scholarly journals Nanocellulose-Based Materials for Water Treatment: Adsorption, Photocatalytic Degradation, Disinfection, Antifouling, and Nanofiltration

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3008
Author(s):  
Ahmed Salama ◽  
Ragab Abouzeid ◽  
Wei Sun Leong ◽  
Jaison Jeevanandam ◽  
Pieter Samyn ◽  
...  
Keyword(s):  
Water Treatment ◽  
Surface Chemistry ◽  
Photocatalytic Degradation ◽  
Organic Dyes ◽  
Synthesis Methods ◽  
Nano Materials ◽  
Produce Water ◽  
Treatment Processes ◽  
Effective Removal ◽  
Wastewater Pollutants

Nanocelluloses are promising bio-nano-materials for use as water treatment materials in environmental protection and remediation. Over the past decades, they have been integrated via novel nanoengineering approaches for water treatment processes. This review aims at giving an overview of nanocellulose requirements concerning emerging nanotechnologies of waster treatments and purification, i.e., adsorption, absorption, flocculation, photocatalytic degradation, disinfection, antifouling, ultrafiltration, nanofiltration, and reverse osmosis. Firstly, the nanocellulose synthesis methods (mechanical, physical, chemical, and biological), unique properties (sizes, geometries, and surface chemistry) were presented and their use for capturing and removal of wastewater pollutants was explained. Secondly, different chemical modification approaches surface functionalization (with functional groups, polymers, and nanoparticles) for enhancing the surface chemistry of the nanocellulose for enabling the effective removal of specific pollutants (suspended particles, microorganisms, hazardous metals ions, organic dyes, drugs, pesticides fertilizers, and oils) were highlighted. Thirdly, new fabrication approaches (solution casting, thermal treatment, electrospinning, 3D printing) that integrated nanocelluloses (spherical nanoparticles, nanowhiskers, nanofibers) to produce water treatment materials (individual composite nanoparticles, hydrogels, aerogels, sponges, membranes, and nanopapers) were covered. Finally, the major challenges and future perspectives concerning the applications of nanocellulose based materials in water treatment and purification were highlighted.

Rapid photocatalytic degradation of cationic organic dyes using Li-doped Ni/NiO nanocomposites and their electrochemical performance

2021 ◽  
Author(s):  
R. Ranjitha ◽  
K. N. Meghana ◽  
V. G. Dileep Kumar ◽  
Aarti S. Bhatt ◽  
B. K. Jayanna ◽  
...  
Keyword(s):  
Energy Storage ◽  
Water Treatment ◽  
Electrochemical Performance ◽  
Photocatalytic Degradation ◽  
Organic Dyes

This work reports novel bi-functional Li-doped Ni/NiO nanocomposites as potential candidates for energy storage and water treatment applications.

Tuning the enhanced coagulation process to obtain best chlorine and THM profiles in the distribution system

2004 ◽  
Vol 4 (4) ◽  
pp. 235-243 ◽  
Author(s):  
I. Fisher ◽  
G. Kastl ◽  
A. Sathasivan ◽  
P. Chen ◽  
J. van Leeuwen ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Distribution System ◽  
Substantial Reduction ◽  
Produce Water ◽  
Enhanced Coagulation ◽  
System A ◽  
Treatment Processes ◽  
The Impact

Water treatment processes produce water with low turbidity and colour. It is also now becoming necessary to reduce DOC (Dissolved Organic Carbon) so that less chlorine is lost in a distribution system and less THMs (trihalomethanes) are formed. Enhanced coagulation (exceeding other requirements) at pH of about 5-6 is known to significantly reduce DOC so that acceptable water quality can be achieved at the tap. In this paper, models are integrated to project the impact of water treatment on water quality through the entire distribution system. A DOC removal model, which predicts DOC resulting from a given coagulant, its dose and the coagulation pH, is used to simulate the treatment. By linking this model of DOC removal with models of chlorine decay and THM formation, the impact of treatment on chlorine and THM concentrations in a distribution system can be simulated. This method was applied in a case study with relatively high initial DOC. It was shown that more DOC can be removed by using ferric coagulant than the current practice achieves. This would result in an improved chlorine profile and a substantial reduction in THM concentrations.

Role of Nanocatalyst (photocatalysts) for waste water treatment

2020 ◽  
Vol 16 ◽  
Author(s):  
Muhammad Sagir ◽  
Muhammad Bilal Tahir
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Waste Water Treatment ◽  
Nano Materials ◽  
Nano Technology ◽  
Treatment Processes ◽  
Photo Catalysis ◽  
Carbon Nano Tubes ◽  
Large Research

Background: The aim of current study is to understand the application of Nano-technology in the field of water and waste water treatment processes due to increasing scarcity of water as time goes on.The knowledge about the effect of various photo catalysts on the treatment of waste water is also compiled here. Introduction: In recent years, many researches have been working on the projects for the removal of organic & inorganic pollutants from water using photo catalysts which provide more efficient, economical and as well as pollution free processes to some extent. Nanomaterials are found in large research categories and are used in variety of applications. Method: Photo catalysis using Iron, Zinc, Silver, Metal oxides, SnO2, Carbon Nano-tubes, Nano composites & Membranes are focused in this paper. Result: Discussion regarding various parameters as well as future aspects of nanoparticles on waste water treatment are highlighted. Impacts of nanoparticles on health is also incorporated here. Conclusion: Considering the current speed of development and revolution in tech, Nano materials for this type of applications seems very promising.

Synthesis and characterization of vanadium-doped Mo(O,S)2 oxysulfide for efficient photocatalytic degradation of organic dyes

2020 ◽  
Vol 44 (45) ◽  
pp. 19868-19879
Author(s):  
Sleshi Fentie Tadesse ◽  
Dong-Hau Kuo ◽  
Worku Lakew Kebede ◽  
Lalisa Wakjira Duresa
Keyword(s):  
Low Temperature ◽  
Photocatalytic Degradation ◽  
Organic Dyes ◽  
Low Cost ◽  
Synthesis And Characterization ◽  
Synthesis Methods ◽  
Degradation Of Dyes

We developed simple and low cost synthesis methods at low temperature to synthesize V-doped Mo(O,S)2 for the photocatalytic degradation of dyes.

scholarly journals New water treatment technology - homogeneous membrane electrodialysis

2019 ◽  
Vol 79 ◽  
pp. 03003
Author(s):  
Guorui Tang ◽  
Kuan He ◽  
Deqing Liu
Keyword(s):  
Water Treatment ◽  
Ion Exchange ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Treatment Technology ◽  
Ion Exchange Capacity ◽  
Treatment Processes ◽  
Effective Removal ◽  
Physical And Chemical ◽  
Exchange Membrane

This paper introduces the structure and technical principle of the homogeneous membrane electrodialyzer, and describes that the homogeneous ion exchange membrane has excellent ion exchange capacity, low water loss rate, stable physical and chemical properties and effective removal of organic matter. The homogeneous membrane electrodialysis technology should be combined with other water treatment processes in practice to achieve better treatment results.

Water Treatment Considerations–Aquatic Humus

1983 ◽  
Vol 15 (S2) ◽  
pp. 95-101 ◽  
Author(s):  
E T Gjessing
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Health Effects ◽  
Surface Waters ◽  
Cold Climate ◽  
Treatment Processes ◽  
Aquatic Humus ◽  
Treatment Considerations

For several reasons the surface waters in cold climate areas are coloured due to humic substances. There are two major objections against humus in drinking water, the first is concerned with aesthetical and practical problems and the second is due to indirect negative health effects. There are essentially three different methods in use today for the removal or reduction of humus colour in water: (1) Addition of chemicals with the intention of reducing the “solubility”, (2) Addition of chemicals in order to bleach or mineralize the humus, and (3) Filtration with the intention of removal of coloured particles and some of the “soluble” colour. The treatment processes are discussed.

Practical Guide to Determine the Impact of Radon and Other Radionuclides on Water Treatment Processes

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1255-1264
Author(s):  
K. L. Martins
Keyword(s):  
Activated Carbon ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Packed Tower ◽  
Treatment Processes ◽  
Radioactivity Exposure ◽  
The Impact ◽  
Percent Removal

During treatment of groundwater, radon is often coincidentally removed by processes typically used to remove volatile organic compounds (VOCs)-for example, processes such as liquid-phase granular activated carbon (LGAC) adsorption and air stripping with vapor-phase carbon (VGAC). The removal of radon from drinking water is a positive benefit for the water user; however, the accumulation of radon on activated carbon may cause radiologic hazards for the water treatment plant operators and the spent carbon may be considered a low-level radioactive waste. To date, most literature on radon removal by water treatment processes was based on bench- or residential-scale systems. This paper addresses the impact of radon on municipal and industrial-scale applications. Available data have been used todevelop graphical methods of estimating the radioactivity exposure rates to facility operators and determine the fate of spent carbon. This paper will allow the reader to determine the potential for impact of radon on the system design and operation as follows.Estimate the percent removal of radon from water by LGAC adsorbers and packed tower air strippers. Also, a method to estimate the percent removal of radon by VGAC used for air stripper off-gas will be provided.Estimate if your local radon levels are such that the safety guidelines, suggested by USEPA (United States Environmental Protection Agency), of 25 mR/yr (0.1 mR/day) for radioactivity exposure may or may not be exceeded.Estimate the disposal requirements of the waste carbon for LGAC systems and VGAC for air stripper “Off-Gas” systems. Options for dealing with high radon levels are presented.

Removal of sulphite-reducing clostridia spores by full-scale water treatment processes as a surrogate for protozoan (oo)cysts removal

2000 ◽  
Vol 41 (7) ◽  
pp. 165-171 ◽  
Author(s):  
W. A. Hijnen ◽  
J. Willemsen-Zwaagstra ◽  
P. Hiemstra ◽  
G. J. Medema ◽  
D. van der Kooij
Keyword(s):  
Water Treatment ◽  
Removal Efficiency ◽  
Water Quality Monitoring ◽  
Full Scale ◽  
Process Conditions ◽  
Safe Drinking Water ◽  
Unit Process ◽  
Treatment Processes ◽  
Scale Unit ◽  
Micro Organisms

At eight full-scale water treatment plants in the Netherlands the removal of spores of sulphite-reducing clostridia (SSRC) was determined. By sampling and processing large volumes of water (1 up to 500 litres) SSRC were detected after each stage of the treatment. This enabled the assessment of the removal efficiency of the full-scale unit processes for persistent micro-organisms. A comparison with literature data on the removal of Cryptosporidium and Giardia by the same type of processes revealed that SSRC can be considered as a potential surrogate. The average Decimal Elimination Capacity (DEC) of the overall treatment plants ranged from 1.3–4.3 log. The observed actual log removal of SSRC by the unit processes and the overall treatment at one of the studied locations showed that the level of variation in removal efficiency was approximately 2 log. Moreover, from the actual log removal values it was observed that a low SSRC removal by one unit process is partly compensated by a higher removal by subsequent unit processes at this location. SSRC can be used for identification of the process conditions that cause variation in micro-organism removal which may lead to process optimization. Further research is necessary to determine the optimal use of SSRC in water quality monitoring for the production of microbiologically safe drinking water.

scholarly journals Recent Achievements in Development of TiO2-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1338 ◽  
Author(s):  
Klara Perović ◽  
Francis M. dela Rosa ◽  
Marin Kovačić ◽  
Hrvoje Kušić ◽  
Urška Lavrenčič Štangar ◽  
...  
Keyword(s):  
Water Treatment ◽  
Transition Metal ◽  
Photocatalytic Degradation ◽  
Water Splitting ◽  
Water Purification ◽  
Degradation Mechanism ◽  
Living Environment ◽  
Solar Irradiation ◽  
Metal Chalcogenides ◽  
Photocatalytic Water Splitting

Clean water and the increased use of renewable energy are considered to be two of the main goals in the effort to achieve a sustainable living environment. The fulfillment of these goals may include the use of solar-driven photocatalytic processes that are found to be quite effective in water purification, as well as hydrogen generation. H2 production by water splitting and photocatalytic degradation of organic pollutants in water both rely on the formation of electron/hole (e−/h+) pairs at a semiconducting material upon its excitation by light with sufficient photon energy. Most of the photocatalytic studies involve the use of TiO2 and well-suited model compounds, either as sacrificial agents or pollutants. However, the wider application of this technology requires the harvesting of a broader spectrum of solar irradiation and the suppression of the recombination of photogenerated charge carriers. These limitations can be overcome by the use of different strategies, among which the focus is put on the creation of heterojunctions with another narrow bandgap semiconductor, which can provide high response in the visible light region. In this review paper, we report the most recent advances in the application of TiO2 based heterojunction (semiconductor-semiconductor) composites for photocatalytic water treatment and water splitting. This review article is subdivided into two major parts, namely Photocatalytic water treatment and Photocatalytic water splitting, to give a thorough examination of all achieved progress. The first part provides an overview on photocatalytic degradation mechanism principles, followed by the most recent applications for photocatalytic degradation and mineralization of contaminants of emerging concern (CEC), such as pharmaceuticals and pesticides with a critical insight into removal mechanism, while the second part focuses on fabrication of TiO2-based heterojunctions with carbon-based materials, transition metal oxides, transition metal chalcogenides, and multiple composites that were made of three or more semiconductor materials for photocatalytic water splitting.

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