Condition Optimization of Dissolved Air Flotation-Filter and Mechanism Research

2011 ◽  
Vol 374-377 ◽  
pp. 975-981
Author(s):  
Ying Li ◽  
Ke Feng Zhang ◽  
Mei Li
Keyword(s):  
Yellow River ◽  
Filter Material ◽  
Reflux Ratio ◽  
Biological Degradation ◽  
Reservoir Water ◽  
Dissolved Air Flotation ◽  
Average Value ◽  
Condition Optimization ◽  
Activated Carbon Filter ◽  
Micro Organisms

DAFF’s treatment effect on Yellow River reservoir water under different reflux ratios is studied in this paper. Determination of indicators are turbidity、CODMn、NH4+-N、UV254、particle counter and unconventional indicators, such as biomass、TOC、olfactory threshold and smell of factors. The best reflux ratio is 14%; The average value of NH4+-N、CODMn 、UV254、and turbidity of carbon-sand filter’s outlet is 0.125、1.61mg/L、0.033cm-1 and 0.21NTU, accordingly, the average removal rates are 58.64 %、40.44 %、27.96 % and 90.26 %; The micro-organisms in filter material are mainly existed in the upper layer of activated carbon filter; The micro-organisms provide carbon-sand filter beneficial conditions for its biological degradation effect.

Research on treating algae-polluted reservoir water by the process of pre-oxidation/dissolved air flotation/carbon sand filter

2018 ◽  
Vol 19 (3) ◽  
pp. 823-830 ◽  
Author(s):  
Yonglei Wang ◽  
Wenhao Wang ◽  
Ruibao Jia ◽  
Mei Li ◽  
Baozhen Liu ◽  
...  
Keyword(s):  
Removal Rate ◽  
Water Diversion ◽  
Reflux Ratio ◽  
Reservoir Water ◽  
Combined Process ◽  
Dissolved Air Flotation ◽  
Blue Green Algae ◽  
Operation Conditions ◽  
Air Flotation ◽  
Dissolved Air

Abstract As the water diversion reservoir showed high organic matter and high algae in summer, the potassium permanganate pre-oxidation/dissolved air flotation/carbon sand double filter process was developed. The test results show that the optimum operation conditions of the combined process were as follows: the dosage of KMnO4 was 0.3 mg/L, the dosage of polymeric aluminum ferric chloride (PAFC) was 3.0 mg/L (Al3+), the reflux ratio was 10%, and the dissolved gas pressure was 0.3 Mpa. Taking Ji'nan Queshan reservoir water algae pollution as the research object, the average removal rate of chlorophyll a, blue-green algae, turbidity, particle number and total organic carbon (TOC) reached 66.64%, 95.44%, 94.45%, 99.34% and 46.68%, respectively; the methylisoborneol (MIB) removal rate was 92.47%, the odor level decreased with process flow from raw water level 4 to effluent level 1.5, geosmin (GSM) dropped below the detection limit, and the total removal rate of trihalomethane formation potential (THMFP) was 33.56%. The effluent of the combined process meets the requirements of the Hygienic Standard for Drinking Water (GB5749-2006) after it is disinfected.

Degradation of Oil by Land Disposal

1987 ◽  
Vol 19 (8) ◽  
pp. 99-105 ◽  
Author(s):  
G. Tesan ◽  
D. Barbosa
Keyword(s):  
Nutrient Availability ◽  
Filter Cake ◽  
Test Procedure ◽  
Pilot Scale ◽  
Effluent Treatment ◽  
Biological Degradation ◽  
Chemical Fertilizers ◽  
Land Disposal ◽  
Micro Organisms

The work presented consists of a test procedure applied at a pilot scale using soil as a biological degradation agent. The experiments described were carried out with oily residues considered as wastes difficult to degrade by other means. The tests were applied to filter cake with activated clay containing 40% oil and oily residues from re-refining of lubricants to give white oils and vaseline. The effect of the amount of moisture is evaluated using a mechanical stirrer to improve the interaction between the wastes and microorganisms. The following are also evaluated: nutrient availability; incorporation of micro-organisms into the soil; introduction of chemical fertilizers; and, injections of sludge from effluent treatment plants.

Enhanced rapid gravity filtration and dissolved air flotation for pre-treatment of river thames reservoir water

1998 ◽  
Vol 37 (2) ◽  
pp. 35-42 ◽  
Author(s):  
M. J. Bauer ◽  
R. Bayley ◽  
M. J. Chipps ◽  
A. Eades ◽  
R. J. Scriven ◽  
...  
Keyword(s):  
Water Treatment ◽  
Water Supply ◽  
21St Century ◽  
Reservoir Water ◽  
Dissolved Air Flotation ◽  
Lowland Rivers ◽  
Air Flotation ◽  
Pre Treatment ◽  
Counter Current ◽  
Dissolved Air

Thames Water treats approximately 2800Ml/d of water originating mainly from the lowland rivers Thames and Lee for supply to over 7.3million customers, principally in the cities of London and Oxford. This paper reviews aspects of Thames Water's research, design and operating experiences of treating algal rich reservoir stored lowland water. Areas covered include experiences of optimising reservoir management, uprating and upgrading of rapid gravity filtration (RGF), standard co-current dissolved air flotation (DAF) and counter-current dissolved air flotation/filtration (COCO-DAFF®) to counter operational problems caused by seasonal blooms of filter blocking algae such as Melosira spp., Aphanizomenon spp. and Anabaena spp. A major programme of uprating and modernisation (inclusion of Advanced Water Treatment: GAC and ozone) of the major works is in progress which, together with the Thames Tunnel Ring Main, will meet London's water supply needs into the 21st Century.

The role of particle size and density in dissolved air flotation and sedimentation

1997 ◽  
Vol 36 (4) ◽  
pp. 177-189 ◽  
Author(s):  
A. Vlaški ◽  
A. N. van Breemen ◽  
G. J. Alaerts
Keyword(s):  
Kinetic Modelling ◽  
Single Cells ◽  
Process Efficiency ◽  
Laboratory Model ◽  
Reservoir Water ◽  
Dissolved Air Flotation ◽  
Floc Size ◽  
Air Flotation ◽  
G Value ◽  
Dissolved Air

Conventional (sedimentation) and advanced (dissolved air flotation) treatment were studied in the context of removal of the single cells form of the cyanobacteria Microcystis aeruginosa. This cyanobacterium species is recognised as an ideal surrogate for process removal efficiency assessment of particles of the problematic size range (3-10 m). The agglomeration (coagulation/flocculation) phase has been indicated as essential and determining the down-stream process efficiency, hence it is a prerequisite for process improvement. Relevant process parameters have been addressed on a laboratory (model water) and pilot plant (reservoir water) scale, including the influence of coagulant (FeCl3) dose, coagulation pH, flocculation time, energy input (G value), single stage versus tapered flocculation and application of cationic polymer as coagulant aid. The process efficiency was assessed as a function of the preceeding agglomeration (coagulation/flocculation) phase and the obtained particle (floc) size distributions. The particle (floc) size - density relationship was addressed in the context of more accurate process kinetic modelling.

Ceramic microfiltration; a novel and compact process for the treatment of surface water

2018 ◽  
Vol 18 (6) ◽  
pp. 2035-2043 ◽  
Author(s):  
C. Rockey ◽  
D. C. Metcalfe ◽  
G. Galjaard ◽  
H. Shorney-Darby ◽  
J. Zheng
Keyword(s):  
Membrane Fouling ◽  
Water Source ◽  
Ceramic Membranes ◽  
Pilot Scale ◽  
Product Formation ◽  
Reservoir Water ◽  
Dissolved Air Flotation ◽  
Traditional Process ◽  
High Concentrations ◽  
Dissolved Air

Abstract In-line coagulation adsorption (ILCA) followed by ceramic microfiltration (CMF) was tested at pilot scale and compared to a full scale traditional process consisting of coagulation and dissolved air flotation (DAF) followed by rapid gravity sand filtration (RGF), for treating a reservoir water source which is prone to high concentrations of algae. The ILCA CMF process was shown to remove 10–16% more dissolved organic carbon (DOC) and reduced disinfection by-product formation potential (DBPFP) by 9–13% in comparison to conventional treatment (optimised coagulation). ILCA effectively controlled membrane fouling allowing the ceramic membranes to be operated at high flux (200 l/m2h) with low membrane fouling (0.9–1.9 kPa/day). A process comprising ILCA and direct ceramic microfiltration was shown to provide very stable treated water quality under a range of challenging conditions. Additionally, the process is more compact showing significant reductions (circa 60%) in footprint relative to a conventional DAF/RGF process.

Dissolved air flotation in potable water treatment: the Dutch experience

1995 ◽  
Vol 31 (3-4) ◽  
pp. 149-157 ◽  
Author(s):  
Jan van Puffelen ◽  
Paul J. Buijs ◽  
Peter N. A. M. Nuhn ◽  
Wim A. M. Hijnen
Keyword(s):  
Dissolved Air Flotation ◽  
Flotation Process ◽  
Direct Filtration ◽  
Advantages And Disadvantages ◽  
Air Flotation ◽  
Water Companies ◽  
Micro Organisms ◽  
Chlorophyll A Content ◽  
Dutch Experience ◽  
Dissolved Air

This paper reviews the experience the drinking water companies in The Netherlands have gained in the last twenty years in the field of dissolved air flotation. An overview of the Dutch flotation plants with their individual objectives is presented. The efficiency of flotation towards the removal of different parameters, such as turbidity, organic matter and micro-organisms is good, which is illustrated by data from the water companies. Both in the past and at present water companies compare flotation to other floc separation techniques, such as sedimentation or direct filtration. Specially for waters with (relative) low turbidity and high chlorophyll-a content, flotation proved (in combination with rapid sand filtration) to be very effective. The efficiency of the flotation process has been improved by the development of different nozzle-types. Some of these types are described here, each with their advantages and disadvantages. In general dissolved air flotation has proved to be as sturdy and reliable as sedimentation techniques, such as lamellae settling.

Comparative Study of Dissolved Air Flotation and Sedimentation Process for Treating Reservoir Water with Low Temperature, Low Turbidity and High Natural Organic Matter

2011 ◽  
Vol 71-78 ◽  
pp. 2767-2771 ◽  
Author(s):  
Jing Zou ◽  
Jun Tao Zhu ◽  
Chao Pan ◽  
Jun Ma
Keyword(s):  
Water Quality ◽  
Low Temperature ◽  
Bubble Column ◽  
Reservoir Water ◽  
Dissolved Air Flotation ◽  
Sedimentation Process ◽  
Air Flotation ◽  
Better Than ◽  
Glass Bubble ◽  
Dissolved Air

In this research, the dissolved air flotation (DAF) were tried to treat drinking water to replace traditional sedimentation technology. Experimental study of sedimentation process and DAF was carried out in a jet tester and a glass bubble column respectively. The experimental results demonstrated that the indicators of water quality such as turbidity, chromaticity and CODMn after two processes decreased firstly and then increased with the PAC-dose increasing, and 7.41 mg Al L-1 was the optimum PAC dosage. Moreover, with the optimum PAC dosage, water quality after DAF proved much better than that after sedimentation process. As a result, DAF is a more effective technology to treat the reservoir water with low temperature, low turbidity and high NOM.

High rate settler in biological system for oil and soap wastewater treatment

1995 ◽  
Vol 32 (11) ◽  
pp. 39-44 ◽  
Author(s):  
S. I. Abou-Elela ◽  
A. Ashmawy ◽  
H. I. Aly ◽  
H. M. Ahmed
Keyword(s):  
High Rate ◽  
Nile River ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Biological Degradation ◽  
Inorganic Pollutants ◽  
Dissolved Air Flotation ◽  
Biological Unit ◽  
Untreated Wastewater ◽  
Dissolved Air

Wastewater from an oil and soap company provided the material of this study. The company discharges 31,000 m3/d of untreated wastewater into the Nile River. The wastewater was highly contaminated with organic and inorganic pollutants. An end-of-pipe treatment scheme was devised of dissolved air flotation with/without alum followed by biological degradation. The biological unit was compact and comprised an aeration tank based on a completely mixed activated sludge process followed by a high rate settler. The unit was operated at two organic loads, namely 1.44 and 2.88 kg BOD5/m3/d. The results obtained showed that this scheme of treatment produced a high quality effluent suitable for disposal into surface water or reuse. Also, the high rate settler acted as a biological reactor as well as a settler for finely divided organic matter.

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