Photochemical origin of reactive radicals and halogenated organic substances in natural waters: A review

2021 ◽  
Vol 401 ◽  
pp. 123884
Author(s):  
Yongxia Dong ◽  
Wenya Peng ◽  
Yunjiao Liu ◽  
Zhaohui Wang
Keyword(s):  
Natural Waters ◽  
Organic Substances ◽  
Reactive Radicals

scholarly journals The Reactions nd resistance of Fishes to Carbon Dioxide and Carbon Monoxide

1918 ◽  
Vol 11 (1-10) ◽  
pp. 557-571
Author(s):  
Morris Wells
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Fresh Water ◽  
Natural Waters ◽  
Aquatic Organisms ◽  
Toxic Action ◽  
Organic Substances ◽  
The Many

Carbon monoxide and carbon dioxide are both present in the waste that is diverted into natural waters by many works where illuminating gas is manufactured and, since the waste as a whole is known to be exceedingly poisonous to aquatic organisms, the role played in its toxic action by the two gases in question was investigated at the time that the many other organic substances of which the waste is composed were studied by Shelford. The investigation has shown that both of the gases are poisonous to fresh-water fishes even when present in the water in relatively small proportions, but the monoxide has been found to be by far the more deadly of the two.

scholarly journals Investigation of factors of the appearance of odor in river water at the water intake of Rostov-On-Don

2021 ◽  
Vol 937 (2) ◽  
pp. 022060
Author(s):  
Denis Butko ◽  
Yana Lazareva ◽  
Marina Sharkova
Keyword(s):  
River Water ◽  
Natural Waters ◽  
Supply System ◽  
Organic Substances ◽  
Water Treatment Plants ◽  
Reagent Treatment ◽  
Don River ◽  
Carbonated Water ◽  
Altered Form

Abstract The paper presents a study of quality of natural waters and water in a centralized water supply system during the period of an increase in the “Smell” indicator in the spring of 2021. The chemical and physical properties of water, the results of quality and quantity of studying the variety I phytoplankton in the most difficult period of deterioration in quality of river water. Low water and exceeding MPC concentrations of organic substances in river water. The Don River causes altered form odorant substance as evidenced by the results of determination in water 1,2,3- t rihlorbenzol and geosmin, hexachloroethane and aniline shown in operation. Barrier function of reagent treatment methods used at water treatment plants in the lower reaches of the river. The Don River, even when combined with carbonated water, is deficient in odor-producing substances.

Interaction of ions of heavy metals and organic toxicants with humic substances in system ‘atmospheric precipitation - lysimetric waters - lake waters’ of the Reserve of the European Territory of Russia: climatic, technogenic, geochemical fact

2021 ◽  
Author(s):  
Marina Dinu
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Humic Substances ◽  
Natural Waters ◽  
Atmospheric Precipitation ◽  
Organic Substances ◽  
Alkaline Lake ◽  
Autochthonous Organic Matter ◽  
Lake Waters ◽  
Lysimetric Waters

<p>The reactions of toxicants with organic substances of a humic nature are complex and depend on many geochemical factors. Differences in the mechanisms of the selected toxicants binding with organic natural substances of various natural waters - atmospheric precipitation, lake waters (acidic and alkaline), lysimetric waters are especially interesting. Due to significant concentration differences, features of functional groups and size distribution of components, the inactivation features of humic substances are selective and highly variable. We studied the waters of an acid lake near the city of Valday (Valday National Park, conditionally a background lake) and alkaline lake Valday (city of Valday, local technogenic influence). Near each lake there was a sediment collector (a container for collecting atmospheric precipitation) and a lysimeter (a container under the soil for collecting soil moisture) under the humus horizon (about 20 cm). Particular attention was paid to soil (lysimetric) waters with varying degrees of anthropogenic impact. We considered the behavior of a large group of heavy metals, as well as benzopyrene. To assess the composition and qualitative features of organic substances, gas chromatography-mass spectrometric methods of analysis were used. Chromatographic methods were used to assess the molecular weight distribution of the components. Possible reaction mechanisms were studied by IR spectral methods. Evaluation of the reactivity of organic substances was carried out by the methods of dynamic light scattering (zeta potential, MM, size) using the "Zeta-sizer nano". In addition to humic substances in the waters, the contents of autochthonous organic matter were estimated, especially in an alkaline lake, which in some periods prevailed over humic ones. In addition to humic substances in the waters, the contents of autochthonous organic matter were estimated, especially in an alkaline lake, which in some periods prevailed over humic ones. For separation, exchange technique and fluorometric evaluations were used. We conducted research in the period 2015-2020, sampling was carried out in spring, summer, autumn. Thus, we studied the circulation (in miniature) of changes in the protective properties of humic substances, depending on a large number of factors.</p>

scholarly journals Formation of organic deposits on low-preassure reverse osmotic membranes in treating water from surface sources

Vestnik MGSU ◽  
2019 ◽  
pp. 1180-1195
Author(s):  
Yu Dan Su ◽  
Alexei G. Pervov ◽  
Xuan Quyet Nguyen
Keyword(s):  
Reverse Osmosis ◽  
Organic Pollutants ◽  
Natural Waters ◽  
Tap Water ◽  
Total Carbon ◽  
Gas Liquid Chromatography ◽  
Organic Substances ◽  
Pre Treatment ◽  
Carbon Determination ◽  
Organic Deposits

Introduction. In this paper, we investigate the interaction of organic pollutants with nanofiltration and reverse osmosis membranes in natural water on the basis of experimental data and available literature information. The rates of formation of various organic deposits (humic acids changing the water colour and forming low-molecular organic compounds characterised by an oxidation index) on membranes during purifying river and pre-treated water are presented. Aim: To determine the required efficiency of removing organic substances from surface waters at the pre-treatment stage prior to water treatment by reverse osmosis on the basis of measuring the rates of adsorption of organic substances on membranes and predicting the amount of as-formed organic deposits. Methods and materials. Methods for determining the adsorption rate of organic pollutants using gas-liquid chromatography and total carbon determination are described. The advantages of spectrogram analysis in assessing water quality are specified. The formation rates of high- and low-molecular organic substances, which produce colouring and characterise water oxidisability, respectively, were determined using a membrane test unit. Results. According to the rates of forming organic deposits on membranes both during the processing of river water with a colour of 60 PCU and purified (tap) water with a colour of 18 PCU, organic substances adsorbed on membranes are shown to have little effect on the efficiency of the reverse osmosis process. In addition, the rate of depositing organic substances on the membranes under study is established to be significantly lower than that using sparingly soluble salts (calcium carbonate). Conclusion. Our results demonstrate that organic deposits formed on the membranes under study have an insignificant effect on the membrane performance. Therefore, pre-treatment aimed at removing organic substances when purifying natural waters with colour indices of up to 60 PCU is not required.

Impact potentiel du flottage du bois sur le milieu aquatique

1981 ◽  
Vol 57 (1) ◽  
pp. 22-29
Author(s):  
S. A. Visser ◽  
P. Couture
Keyword(s):  
Aquatic Environment ◽  
Natural Waters ◽  
Organic Substances ◽  
Laboratory Studies ◽  
Quality Factors ◽  
Low Oxygen ◽  
Fish Eggs ◽  
Lethal Effects ◽  
Du Bois ◽  
Toxic Organic Substances

Some aspects are discussed of the consequences of logging operations on natural waters. The release into the aquatic environment of certain types of organic substances from logs can result in an increase in the colour and odour of the water. It appears that bark in particular is responsible for the deterioration of the water quality. Factors such as age and species of the tree and the environmental conditions of the water do mainly determine the nature and effectiveness of the microbial degradation of the tree trunk. Different constituents such as simple sugars, polysaccharides, cellulose, hemicellulose, pectins, lignins, amino acids, peptides, proteins, fatty and other organic acids, as well as phenols can, each to a different degree, be degraded by various types of microbes, in particular by fungi. Substances liberated from the bark and the wood, as well as their products of degradation could exert a stress on several types of organisms in the aquatic environment. Although no specific case of acute toxicity has as yet been reported, some laboratory studies have indicated sub-lethal effects involving fish (blockage of their respiratory system), fish eggs (reduction in the number of hatchings) and algae (reduction in growth rate). In certain instances these effects could be ascribed either to the presence of toxic organic substances or to low oxygen levels.

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