In this paper, we have analyzed parts of printed circuit board (PCB) and liquid crystal display (LCD) screens of mobile phones and computers, quantitative and qualitative chemical compositions of individual components, and complete PCBs were determined. Differential thermal analysis (DTA) and differential scanning calorimetry (DSC) methods were used to determine the temperatures of phase transformations, whereas qualitative and quantitative compositions of the samples were determined by X-ray fluorescence spectrometry (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES), and scanning electron microscopy (SEM)-energy dispersive X-ray spectrometry (EDS) analyses. The microstructure of samples was studied by optical microscopy. Based on results of the analysis, a procedure for recycling PCBs is proposed. The emphasis was on the effects that can be achieved in the recycling process by extraction of some parts before the melting process. In addition, newly developed materials can be an adequate substitute for some of the dangerous and harmful materials, such as lead and arsenic are proposed, which is in accordance with the European Union (EU) Restriction of the use of certain hazardous substances (RoHS) directive as well as some alternative materials for use in the electronics industry instead of gold and gold alloys.

Samples of pond sediment, fish, and shrimp were collected from the Ramsar site at Mai Po marshes, Hong Kong (south China), and samples of pond sediment, fish, and shrimp, as well as eggs of water birds (Chinese Pond Herons (Ardeola bacchus) and Little Egrets (Egretta garzetta)), were collected from two smaller wetland sites at Jiangsu Province (mid-China), between 2004 and 2007. Accumulation levels of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the biota were used to calculate biota–sediment accumulation factor (BSAF) and bioaccumulation factor (BAF). For fish and shrimp, BSAFs of OCPs (3.8–56) were greater than those of PAHs (0.12–6.3). BSAFs and BAFs of 11–79 and 4–34, respectively, were registered for OCPs in eggs of the birds and were greater than those for PAHs (0.11–1.5 and 0.02–1.3, respectively). Assuming that fish were the main prey of the birds, greater bioaccumulation of OCPs was detected for both bird species (BAFs = 4.5–34), while accumulation of PAHs was only detected in Little Egret (BAF = 1.3). A significant linear relationship (p < 0.01) was observed between concentrations of OCPs in bird eggs and in the prey fish. The present study provides a new possibility of using OCP levels detected in prey fish to predict the extent of OCPs contamination in eggs of waterbirds including the endangered species, as a noninvasive method.

The planktonic diatom genus Pseudo-nitzschia contains several genetically closely related species. Some of these can produce domoic acid, a potent neurotoxin. Thus, monitoring programs are needed to screen for the presence of these toxic species. Unfortunately, many are impossible to distinguish using light microscopy. Therefore, we assessed the applicability of microarray technology for detection of toxic and non-toxic Pseudo-nitzschia species in the Gulf of Naples (Mediterranean Sea). Here, 11 species have been detected, of which at least 5 are potentially toxic. A total of 49 genus- and species-specific DNA probes were designed in silico against the nuclear LSU and SSU rRNA of 19 species, and spotted on the microarray. The microarray was tested against total RNA of monoclonal cultures of eight species. Only three of the probes designed to be species-specific were indeed so within the limits of our experimental design. To assess the effectiveness of the microarray in detecting Pseudo-nitzschia species in environmental samples, we hybridized total RNA extracted from 11 seasonal plankton samples against microarray slides and compared the observed pattern with plankton counts in light microscopy and with expected hybridization patterns obtained with monoclonal cultures of the observed species. Presence of species in field samples generally resulted in signal patterns on the microarray as observed with RNA extracted from cultures of these species, but many a-specific signals appeared as well. Possible reasons for the numerous cross reactions are discussed. Calibration curves for Pseudo-nitzschia multistriata showed linear relationship between signal strength and cell number.

Phosphogypsum (PG) is a by-product of the phosphorus–fertiliser industry and represents an environmental concern since it contains pollutants such as cadmium (Cd). We have recently shown that the overexpression of a proton pump gene (TaVP1) in transgenic tobacco (Nicotiana tabacum) led to an enhanced Cd tolerance and accumulation. The aim of this study was to evaluate the potential of transgenic Arabidopsis thaliana plants harbouring the TaVP1 gene to phytoremediate phosphogypsum. A pot experiment was carried out under greenhouse conditions. Transgenic A. thaliana plants harbouring the TaVP1 gene were grown on various substrates containing phosphogypsum (0, 25, 50 and 100 %) for 40 days. At the end of the growth period, we examined the growth (germination, root length, fresh weight) and physiological parameters (chlorophyll and protein contents, catalase activity and proteolysis) as well as the cadmium, Mg, Ca, and P contents of the A. thaliana plants. In order to evaluate Cd tolerance of the A. thaliana lines harbouring the TaVP1 gene, an in vitro experiment was also carried out. One week-old seedlings were transferred to Murashige and Skoog agar plates containing various concentrations of cadmium; the germination, total leaf area and root length were determined. The growth and physiological parameters of all A. thaliana plants were significantly altered by PG. The germination capacity, root growth and biomass production of wild-type (WT) plants were more severely inhibited by PG compared with the TaVP1 transgenic A. thaliana lines. In addition, TaVP1 transgenic A. thaliana plants maintained a higher antioxidant capacity than the WT. Interestingly, elemental analysis of leaf material derived from plants grown on PG revealed that the transgenic A. thaliana line accumulated up to ten times more Cd than WT. Despite its higher Cd content, the transgenic A. thaliana line performed better than the WT counterpart. In vitro evaluation of Cd tolerance showed that TaVP1 transgenic A. thaliana lines were more Cd-tolerant than the WT plants. These results suggested that ectopic expression of a vacuolar proton pump in A. thaliana plants can lead to various biotechnological applications including the phytoremediation of industrial wastes.

Reactive dyes account for one of the major sources of dye wastes in textile effluent. In this study, decolorization of the monoazo dye, Acid Orange 7 (AO7) by the Enterococcus faecalis strain ZL that isolated from a palm oil mill effluent treatment plant has been investigated. Decolorization efficiency of azo dye is greatly affected by the types of nutrients and the size of inoculum used. In this work, one-factor-at-a-time (method and response surface methodology (RSM) was applied to optimize these operational factors and also to study the combined interaction between them. Analysis of AO7 decolorization was done using Fourier transform infrared (FTIR) spectroscopy, desorption study, UV–Vis spectral analysis, field emission scanning electron microscopy (FESEM), and high performance liquid chromatography (HPLC). The optimum condition via RSM for the color removal of AO7 was found to be as follows: yeast extract, 0.1 % w/v, glycerol concentration of 0.1 % v/v, and inoculum density of 2.5 % v/v at initial dye concentration of 100 mg/L at 37 °C. Decolorization efficiency of 98 % was achieved in only 5 h. The kinetic of AO7 decolorization was found to be first order with respect to dye concentration with a k value of 0.87/h. FTIR, desorption study, UV–Vis spectral analysis, FESEM, and HPLC findings indicated that the decolorization of AO7 was mainly due to the biosorption as well as biodegradation of the bacterial cells. In addition, HPLC analyses also showed the formation of sulfanilic acid as a possible degradation product of AO7 under facultative anaerobic condition. This study explored the ability of E. faecalis strain ZL in decolorizing AO7 by biosorption as well as biodegradation process.

Estuarine areas represent complex and highly changing environments at the interface between freshwater and marine aquatic ecosystems. Therefore, the aquatic organisms living in estuaries have to face highly variable environmental conditions. The aim of this work was to study the influence of environmental changes from either natural or anthropogenic origins on the physiological responses of Mytilus edulis. Mussels were collected in the Vilaine estuary during early summer because this season represents a critical period of active reproduction in mussels and of increased anthropogenic inputs from agricultural and boating activities into the estuary. The physiological status of the mussel M. edulis was evaluated through measurements of a suite of biomarkers related to: oxidative stress (catalase, malondialdehyde), detoxication (benzopyrene hydroxylase, carboxylesterase), neurotoxicity (acetylcholinesterase), reproductive cycle (vitelline, condition index, maturation stages), immunotoxicity (hemocyte concentration, granulocyte percentage, phagocytosis, reactive oxygen species production, oxidative burst), and general physiological stress (lysosomal stability). A selection of relevant organic contaminant (pesticides, (polycyclic aromatic hydrocarbons, polychlorobiphenyls) was measured as well as environmental parameters (water temperature, salinity, total suspended solids, turbidity, chlorophyll a, pheopigments) and mussel phycotoxin contamination. Two locations differently exposed to the plume of the Vilaine River were compared. Both temporal and inter-site variations of these biomarkers were studied. Our results show that reproduction cycle and environmental parameters such as temperature, organic ontaminants, and algal blooms could strongly influence the biomarker responses. These observations highlight the necessity to conduct integrated environmental approaches in order to better understand the causes of biomarker variations.

Ciliated protozoa (ciliates) play important ecological roles in coastal waters, especially regarding their interaction with environmental parameters. In order to increase our knowledge and understanding on the functional structure of ciliate communities and their relationships to environmental conditions in marine ecosystems, a 12-month study was carried out in a semi-enclosed bay in northern China. Samples were collected biweekly at five sampling stations with differing levels of pollution/eutrophication, giving a total of 120 samples. Thirteen functional groups of ciliates (A–M) were defined based on their specific spatio-temporal distribution and relationships to physico-chemical parameters. Six of these groups (H–M) were the primary contributors to the ciliate communities in the polluted/eutrophic areas, whereas the other seven groups (A–G) dominated the communities in less polluted areas. Six groups (A, D, G, H, I and K) dominated during the warm seasons (summer and autumn), with the other seven (B, C, E, F, J, L and M) dominating in the cold seasons (spring and winter). Of these, groups B (mainly aloricate ciliates), I (aloricate ciliates) and L (mainly loricate tintinnids) were the primary contributors to the communities. It was also shown that aloricate ciliates and tintinnids represented different roles in structuring and functioning of the communities. The results suggest that the ciliate communities may be constructed by several functional groups in response to the environmental conditions. Thus, we conclude that these functional groups might be potentially useful bioindicators for bioassessment and conservation in marine habitats.

In the last decade, various molecular methods (e.g., fluorescent hybridization assay, sandwich hybridization assay, automatized biosensor detection, real-time PCR assay) have been developed and implemented for accurate and specific identification and estimation of marine toxic microalgal species. This review focuses on the recent quantitative real-time PCR (qrt-PCR) technology developed for the control and monitoring of the most important taxonomic phytoplankton groups producing biotoxins with relevant negative impact on human health, the marine environment, and related economic activities. The high specificity and sensitivity of the qrt-PCR methods determined by the adequate choice of the genomic target gene, nucleic acid purification protocol, quantification through the standard curve, and type of chemical detection method make them highly efficient and therefore applicable to harmful algal bloom phenomena. Recent development of qrt-PCR-based assays using the target gene of toxins, such as saxitoxin compounds, has allowed more precise quantification of toxigenic species (i.e., Alexandrium catenella) abundance. These studies focus only on toxin-producing species in the marine environment. Therefore, qrt-PCR technology seems to offer the advantages of understanding the ecology of harmful algal bloom species and facilitating the management of their outbreaks.

Extracellular polymeric substances (EPS) are, along with microbial cells, the main components of the biological sludges used in wastewater treatment and natural biofilms. EPS play a major role in removing pollutants from water by means of sorption. The ability of soluble EPS (S-EPS) and bound EPS (B-EPS) derived from various bacterial aggregates (flocs, granules, biofilms) to bind at pH 7.0 ± 0.1 to two pharmaceutical substances, acetaminophen (ACE) and erythromycin ethylsuccinate (ERY), has been investigated using the fluorescence quenching method. Two intense fluorescence peaks, A (Ex/Em range, 200-250/275-380 nm) and B (Ex/Em range, 260-320/275-360 nm), corresponding respectively to the aromatic protein region and soluble microbial by-product-like region, were identified in a three-dimensional excitation-emission matrix of EPS samples. The fluorescence peak, which corresponds to humic-like substances, was also identified though at low intensity. The ability of EPS to bind ACE was found to exceed that for ERY. The aromatic protein fraction of EPS displays a slightly higher affinity for drugs than that shown by the soluble microbial by-product-like fraction. The S-EPS and B-EPS present the same affinity for ACE and ERY. The effective quenching constants (log K) derived from the Stern-Volmer Equation equaled at peak A (with S-EPS): 3.7 ± 0.2 to 4.0 ± 0.1 for ACE and 2.1 ± 0.3 to 2.7 ± 0.1 for ERY. With B-EPS, these values were 3.9 ± 0.1 to 4.0 ± 0.1 for ACE and 2.0 ± 0.2 to 2.6 ± 0.1 for ERY. Our results suggest that the weaker EPS affinity for ERY than for ACE serves to partially explain why only about 50-80 % of ERY is removed from wastewater at the treatment plant. Moreover, this work demonstrates that EPS from natural river biofilms are able to bind drugs, which in turn may limit the mobility of drugs in natural waters.

Methane-oxidizing bacteria (methanotrophs) in the soil are a unique group of methylotrophic bacteria that utilize methane (CH4) as their sole source of carbon and energy which limit the flux of methane to the atmosphere from soils and consume atmospheric methane. A field experiment was conducted to determine the effect of nitrogen application rates and the nitrification inhibitor dicyandiamide (DCD) on the abundance of methanotrophs and on methane flux in a grazed pasture soil. Nitrogen (N) was applied at four different rates, with urea applied at 50 and 100 kg N ha(-1) and animal urine at 300 and 600 kg N ha(-1). DCD was applied at 10 kg ha(-1). The results showed that both the DNA and selected mRNA copy numbers of the methanotroph pmoA gene were not affected by the application of urea, urine or DCD. The methanotroph DNA and mRNA pmoA gene copy numbers were low in this soil, below 7.13 × 10(3) g(-1) soil and 3.75 × 10(3) μg(-1) RNA, respectively. Daily CH4 flux varied slightly among different treatments during the experimental period, ranging from -12.89 g CH4 ha(-1) day(-1) to -0.83 g CH4 ha(-1) day(-1), but no significant treatment effect was found. This study suggests that the application of urea fertilizer, animal urine returns and the use of the nitrification inhibitor DCD do not significantly affect soil methanotroph abundance or daily CH4 fluxes in grazed grassland soils.