scholarly journals Froth Production in Potable Water without Chemicals

2019 ◽  
Author(s):  
Ghanim Hassan ◽  
Robert G. J. Edyvean
Keyword(s):  
Drinking Water ◽  
Driving Force ◽  
Potable Water ◽  
Froth Flotation ◽  
Operating Parameters ◽  
Air Bubbles ◽  
Air Flow Rate ◽  
Pharmaceutical Industries ◽  
Solid Liquid ◽  
Solid Liquid Separation

Abstract. Froth flotation is a well-known solid-liquid separation technique. Hydrophobicity is the main driving force for such processes. Hydrophobic solids attach to air bubbles and rise up while hydrophilic or less hydrophobic species settle down. Froth can be produced with chemical frothers such as alcohols and polyglycols. However, the use of chemicals limits the use of this separation method in applications such as drinking water, food, and pharmaceutical industries. Therefore, developing a technique that produces froth without adding any chemicals would be useful to such industries. This work demonstrates that with suitable operating parameters a 27 cm froth height can be obtained in a 20 cm diameter column by using an air flow rate of 130 l/min.

scholarly journals The Ability of Froth Formed without Chemicals to Hold Bacteria

2019 ◽  
Author(s):  
Ghanim Hassan ◽  
Robert G. J. Edyvean
Keyword(s):  
Drinking Water ◽  
Froth Flotation ◽  
Operating Conditions ◽  
Optimum Conditions ◽  
Bacterial Concentration ◽  
Taste And Odor ◽  
Water Taste ◽  
The University ◽  
Solid Liquid ◽  
Solid Liquid Separation

Abstract. Froth flotation is a solid-liquid separation technique that uses hydrophobicity as a driving force. Bacteria and other drinking water microorganisms tend to be hydrophobic and can be removed from water using this application. The biggest limitation against using froth flotation in the drinking water industry is the difficulty of producing froth without chemical frothers and holding bacteria in this froth without chemical collectors which deteriorate water taste and odor. Recently, researchers at the University of Sheffield described a method for producing froth using only water and compressed air. This has enabled froth flotation to be studied as an alternative to biocides for the removal of bacteria from drinking water. This work examines the ability of froth, produced by controlling air pumping through a water column, to hold bacteria. Bacteria are moved to the top of the column and collected in the froth. The operating conditions determine the percentage of bacteria removed. At optimum conditions, froth can hold up to 2×108 cfu/ml of bacteria. It has been found that air pumping at 130 l/min in a 20 cm diameter column will give the highest froth bacterial content. Time to reach stable froth bacterial concentration is decreased by increasing other variables.

scholarly journals On the Use of Iron Chloride and Starch for Clarification in Drinking Water Treatment

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Gomes CEP ◽  
Oliveira HA ◽  
Azevedo AC ◽  
Rubio J
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Iron Chloride ◽  
Raw Water ◽  
Polyaluminum Chloride ◽  
Gelatinized Starch ◽  
Slow Mixing ◽  
Solid Liquid ◽  
Solid Liquid Separation

In drinking water treatment plants, chemical reagents are employed to aggregate and remove suspended particles. However, not all reagents are eco-friendly and exists concerns over environmental, economic, and health issues. This study shows features of the sustainability of commercial coagulants/flocculants and presents experimental research on floc characterization and settling of dispersed solids with a combination of Ferric Chloride (FeCl3 ) and gelatinized starch. Bench studies were conducted using kaolin suspensions and results were validated with raw water collected from a river (Rio dos Sinos, Brazil). Flocculation indexes, floc structure, and residual turbidities were compared with Polyaluminum Chloride (PAC), as a reference. All techniques showed that the combination of FeCl3 and starch formed well-structured, larger, and more settleable flocs than those produced with PAC. Superficial loadings, in a continuous separation tank (2 to 4 m.h-1) were studied with and without lamellae. Best results were obtained with 15 mg.L-1 Fe3+ and 10 mg.L-1 starch, with a velocity gradient, G, of 60 s-1 in the slow mixing and with 60° inclined lamellae spaced 1.3 cm apart. Best conditions were applied to the clarification of the raw water and again, due to the rapid settling of flocs with FeCl3 and starch, better results were obtained compared to PAC. A turbidity reduction of 94% and a residual value of 2.5 NTU with superficial loadings of 3 m.h-1 were obtained. Results were discussed in terms of interfacial and operating parameters and a promising potential for the combination of FeCl3 with starch for solid/liquid separation was envisaged.

A review on various designs of solar still

2021 ◽  
pp. 1-22
Author(s):  
Md. Raquibul Hasan
Keyword(s):  
Drinking Water ◽  
Brackish Water ◽  
Potable Water ◽  
Saline Water ◽  
Operating Parameters ◽  
Solar Still ◽  
Water Distillation ◽  
Solar Desalination ◽  
Drinking Purposes ◽  
Day By Day

The availability of drinking water is reducing day by day, whereas the freshwater necessity is tremendously increasing. There is a need for some sustainable water distillation (purification) to overcome this problem. Solar desalination is a technique used to convert brackish or saline water into potable water, and solar still is a useful device to distil brackish water for drinking purposes. Numerous designs of the solar still system have been developed worldwide. Many researchers outlined mathematical terms, performed experiments and validated the outcome from the various types of solar stills by varying the design and operating parameters. In this article, a review of the active and passive solar stills' performance has been carried out.

scholarly journals Development and Commissioning of a Small-Scale, Modular and Integrated Plant for the Quasi-Continuous Production of Crystalline Particles

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 663
Author(s):  
Timo Dobler ◽  
Simon Buchheiser ◽  
Marco Gleiß ◽  
Hermann Nirschl
Keyword(s):  
Modular Design ◽  
Continuous Production ◽  
Small Scale ◽  
Distribution Width ◽  
Pharmaceutical Industries ◽  
The Individual ◽  
Almost All ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
High Degree

Increasing global competition, volatile markets and the demand for individual products challenge companies in almost all business sectors and require innovative solutions. In the chemical and pharmaceutical industries, these include modular design, the integration of several unit operations in one apparatus and the development of small-scale, versatile multipurpose plants. An example for such a modular, integrated and small-scale system is the belt crystallizer. This device combines the process steps cooling crystallization, solid-liquid separation and contact drying in a single plant. The basis of the apparatus is a belt filter in which the vacuum trays below the filter medium are replaced by temperature control and filtration units. Due to identical dimensions, it is possible to arrange the individual functional units in any order, which in turn allows a high degree of flexibility and rapid adaptation to customer requirements. Within the scope of the publication, the commissioning of the belt crystallizer takes place. First of all, the general functionality of the plant concept is demonstrated using sucrose as model system. Further experiments show that the particle size and the distribution width of the manufactured crystals can be specifically influenced by the selected process parameters, e.g., temperature profile during cooling and residence time.

scholarly journals Electrochemical treatment of dye wastewater using nickel foam electrode

2021 ◽  
Author(s):  
Saravanathamizhan Ramanujam ◽  
Kaavya Muthumanickam
Keyword(s):  
Stainless Steel ◽  
Electrolyte Concentration ◽  
Nickel Foam ◽  
Supporting Electrolyte ◽  
Electrochemical Treatment ◽  
Operating Parameters ◽  
Subsequent Stage ◽  
Dye Wastewater ◽  
Solid Liquid ◽  
Solid Liquid Separation

Removal of dye from wastewater has been investigated using the electrocoagulation method. Batch experiment has been conducted to remove the color from synthetically prepared acid red 87dye wastewater. Stainless steel and nickel foam sheets are used as cathode and anode, respectively. The effect of some operating parameters, such as current density, initial dye concentration and supporting electrolyte concentration, on color removal has been studied. It can be observed from the present investigations that the nickel foam electrode effectively removes color from the wastewater. Nickel hydroxyl species formed during the operation and also, nickel (II) hydroxide flocs formed in a subsequent stage, trap colloidal precipitates and make solid-liquid separation easier during the flotation stage. These stages of electrocoagulation must be optimized to design an economically feasible process.

NOMINAL DESIGN AND OPERATING PARAMETERS OF AQUATUBULAR STEAM GENERATORS FEED BY SOLID, LIQUID AND GASEOUS FUELS: A CASE STUDY

2019 ◽  
Author(s):  
Daniel Mazzette Souza ◽  
Wellington Balmant ◽  
JOSÉ VIRIATO COELHO VARGAS ◽  
Fernando Bóçon
Keyword(s):  
Operating Parameters ◽  
Steam Generators ◽  
Gaseous Fuels ◽  
Solid Liquid

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

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