The partial phase transformation of nanometer TiO₂ powder from anatase phase to rutile phase was realized by heat-treatment and a new TiO₂ photocatalyst which could be excited by visible light was obtained. The heat-treated TiO₂ powder at different stage of transition crystal was characterized and monitored by XRD, TEM, FT-IR and UV-vis DRS methods. The test of photocatalytic activity of the heat-treated TiO₂ powder was carried out by the photocatalytic degradation of rhodamine B and acid orange II dyes, respectively, in aqueous solution under visible light irradiation. The results indicate that the nanometer TiO₂ photocatalyst heat-treated at 500°C for 60 min shows the highest photocatalytic activity, that is, it can effectively degrade the rhodamine B and acid orange II under visible light irradiation. The remarkable improvement of photocatalytic activity of heat-treated TiO₂ powder at 500°C for 60 min was mainly illustrated by the formation of special interphase between rutile and anatase phases, which not only restrains the recombination of photogenerated electrons and holes, but also reduces the adsorbability of nanometer anatase TiO₂ powder properly for various dyes. Additionally, the effects of dye-assisting chemicals such as Na₂CO₃ and NaCl on the photocatalytic degradation were also studied.

Polycyclic aromatic hydrocarbons (PAHs) were measured in two wetland plant species grown outdoors in pots of sediment contaminated with up to 730,000 μg/kg total PAHs. After approximately 3 months, the plants were harvested, cleaned, and analyzed for an expanded suite of PAHs which included both the 16 priority PAHs and 22 alkyl PAH homologs. Sediment and air samples were also collected and analyzed. PAH compounds were detected in all of the samples, with the highest concentrations in the contaminated sediment. The root sample concentrations were generally about one order of magnitude lower than that of the sediment, and were strongly correlated with the concentration in the sediment in which they were grown. The concentrations in foliage were much lower and did not correlate with sediment concentration. Concentrations of low molecular weight PAH compounds detected in the foliage were not significantly lower in plants grown in control sediments, suggesting that the sediment is not the primary source of these PAHs. Several high molecular weight PAHs were detected only in plants grown in contaminated sediment. Plants of both species grown in control sediment were larger than plants grown in contaminated sediment.

Natural gas storage produced waters (NGSPWs) are brought to the surface when natural gas is reclaimed from underground storage. These waters may have a variety of constituents of concern that need to be treated before the water can be reused or discharged to receiving aquatic systems. The objective of this study was to characterize NGSPWs to discern potential constituents of concern that may limit surface discharge or beneficial reuse of these waters. We conducted a strategic review of literature, analyses of produced water composition records, and analyses of produced water samples provided by natural gas storage companies. Although NGSPWs varied widely in composition, primary constituents of concern included: chlorides (salinity), metals, metalloids, and organic compounds (e.g. oil and grease). Chlorides are the predominant constituent of concern in most NGSPWs. Strategies for risk mitigation of NGSPWs will need to be both robust and site specific to deal with the diverse composition of these waters.

Regional botanical surveys supported by field experiments suggest that atmospheric nitrogen deposition threatens the balance between species and causes loss of biodiversity within plant communities. Methods are required to monitor the nitrogen status of vegetation at a landscape scale and therefore the potential for ecological change. Remote sensing has the potential to monitor a number of plant biophysical and chemical variables, but its application to monitor the nitrogen status of native vegetation remains limited and untested. Using field spectroscopy, canopy reflectance measurements were taken from two heathland field sites and heather (Calluna vulgaris) plants grown in a greenhouse. The nitrogen concentration was determined through destructive sampling and chemical analysis. Stepwise multiple regression analysis was used to identify the wavebands most associated with nitrogen concentration and despite high variation in the selected wavebands between the three datasets, most of these wavebands were associated with nitrogen and protein absorption features within the spectral region 1,990–2,170 nm. Results highlight the potential of remote sensing as a bio-monitoring technique to estimate foliar nitrogen status in native plants.

Soil and water samples were analysed for trace metals and As in two watercourses and 14 sampling plots in a salt marsh polluted by mine wastes in SE Spain. Groundwater levels, soil pH and Eh were measured 'in situ' for a 12-month period in each sampling plot, and total calcium carbonate was also determined. Low concentrations of soluble metals (maximum Mn 1.089 mg L-¹ and maximum Zn 0.553 mg L-¹) were found in the watercourses. However, total metal contents were extremely high in the soils of a zone of the salt marsh (maximum 1,933 mg kg-¹ of Mn, 62,280 mg kg-¹ of Zn, 16,845 mg kg-¹ of Pb, 77 mg kg-¹ of Cd, 418 mg kg-¹ of Cu and 725 mg kg-¹ of As), and soluble metals in the pore water reached 38.7 mg L-¹ for Zn, 3.15 mg L-¹ for Pb, 48.0 mg L-¹ for Mn, 0.61 mg L-¹ for Cd and 0.29 mg L-¹ for As. Variable concentrations with depth indicate a possible re-mobilisation of the metals, which could be related to spatial and temporal variations of water table level, pH and Eh and to the presence of calcium carbonate. A tendency for the Eh to decrease in the warmest months and to increase in the coldest ones was found, especially, in plots that received water with a high content of dissolved organic carbon. Hence, the existence of nutrient effluent-enriched water may modify the physical-chemical conditions of the soil-water system and influence metal mobility.

The objective of this study was to demonstrate the use of chemical biomarkers (fecal sterols and bile acids) to identify selected sources of fecal pollution in the environment. Fecal sterols and bile acids were determined for pig, horse, cow, and chicken feces. Ten to twenty-six fresh fecal samples were collected for each animal, and the concentrations of fecal sterols (coprostanol, epicoprostanol, cholesterol, cholestanol, stigmastanol, and stigmasterol) and bile acids (lithocholic acid, deoxycholic acid, cholic acid, chenodeoxycholic acid, ursodeoxycholic acid, hyodeoxycholic acid) were determined using a gas chromatography and mass spectrometer (GC-MS) technique. Correlation study was performed among sterol and bile acid variables for selected animals, and a ratio (cholesterol + epicoprostanol)/(deoxycholic acid + chenodeoxycholic acid + hyodeoxycholic acid) has been proposed as an indicator for assessing fecal input. The levels of (cholesterol + epicoprostanol)/(deoxycholic acid + chenodeoxycholic acid + hyodeoxycholic acid) in horse, cow, chicken and pig were observed 3.258 ± 1.191, 1.921 ± 1.006, 1.013 ± 0.726, and 0.205 ± 0.119 respectively and the ratio of horse: cow: chicken: pig was 16: 9: 5: 1. This ratio suggests the potential of sterol and bile acid biomarkers in identifying sources and occurrence of fecal matter. While additional work using polluted water (as opposed to fresh fecal samples) as well as multiple pollution sources are needed to investigate the transport of these biomarkers into water bodies.

An open limestone channel (OLC) was constructed within an existing drain to treat the acidic and metal-rich drainage waters generated from an acid sulfate soil (ASS) catchment. The OLC was constructed downstream of a catchment pump and it consisted of a series of ponds and limestone sections. The accumulation of sediment over the limestone, preventing contact of limestone with acidic water, was the greatest problem impacting the OLC in its first year of operation. The continuous or sporadic operation of the catchment pump (at 120 l/s) was not sufficient to flush sediment from the limestone. The accumulation of large amounts of sediment onto the limestone reduced the amount of alkalinity and calcium released into solution. However, if the sediment is removed by agitating the limestone then an equivalent or greater amount of alkalinity may be added to solution and more metals removed from solution compared to fresh limestone. The coating on the limestone had a high concentration of manganese oxides in addition to slightly lower concentrations of aluminium and iron. Removal of these metals from the water was due to the increase in pH produced by limestone dissolution in addition to sorption reactions of the existing coating which had natural microbial activity.

As a new member of the European Union (EU), Romania has to align its economy with that of other EU partners, including the addition of a proactive component to environmental protection. This requires the development of a transitive approach capable of overcoming the difficulties of implementing the sustainability paradigm within an emerging market-oriented economy, which despite its progress, is still not fully prepared to understand and accept sustainability. This paper describes such a transition, showing how INCD ECOIND (the main Romanian Research and Development entity in the field of industrial ecology) reshaped its policies to include in current projects developed with Romanian partners the following elements: the Integrated Pollution Prevention and Control (IPPC) Directive, components relating to the REACH Process; the Environmental Management Accounting (EMA) mainframe and assistance in cultivating Corporate Social Responsibility (CSR) as an intrinsic part of modern enterprise. Lessons learned from previous and current projects are presented, underlining the complexity of obstacles met and problem-solving procedures derived and verified in practice.

Metal (Cu, Mn, Ni, Zn, Fe) concentrations in marine sediment and zooplankton were investigated in Izmir Bay of the Eastern Aegean Sea, Turkey. The study aimed to assess the levels of metal in different environmental compartments of the Izmir Bay. Metal concentrations in the sediment (dry weight) ranged between 4.26-70.8 μg g-¹ for Cu, 233-923 μg g-¹ for Mn, 14.9-127 μg g-¹ for Ni, 25.6-295 μg g-¹ for Zn, 12,404-76,899 μg g-¹ for Fe and 38,226-91,532 μg g-¹ for Al in the Izmir Bay. Maximum metal concentrations in zooplankton were observed during summer season in the inner bay. Significant relationships existed between the concentrations of certain metals (Al, Fe, Mn and Ni) in sediment, suggesting similar sources and/or similar geochemical processes controlling such metals. Higher concentrations of Cu, Zn and percent organic matter contents were found in the middle-inner bays sediments. Based on the correlation matrix obtained for metal data, organic matter was found to be the dominant factor controlling Cu and Zn distributions in the sediment. In general, mean Cu and Zn levels in the bay were above background concentrations in Mediterranean sediments. Zooplankton metal concentrations were similar to sediment distributions.

Hyperaccumulating plants are increasingly investigated in combination with EDTA addition to soil for phytoremediation of heavy metal contaminated soils. A 60-day incubation experiment was carried out to investigate the effects of heavy metal release during the decomposition of Zn-rich (15.7 mg g-¹ dry weight) Arabidopsis halleri litter on C mineralization, microbial biomass C, biomass N, ATP, and adenylate energy charge (AEC). These effects were investigated in two soils with different Zn, Cu, and Pb levels, with and without EDTA addition to soil. The sole addition of Zn-rich A. halleri litter to the two soils did not increase the contents of NH₄NO₃ extractable Zn, only with the combined additions of EDTA and litter was there a considerable increase, being equivalent to three times the added amount in the low metal soil and to 50% in the high metal soil. Litter amendment increased the CO₂ evolved; being equivalent to 44% of the added C in the two soils, but EDTA addition had no significant effect on CO₂ evolution. Litter amendment resulted also in an 18% increase in microbial biomass C, 27% increase in ATP and 6% increase in AEC in the two soils, but EDTA had again no effect on these indices at both metal levels. In contrast, the sole addition of litter had no effect on microbial biomass N, but EDTA addition increased microbial biomass N on average by 49%. The application of EDTA for chelate-assisted phytoextraction should in the future consider the risk of groundwater pollution, which is intensified by resistance of EDTA to microbial decomposition.