The objectives of this study were to determine the capacity of the freshwater calanoid copepod Argyrodiaptomus falcifer (Daday, 1905) to accumulate Cr from water, to know the bioconcentration factors in order to evaluate its potential as a biomonitor, and to compare this with data previously obtained with Daphnia magna Straus under identical conditions. By static bioassays using triplicates and a control, a pool of A. falcifer was exposed to three concentrations of Cr (VI): 150 μg/L (T1), 280 μg/L (T2), and 350 μg/L (T3) for 48 h to later determine by Instrumental Neutron Activation Analysis the amount of Cr accumulated. A. falcifer accumulated Cr in all the three concentrations tested. The comparison of T1, T2, and T3 and the control showed significant differences (p < 0.05) but not between the treatments (p > 0.05). On the other hand, A. falcifer accumulated more Cr than D. magna, but these differences were not significant (p > 0.05). Almost no information is available about metal toxicity in freshwater copepods so the reported results are of high importance in order to detect good biomonitors of freshwater Cr-polluted environments.

We report observations of primary and secondary atmospheric pollutants such as nitrogen oxides, sulfur dioxide, toluene, and ozone during the period February 2002 to August 2003 in Puertollano, an industrial area located in central-southern Spain. The measurements were performed using a commercial differential optical absorption spectroscopy instrument. From the hourly data, we have analyzed the mean seasonal levels and the daily evolution and we have examined the occurrence of elevated pollution episodes. The daily cycles of NO, NO₂, SO₂, and toluene were characterized by an early-morning maximum whereas O₃ peaks were monitored around noon. Seasonally, the highest hourly mean concentrations of NO, NO₂, SO₂, and toluene, 14.2, 27.0, 34.4, and 12.1 μg m⁻³ respectively, were found in the winter while O₃ summer levels reached 119.1 μg m⁻³. The dataset presented here shows episodic occurrences of elevated concentrations that exceeded the maximum levels established in the European Directives. For instance, hourly values for SO₂ were repeatedly measured above 350 μg m⁻³. During the period of measurements, the O₃ thresholds (i.e., hourly value of 240 μg m⁻³) defined to protect the human health have also been exceeded numerous times. Finally, we investigate daily and seasonal patterns in pollution levels within the context of local meteorology and photochemistry, vehicular traffic, and industrial emissions.

Cr(VI) is a well-known highly toxic metal, considered a priority pollutant. Industrial sources of Cr(VI) include leather tanning, cooling tower blowdown, plating, electroplating, anodizing baths, rinse waters, etc. This article includes a survey of removal techniques for Cr(VI)-contaminated aqueous solutions. A particular focus is given to adsorption, membrane filtration, ion exchange, and electrochemical treatment methods. The primary objective of this article is to provide recent information about the most widely used techniques for Cr(VI) removal.

Fish and piscivorous bird eggs collected in 2003 from Lake Maggiore (Italy), were analysed for PCB and DDT contamination. Lake Maggiore has been severely polluted by DDT through production of the pesticide within its catchment. Although agricultural application of DDT was banned in Italy in the 1978, industrial production continued until 1996, with enough contamination of water and soil for serious bioaccumulation in the lake biota. PCB and DDT concentrations in a whitefish (Coregonus macrophthalmus Nusslin 1882) were seen to be dependent on season and fish age, but not on sex. The average increase of the lipid-normalised concentration of DDTs and PCBs was two-fold across season and also across age, resulting in an overall increase of four fold. The seasonal variation was related to the eco-physiological cycle of the fish and to the contamination dynamic of the lake, while the effect of the fish age was explained on the base of biomagnification-related mechanisms. A fugacity model was applied to predict the age-dependent bioaccumulation potential of PCBs, whose concentrations were rather stable in recent years in the lake. Predicted values for compounds with negligible biotransformation were in good agreement with experimental data (calculated vs. experimental mean difference of 14%), and a relationship between the increase of experimental age-dependent concentration and K ow was observed. The good correspondence between the predicted and the measured values for most PCB congeners confirmed the general inability of fishes to biotransform these compounds. On the contrary, the importance of biotransformation processes was recognised in birds; eggs of a fish eating bird (Podiceps cristatus) from the same area selectively bioaccumulated p,p'-DDE. For PCBs, congener 149 appears to be completely metabolized by the bird species, and congeners 95, 101, 132, 151 and 174 were reduced as well. The role of the meta-para free position on at least one phenyl ring of PCB congeners in biotransformation processes was confirmed.

This study investigated sludge granulation inoculated with various mixtures of aerobic and anaerobic sludge at low dissolved oxygen (DO; 0.3-0.6 mg/l) or aerobic (>2.5 mg/l) conditions in four parallel flow reactor systems. Formation of high-density coupled granules was achieved in the reactor system inoculated with anaerobic and aerobic sludge seeds (1:1 mass ratio) at low DO concentrations, with a mean size of 2.5 mm after only 27 days of cultivation. The highest ratio of protein (PN) to polysaccharide (PS; 3.3) was observed for the coupled sludge compared to granules cultivated under aerobic conditions. The PN/PS ratio correlated well with high hydrophobicity, low sludge volumetric index, and compact granular structure. Activity tests of the specific anaerobic and aerobic biomass confirmed that anaerobes and aerobes coexisted in the same coupled granule. Based on the optical microscopic and SEM observations, the process of coupled granule formation was proposed.

Short term influence of silica, palladium, gold and copper nanoparticles on a soil microbial community and the germination of lettuce seeds are investigated in this study at two different concentrations of nanoparticles. Results show a statistically insignificant influence of the nanoparticles in the soil on the number of colony forming units, peak areas of methyl ester of fatty acids in the FAME profile or on the total soil community metabolic fingerprint (P > 0.05). Also, all nanoparticles tested in the study influenced the growth of lettuce seeds as measured through shoot/root ratios of the germinated plant (P < 0.05).

The goal of this work was to study quantitatively lead bioaccumulation from a lead-doped nutrient medium by using a living aquatic macrophytes Pistia stratiotes. Several sets of aquatic plants with approximately 30 g weight were grown in greenhouse conditions and in hydroponic solutions supplied with a non-toxic Pb²⁺ concentration. The synchrotron radiation total X-ray fluorescence spectrometry was used to determine the metal concentrations in dry plants and hydroponic media as a function of time. Four different non-structural bioaccumulation models were applied to describe the process dynamics and to estimate the accumulated lead maximum capacity and rate constants. According to the experimental data, both biosorption and bioaccumulation mechanisms can be considered. Due to the low desorption rate constant, the experimental data were well described by the irreversible kinetic model. The results concerning modeling of living macrophytes' metal bioaccumulation kinetics can be used to predict the heavy metal removal dynamics from wastewaters in artificial wetlands.

Sediment cores were collected from the central and northern parts of Lake Dianchi, a large and shallow eutrophic lake situated in southwest China. Total organic carbon, total nitrogen (TN), and total phosphorus (TP) as well as the δ¹³C and δ¹⁵N were analyzed in the sediment cores. Age model of the sediment cores were established according to ¹³⁷Cs geochronology, which reveals that the sedimentary record covers a period of the last 50 years. During that time, Dianchi had been undergoing a distinct conversion from oligotrophic to eutrophic, as a result of increasing nutrient loadings. The two cores displayed similar increases for values of TN and δ¹⁵N, and the variations of the both parameters matched well with that of TP, which presumably suggested that δ¹⁵N is a reliable proxy for anthropogenic nutrient input. Also, dynamics of δ¹⁵N and TP showed that anthropogenic nutrients input seemed to start in the 1970s. The upward elevation of δ¹⁵N might be ascribed to the increasing input of isotopically heavier dissolved inorganic nitrogen and the accelerated denitrification process when the lake water was oxygen-depleted. The less variation of δ¹⁵N in the uppermost several centimeters of both cores were probably the result of pollution controls carried out by the local government in the recent decade. The upward increasing of δ¹³C in the two cores seemed to be induced by the enhanced productivity since 1980, which was in accordance with limnological observation. Therefore, δ¹³C values were believed to be an effective proxy for reconstructing the history of eutrophication in Lake Dianchi. In addition, this study also suggested that carbon and nitrogen isotopes are applicable to large, shallow lakes in interpreting the past environmental change.

Soils in areas of mining and smelting of Pb-Zn ores in Southern Poland are strongly enriched in heavy metals (Zn, Pb, Fe, Cd, Tl, As). The highest concentrations of Zn (<55,506 mg kg⁻¹), Pb (<8,262 mg kg⁻¹), Cd (<220 mg kg⁻¹) and Tl (<67 mg kg⁻¹) are linked to the fine fractions of upper soil layers in sites contaminated by past exploitation and processing of ores. The high stress of metals, and the negative influence of acid waste drainage has limited the development of flora and fauna in these areas. The increasing ability of plants to grow is due to the positive symbiotic action of fungi and bacteria. The mycorrhizal communities were identified in rhizospheres rich in unstable Zn-Pb-Fe sulphides such as sphalerite, galena, pyrite and marcasite and carbonates of Zn (smithsonite) and Pb (cerussite). They occur in associations with sulphates, e.g., gypsum. In parts of fungi, secondary mineral phases containing Zn, Pb, Fe and Mn occur. Metal-bearing aggregates formed during symbiotic action between myccorhiza and bacteria connected with them. They enhance the binding of bio-available ions of Zn, Pb and Mn in the most unstable phases. Metal contents in the mycorrhizal parts of the rhizospheric soils were determined by Atomic Absorption Spectroscopy. Mineralogical investigations involved X-ray diffraction, scanning electron microscopy with energy dispersive spectrometry.

The sorption behavior of bisphenol A (BPA) on marine sediments treated using different methods was investigated in batch equilibrium experiments. Adsorption isotherms were well fitted to Freundlich model and the model parameters, K F and n, had been evaluated. When temperature decreased from 308 to 288 K, Freundlich constant (K F) increased about 200%. K F increased by approximately 92.6% with increase of salinity from 1:2 artificial seawater (1:2 ASW) to ASW conditions. The plateau sorption capacity was around 0.8579 mg/g in the pH range 7.46-8.34, whereas the adsorption capacity decreased from 0.8579 to 0 mg/g when pH from 8.34 to 8.91, suggesting that the undissociated species were adsorbed more readily and that electrostatic repulsion may inhibit sorption as pH increases. The increase of K F value between the two media from natural seawater to ASW was around 25.3%, indicating the presence of dissolved organic matter appeared to have a significant effect on sorption. Mineral surface of sediment, together with microporosity of sediment, showed to be primarily responsible for the sorption of BPA.