Nano-zero-valent iron/activated carbon (nZVI/AC) composite was evaluated for its effectiveness in the stabilization of Cu, Pb, Cd, and Cr in dredged river sediment. Synthetic precipitation leaching procedure (SPLP) and toxicity characteristic leaching procedure (TCLP) were adopted to compare the effects of nZVI/AC dosage, particle size, time duration, and temperature on heavy metal leachability. The results show that leachability dropped considerably with the addition of nZVI/AC and powdered particles in the size of 0.075–0.18 mm was more effective in stabilization than granular ones. Stabilization effect was stable in long-term and robust against changes in temperature. Tessier sequential extraction revealed that heavy metals were associated with solid particle, inorganic or organic matters in sediment. The addition of nZVI/AC was able to convert relatively weakly bound heavy metals into more strongly bound species and thus reduce the bioavailability and toxicity. Also, the standard potential of heavy metals may decide the mechanism of stabilization process.

In order to reduce the costs, the recycle of spent TiO₂-based SCR-DeNOₓ catalysts were employed as a potential catalytic support material for elemental mercury (Hg⁰) oxidation in simulated coal-fired flue gas. The catalytic mechanism for simultaneous removal of Hg⁰ and NO was also investigated. The catalysts were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) method. Results indicated that spent TiO₂-based SCR-DeNOₓ catalyst supported Ce-Mn mixed oxides catalyst (CeMn/SCR₁) was highly active for Hg⁰ oxidation at low temperatures. The Ce₁.₀₀Mn/SCR₁ performed the best catalytic activities, and approximately 92.80 % mercury oxidation efficiency was obtained at 150 °C. The inhibition effect of NH₃ on Hg⁰ oxidation was confirmed in that NH₃ consumed the surface oxygen. Moreover, H₂O inhibited Hg⁰ oxidation while SO₂ had a promotional effect with the aid of O₂. The XPS results illustrated that the surface oxygen was responsible for Hg⁰ oxidation and NO conversion. Besides, the Hg⁰ oxidation and NO conversion were thought to be aided by synergistic effect between the manganese and cerium oxides.

Fenton oxidation and ultrasound-based pretreatment have been applied to improve the treatment of real industrial wastewater based on the use of biological oxidation. The effect of operating parameters such as Fe²⁺ loading, contact time, initial pH, and hydrogen peroxide loading on the extent of chemical oxygen demand (COD) reduction and change in biochemical oxygen demand (BOD₅)/COD ratio has been investigated. The optimum operating conditions established for the pretreatment were initial pH of 3.0, Fe²⁺ loading of 2.0, and 2.5 g L⁻¹ for the US/Fenton/stirring and Fenton approach, respectively, and temperature of 25 °C with initial H₂O₂ loading of 1.5 g L⁻¹. The use of pretreatment resulted in a significant increase in the BOD₅/COD ratio confirming the production of easily digestible intermediates. The effect of the type of sludge in the aerobic biodegradation was also investigated based on the use of primary activated sludge (PAS), modified activated sludge (MAS), and activated sludge (AS). Enhanced removal of the pollutants as well as higher biomass yield was observed for MAS as compared to PAS and AS. The use of US/Fenton/stirring pretreatment under the optimized conditions followed by biological oxidation using MAS resulted in maximum COD removal at 97.9 %. The required hydraulic retention time for the combined oxidation system was also significantly lower as compared to only biological oxidation operation. Kinetic studies revealed that the reduction in the COD followed a first-order kinetic model for advanced oxidation and pseudo first-order model for biodegradation. The study clearly established the utility of the combined technology for the effective treatment of real industrial wastewater.

Countries try to stabilize the demand for energy on one hand and sustain economic growth on the other, but the worsening global warming and climate change problems have put pressure on them. This paper estimates the environmental Kuznets curve over the period 1971–2010 in Turkey both in the short and the long run. For this purpose, the unit root test with structural breaks and the cointegration analysis with multiple endogenous structural breaks are used. The effects of energy consumption and export product diversification on CO₂ emissions are also controlled in the dynamic empirical models. It is observed that the environmental Kuznets curve hypothesis is valid in Turkey in both the short run and the long run. The positive effect on energy consumption on CO₂ emissions is also obtained in the long run. In addition, it is found that a greater product diversification of exports yields higher CO₂ emissions in the long run. Inferences and policy implications are also discussed.

Dynamic modelling and simulation of a nanofiltration-forward osmosis integrated complete system was done along with economic evaluation to pave the way for scale up of such a system for treating hazardous pharmaceutical wastes. The system operated in a closed loop not only protects surface water from the onslaught of hazardous industrial wastewater but also saves on cost of fresh water by turning wastewater recyclable at affordable price. The success of dynamic modelling in capturing the relevant transport phenomena is well reflected in high overall correlation coefficient value (R ² > 0.98), low relative error (<0.1) and Willmott d-index (<0.95). The system could remove more than 97.5 % chemical oxygen demand (COD) from real pharmaceutical wastewater having initial COD value as high as 3500 mg/L while ensuring operation of the forward osmosis loop at a reasonably high flux of 56–58 l per square meter per hour.

The concentration and geochemical fractionation of six trace metals related with environmental quality assessment, namely Cd, Cr, Cu, Ni, Pb, and Zn, in 30 surface sediments from both inshore and offshore areas of the Taiwan Strait were measured to investigate their distribution characteristics, evaluate their potential mobility, and assess their pollution status. The geoaccumulation index results indicated that, on average, the studied metals presented an order of Cd > Pb > Ni > Zn > Cu > Cr and were practically in uncontaminated status except Cd. The results of the sequential extraction analysis indicated that, on average, the studied metals were mostly accumulated in residual fraction except Cd whose concentration was the highest in the acid soluble fraction presenting a high risk to the environment, and their mobility decreased in the sequence of Cd > Pb > Ni > Cu > Zn > Cr. Based on the mean probable effect level quotients, the combination of the studied metals had an 8 % probability of being toxic at two sampling sites and had a 21 % probability of being toxic at the rest of sites. The spatial distribution of the studied metals in total concentrations and different geochemical fractions corroborated the previous findings about the possible sediment transportation routes in and around the Taiwan Strait.

The objective of this study was to determine the effect of the biostimulant Kelpak and different nitrogen rates on cellulose, hemicellulose and lignin contents as well as non-structural carbohydrates in orchard grass and Braun’s festulolium. The experiment was a split-plot arrangement with three replicates. It was set up at the experimental facility of the University of Natural Sciences and Humanities, Siedlce, in late April 2009. The following factors were examined: biostimulant with the trade name Kelpak SL applied at 2 dm³ ha⁻¹ and a control—no biostimulant; nitrogen application rates 50 and 150 kg ha⁻¹ and a control (0 kg ha⁻¹); pure stands of grass species grown in monoculture—orchard grass (Dactylis glomerata), cv. Amila,—Braun’s festulolium (Festulolium braunii), cv. Felopa. Kelpak significantly increased non-structural carbohydrates, and increasing nitrogen rates reduced the concentration of these components in plants. Increasing nitrogen rates significantly decreased cellulose, hemicellulose, lignin and non-structural carbohydrate contents. Compared with orchard grass, Braun’s festulolium proved to be of a higher nutritional value due to lower cellulose, hemicellulose and lignin contents and more non-structural carbohydrates. The aforementioned contents in the grasses differed significantly depending on the cut. Most cellulose and non-structural carbohydrates were determined in second-cut grass whereas most hemicellulose and lignin in second-cut grass.

Spoil heaps are the visible footprint of hydropower production, particularly in vulnerable alpine environments. Speeding up vegetation development by seeding commercial grass species has been a common restoration practice for the last 50 years, but we lack information on whether seeded species decline and allow native plant cover to develop. We visually estimated cover of native vascular plants and five seeded grass species (Agrostis capillaris, Festuca ovina, Festuca rubra, Schedonorus pratensis and Phleum pratense) on eight spoil heaps at different elevations (boreal–alpine zone) in western Norway. Spoil heap vegetation was censused twice (9–20 and 24–36 years after spoil heap construction); the undisturbed surrounding vegetation was also censused on the second occasion. Total cover on the spoil heaps showed some increase, but remained far below that in surrounding areas. Cover of seeded grass species in the surroundings was low (but not negligible), indicating suboptimal establishment ability. Seeded species usually covered less than 20 % of the spoil heaps, and only F. rubra, F. ovina and A. capillaris contributed substantially. Proportional cover indicated better initial establishment by seeded species, but their cover decreased between the censuses on all but the highest located spoil heap. The persistence of seeded grass species is problematic, and despite the decrease in proportional cover, they are likely to persist for decades on spoil heaps, posing a risk of invasion of surrounding areas. We therefore recommend replacing the practice of seeding with more appropriate restoration measures.

In southeastern Democratic Republic of Congo, unique metallophyte communities supporting numerous endemic species occurred on the highly mineralized copper cobalt (Cu–Co) hills throughout the province. These hills are economically valuable mineral reserves; mining activities represent therefore a threat to the long-term persistence of these communities. Ex situ conservation program was set up by a mining company to rescue and conserve the diversity of Cu–Co communities until restoration activities are initiated. Two kinds of Cu–Co communities: the steppe and the steppic savanna, were translocated using topsoil spreading and whole-turf translocation. In this study, we assessed the effectiveness of these two techniques in conserving Cu–Co communities and their potential use in future restoration programs. More than 2 years after the translocation, whole-turf translocation appeared to be the better technique for ex situ conservation of endemic Cu–Co species. Not only did whole-turf successfully translocate numerous target species that were not present in the topsoil areas, but it also resulted in fewer ruderal and non-target species compared to topsoil spreading. Topsoil spreading recorded low seedling emergence from seed bank due to large proportions of dormant seeds or the absence of a seed bank, especially for the steppic savanna. Restoration of the steppe is currently more successful than for steppic savanna where the lack of dominant and structuring species likely contributed to divergence in species composition compared to reference ecosystem. Our study stresses the fact that tropical old-growth grasslands, which require probably several centuries to assemble, are difficult to restore or translocate.

The impact of viaduct construction on the vegetation of a river valley was studied in Central Poland (Natura 2000 site PLH100006). The research aimed at assessing the suitability of ALS (airborne laser scanning), soil, and botanical data for monitoring the environmental effects of right-of-way reclamation 1 year after the road construction. Based on the data mentioned above, the following problems were identified: changes in topography and hydrological conditions of the valley as a result of improper land levelling, the use of inadequate soil for reclamation, no spontaneous regeneration of natural vegetation along the entire right-of-way, as well as the abundant occurrence of invasive species. The results of analysis were used to define strategies for mitigation of adverse impacts of the viaduct construction.