[Typhus bacteriophages from polluted water in large and small shores and their photosensitivity].
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Sanitary-chemical, bacteriological and toxicological characterization of sediments in the regions of the pulp and paper mills sewage letting out are given. Methods of the analytical control are offered.
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The aim of this study was to determine the potential genotoxic activity of polluted water samples taken from wastewater from selected industrial plants in Kraków: 1. the Thermal-electric Power Station 2. the Institute of Metal Cutting. The recently developed single cell gel assay (SCG or comet assay), which is a quick and simple technique for the evaluation of DNA damage and repair in individual cells, was used. The assay was carried out on human hepatoma cells (Hep G2) as target cells. A greater number of cells with comets was observed in those treated in vitro with the polluted water samples (70%-88%) than in those in the control (22%, 33%). These preliminary results indicate that comet assay can have an application in biomonitoring studies for determining the potential genotoxicity of water pollutants.
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AIMS: This paper compares the faecal streptococci count on 25 samples of polluted waters obtained with three techniques: most probable number (MPN), membrane filtration (MF) and pour plate (PP) methods. Although the PP method is a simple technique, familiar to water bacteriologists, it is not recommended in the international methods. METHODS AND RESULTS: For the MPN method, azide dextrose broth and ethyl violet azide broth were employed. For the MF technique, Millipore filters were placed onto azide maltose agar (KF agar), while for the PP method, 1 ml of a decimal water dilution was added to (Kennel Faecal) KF medium. Regression analysis and Friedman's ANOVA were performed to determine the relationship between faecal streptococci counts obtained with the three techniques. Statistical analysis of the results showed that the MPN, MF and PP techniques were equally valid with respect to faecal streptococci enumeration in polluted waters. CONCLUSION: Since the PP method was found to be as good as the other techniques, it may be preferred in polluted waters. It is more economical in terms of both time and materials than the MPN count, and it is as accurate as the MF count. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicates that the PP method, although not recommended internationally, is a reliable alternative to MF and MPN.
Some biotic and abiotic soil components are able to catalyze phenol oxidation, producing water-insoluble polymers. In phenol-polluted water bodies, this phenomenon could be exploited to prevent phenol dispersion. The reaction kinetics of phenol polymerization catalyzed by soil samples drawn from unsaturated and aquifer layers was measured in slurry, aerated batch reactors. Catechol was used as a model phenol. The observed catalytic activity is essentially abiotic and can be attributed to inorganic soil components. The rate of phenol removal is first-order with respect to both catechol and soil concentration. Soil activity towards other phenolic compounds was tested, as well. Diphenols show the highest reactivity. Comparisons were performed with the enzymatic activity of phenol oxidases-containing mushroom tissues whose use has been envisaged in the treatment of phenol-polluted waters. The use of phenol oxidases can complement the intrinsic activity of soil for the removal of recalcitrant phenols.
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The count of coliphages in naturally polluted waters was found to be dependent on many experimental factors. If Escherichia coli C was used as a host strain, consistently higher counts were obtained than with other strains (B,K-12-derivatives). This could be explained partly by the absence of a restriction system in C. A nutrient medium (modified Scholtens' agar, MSA) was developed with optimal concentrations of calcium- and magnesium-ions. MSA was compared with other media used for phage work and was found to give higher counts than all but one medium, Phage Assay Agar (PAA), which performed equally. If plating was done in a single agar layer in a large-size Petri-dish, higher counts were found than with the well-known double-agar-layer method.
Water pollution exerts major stress on water systems and the challenge is to ensure security in river basins for both water-dependent activities and for the aquatic ecosystems. The workshop focused on protection of good ecological status, quality criteria, priorities for action, and on achievement of sustainable improvements. The three keynote speakers presented the concept applied in the EU Water Framework Directive, the need for a multi-stakeholder collaboration in order to reach a good ecological status of waters and a concrete example of interactive planning of water protection measures in a transboundary lake. The additional paper presentations addressed specific pollution problems in catchments, the effect of environmental user fees and ecosystem indicators.
The potential applications of immobilized bitter gourd peroxidase in the treatment of model wastewater contaminated with phenols have been investigated. The synthetic water was treated with soluble and immobilized enzyme preparations under various experimental conditions. Maximum removal of phenols was found in the buffers of pH values 5.0-6.0 and at 40 degrees C in the presence of 0.75 mM H(2)O(2). Fourteen different phenols were independently treated with soluble and immobilized bitter gourd peroxidase in the buffer of pH 5.6 at 37 degrees C. Chlorinated phenols and native phenol were significantly removed while other substituted phenols were marginally removed by the treatment. Phloroglucinol and pyrogallol were recalcitrant to the action of bitter gourd peroxidase. Immobilized bitter gourd peroxidase preparation was capable of removing remarkably high percentage of phenols from the phenolic mixtures. Significantly higher level of total organic carbon was removed from the model wastewater containing individual phenol or complex mixture of phenols by immobilized bitter gourd peroxidase as compared to the soluble enzyme. 2,4-dichlorophenol and a phenolic mixture were also treated in a stirred batch reactor with fixed quantity of enzyme for longer duration. The soluble bitter gourd peroxidase ceased to function after 3h while the immobilized enzyme was active even after 6h of incubation with phenolic solutions.
Arsenic is known to be a hazardous contaminant in drinking water that causes arsenical dermatitis and skin cancer. In the present work, the potential use of a variety of synthetic zeolites for removal of arsenic from water below the current and proposed EPA MCL has been examined at room temperature. Experiments have been conducted to examine the extent of arsenic removal as a function of pH. The effect of initial arsenic concentration and liquid to solid ratio in the batch reactions has also been studied. Zeolite NH4+/Y (NY6) showed significant arsenate removal capacity over a wide initial pH range of 2-12. Zeolite NY6 achieved this performance by buffering the initial pH to within a range of 3.5 < pH < 7 where uptake of arsenate onto aluminol surface groups is at a maximum. The high aluminum content of NY6 (i.e. low Si/Al ratio) was an important factor governing the improved performance of this zeolite relative to other tested zeolites with higher Si/Al ratio. The pH buffering capacity of NY6 could lead to savings in cost and process time for industrial effluent treatment due to avoidance of a pH pre-conditioning step prior to arsenate removal.
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With the increasing amount and variety of pollution of surface and other waters in the modern world, there is an increasing need for simple, rapid and reliable methods for assessing the degree of purity or contamination of water. Partly for historical reasons, chemical methods have been used more widely than biological ones, although the latter possess certain advantages not shared by the former.Much important work on the biological assessment of water pollution has been done in Central Europe, and the author of this paper reviews the more significant of the modern methods evolved there. Some are ecological, some physiological; and certain of them merit consideration as standardizable procedures, applicable over a wider range of waters than those for which they were developed. To this end it will be necessary to conduct carefully controlled field trials under varying climatic and other conditions.