Purification of Water by Ferrites - Mini Review

Solar photocatalysis as a potential green technology for the removal of traces of the dye pollutant Indigo carmine (IC) from water is investigated using ZnO as the catalyst. Degradation/decolorization alone does not result in complete decontamination as seen from the significant Chemical Oxygen Demand (COD) of water even after the parent compound has disappeared completely. The degradation proceeds through many intermediates which also get mineralized eventually but slowly. Oxalic acid is identified as a stable slow mineralizing degradation product which itself is formed from other transient intermediates. Effect of various parameters such as catalyst dosage, concentration of the dye, pH, temperature, presence of contaminant salts etc. on the degradation is investigated and quantified. Oxidants such as S2O82- and H2O2 have only moderate influence on the degradation. The degradation follows variable kinetics depending on the concentration of the substrate. The reaction proceeds very slowly in the absence of O2 indicating the importance of reactive oxygen species and hydroxyl free radicals in photocatalysis. H2O2 formed insitu in the system undergoes concurrent decomposition resulting in stabilization in its concentration. The study demonstrates that solar photocatalysis can be used as a viable tool for the purification of water contaminated with traces of IC.

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Purification of water from dissolved gases in a film unit with discrete-rough walls

Safety and Reliability of Power Industry ◽

10.24223/1999-5555-2018-11-1-48-53 ◽

2018 ◽

Vol 11 (1) ◽

pp. 48-53

Author(s):

E. A. Lapteva ◽

G. K. Shagieva ◽

A. G. Laptev

Keyword(s):

Dissolved Gases ◽

Rough Walls ◽

Purification Of Water

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Purification of water contaminated with heavy metals by example of lead as promising material based on graphene nanostructures

Perspektivnye Materialy ◽

10.30791/1028-978x-2020-9-34-43 ◽

2020 ◽

pp. 34-43

Author(s):

N. R. Memetov ◽

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A. V. Gerasimova ◽

A. E. Kucherova ◽

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...

Keyword(s):

Adsorption Process ◽

Phenol Formaldehyde ◽

Phenol Formaldehyde Resin ◽

Formaldehyde Resin ◽

Parameter Estimates ◽

Maximum Adsorption Capacity ◽

Ecological Situation ◽

Characteristic Parameters ◽

Purification Of Water ◽

Graphene Nanostructures

The paper evaluates the effectiveness of the use of graphene nanostructures in the purification of lead (II) ions to improve the ecological situation of water bodies. The mechanisms and characteristic parameters of the adsorption process were analyzed using empirical models of isotherms at temperatures of 298, 303, 313 and 323 K, which correspond to the following order (based on the correlation coefficient): Langmuir (0.99) > Temkin (0.97) > Dubinin – Radushkevich (0.90). The maximum adsorption capacity of the material corresponds to the range from 230 to 260 mg/g. We research the equilibrium at the level of thermodynamic parameter estimates, which indicates the spontaneity of the process, the endothermic nature and structure change of graphene modified with phenol-formaldehyde resin during the adsorption of lead (II) ions, leading to an increase in the disorder of the system.

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THE INTEGRAL SIGNIFICANCE OF FRESHWATER MOLLUSKS IN THE SELF-PURIFICATION OF WATER IN THE VOLGA DELTA

NATURAL SCIENCES ◽

10.21672/1818-507x-2016-55-2-027-032 ◽

2016 ◽

Vol 55 (2) ◽

pp. 027-032

Author(s):

Yulia N. Shaplygina ◽

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Tatyana F. Kurochkina ◽

Botagoz M. Nasibulina ◽

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...

Keyword(s):

The Self ◽

Volga Delta ◽

Freshwater Mollusks ◽

Purification Of Water

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Superhydrophobic Sands for the Preservation and Purification of Water

Coatings ◽

10.3390/coatings11020151 ◽

2021 ◽

Vol 11 (2) ◽

pp. 151

Author(s):

Yuyang Liu ◽

Chang-Hwan Choi

Keyword(s):

Water Surface ◽

Particulate Material ◽

Self Assembled Monolayer ◽

Hydrophobic Coatings ◽

Hydrophobic Coating ◽

Evaporation Loss ◽

Zno Nanocrystals ◽

Sand Particles ◽

Purification Of Water ◽

Nanoscale Roughness

Sand, a cheap and naturally abundant particulate material, was modified with photocatalytic and hydrophobic coatings to reduce evaporation loss and facilitate the purification of water. The first-level photocatalytic coatings (TiO2 or ZnO nanocrystals) rendered nanoscale roughness on the surface of the sand. The additional second-level hydrophobic coating of a self-assembled monolayer of octyltrimethoxysilane (OTS) made the sand particles superhydrophobic because of the nanoscale roughness imposed by the nanocrystals. The superhydrophobic sand particles, floating on the free surface of water due to their superhydrophobicity, significantly reduced the evaporation loss of water by 60%–90% in comparison to an uncovered water surface. When the outer hydrophobic coatings are weathered or disengaged, the inner photocatalytic coatings become exposed to water. Then, the sand particles act as photocatalysts to degrade the contaminants in water under solar radiation.

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Recent Progress in the Membrane Distillation and Impact of Track-Etched Membranes

Polymers ◽

10.3390/polym13152520 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2520

Author(s):

Arman B. Yeszhanov ◽

Ilya V. Korolkov ◽

Saule S. Dosmagambetova ◽

Maxim V. Zdorovets ◽

Olgun Güven

Keyword(s):

Water Purification ◽

Vinylidene Fluoride ◽

Liquid Radioactive Waste ◽

Theoretical Models ◽

Membrane Distillation ◽

Narrow Pore Size Distribution ◽

Poly Ethylene Terephthalate ◽

Poly Vinylidene Fluoride ◽

Poly Ethylene ◽

Purification Of Water

Membrane distillation (MD) is a rapidly developing field of research and finds applications in desalination of water, purification from nonvolatile substances, and concentration of various solutions. This review presents data from recent studies on the MD process, MD configuration, the type of membranes and membrane hydrophobization. Particular importance has been placed on the methods of hydrophobization and the use of track-etched membranes (TeMs) in the MD process. Hydrophobic TeMs based on poly(ethylene terephthalate) (PET), poly(vinylidene fluoride) (PVDF) and polycarbonate (PC) have been applied in the purification of water from salts and pesticides, as well as in the concentration of low-level liquid radioactive waste (LLLRW). Such membranes are characterized by a narrow pore size distribution, precise values of the number of pores per unit area and narrow thickness. These properties of membranes allow them to be used for more accurate water purification and as model membranes used to test theoretical models (for instance LEP prediction).

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