, but it had a little change with temperature and decreased slightly with increasing pH. Adsorption data of the samples were modeled by the pseudo-first-order and pseudo-second-order kinetic equations in order to investigate dye adsorption mechanism. It was found that the adsorption kinetics of the resin followed a pseudo-second-order model with rate constant (k 2) of 2.5 × 10−3 and 1.8 × 10−2 g (mg−1 min−1) for indigo carmine and eriochrome black-T, respectively. Equilibrium isotherms were analyzed using the Langmuir and Freundlich isotherms. It was seen that the Freundlich model fits the adsorption data better than the Langmuir model.

Mature landfill leachate contains some macromolecular organic substances that are resistant to biodegradation. The photocatalytic process helps to enhance biodegradability of landfill leachate. Batch experiments were employed to determine the optimum conditions for removal of organic matter by UV-TiO2 photocatalysis. Under optimum conditions, the removal of chemical oxygen demand (COD), dissolved organic carbon (DOC), biological oxygen demand (BOD), and color was determined. Moreover, gas chromatography coupled with mass spectrometry (GC/MS) was used to analyze the organic matter in the treated leachate before and after treatment by the photocatalysis. The experimental results indicated that the removal of COD, DOC, and color by UV-TiO2 photocatalysis could reach above 60%, 70% and 97%, respectively. Under optimal conditions, the ratio of biological oxygen demand (BOD)/chemical oxygen demand (COD) was elevated from 0.09 to 0.39, representing substantial improvement in biodegradability. GC/MS analysis revealed that 37 out of 72 kinds of organic pollutants in the leachate remained after 72 h treatment. Esters were produced during photocatalytic process and ketones, hydrocarbons, aromatic hydrocarbons, hydroxybenzenes, and acids were easier to be degraded during photocatalytic oxidation processes. The UV-TiO2 photocatalysis systems proposed may be a cost-effective approach for pre-treatment of landfill leachate.

We have examined populations of brown trout in low-conductivity mountain lakes (5.0–13.7 μS/cm and 0.14–0.41 mg/l Ca) in southwestern Norway during the period 2000–2010. Inlets to the lakes were occasionally even more dilute (2007; conductivity = 2.9–4.8 μS/cm and Ca = 0.06–0.17 mg/l). The combination of pH and conductivity was the best predictor to fish status (CPUE), indicating that availability of essential ions was the primary restricting factor to fish populations in these extremely diluted water qualities. We suggest that conductivity <5 μS/cm is detrimental to early life stages of brown trout, and subsequently that there are lakes in these mountains having too low conductivity to support self-reproducing trout populations. Limited significance of alkalinity, Ca, Al, and color suggests that effects of ion deficit apparently overruled the effects of other parameters.

A bacterial water quality model (BWQM) was developed and used to evaluate the impacts of cattle farming and climate change on the stream fecal coliform pollution in the Salmon River watershed in south-central British Columbia, Canada. The accuracy of the model simulation was evaluated using the Nash-Sutcliffe coefficient of efficiency (COE). The BWQM simulated the observed field data well, with the values of the COE ranging from 0.76 to 0.78 for the stream flow, from 0.55 to 0.60 for the fecal coliform (FC) concentration, and from 0.85 to 0.89 for the FC loading. The BWQM captured more than 79%, 66%, and 90% variation of the daily stream flow, FC concentration, and FC loading, respectively. The BWQM predicts that between 70% and 80% of the FC were transferred from the cattle farm to the Salmon River through the snowmelt-caused surface runoff during late winter and early spring, with the balance 20% to 30% coming from the soil-lateral flow and the groundwater return flow. The model also indicates that the stream FC concentration is sensitive to the distance of the cattle farm to the Salmon River. The model scenario analysis reveals that the climate change, at an assumed 1°C increment of daily air temperature, results in an increase in the stream FC concentration in the spring, fall, and winter, but there is also a decrease in the summer. The increased air temperature also changes the seasonal pattern of the stream FC concentration. Rainfall can reduce the stream FC concentration and mitigate the impact of the increased air temperature on the stream FC concentration as long as it does not result in a surface runoff or flooding event.