Vegetable and synthetic tannins induce hormesis/toxicity in sea urchin early development and in algal growth

Mimosa tannin and phenol-based synthetic tannin (syntan) were tested for toxicity to sea urchin (Paracentrotus lividus and Sphaerechinus granularis) early development and to marine algal growth (Dunaliella tertiolecta). Sea urchin embryogenesis was affected by vegetable tannin and syntan water extracts (VTWE and STWE) at levels >or=1mg/L. Developmental defects were significantly decreased at VTWE and STWE levels of 0.1 and 0.3mg/L when control cultures displayed suboptimal quality, i.e. <70% "viable" (normal or retarded) larvae. Fertilization success of sea urchin sperm was increased up to 0.3 mg/L STWE or VTWE, then was inhibited by increasing tannin levels (1-30 mg/L). Offspring abnormalities, following sperm exposure to VTWE or STWE, showed the same shift from hormesis to toxicity. Cell growth bioassays in D. tertiolecta exposed to VTWE or STWE (0.1-30 mg/L) showed non-linear concentration-related toxicity. Novel criteria are suggested in defining control quality that should reveal hormetic effects.     

Prokaryotic life in a potash-polluted marsh with emphasis on N-metabolizing microorganisms

Prokaryotic life along the salt gradient of the potash marsh resulting from mining waste at Schreyahn, Northern Germany, was screened for the distribution of total prokaryote (assessed by the 16S rRNA gene) and of N2-fixing (nifH gene), denitrifying (nosZ) and nitrifying (amoA) microorganisms. Information on prokaryotes was retrieved from the different soil sites (a) by culturing in conventional media, (b) by isolating the DNA, amplifying the target genes by PCR followed by sequencing, (c) by employing the recently developed computer program (TReFID [R?sch, C., Bothe, H., 2005. Improved assessment of denitrifying, N2-fixing, and total-community bacteria by terminal restriction fragment length polymorphism analysis using multiple restriction enzymes. Applied and Environmental Microbiology 71, 2026-2035]) based on tRFLP data. New sequences were obtained as well as ones that were almost identical to those found at far distant locations. Whereas the distribution of plants strictly follows the salt gradient, this is apparently not the case with prokaryotes. Bacteria of hypersaline areas coexist with salt-non-tolerant species. The recently developed TReFID program is successfully applied to characterize a prokaryote community structure.     

Factors affecting river health and its assessment over broad geographic ranges: the Western Australian experience

AusRivAS is an Australia-wide program that measures river condition using predictive models to compare the macroinvertebrate families occurring at a river site with those expected if the site were in natural condition. Results of assessment of 685 sites across all major rivers in Western Australia are presented. Most rivers were in relatively natural condition in the northern half of the state where the human population is low and pastoralism is the major land use. In the south, where the human population is higher and agriculture is more intensive, rivers were mostly more disturbed. AusRivAS assessment produced some erroneous results in rivers of the south-west cropping zone because of the lack of appropriate reference site groups and biased distribution of sampling sites. Collecting low numbers of animals from many forested streams, because of low stream productivity and samples that were difficult to sort, also affected assessments. Overall, however, AusRivAs assessment identified catchment processes that were inimical to river health. These processes included salinisation, high nutrient and organic loads, erosion and loss of riparian vegetation. River regulation, channel modification and fire were also associated with river degradation. As is the case with other assessment methods, one-off sampling at individual sites using AusRivAS may be misleading. Seasonal drought, in particular, may make it difficult to relate conditions at the time of sampling to longer-term river health. AusRivAS has shown river condition in Western Australia is not markedly different from other parts of Australia which, as a whole, lacks the substantial segments of severely degraded river systems reported in England.     

Pesticide Residues in Bovine Milk from a Predominantly Agricultural State of Haryana, India

One hundred forty seven samples of bovine milk were collected from 14 districts of Haryana, India during December 1998–February 1999 and analysed for the presence of organochlorine pesticide (OCPs) residues. ∑HCH, ∑DDT, ∑endosulfan and aldrin were detected in 100%, 97%, 43% and 12% samples and with mean values of 0.0292, 0.0367, 0.0022 and 0.0036 μg/ml, respectively. Eight percent samples exceeded the maximum residue limit (MRL) of 0.10 mg/kg as recommended by WHO for ∑HCH, 4% samples of 0.05 mg/kg for α-HCH, 5% samples of 0.01 mg/kg for γ-HCH, 26% samples of 0.02 mg/kg for β-HCH as recommended by PFAA and 24% samples of 0.05 mg/kg as recommended by FAO for ∑DDT. Concentrations of β-HCH and p,p′-DDE were more as compared to other isomers and metabolites of HCH and DDT.     

Nitrogen and metals in two regions in Central Europe: Significant differences in accumulation in mosses due to land use?

The study was conducted to test the hypothesis that the regional variability of nitrogen (N) and metal accumulations in terrestrial ecosystems are due to historical and recent ways of landuse. To this end, two regions of Central Europe were selected for investigation: the Weser-Ems Region (WER) and the Euro Region Nissa (ERN). They were assumed to have land use-specific accumulation profiles. Thus, the metal and N accumulations in both regions were examined by means of geostatistically based comparative moss analysis. The sampling and chemical analysis of mosses were conducted in accordance with the convenient guidelines and methods, respectively. The spatial representativity of the sampling sites was computed by means of a land classification which was calculated for Europe by means of classification trees and GIS-techniques. The differences of deposition loads were tested for statistical significance with regard to time and space. The measurement values corroborated the decline of metal accumulation observed since the beginning of the European Metals in Mosses Surveys in 1990. The metal loads of the mosses in the ERN exceeded those in the WER significantly. The opposite holds true for the N concentrations: those in the WER were significantly higher than those in the ERN. The reduction of emissions from power plants, factories and houses was strongly correlated with the decline of deposition and bioaccumulation of metals. As proved by the European Metals in Mosses Surveys, this tendency is due to successful environmental policies. But no such success could be verified by monitoring the accumulation of N in mosses.     

Comparative evaluation of a bioluminescent bacterial assay in terrestrial ecotoxicity testing

Despite the widespread and successful use of luminescence-based bioassays in water testing, their applications to soils and sediments is less proven. In part this is because such bioassays have mainly been carried out in an aqueous-based medium and, as such, favour contaminants that are readily water-soluble. In this study, aqueous solutions and soils contaminated with heavy metals (HM), polar organic contaminants and hydrophobic organic contaminants (HOCs) were tested using a range of luminescence-based bioassays (Vibrio fischeri, Escherichia coli HB101 pUCD607 and Pseudomonas fluorescens 10586r pUCD607). For the first two chemical groups, the assays were highly reproducible when optimised extraction procedures were employed but for HOCs the bioassay response was poor. Quantitative structure-activity relationships (QSARs) obtained from aqueous solutions had a linear response although correlation for the chemicals tested using bacterial bioassays was significantly less sensitive than that of sublethal tests for Tetrahymena pyriformis. Bacterial and Dendrobaena veneta bioassay responses to extracts from HM amended soils showed that a clear relationship between trophic levels could be obtained. There is no doubt that the wide range of bioluminescent-based bioassays offers complementary applications to traditional testing techniques but there is a significant need to justify and optimise the extraction protocol prior to application.     

Vanadium recovery from oil fly ash by leaching, precipitation and solvent extraction processes

In order to reduce the environmental impact due to land disposal of oil fly ash from power plants and to valorize this waste material, the removal of vanadium was investigated using leaching processes (acidic and alkaline treatments), followed by a second step of metal recovery from leachates involving either solvent extraction or selective precipitation. Despite a lower leaching efficiency (compared to sulfuric acid), sodium hydroxide was selected for vanadium leaching since it is more selective for vanadium (versus other transition metals). Precipitation was preferred to solvent extraction for the second step in the treatment since: (a) it is more selective; enabling complete recovery of vanadate from the leachate in the form of pure ammonium vanadate; and (b) stripping of the loaded organic phase (in the solvent extraction process) was not efficient. Precipitation was performed in a two-step procedure: (a) aluminum was first precipitated at pH 8; (b) then ammonium chloride was added at pH 5 to bring about vanadium precipitation.     

Passive drainage and biofiltration of landfill gas: Australian field trial

In Australia a significant number of landfill waste disposal sites do not incorporate measures for the collection and treatment of landfill gas. This includes many old/former landfill sites, rural landfill sites, non-putrescible solid waste and inert waste landfill sites, where landfill gas generation is low and it is not commercially viable to extract and beneficially utilize the landfill gas. Previous research has demonstrated that biofiltration has the potential to degrade methane in landfill gas, however, the microbial processes can be affected by many local conditions and factors including moisture content, temperature, nutrient supply, including the availability of oxygen and methane, and the movement of gas (oxygen and methane) to/from the micro-organisms. A field scale trial is being undertaken at a landfill site in Sydney, Australia, to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions at low to moderate gas generation landfill sites. The design and construction of the trial is described and the experimental results will provide in-depth knowledge on the application of passive gas drainage and landfill gas biofiltration under Sydney (Australian) conditions, including the performance of recycled materials for the management of landfill gas emissions.     

Integrated catalytic wet air oxidation and aerobic biological treatment in a municipal WWTP of a high-strength o-cresol wastewater

This study examines the feasibility of coupling a Catalytic Wet Air Oxidation (CWAO), with activated carbon (AC) as catalyst, and an aerobic biological treatment to treat a high-strength o-cresol wastewater. Two goals are pursued: (a) To determine the effect of the main AC/CWAO intermediates on the activated sludge of a municipal WasteWater Treatment Plant (WWTP) and (b) To demonstrate the feasibility of coupling the AC/CWAO effluent as a part of the influent of a municipal WWTP. In a previous study, a high-strength o-cresol wastewater was treated by AC/CWAO aiming to establish the distribution of intermediates and the biodegradability enhancement. In this work, the biodegradability, toxicity and inhibition of the most relevant intermediates detected in the AC/CWAO effluent were determined by respirometry. Also, the results of a pilot scale municipal WWTP study for an integrated AC/CWAO-aerobic biological treatment of this effluent are presented. The biodegradation parameters (i.e. maximum oxygen uptake rate and oxygen consumption) of main AC/CWAO intermediates allowed the classification of the intermediates into readily biodegradable, inert or toxic/inhibitory compounds. This detailed study, allowed to understand the biodegradability enhancement exhibited by an AC/CWAO effluent and to achieve a successful strategy for coupling the AC/CWAO step with an aerobic biological treatment for a high-strength o-cresol wastewater. Using 30%, as COD, of AC/CWAO effluent in the inlet to the pilot scale WWTP, the integrated AC/CWAO-biological treatment achieved a 98% of total COD removal and, particularly, a 91% of AC/CWAO effluent COD removal without any undesirable effect on the biomass.     

Seasonal variations of selected herbicides and related metabolites in water, sediment, seaweed and clams in the Sacca di Goro coastal lagoon (Northern Adriatic)

This study assesses the status of Sacca di Goro coastal lagoon (Northern Adriatic, Italy) with respect to watershed pollution. Because 80% of its watershed is devoted to agriculture, plant protection products and their metabolites were found in the water column, sediments (the upper 0-15 cm layer), macroalgae (Ulva rigida) and clams (Tapes philippinarum). Five seasonal sampling campaigns were performed from May 2004 to April 2005 and concentrations measured in five stations in the lagoon and six in the watershed. Relatively high concentrations of the s-triazine - terbuthylazine -, urea herbicides - diuron - and alachlor were detected through the year mainly at stations directly influenced by the Po di Volano inflow. The concentrations of products in use follow a clear seasonal pattern with spring peaks. This pattern is also visible in the sediments as well as in biota. Among metabolites, hydroxylated compounds prevailed, often with concentrations greater than those of the parent compounds. For the most part of the year, the concentrations in biota were close to detection limits, with concentration peaks in spring.