scholarly journals Cu2O as an emerging semiconductor in photocatalytic and photoelectrocatalytic treatment of water contaminated with organic substances: a review

RSC Advances ◽  
2020 ◽  
Vol 10 (60) ◽  
pp. 36514-36525
Author(s):  
Babatunde A. Koiki ◽  
Omotayo A. Arotiba
Keyword(s):  
Water Treatment ◽  
Organic Substances ◽  
Wide Range ◽  
Toxic Organic Substances

A wide range of semiconductor photocatalysts have been used over the years in water treatment to eliminate toxic organic substances from wastewater.

Stirring and aeration system for the upgrading of small waste water treatment plants

1994 ◽  
Vol 29 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Marcus Höfken ◽  
Katharina Zähringer ◽  
Franz Bischof
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Large Scale ◽  
Waste Water Treatment ◽  
Water Treatment Plants ◽  
Waste Water Treatment Plants ◽  
Basic Fluid ◽  
Aeration System ◽  
Technical Realization ◽  
Wide Range

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications. This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

scholarly journals A Perspective on the Application of Covalent Organic Frameworks for Detection and Water Treatment

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1651
Author(s):  
Cristina Arqueros ◽  
Félix Zamora ◽  
Carmen Montoro
Keyword(s):  
Water Treatment ◽  
Resource Scarcity ◽  
Covalent Organic Frameworks ◽  
Design Strategies ◽  
Free Standing ◽  
Water And Wastewater Treatment ◽  
Design And Synthesis ◽  
Water Detection ◽  
Wide Range ◽  
Quality Water

Global population growth and water resource scarcity are significant social problems currently being studied by many researchers focusing on finding new materials for water treatment. The aim is to obtain quality water suitable for drinking and industrial consumption. In this sense, an emergent class of crystalline porous materials known as Covalent-Organic Frameworks (COFs) offers a wide range of possibilities since their structures can be designed on demand for specific applications. Indeed, in the last decade, many efforts have been made for their use in water treatment. This perspective article aims to overview the state-of-the-art COFs collecting the most recent results in the field for water detection of pollutants and water treatment. After the introduction, where we overview the classical design strategies on COF design and synthesis for obtaining chemically stable COFs, we summarize the different experimental methodologies used for COFs processing in the form of supported and free-standing membranes and colloids. Finally, we describe the use of COFs in processes involving the detection of pollutants in water and wastewater treatment, such as the capture of organic compounds, heavy metals, and dyes, the degradation of organic pollutants, as well as in desalination processes. Finally, we provide a perspective on the field and the potential technological use of these novel materials.

The Forming of Model Colloid System

2014 ◽  
Vol 971-973 ◽  
pp. 266-269 ◽  
Author(s):  
Denis A. Voyno ◽  
Ksenia I. Machekhina ◽  
Ludmila N. Shiyan
Keyword(s):  
Water Treatment ◽  
Zeta Potential ◽  
Electrostatic Interaction ◽  
Organic Substance ◽  
Test System ◽  
Molar Ratio ◽  
Organic Substances ◽  
Mechanism Of Formation ◽  
Iron Silicon ◽  
Colloid System

The paper reports on the creation of a model colloid test system which is similar to groundwater and it can be used as a test system in the water treatment. It is found that at the molar ratio iron/silicon/organic substance is equal to1/7/2 and two orders such as organic substances-Si-Fe and Si-organic substances-Fe, stable colloid system is formed. The mechanism of formation of iron colloid system is described by three steps. The first is the formation of the organosilicon complexes. The second is oxidation of the iron and forming of Fe (OH)3. The last is forming a sol at zeta potential is - 35 mV with electrostatic interaction.

scholarly journals Removing Iron and Organic Substances from Water over the Course of Its Treatment with the Application of Average and Highly Alkaline Polyaluminium Chlorides

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1367
Author(s):  
Izabela Krupińska
Keyword(s):  
Water Treatment ◽  
Human Consumption ◽  
Iron Ions ◽  
Organic Substances ◽  
Iron Compounds ◽  
Polyaluminum Chloride ◽  
Coagulation Process ◽  
Lack Of Information ◽  
Organic Complexes ◽  
Polyaluminium Chloride

In topic-related literature pertaining to the treatment of water, there is a lack of information on the influence of iron ions in highly basic polyaluminum chlorides on the efficiency of purifying water with increased contents of organic substance. The aim of this work was to determine the changes in the content of organic substances as well as iron compounds in water intended for human consumption following unit treatment processes with particular attention paid to the coagulation process. As coagulants, polyaluminium chloride PAXXL10 with an alkalinity of 70%, as well as polyaluminium chloride PAXXL1911 with an alkalinity of 85% the composition of which also contained iron, were tested. The analysis of the obtained results showed that iron compounds and organic substances were removed to the greatest extent by the coagulation process, which also had a significant influence on the final efficiency of water treatment. The effectiveness of water treatment was determined by the type of tested polyaluminum chloride, which influenced the formation of iron-organic complexes. The reason behind the formation of colored iron-organic complexes during coagulation using PAXXL1911 coagulant was the high pH (approx. 8), at which the functional groups of organic substances, due to their dissociation, are more reactive in relation to iron, and possibly the fact of introducing additional iron ions along with the coagulant.

Occurrence of pathogenic microorganisms in the Saint Lawrence River (Canada) and comparison of health risks for populations using it as their source of drinking water

2000 ◽  
Vol 46 (6) ◽  
pp. 565-576 ◽  
Author(s):  
Pierre Payment ◽  
Aminata Berte ◽  
Michèle Prévost ◽  
Bruno Ménard ◽  
Benoît Barbeau
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Fecal Coliforms ◽  
Giardia Infection ◽  
Bacterial Indicators ◽  
Treatment Practices ◽  
Water Treatment Plants ◽  
Wide Range ◽  
Annual Risk

A 300-km portion of the Saint Lawrence hydrological basin in the province of Québec (Canada) and 45 water treatment plants were studied. River water used by drinking water treatment plants was analyzed (6-L sample volumes) to determine the level of occurrence of bacterial indicators (total coliforms, fecal coliforms, and Clostridium perfringens) and pathogens (Giardia lamblia, Cryptosporidium, human enteric viruses). Pathogens and bacterial indicators were found at all sites at a wide range of values. Logistic regression analysis revealed significant correlations between the bacterial indicators and the pathogens. Physicochemical and treatment practices data were collected from most water treatment plants and used to estimate the level of removal of pathogens achieved under cold (0°C-4°C) and warm (20°C-25°C) water temperature conditions. The calculated removal values were then used to estimate the annual risk of Giardia infection using mathematical models and to compare the sites. The estimated range of probability of infection ranged from 0.75 to less than 0.0001 for the populations exposed. Given the numerous assumptions made, the model probably overestimated the annual risk, but it provided comparative data of the efficacy of the water treatment plants and thereby contributes to the protection of public health.Key words: public health, drinking water, health risk, pathogen occurrence.

scholarly journals The Means to Improve Water Treatment and to Enhance Power Engineering Performance of the Water Source Heat Pump

2018 ◽  
Vol 61 (4) ◽  
pp. 372-380 ◽  
Author(s):  
L. R. Junussova ◽  
S. K. Abildinova ◽  
M. B. Aliyarova ◽  
S. V. Chicherin ◽  
T. Ja. Junussov
Keyword(s):  
Water Treatment ◽  
Heat Pump ◽  
Natural Water ◽  
Alternating Current ◽  
Power Engineering ◽  
Current Frequency ◽  
Heat Pump Unit ◽  
Wide Range ◽  
Compressor Performance

The subject matter of the paper is related to scientific-and-theoretical basis of power engineering characteristics of heat pump directly depending on the quality of treated water for reliable and uninterrupted operation of heat pump evaporator and compressor. On the basis of experimental data, energy parameters of the heat pump are calculated. The method of the combined technology of the heat pump “water – air” operation is considеred, the efficiency of which is based on the preliminary improvement of the quality of water softened with the use of a membrane ultrafiltration unit. This solution made it possible to reduce the load on the filters and to exclude the use of chemical reagents used in the classical schemes of water heating facilities. In order to improve the operation of the heat pump compressor, a method based on altering the speed of rotation of the shaft by means of electronic microprocessor devices has been proposed. To regulate the compressor performance, a frequency converter with a wide range of alternating current frequency is used. The intervals of alteration of frequency of the alternating current corresponding to energy-efficient values of coefficient of transformation of energy of the heat pump are investigated. The values of the energy conversion coefficient of the heat pump obtained in the course of experiments and determined by calculation are consistent within the experimental errors with the regulation of the compressor performance. The suggested experimental device made it possible to determine the dependence of the main characteristics of the unit of the heat pump unit on the number of revolutions of the compressor and to find out an effective range of its control (50–180 %). The development of advanced technologies for natural water treatment under conditions of increased anthropogenic loads on natural water sources is a priority one among the fundamental and applied research in the field of water treatment.

Action of Organic Accelerators in Buna-S

1943 ◽  
Vol 16 (1) ◽  
pp. 184-202
Author(s):  
George R. Vila
Keyword(s):  
Natural Rubber ◽  
Fundamental Importance ◽  
Careful Study ◽  
Organic Substances ◽  
Unsaturated Polymer ◽  
Indefinite Number ◽  
Wide Range ◽  
Present Emergency

Abstract Buna-S is an unsaturated polymer capable of undergoing vulcanization. This may be effected by the application of heat in the presence of sulfur. The process is accelerated by certain organic substances which are used widely for a similar purpose in natural rubber. Preliminary teats have indicated that most of them are applicable to Buna-S, and appear superior to any other chemicals yet investigated. This is fortunate in view of the present emergency, as plants for their manufacture already exist and the industry is familiar with their use. In spite of superficially similar effects, more careful study has indicated that it is an oversimplification to assume various accelerators will produce ideptical effects in both polymers. A wide range of materials is now available to the industry, and the task of accurately evaluating all of them is complex. In addition, an indefinite number of combinations are theoretically possible. The present investigation was undertaken to determine what effect different chemical types of organic accelerators were likely to have on properties of fundamental importance.

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