Photochemical transformation of benzotriazole, relevant to sunlit surface waters: Assessing the possible role of triplet-sensitised processes

2016 ◽  
Vol 566-567 ◽  
pp. 712-721 ◽  
Author(s):  
Angelica Bianco ◽  
Debora Fabbri ◽  
Marco Minella ◽  
Marcello Brigante ◽  
Gilles Mailhot ◽  
...  
Keyword(s):  
Surface Waters ◽  
Photochemical Transformation

scholarly journals Relative importance of the bacteria Brucella, Salmonella, Staphylococcus and other indicator bacteria in some mountain farm waters in West-Cameroon (Central Africa) and the potential role of some environmental factors

2020 ◽  
Vol 8 (2) ◽  
pp. 081-084
Author(s):  
Pierrette Ngo Bahebeck ◽  
Mireille Ebiane Nougang ◽  
Paul Alain Nana ◽  
Claire Stéphane Metsopkeng ◽  
Antoine Tamsa Arfao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Surface Waters ◽  
Brucella Abortus ◽  
Physicochemical Parameters ◽  
Potential Role ◽  
Abiotic Factors ◽  
Central Africa ◽  
Mountainous Regions ◽  
Brucella Suis

A bacteriological and physicochemical study was conducted in the waters of farms in mountainous regions of Cameroon. The different water samples were collected during two campaigns in December 2018 and February 2019. Ten stations representing the drinking water supply points in our study area were identified. The results showed that these waters contained both pathogenic and commensal fecal bacteria. The highest abundances reached 10x103 CFU/100mL for Salmonella sp., 72x103 CFU/100mL for Staphylococcus aureus, 102x103 CFU/100mL for Brucella suis and 40x103 CFU/100mL for Brucella abortus. These abundances were subject to space-time fluctuations. Water contamination by tweezers was not general and was present only in surface waters (rivers and ponds). The water in the ponds, rivers and wells analyzed were all basic, with low mineralization on average. The dissolved oxygen ranged from 37.5 to 70.6%, nitrate from 3.7 to 19.8 mg/L and iron from 0.01 to 3.5 mg/L. Most of the physicochemical parameters were relatively stable during the two campaigns. The degree of correlation between the physicochemical parameters and the abundance dynamics of the isolated bacteria was heterogeneous. This was clearly more pronounced with Salmonella sp. and Brucella suis. This would be due to the fraction of metabolically active cells present when the bacteria are exposed to unfavorable conditions. Correlations with the abiotic factors were less marked with Staphylococcus aureus and Brucella abortus; this would be due to their tolerance to environmental stresses.

scholarly journals Reversibility of acidification: soils and surface waters

1990 ◽  
Vol 97 ◽  
pp. 169-191 ◽  
Author(s):  
Richard F. Wright ◽  
Michael Hauhs
Keyword(s):  
Surface Waters ◽  
Predictive Models ◽  
Large Scale ◽  
Acidic Deposition ◽  
Nitrogen Saturation ◽  
Future Climate Change ◽  
Water Acidification ◽  
Catchment Scale ◽  
Empirical Relationships

SynopsisAs empirical relationships between acidic deposition and its effects on soils and surface waters have become increasingly understood, the focus of attention has shifted to the reversal of acidification in response to decreased amounts of acidic deposition.Recent decreases in acidic deposition, in both North America and parts of Europe, have initiated the reversal of acidification and the recovery of impacted ecosystems. Reversal has also been investigated in large-scale experiments with whole ecosystems. Predictive models can account for much of this empirical and experimental data, at least at the catchment scale, over periods of years.Discrepancies between observed and predicted effects are attributable in part to the increasingly important role of nitrogen in soil and water acidification. ‘Nitrogen saturation’ threatens to offset the incipient recovery following decreases in SO2 emissions. Future climate change might further exacerbate the problem by increasing the rate of mineralisation of soil organic matter and releasing stored nitrogen.

scholarly journals Geochemical background - an environmental perspective

Mineralogia ◽  
2011 ◽  
Vol 42 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Agnieszka Gałuszka ◽  
Zdzisław Migaszewski
Keyword(s):  
Surface Waters ◽  
Pollution Prevention ◽  
Quality Criteria ◽  
Mineral Deposits ◽  
New Mineral ◽  
Geochemical Background ◽  
Basic Tool ◽  
Methods Of Evaluation ◽  
Environmental Compartments

Geochemical background - an environmental perspectiveThis article presents the concept of geochemical background from an environmental perspective. The idea of establishing the typical concentrations of elements in various environmental compartments, proposed by exploratory geochemists almost 50 years ago was important for the detection of anomalous element concentrations, thus providing a basic tool in the search for new mineral deposits. At present, the knowledge of the geochemical background of hazardous elements is essential for: defining pollution, identifying the source of contamination, and for establishing reliable environmental quality criteria for soils, sediments and surface waters. The article presents geochemical methods of evaluation of anthropogenic influence on the environment and discusses the problem of defining and understanding the term "geochemical background" and related terms in environmental sciences. It also briefly presents methods of geochemical background evaluation based on the results of environmental sample analyses. It stresses the role of geochemical background in our understanding of environmental pollution and pollution prevention.

Seasonal and Water Column Trends of the Relative Role of Nitrate and Nitrite as *OH Sources in Surface Waters

2007 ◽  
Vol 97 (8) ◽  
pp. 699-711 ◽  
Author(s):  
Davide Vione ◽  
Claudio Minero ◽  
Valter Maurino ◽  
Ezio Pelizzetti
Keyword(s):  
Water Column ◽  
Surface Waters ◽  
Relative Role ◽  
Nitrate And Nitrite

Photochemical transformation of atrazine and formation of photointermediates under conditions relevant to sunlit surface waters: Laboratory measures and modelling

2013 ◽  
Vol 47 (16) ◽  
pp. 6211-6222 ◽  
Author(s):  
Giulia Marchetti ◽  
Marco Minella ◽  
Valter Maurino ◽  
Claudio Minero ◽  
Davide Vione
Keyword(s):  
Surface Waters ◽  
Photochemical Transformation ◽  
Laboratory Measures

Potential application of manganese coated sand in the removal of Mn(II) from aqueous solutions

2007 ◽  
Vol 56 (7) ◽  
pp. 153-160 ◽  
Author(s):  
D. Tiwari ◽  
M.R. Yu ◽  
M.N. Kim ◽  
S.M. Lee ◽  
O.H. Kwon ◽  
...  
Keyword(s):  
Water Treatment ◽  
Aqueous Solutions ◽  
Manganese Dioxide ◽  
Sodium Hypochlorite ◽  
Surface Waters ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Column Studies ◽  
Coated Sand

The aim of this study was to explore the applicability of manganese coated sand (MCS) in the presence and absence of sodium hypochlorite for the removal of Mn(II) (2 mg/L) from aqueous solutions. Sand itself is widely used as a filter media for the treatment of wastewaters and it was reported that during the treatment, Mn(II), which is present in the wastewater, is to be deposited on the surface of sand in the form of manganese dioxide. The present investigation dealt with various MCS samples, prepared in the laboratory by various doses of Mn(II) (i.e. from 0.05 to 0.2 mol/L) and the samples were obtained from the pilot plant and naturally coated in the water treatment plant for the removal of Mn(II) in the batch and column studies. Moreover, it was realised that the role of hypochlorite is multifunctional as it not only enhances the uptake of Mn(II) on the surface of MCS through oxidation of Mn(II) into Mn(IV) and hence the formation of manganese dioxide, but it was also supposed to disinfect the bacteria or harmful pathogens from the waste/surface waters. The results obtained clearly inferred that various MCS samples used for the removal of Mn(II) from aqueous solutions showed comparable removal efficiency. However, the presence of sodium hypochlorite greatly enhanced the removal of Mn(II) as more than 80% Mn(II) was removed in the presence of sodium hypochlorite at around pH 6.5. Similarly, while comparing the column data it was again noted that the breakthrough points occurred after the 4,100 and 6,500 bed volumes, respectively, in the absence and in the presence of sodium hypochlorite (2 mg/L).

Study of the photochemical transformation of 2-ethylhexyl 4-(dimethylamino)benzoate (OD-PABA) under conditions relevant to surface waters

2016 ◽  
Vol 88 ◽  
pp. 235-244 ◽  
Author(s):  
P. Calza ◽  
D. Vione ◽  
F. Galli ◽  
D. Fabbri ◽  
F. Dal Bello ◽  
...  
Keyword(s):  
Surface Waters ◽  
Photochemical Transformation

Effect of multicomponent fouling during microfiltration of natural surface waters containing nC60 fullerene nanoparticles

2017 ◽  
Vol 3 (4) ◽  
pp. 744-756 ◽  
Author(s):  
R. Floris ◽  
G. Moser ◽  
K. Nijmeijer ◽  
E. R. Cornelissen
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Surface Waters ◽  
Membrane Fouling ◽  
Industrial Water ◽  
Water Composition ◽  
Water Treatment Plants ◽  
Fullerene Nanoparticles ◽  
Microfiltration Membranes

To understand and mitigate the role of surface water composition and associated membrane fouling in the removal of nC60 nanoparticles by low-pressure membranes, experiments were carried out with microfiltration membranes using natural feed waters, mimicking separation in real industrial water treatment plants.

Marine Pelagic Ciliates and Their Productivity During Summer in Plymouth Coastal Waters

1992 ◽  
Vol 72 (1) ◽  
pp. 265-268 ◽  
Author(s):  
E. D. Pilling ◽  
R. J. G. Leakey ◽  
P. H. Burkill
Keyword(s):  
Surface Waters ◽  
Coastal Waters ◽  
Food Resource ◽  
Water Bottle ◽  
Ecological Role ◽  
Ciliate Community ◽  
June July ◽  
Present Pilot Study ◽  
Trophic Role

The ciliate list for Plymouth waters has been extended by 14 species using modern taxonomic techniques. Ciliates were abundant in the plankton where they formed a significant food resource. Their community biomass and production was estimated to average 12 µ C 1 and 9 µ C 1 respectively during the summer. The ciliate community was dominated by a diverse assemblage of aloricate choreotrichs, suggesting a complex trophic role for this protozoan group.Ciliate protozoans are ubiquitous and often abundant in marine waters where they are frequently considered to play an important ecological role in trophic flux and nutrient cycling within the plankton (Fenchel, 1987). In spite of this, however, their ecological role in British coastal waters is poorly understood. In Plymouth waters, for instance, there has been only one previous study of marine pelagic Protozoa (Lackey & Lackey, 1963), despite the presence of a marine laboratory in the region for over 100 years. As the study by Lackey & Lackey (1963) focused solely upon the taxonomy of local protists, the ecological role of protozoans in Plymouth waters is unknown. To redress this anomaly the present pilot study was undertaken in Plymouth waters with the following objectives: to identify the dominant ciliates from this region using techniques unavailable to Lackey & Lackey (1963), to quantify ciliate abundance and cell sizes, and to estimate their biomass and production.Triplicate water samples were collected, using a 3-litre water bottle, from surface waters at each of four stations along a 20-km transect between Plymouth Sound (50°21'N 04°09'W) and the Eddystone Rock (50°ll'N 04°16'W) during June, July and August 1988.

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