Part I Introduction, 2 The Concept and Reality of the International Watercourse System

2019 ◽  
Author(s):  
McCaffrey Stephen C
Keyword(s):  
Surface Water ◽  
Fresh Water ◽  
Surface Waters ◽  
Water System ◽  
Hydrologic Cycle ◽  
The Other ◽  
System P ◽  
Rivers And Lakes ◽  
Condensation Surface ◽  
Absolute Control

This chapter examines the behavior of Earth’s water system and the concept of the international watercourse. Most of the water on Earth is in constant motion in the hydrologic cycle, which consists of the evaporation of water into the atmosphere, chiefly from the sea, and its return to Earth through precipitation and condensation. Surface waters contained in rivers and lakes are merely one small part of Earth’s hydrologic cycle. Because there is always groundwater underlying, and related to, surface water, any attempt to regulate one without addressing the other would be futile. Moreover, the constant movement of Earth’s water through the hydrologic cycle means that it would be futile for any one state to attempt to subject fresh water within its borders to absolute control.

Temporal variability of disinfection by-products concentration in urban public water system

2013 ◽  
Vol 14 (4) ◽  
pp. 393-398
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Temporal Variability ◽  
Water System ◽  
The Other ◽  
Major Constituent ◽  
System P ◽  
Public Water System ◽  
Drinking Water Samples ◽  
By Products

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.

scholarly journals ATIVIDADE INIBITÓRIA DE PESTICIDAS PIRETROIDES SOBRE A GLUTATIONA S-TRANSFERASE

Química Nova ◽  
2021 ◽  
Author(s):  
Eliane Ribeiro ◽  
Mihaela Badea ◽  
Danilo Ribeiro ◽  
Andressa Costa ◽  
Djanira dos Santos ◽  
...  
Keyword(s):  
Surface Waters ◽  
In Silico ◽  
Competitive Inhibition ◽  
Environmental Contaminants ◽  
The Other ◽  
Inhibition Mechanism ◽  
Glutathione S Transferase ◽  
Pyrethroid Pesticides ◽  
Rivers And Lakes ◽  
Ic50 Values

INHIBITORY ACTIVITY OF PYRETHROID PESTICIDES ON GLUTATHIONE S-TRANSFERASE. Glutathione S-transferase (GST) is one of the enzymes used to evaluate the effects caused by environmental contaminants. The aim of this work was to study the effects of four pyrethroid compounds (allethrin, cypermethrin, deltamethrin and fenpropathrin) on the catalytic activity of GST and to estimate the potential for environmental contamination in silico of these insecticides. Spectrophotometric analyses showed that the activity of the GST enzyme was inhibited by the four pesticides, with the values for the inhibition constant (Ki) varying from 0.12 to 20 µmol L-1, with the following order of inhibition from the highest to the lowest Ki value: deltamethrin > cypermethrin > allethrin > fenpropathrin. They presented a competitive and non-competitive inhibition mechanism depending on the compound. The IC50 values (concentration that inhibits 50% of the enzyme activity) showed the insecticide deltamethrin with greater inhibitory capacity, since it reduced the activity of the GST enzyme by half, even though it was in a lower concentration in relation to the other analyzed compounds. The in silico evaluation indicated the possibility of most of the insecticides contaminating the surface waters (rivers and lakes) adhered to the suspended sediment, but did not show any potential for contamination of groundwater through leaching.

Analysis of selected surface water components in the town of Siedlce, Poland

2014 ◽  
Vol 43 (1) ◽  
Author(s):  
Mariusz Kluska ◽  
Anna Marciniuk-Kluska
Keyword(s):  
Surface Water ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Surface Waters ◽  
Research Study ◽  
Absorption Spectrometry ◽  
The Other ◽  
Quality Class ◽  
Class 1 ◽  
The Town

AbstractThe paper presents results of a research study into levels of selected surface water components in Siedlce, Poland. Water was sampled in the Muchawka Reservoir and the Muchawka River in March, July and November 2012. Two techniques were applied in the study: isotachophoresis and atomic absorption spectrometry. The analysis results of water sampled in the Muchawka Reservoir indicate that they are borderline compliant with standards for the Class 1 surface waters. On the other hand, the Muchawka River samples were found to be out of any quality class.

Instruments to reduce the leaching of heavy metals from building materials in the Netherlands

2007 ◽  
Vol 55 (3) ◽  
pp. 79-85 ◽  
Author(s):  
A.J.H. van Breemen ◽  
P.H.M. Vermij
Keyword(s):  
Heavy Metals ◽  
Surface Water ◽  
The Netherlands ◽  
Surface Waters ◽  
Best Practice ◽  
Building Materials ◽  
Construction Materials ◽  
Water System ◽  
Sealing Material ◽  
Metal Building

In the Netherlands the leaching of heavy metals from metal building and constructing materials results in serious contamination problems in the water system. The most common sources of these heavy metals in construction materials are copper waterworks and roofs, zinc roofs, gutters and rain pipes, zinced steel, stainless steel, and lead sealing material. In urban waters the surface water and sediment standards are often exceeded. Although building and construction materials are certainly not the only source of heavy metals, they are an important part of the problem. This article focuses on six instruments that are in use in the Netherlands to try to reduce impact on the surface waters. In addition to this, national as well as international, a reconsideration of the risks and surface water standards for several heavy metals is considered. A balanced use of instruments can be considered as the application of a best practice.

Groundwater protection and diffuse nitrogen emissions to surface waters – which catchment areas have to be considered?

2007 ◽  
Vol 7 (3) ◽  
pp. 103-110
Author(s):  
C. Schilling ◽  
M. Zessner ◽  
A.P. Blaschke ◽  
D. Gutknecht ◽  
H. Kroiss
Keyword(s):  
Surface Water ◽  
Total Nitrogen ◽  
Surface Waters ◽  
Flow Path ◽  
Emission Model ◽  
Catchment Scale ◽  
Danube Basin ◽  
Nitrogen Emissions ◽  
Nitrogen Levels ◽  
Catchment Areas

Two Austrian case study regions within the Danube basin have been selected for detailed investigations of groundwater and surface water quality at the catchment scale. Water balance calculations have been performed using the conceptual continuous time SWAT 2000 model to characterise catchment hydrology and to identify individual runoff components contributing to river discharge. Nitrogen emission calculations have been performed using the empirical emission model MONERIS to relate individual runoff components to specific nitrogen emissions and for the quantification of total nitrogen emissions to surface waters. Calculated total nitrogen emissions to surface waters using the MONERIS model were significantly influenced by hydrological conditions. For both catchments the groundwater could be identified as major emission pathway of nitrogen emissions to the surface waters. Since most of the nitrogen is emitted by groundwater to the surface water, denitrification in groundwater is of considerable importance reducing nitrogen levels in groundwater along the flow path towards the surface water. An approach was adopted for the grid-oriented estimation of diffuse nitrogen emissions based on calculated groundwater residence time distributions. Denitrification in groundwater was considered using a half life time approach. It could be shown that more than 90% of the total diffuse nitrogen emissions were contributed by areas with low groundwater residence times and short distances to the surface water. Thus, managing diffuse nitrogen emissions the location of catchment areas has to be considered as well as hydrological and hydrogeological conditions, which significantly influence denitrification in the groundwater and reduce nitrogen levels in groundwater on the flow path towards the surface water.

Sewers and the Quality of Canals and Ditches in Amsterdam

1993 ◽  
Vol 27 (5-6) ◽  
pp. 61-67 ◽  
Author(s):  
E. Jacobs ◽  
J. W. van Sluis
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Sediment Quality ◽  
Water System ◽  
Water Systems ◽  
Sewer System ◽  
Water And Sediment ◽  
Combined Sewer ◽  
Water And Sediment Quality

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.

scholarly journals Microplastics distribution in the Eurasian Arctic is affected by Atlantic waters and Siberian rivers

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Evgeniy Yakushev ◽  
Anna Gebruk ◽  
Alexander Osadchiev ◽  
Svetlana Pakhomova ◽  
Amy Lusher ◽  
...  
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
Water Masses ◽  
The Arctic ◽  
Plastic Pollution ◽  
Siberian River ◽  
Highest Weight ◽  
Surface Samples ◽  
Atlantic Origin ◽  
Type Size

AbstractPlastic pollution is globally recognised as a threat to marine ecosystems, habitats, and wildlife, and it has now reached remote locations such as the Arctic Ocean. Nevertheless, the distribution of microplastics in the Eurasian Arctic is particularly underreported. Here we present analyses of 60 subsurface pump water samples and 48 surface neuston net samples from the Eurasian Arctic with the goal to quantify and classify microplastics in relation to oceanographic conditions. In our study area, we found on average 0.004 items of microplastics per m3 in the surface samples, and 0.8 items per m3 in the subsurface samples. Microplastic characteristics differ significantly between Atlantic surface water, Polar surface water and discharge plumes of the Great Siberian Rivers, allowing identification of two sources of microplastic pollution (p < 0.05 for surface area, morphology, and polymer types). The highest weight concentration of microplastics was observed within surface waters of Atlantic origin. Siberian river discharge was identified as the second largest source. We conclude that these water masses govern the distribution of microplastics in the Eurasian Arctic. The microplastics properties (i.e. abundance, polymer type, size, weight concentrations) can be used for identification of the water masses.

Insights into the electrochemical degradation of phenolic lignin model compounds in protic ionic liquid-water system

2021 ◽  
Author(s):  
Guangyong Liu ◽  
Qian Wang ◽  
Dongxia Yan ◽  
Yaqin Zhang ◽  
Chenlu Wang ◽  
...  
Keyword(s):  
Water System ◽  
Value Added ◽  
Electrochemical Degradation ◽  
Aryl Ether ◽  
Model Compounds ◽  
Protic Ionic Liquid ◽  
Lignin Model Compounds ◽  
Mild Conditions ◽  
System P ◽  
Lignin Model

Cleavage of aryl ether (Caryl-O) bonds is crucial for conversion and value-added utilization of lignin and its derivatives, but remains extremely challenging under mild conditions due to strong Caryl-O linkages....

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