The objective of this research was the evaluation of the effects of exogenous added surfactants on hydrocarbon biodegradation and on cell surface properties. Crude oil hydrocarbons are often difficult to remove from the environment because of their insolubility in water. The addition of surfactants enhances the removal of hydrocarbons by raising the solubility of these compounds. These surfactants cause them to become more vulnerable to degradation, thereby facilitating transportation across the cell membrane. The obtained results showed that the microorganism consortia of bacteria are useful biological agents within environmental bioremediation. The most effective amongst all, as regards biodegradation, were the consortia of Pseudomonas spp. and Bacillus spp. strains. The results indicated that the natural surfactants (rhamnolipides and saponins) are more effective surfactants in hydrocarbon biodegradation as compared to Triton X-100. The addition of natural surfactants enhanced the removal of hydrocarbon and diesel oil from the environment. Very promising was the use of saponins as a surfactant in hydrocarbon biodegradation. This surfactant significantly increases the organic compound biodegradation. In the case of those surfactants that could be easily adsorbed on cells of strains (e.g., rhamnolipides), a change of hydrophobicity to ca. 30-40% was noted. As the final result, an increase in hydrocarbon biodegradation was observed.

Mechanism of zinc iron removal by zero-valent iron was discussed through zinc removal responses to several operational conditions of a packed column reactor with zero-valent iron powder. The adsorption isotherm observed implied that a kind of chemisorption was responsible for zinc removal. Zinc removal by zero-valent iron was enhanced by dissolved oxygen and ferric ion addition. However, it was deteriorated under acidic pH. In addition, zinc adsorbed on zero-valent iron was eluted by a reducing agent such as citric acid, whereas the zinc was not eluted by diluted sulfuric acid. Consequently, the zinc removal mechanism by zero-valent iron was inferred to be as follows: Zero-valent iron was firstly corroded and oxidized into ferric ion by dissolved oxygen. The ferric ion was precipitated as iron hydroxide onto the surface of the zero-valent iron powder. Zinc ion was adsorbed on and/or coprecipitated with the iron hydroxide. The iron hydroxide was finally oxidized and transformed into iron oxides.

This paper compares lake chemistry in the Adirondack region of New York measured by the Temporally Integrated Monitoring of Ecosystems (TIME) and Adirondack Long-Term Monitoring (ALTM) programs by examining the data from six lakes common to both programs. Both programs were initiated in the early 1990s to track the efficacy of emission reduction policies and to assess the full impacts of acid deposition on surface water chemistry. They now serve to inform on the emerging chemical recovery of these waters. The Adirondack TIME program utilizes a probability-based approach to assess chronic acidification in a population of lakes using one summer sample per year. The ALTM attempts to track changes in both chronic and episodic acidification across a gradient of lake types using monthly samples. The ALTM project has two important attributes that contrast with the TIME program in the Adirondacks: higher temporal resolution (monthly versus once during the summer or fall) and speciation of aluminum. In particular, the ALTM program provides inorganic monomeric aluminum (AlIM), the fraction of Al that is most toxic. The monthly sampling of the ALTM program includes the spring snowmelt period when acid-neutralizing capacity and pH are near their lowest and Al levels are near their highest. We compare chemistry trends (1992–2008) for sulfate, nitrate, base cations, dissolved organic carbon, hydrogen ion, acid neutralizing capacity, and Al for the six lakes common to both programs. We also compare relatively high springtime AlIM concentrations from the ALTM with relatively low summertime total Al concentrations from the TIME, showing that the ALTM program provides a more biologically relevant indicator of the effects of acid deposition, illustrating the value of the complementary monitoring efforts in the Adirondack region.

Environmental constrains and anthropogenic changes can contribute simultaneously to the limitation of plant performance in Mediterranean urban areas. Photosynthetic efficiency of Quercus ilex L. leaves from the urban area of Naples was evaluated by comparison with leaves from remote site (Vesuvius National Park). The photosynthetic performance of leaves with different age (current year [CY], 1- [1Y] and 2-year old [2Y]) was assessed by measurements of gas exchange, chlorophyll fluorescence and pigment contents. The photosynthetic activity at the urban site was higher than that at the remote site for the CY leaves, while the opposite was observed for the 1Y and 2Y leaves. The growth of Q. ilex trees was mainly sustained by the CY leaves at the urban site, whereas at the remote site the photosynthetic activity was not affected by leaf ageing. In the urban environment, Q. ilex leaves strongly decreased the photosynthetic performance with leaf ageing as highlighted by leaf gas exchanges, although the photochemistry did not show any significant change. The mature leaves of urban site drove the reductive power deriving from the photochemistry more in non-assimilative processes rather than in carbon assimilative ones, avoiding a strong decrease of PSII photochemical efficiency.

Fluid catalytic cracking of heavy ends to high-value liquid fuels is a common unit operation in oil refineries. In this process, the heavy feedstock that contains sulfur is cracked to light products. Sulphur content is hence redistributed in the liquid and gaseous products and coke of the catalyst used in this process. The coke is later burnt in the regenerator releasing sulfur into the discharged flue gas as SO₂. In the present work, comprehensive emission inventories for a fluid catalytic cracking unit in a typical oil refinery are prepared. These inventories are based on calculations that assume complete combustion of catalyst coke in the regenerator. Yearly, material balances for both SO₂ and particulate matters emissions are carried out taking into account seasonal variations in the operation of the process unit. The results presented in this article reflect the variation of sulfur in feedstock originating from various units in the refinery. The refinery operations are not dependant on seasons but controlled by market-driven conditions to maximize the profit. The seasonal impact on refinery emissions is minimal due to its operation at optimum capacity fulfilling the international market demand. The data presented and analyzed here can be used to assess the hazardous impact of SO₂ and particulate matter emissions on surrounding areas of the refinery.

Pine needles were selected as cost-effective and easy collectable matrices suitable for long-term monitoring of the lower troposphere pollution with polycyclic aromatic hydrocarbons (PAHs). Overall, 27 sampling sites around the island of Crete were selected, and upon availability, second- and third-year needles from two pine species (Pinus brutia Ten. and Pinus pinea L.) were collected. In general, the results for both pine species showed that sites belonging in the urban group yielded the highest contamination levels when compared to the rural and the remote ones and that third-year needles had higher PAH contamination than the second-year ones. Phenanthrene was the prevailing PAH, representing 39% and 46% of the total contamination for second- and third-year needles, respectively. Fluoranthene, pyrene, chrysene and fluorene followed, with individual concentrations between 6% and 12%. The dominance of three-ringed PAHs was evidenced for the vast majority of the sites. An urban, rural and remote fingerprint was determined over a more general uniform contamination pattern, and the diagnostic PAH ratios pointed towards mixed petrogenic and pyrogenic sources. Overall, the present findings showed that the presence of PAHs is not negligible throughout the Cretan atmosphere and can be even considered quite high in some areas, especially when comparing the results to the ones found for more densely populated or industry-related areas.

Methane fluxes in alpine ecosystems remain insufficiently studied, especially in terms of the magnitude, temporal, and spatial patterns. To quantify the mean methane emission of alpine ecosystems, methane fluxes were measured among six ecosystems and microsites within each ecosystem at Zoige National Wetland Reserve. The average methane emission from Zoige Plateau was 2.25 mg CH4 m−2 h−1, which fell into the range of methane emission rate reported by a number of studies in other alpine wetlands. Prevailing ecosystem types had important impacts on the methane flux on the landscape scale. In the wet ecosystems, the microsites had different methane emissions resulting from the differences in the depth of water table and associated vegetation characteristics. The identification of the microsites based on their vegetation characteristics thus allows upscaling of methane emissions in these ecosystems. However, in the dry ecosystems showing even methane uptake, the spatial variation in the methane fluxes was low and the vegetation has a poor predicative value for the methane fluxes. There, the soil porosity linked to the gas diffusion rate in soil would be the key factor explaining methane fluxes.

Two greenhouse pot experiments were conducted in Agrinion, Greece, using a randomized block design in four replications, respectively, as follows: The first one included five levels of treated municipal wastewater (TMWW), being used as an irrigation water source. The second one, five levels of applied Cl at a constant soil applied Cd level of 10.36 mg/kg soil, the plants being irrigated with fresh well water. The purpose of these experiments was to study the impact of the Cl × Cd interrelationship on planning TMWW reuse, for the irrigation of Brassica oleracea var. Capitata (cabbage) cv F1 Gloria, ehich was used as test plant, in both of these experiments. It was found that the TMWW Cl content, originating mainly from the procedure of wastewater chlorination, was synergistically interrelated with the toxic heavy metal Cd, increasing its soil availability and cabbage plant leaf uptake (edible plant part). As this increase is directly associated with the consumer's health, it was suggested that the TMWW be subjected to dechlorination process or the disinfection be made by ozonation or UV, which do not include Cl.

Aldama dentata Llave & Lex. is a plant native to Latin America that exhibits metallicolous populations. Its ecophysiological (EP) response to Cu stress, administered as graded soil concentrations (Cs) of the fungicide copper(II) oxychloride, is examined in depth. Using a systems biology- and population dynamics-inspired approach, an r/K-driven model is proposed that satisfactorily explains the plant Cu concentration (Cp) versus Cs EP response curves for the root, shoot, and whole plant. A. dentata was found to be a Cu excluder (ME). The dual role of Cu as a nutrient and toxin at low and high concentrations, respectively, manifested as a parabolic variation of the foliar area where the toxicity appeared as a second-order effect. The power-law variance of biomass (Bp) with Cp expected from the universal allometric scaling law of biology was loosely followed and is discussed in terms of the mode of Cu uptake by the plant and Cu’s dual physiological role. Biometric growth indices reflected the impact of Cu on the photosynthetic energy harvest. The general applicability of the r/K-driven model was corroborated by its successful application to the published Cp–Cs data of the well-known Cu ME, Silene vulgaris. The r–K factors suggest a new quantitative manner of comparing the phytoavailability of the metal and the plant’s accumulation capability across soil types. A. dentata with high root Cp but low Bp diminution could potentially find use as a Cu phytostabilizer.

A fixed-bed photocatalytic reactor equipped with a cylindrical parabolic light concentrator was studied to remove organic dyes from water using natural volcanic ashes particles and nanostructured titania supported on volcanic ashes as photocatalytic materials. The influences of flow rate, photocatalyst and photocatalytic material adsorption capacity were studied. A fixed-bed photocatalytic reactor was designed and built in the laboratory; a methylene blue aqueous solution, used as model compound for dye contaminated water, was fed into the reactor. Methylene blue destruction efficiencies were monitored spectrophotometrically. Combined effects of dye adsorption and photodecomposition on photocatalyst were studied and compared by infrared spectroscopy.