Deep purification of As(V) in drinking water by silica gel loaded with FeOOH and MnO2

2021 ◽  
Vol 28 (6) ◽  
pp. 1692-1706
Author(s):  
Tong-shan Shi ◽  
Feng Jiang ◽  
Pan Wang ◽  
Tong Yue ◽  
Wei Sun
Keyword(s):  
Drinking Water ◽  
Silica Gel ◽  
Deep Purification

scholarly journals Assessing efficiency of pre-ammonization aimed at reducing carcinogenic risks caused by trihalomethanes in drinking water

2020 ◽  
pp. 70-77
Author(s):  
L.A. Deryabkina ◽  
◽  
B.I. Marchenko ◽  
N.K. Plugotarenko ◽  
A.I. Yukhno ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Natural Water ◽  
Water Source ◽  
Water Disinfection ◽  
Residual Chlorine ◽  
Gas Liquid Chromatography ◽  
Initial Water ◽  
Organic Chlorine ◽  
Deep Purification

In most Russian regions there is still a pressing issue related to providing population with high quality and safe drinking water. Up to now, chlorination has been the primary technique applied to disinfect drinking water as it is highly efficient, reliable, and relatively cheap. However, when chlorine is used to disinfect natural water that contains organic pollutants, it results in risks of by-products occurrence. These products are trihalomethanes, epigenetic carcinogenesis promoters that cause elevated carcinogenic risks under oral, inhalation, and subcutaneous exposure. Our research goal was to hygienically assess efficiency of pre-ammonization applied in water treatment procedures in order to prevent occurrence of carcinogenic organic chlorine compounds during chlorination and to minimize carcinogenic risks. We determined trihalomethanes and residual chlorine contents in model samples of natural water taken from a surface water source after chlorination with different doses of chlorine. We examined 52 pair parallel samples that had undergone pre-ammonization with ammonia sulfate and control ones. Trihalomethanes concentrations were determined in model water samples with gas-liquid chromatography. Basing on the results obtained via experiments on laboratory chlorination of river water, we determined quantitative characteristics and built regression models showing dependence between concentrations of organic chlorine compounds occurring due to chlorination (chloroform, dichlorobrommethane, dibromchloromethane) and chlorine doses and preammonization parameters. It was established that pre-ammonization was the most efficient in terms of preventing trihalomethanes occurrence under such disinfection modes when contents of residual active chlorine didn’t exceed recommended levels (0.8–1.2 mg/L). Basic ways to minimize carcinogenic risks caused by trihalomethanes are systemic control over their contents in drinking water during social and hygienic monitoring procedures; preliminary ammonization of water taken from surface water sources; prevention of unjustified hyper-chlorination; preliminary deep purification of initial water; disinfection with ultrasound radiation instead of preliminary chlorination; etc.

scholarly journals Assessing efficiency of pre-ammonization aimed at reducing carcinogenic risks caused by trihalomethanes in drinking water

2020 ◽  
pp. 70-77
Author(s):  
L.A. Deryabkina ◽  
◽  
B.I. Marchenko ◽  
N.K. Plugotarenko ◽  
A.I. Yukhno ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Natural Water ◽  
Water Source ◽  
Water Disinfection ◽  
Residual Chlorine ◽  
Gas Liquid Chromatography ◽  
Initial Water ◽  
Organic Chlorine ◽  
Deep Purification

In most Russian regions there is still a pressing issue related to providing population with high quality and safe drinking water. Up to now, chlorination has been the primary technique applied to disinfect drinking water as it is highly efficient, reliable, and relatively cheap. However, when chlorine is used to disinfect natural water that contains organic pollutants, it results in risks of by-products occurrence. These products are trihalomethanes, epigenetic carcinogenesis promoters that cause elevated carcinogenic risks under oral, inhalation, and subcutaneous exposure. Our research goal was to hygienically assess efficiency of pre-ammonization applied in water treatment procedures in order to prevent occurrence of carcinogenic organic chlorine compounds during chlorination and to minimize carcinogenic risks. We determined trihalomethanes and residual chlorine contents in model samples of natural water taken from a surface water source after chlorination with different doses of chlorine. We examined 52 pair parallel samples that had undergone pre-ammonization with ammonia sulfate and control ones. Trihalomethanes concentrations were determined in model water samples with gas-liquid chromatography. Basing on the results obtained via experiments on laboratory chlorination of river water, we determined quantitative characteristics and built regression models showing dependence between concentrations of organic chlorine compounds occurring due to chlorination (chloroform, dichlorobrommethane, dibromchloromethane) and chlorine doses and preammonization parameters. It was established that pre-ammonization was the most efficient in terms of preventing trihalomethanes occurrence under such disinfection modes when contents of residual active chlorine didn’t exceed recommended levels (0.8–1.2 mg/L). Basic ways to minimize carcinogenic risks caused by trihalomethanes are systemic control over their contents in drinking water during social and hygienic monitoring procedures; preliminary ammonization of water taken from surface water sources; prevention of unjustified hyper-chlorination; preliminary deep purification of initial water; disinfection with ultrasound radiation instead of preliminary chlorination; etc.

scholarly journals SORPTION PRECONCENTRATION AND DETERMINATION OF ANTIMONY AND TELLURIUM ON MODIFIED SILICA GEL

2019 ◽  
pp. 14-18
Author(s):  
V. Vеrbа ◽  
O. Zaporozhets ◽  
I. Кucharenko ◽  
E. Кul'baka
Keyword(s):  
Drinking Water ◽  
Silica Gel ◽  
Maximum Concentration ◽  
Concentration Ratio ◽  
Test Methods ◽  
Anionic Complex ◽  
Visual Test ◽  
Sorption Equilibrium ◽  
Sorption Preconcentration

Antimony and its compounds are widely used in industry, making it one of the priority pollutants of air and the aquatic environment. Excess of antimony is selectively concentrated in a thyroid gland, a liver, a spleen. The manifestation of the toxic effect of antimony is a variety of impaired functions of the human body, so the content of this element in drinking water normalizes is at the level of 5 μg/l. Recently, tellurium has also been increasingly the subject of research by analyst chemists. Tellurium is a biologically active element and its concentrations in the environment are strictly regulated. According to sanitary rules and regulations, the maximum allowable concentration of tellurium in drinking water is 0.01 mg/l. The article is devoted to the elaboration of solid-phase reagents based on the quaternary ammonium salt (QAS) immobilized on silica gel and to the development on this basis of sorption-spectrometric and visual test-methods of the determination of Sb(III) and Te(IV). The mechanism of the interaction between QAS immobilized on silica gel and the anions iodide complex of antimony and tellurium was studied. It was found that it proceeds by the ion-associative mechanism. Conditions of sorption preconcentration of anionic complexes of elements were optimized. For the quantitative sorption of antimony (III), the weight of the sorbent is 0.020 g and the volume of the solution is 25.0 ml. Under these conditions, the anionic complex is sorbed by 98%. The maximum concentration ratio is 1.25 l/g. The sorption equilibrium in the system is established in 20 minutes. For the quantitative extraction of tellurium (IV), the optimal weight of the sorbent is 0.050 g and a solution volume of 25.0 ml. Under these conditions, the degree of sorption reaches about 80%. The maximum concentration ratio is 0.4 l/g. The sorption equilibrium in the system is established in 15 minutes. The influence of foreign ions on the extraction degree of the investigated elements, and also on the magnitude of analytical signal, was studied. Sorptionspectrometric and visual test-methods of the determination of Sb(III) and Te(IV) in pharmaceutical preparation "Antimonium tartaricum" and "Tellurium Metalicum".

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

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