A nitrate-dominant synthetic wastewater simulating slightly polluted water with low C/N and poor biochemical availability was treated in lab-scale vertical-flow (VF)-constructed wetlands, which had Phragmites australis planted with different types of external carbon sources: Platanus acerifolia leaf litters, P. australis litters, glucose and a blank test with no external carbon sources. A comparison of the TN removal and N₂O flux performances among the four wetland reactors indicated higher TN removal efficiencies and N₂O release fluxes in the VF wetland columns with external carbon sources, as measured by the percentage removal of TN (P. acerifolia leaf litters 82.49 %, P. australis litters 70.55 %, glucose 62.50 % and blank 46.45 %) and N₂O flux (P. acerifolia leaf litters 2275.22 μg · m⁻² · h⁻¹, P. australis litters 1920.53 μg · m⁻² · h⁻¹, glucose 1598.57 μg · m⁻² · h⁻¹and blank 1192.08 μg · m⁻² · h⁻¹). This was primarily because of an improved supply of organic carbon from the external carbon sources for heterotrophic denitrification. And, the nitrogen released from the decomposition of plant materials resulted in the N₂O release fluxes to some extent. However, employing P. acerifolia leaf litters and P. australis litters as external carbon sources caused net increases in organics of the final effluent water. Overall, the results not only demonstrated the potential of using external plant carbon sources in VF wetlands to enhance the TN removal efficiency but also showed a risk of excessive organic release and greater N₂O flux feedback to global warming. Hence, future studies are needed to optimise the quantity and method for adding external carbon sources to VF-constructed wetlands so that sufficient nitrate removal efficiency is achieved and the N₂O flux and organic pollution are minimised.

Heavy metals are determinant factors in increasing environmental pollution, and chromium is considered to be of highest concern because of its genotoxicity in microorganisms, animals, and humans. Relatively few studies are focused on the injury induced in plant genetic material. Therefore, the main objective of this work was to evaluate the extent of the cytogenetic damage induced in root meristems of barley (Hordeum vulgare L.) after short-term seed exposure to 10, 100, 250, and 500 μM K₂Cr₂O₇(Cr(VI) concentration is 1.04, 10.39, 25.99, and 51.99 μg ml⁻¹) and 10, 100, 250, and 500 μM CrCl₃(Cr(III) concentration is 0.52, 5.19, 12.99, and 25.99 μg ml⁻¹). Chromium genotoxic potential was proved by significant increases in the rates of the ana-telophase chromosomal aberrations (1.3–2.3 times higher for K₂Cr₂O₇and 1.7–2.2 times higher for CrCl₃, as compared to the control; p < 0.05, p < 0.01) and of metaphase disturbances (5.0–7.5 times more numerous in chromium-treated groups than in control; p < 0.001). The pattern of the chromosomal aberrations is constituted by chromatid bridges, complex aberrations, lagging, and vagrant chromosomes, while the abnormal metaphases are c-like metaphases, sticky metaphases, and metaphases with chromosomes expulsed from equatorial plate. The mitotic indices and the growth of the barley plantlets in the early ontogeny were stimulated by chromium. The changes induced in the frequency of division stages mainly consisted in prophase and telophase accumulation and diminution of metaphase and anaphase proportion.

Carbonaceous material obtained from industrial sewage sludge and Na-zeolitic tuff were used to adsorb cadmium from aqueous solutions in column systems. The Bohart, Thomas, Yoon–Nelson, and mass transfer models were successfully used to fit the adsorption data at different depths, and the constant rates were evaluated. The parameters such as breakthrough and saturation times, bed volumes, kinetic constants, adsorption capacities, and adsorbent usage rates (AUR) were determined. The results show that the breakthrough time increases proportionally with increasing bed height. The adsorption capacity for cadmium for Na-zeolitic tuff was higher than carbonaceous material. The results indicated that the Na-zeolitic tuff is a good adsorbent for cadmium removal.

Oil spills impose serious damage to the environment. A spilled crude oil or its products affect aquatic flora and fauna and influence the atmosphere as well. Such pollutants are especially dangerous for the water ecosystems, where biological self-purification processes are slower (for example the Baltic Sea), than in warmer regions. In this paper, we evaluate a sorption capacity of ecologically friendly natural sorbents, when the crude oil and diesel are spilled on the surface of water. The experiments are carried out in the laboratory, and the water from the Lithuanian Baltic Sea coastline and Curonian Lagoon is used. Moss, straw, wool, sawdust, and peat are the natural sorbents evaluated during the experiments. Chromatographic analysis of crude oil and diesel during the process of sorption was conducted as well. An experiment with some synthetic sorbents was carried out to compare the results with natural ones. The experiments showed that the most suitable material for crude oil or diesel fuel spilled on the water surface is peat. As well, Lagergren’s model was adopted to the case of the sorption processes we have investigated. It can be exploited as a decision support tool while deciding the required time interval to achieve maximum sorption capacity of the sorbent in use.

The present study was conducted to maximize the biosorption of dye by utilizing the native (untreated) pellets of Aspergillus lentulus. The native (55.0 mg/g) and heat-treated (56.7 mg/g) pellets showed excellent dye biosorption capacity which declined upon alginate immobilization (27.2 mg/g). Fourier transform infrared and EDX spectra revealed that phosphate and –CH₃groups are important in determining the biosorption capacity of the pretreated fungal biomass. The operating conditions of the aerated fed batch reactor were optimized and 90 % removal of Acid Blue 120 in 12 h was achieved after five biosorption–desorption cycles. At the end of the fifth cycle, 508.57 mg/L dye could be removed in 60 h with the removal rate of 8.48 mg/L/h. Further, the potential utilization of fungal biomass for the treatment of complex effluent was validated by studying the dye removal from unprocessed textile effluent wherein 58.0 % dye was removed within 4 h of contact.

This study demonstrates the potential of a new BiOCl₀.₈₇₅Br₀.₁₂₅ photocatalyst to degrade pharmaceuticals in water (i.e., carbamazepine (CBZ), ibuprofen (IBF), bezafibrate (BZF), and propranolol (PPL)), under simulated solar irradiation. Different parameters were examined through their influence on CBZ degradation. Increasing the catalyst concentration up to 500 mg/L increased CBZ degradation rate; however, above 500 mg/L, CBZ degradation rate was slightly reduced, most likely due to the catalyst’s light-screening effect at high concentrations. Increasing the pH of the tested solution from 4 to 9 decreased the degree of CBZ adsorption to the catalyst and consequently its degradation rate. Quantum yield for CBZ degradation was found to be 0.75 ± 0.05 % using an integrating sphere for absorbance measurements to correctly account for scattering of light by the suspended catalyst. Degradation rates of all examined compounds (at pH 7) followed the order PPL > BZF > IBF > CBZ (highest rate for PPL). Interestingly, PPL was least adsorbed to the catalyst, implying that adsorption is not always mandatory for efficient degradation with BiOCl₀.₈₇₅Br₀.₁₂₅. Different adsorption mechanisms were hypothesized for the different pharmaceuticals, including hydrophobic attraction for the neutrally charged CBZ and ion exchange for the negatively charged IBF and BZF.

Poses dam in the Seine River estuary acts as receptacle of water drain-offs from highly urbanized and industrialized catchment area; therefore, this water is highly contaminated by trace metals. Most trace elements are mainly bound to particulate matter and are incorporated rapidly into the sediments. Scavenging of these metals in the sediments can be reversible due to several perturbations so as sediments also act as a source of pollutants for the overlying water. For instance, natural events (tide, flood, storm) and anthropogenic processes (water management actions) can cause disturbance of sediments and subsequent remobilization of pollutants to the water column, thereby posing a potential threat for aquatic organisms. The purpose of this study was to evaluate the mobility of trace metals by different methods in the Seine estuary sediments. The surface sediment sampled at Poses dam was characterized by high pollution level of Cd, Cu, Zn, and Pb. The estimation of metal bioavailability through ratio ΣSEM/AVS (simultaneously extracted metals/acid volatile sulfides) indicates a potential bioavailability of trace metals. The chemical partitioning using the European Community of Bureau of Reference sequential extraction method revealed that over 85, 82, and 80 % of the total Cd, Zn, and Pb, respectively, were found to be associated with the exchangeable and reducible fractions of the sediment. Another approach used consists in the quantification of dissolved metals released by sediment resuspension experiments in laboratory under controlled conditions. The results indicated that metals are released rapidly from sediment with a sharp peak at the beginning of the experiment, followed by a fast coprecipitation and/or adsorption processes on the suspended particles. Also, the Cd, Pb, and Ni mobility is higher compared to that of the other metals.

Lake Eğirdir is one of the most important freshwater resources in Turkey. The lake is located at the border of Isparta province in South West Turkey, an area known as the “Lakes District”. Lake Eğirdir is very important to the regional economy, but knowledge of its water quality is somewhat limited. Our objective was to assess the current water quality in Lake Eğirdir and its major tributaries, in order to provide information for future management decisions. The temperature, pH, electrical conductivity (EC), dissolved oxygen (DO) concentration, chemical oxygen demand (COD), nitrogen species concentrations, phosphorus species concentrations, and Chl-a concentrations were monitored monthly at seven sampling points in the lake between December 2010 and November 2011. The total nitrogen (TN) and total phosphorus (TP) loads were determined in the three main tributaries of Lake Eğirdir over the same period. At the end of the water quality assessment period, we determined that the lake water has the characteristics of class 1 waters for nitrogen species and class 2 waters for TP, according to the Turkish surface water quality management regulations. The Chl-a values measured in the lake were lower than expected from the trophic state index (TSI) values because of macrophyte growth in the lake. Interestingly, the total nitrogen/total phosphorus (TN/TP) ratios in the lake were low, possibly indicating that the sediment is a significant internal phosphorus resource in Lake Eğirdir.

Endocrine disruptor compounds (EDCs) are dangerous pollutants largely present in urban, industrial, and agricultural wastes, and through leaching and degradation from/of these matrices, they can reach and contaminate the environment. Bioremediation of polluted systems from EDCs using white rot fungi can be a valuable alternative approach with respect to conventional physical and chemical methods. These fungi have the capacity to biodegrade numerous phenolic contaminants with their unspecific extracellular ligninolytic enzymes. This study investigated the simultaneous removal of the xenoestrogens bisphenol A (BPA), ethynilestadiol (EE2), and 4-n-nonylphenol (NP), the herbicide linuron, and the insecticide dimethoate from a waste landfill leachate (LEACH) adopting a combination of adsorption and biodegradation. Trametes versicolor and Stereum hirsutum were inoculated, separately, on potato dextrose agar alone or added with different adsorbent materials of low cost and wide availability. The substrates with the fungus were superimposed on the contaminated LEACH. The control used was the LEACH overlaid by not inoculated potato dextrose agar. Both fungi showed an adequate tolerance to LEACH. In a period of 20 days, T. versicolor growing on the various substrates removed almost 100 % of BPA, EE2, NP, and linuron, and from 59 to 97 % of dimethoate. S. hirsutum showed a marked degrading activity only towards NP, which was totally removed after 20 days or less with any substrate and, to a lesser extent, linuron. Even in the absence of fungus, the methodology adopted achieved a relevant contaminant removal, with the only exception of the very hydrophilic dimethoate.

The study presented here focuses on the use of monolayer covers for reclaiming two acid-generating tailings sites located in Quebec, Canada. One of these covers is made of non-acid-generating tailings, and the other is made of a silty sand (till). The covers are part of the closure plans that aim at controlling acid mine (rock) drainage at these two sites. Reactive tailings and cover material samples were collected in situ and characterised in the laboratory. Large-size columns (230 cm in height) were set up to evaluate the hydrogeological and geochemical response of the tailings and cover systems. Monthly wetting and drying cycles were repeated over nearly 2 years to simulate climatic conditions. Water content, suction, and oxygen concentrations were monitored, and chemical analyses were performed on the leachate collected at the base during each cycle to follow the evolution of water quality, in terms of pH and concentrations of sulfates and metals. In addition, small columns (45 cm in height) were also set up, with a similar testing program, to assess the hydrogeochemical behaviour of exposed tailings. The specific objective of this experimental program was to evaluate the hydrogeological and geochemical behaviour of the tailings-cover systems under controlled conditions. The results indicate that, for the imposed conditions, the monolayer covers became significantly desaturated, thus insufficiently limiting the oxygen diffusion flux. Consequently, these covers do not efficiently prevent sulfide oxidation within the tailings. The implications of these results are also discussed.