Evaluation of a chemical dissolved air flotation system for the treatment of restaurant dishwasher effluent

2013 ◽  
Vol 40 (12) ◽  
pp. 1164-1172 ◽  
Author(s):  
Wayne Chung ◽  
Stephanie Young
Keyword(s):  
Oxygen Demand ◽  
Process Conditions ◽  
Optimal Process ◽  
Oil And Grease ◽  
Nitrogen And Phosphorus ◽  
Dissolved Air Flotation ◽  
Treated Effluent ◽  
Removal Efficiencies ◽  
Air Flotation ◽  
Dissolved Air

Restaurant dishwashers consume a large quantity of fresh water and produce significant amounts of high strength oily wastewater which may cause serious problems when discharged into the sewer. An analysis of restaurant dishwasher effluent (RDE) from a busy upscale restaurant identified high levels of oil and grease, chemical oxygen demand (COD), biochemical oxygen demand (BOD), alkalinity, pH, and chlorine, but low levels of nitrogen and phosphorus. In this study, RDE was treated using an internationally patented chemical dissolved air flotation (chemical DAF) system. The chemical DAF system was designed so that coagulation, flocculation, and flotation processes could be carried out within the same reactor. The treatment system is therefore small and compact and suitable for use in restaurants where space is limited. The treatment performance of the chemical DAF was evaluated by determining optimal process conditions, contaminant removal efficiencies, and residual contaminant concentrations. It was found that removal efficiencies of 98.90%, 93.16%, 98.68%, 90.04%, and 88.20% could be achieved under optimal process conditions for turbidity, oil, TSS, BOD5, and COD, respectively. Total coliform and E. coli were not detected in either the raw dishwasher effluent or the treated dishwasher effluent due to the use of sodium hypochlorite as a dishwashing sanitizer. Water quality of the treated effluent met the criteria put forth in the Canadian Guidelines for Domestic Reclaimed Water for Use in Toilet and Urinal Flushing, with the exception of BOD5. Present findings suggest that chemical DAF is a promising treatment process for the removal of contaminants from restaurant dishwasher effluent.

scholarly journals Evaluasi Limbah Berbasis Green Productivity di CV.ABC

JUMINTEN ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 93-104
Author(s):  
Amanullah Fathurrahman ◽  
Iriani Iriani ◽  
Dwi Sukma Donoriyanto
Keyword(s):  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Biological Oxygen Demand ◽  
Productivity Index ◽  
Oil And Grease ◽  
Dissolved Air Flotation ◽  
Green Productivity ◽  
Air Flotation ◽  
Productivity Ratio ◽  
Dissolved Air

CV. ABC merupakan pabrik yang bergerak dalam bidang olahan kayu seperti speaker aktif dan mebel-mebel. Dimana perusahaan tersebut memiliki sebuah komitmen internal dalam proses produksinya, agar dapat mengurangi dampak lingkungan dan memelihara ekosistem disekitarnya. Namun dalam kenyataannya, dalam proses produksinya baku mutu air perusahaan melebihi dari standar PERGUBJATIM No. 72 Tahun 2013, COD (Chemical Oxygen Demand) yang diatas batas standar sebesar 61,40 mg/l dan Oil and Grease sebesar 12 mg/l. Dimana akan berdampak pada lingkungan sekitar yang dapat mengganggu kesehatan lingkungan sekitar, selain itu dapat berdampak menurunnya produktivitas dan kinerja lingkungan perusahaan. Dengan adanya permasalahan tersebut pendekatan yang tepat untuk membantu perusahaan agar dapat mampu meningkatkan produktivitas serta kinerja lingkungan tersebut adalah dengan menerapkan metode Green Productivity (GP). Penelitian ini bertujuan untuk dapat mengevaluasi pengelolaan limbah berbasis Green Productivity, serta dapat memberikan usulan perbaikan dalam pengelolaan limbah. Hasil yang didapat diketahui bahwa terdapat 2 alternatif yang dapat menurunkan tingkat BOD (Biological Oxygen Demand), COD (Chemical Oxygen Demand), TSS (Total Suspeded Solid), Oil and Grease. Akan tetapi solusi yang dapat dijadikan usulan perbaikan adalah alternatif 2, yitu pemasangan alat DAF (Dissolved Air Flotation). Keuntungan yang didapatkan CV. ABC dengan alternatif 2 ini adalah peningkatan Green Productivity Index yang ditunjukan Green Productivity Ratio sebesar 13,06 dan Tingkat Produktivitas meningkat sebesar 0,01 %

scholarly journals Bio-Delipidation of Dissolved Air Flotation Pre-Treated Poultry Slaughterhouse Wastewater

2018 ◽  
Author(s):  
Siyasanga Mbulawa ◽  
Seteno Karabo Obed Ntwampe ◽  
Moses Basitere ◽  
Yolanda Mpentshu ◽  
Cynthia Dlangamandla ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Oxygen Demand ◽  
Industrial Applications ◽  
Quality Parameters ◽  
Bacterial Strains ◽  
Oil And Grease ◽  
Dissolved Air Flotation ◽  
Slaughterhouse Wastewater ◽  
Air Flotation ◽  
Dissolved Air

Delipidation is a method of defatting that is generally associated with the removal of residual lipids or lipid groups from matrices in which they are present in minute quantities. The bio-delipidation of protein-rich poultry slaughterhouse wastewater (PSW) pre-treated with a dissolved air flotation (DAF) system was developed using microbial lipases from bacterial strains isolated from the PSW. The efficacy of the bio-delipidation system was quantitatively characterised by comparing the quality parameters i.e., fats, oil and grease (FOGs), turbidity, total suspended solutes (TSS), total chemical oxygen demand (tCOD) and protein concentration of the DAF pre-treated PSW and bio-lipidized samples. As hypothesised, the bio-delipidation system was able to effectively reduce the levels of these quality parameters when crude lipases of Bacillus cereus AB1 (BF3) and Bacillus cereus CC-1 (B30) strains were used. Strain-dependent quality characteristics were also observed in bio-delipidized samples. The study successfully managed to complement physical reduction techniques (DAF) with biological strategies (bio-delipidation) for improved PSW quality, with potential industrial applications.

High-rate dissolved air flotation for water treatment

2001 ◽  
Vol 43 (8) ◽  
pp. 43-49 ◽  
Author(s):  
M. A. P. Raeli ◽  
M. Marchetto
Keyword(s):  
Reynolds Numbers ◽  
Pilot Scale ◽  
Water Velocity ◽  
High Rate ◽  
Raw Water ◽  
Parallel Plates ◽  
Dissolved Air Flotation ◽  
Removal Efficiencies ◽  
Air Flotation ◽  
Dissolved Air

This paper presents the results of an experimental investigation about the performance of a horizontal flow high-rate pilot scale Dissolved Air Flotation (HRDAF) unit containing inclined parallel plates for treating a coloured and low turbidity raw water. Experiments were performed with the DAF unit in order to verify the influence on flotation of : (i) the water velocity (Vh) between the plates, in the range 18 to 96.5 cm.min−1 with corresponding Reynolds numbers between 240 and 1060; (ii) the supplied air (S*) value ranging from 2.2 to 8.5 g of air/m3 of water ; (iii) the angle of the plates (60° or 70°). The best pilot plant operational condition was obtained applying only 4.0 g/m3 (S*) with Vh around 18 cm.min−1 for treatment of water coagulated with a Al2(SO4)3 dosage of 40 mg.l−1. In these conditions, the unit presented very good removal efficiencies of colour (90%, residual of 10 uC), turbidity (88%, residual of 0.8 NTU ) and TSS (94%, residual of 1.8 mg.l−1). Furthermore, the unit could operate at higher Vh values up to 76 cm.min−1 and still present good results. The DAF unit thus behaved as a high rate unit presenting good performance with low air requirement.

Post-Treatment of Effluents from Anaerobic Reactor Treating Domestic Sewage by Dissolved-Air Flotation

1999 ◽  
Vol 40 (8) ◽  
pp. 137-143 ◽  
Author(s):  
R. G. Penetra ◽  
M. A. P. Reali ◽  
E. Foresti ◽  
J. R. Campos
Keyword(s):  
Scale Up ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Domestic Sewage ◽  
Uasb Reactor ◽  
Dissolved Air Flotation ◽  
Operational Conditions ◽  
Apparent Color ◽  
Air Flotation ◽  
Dissolved Air

This paper presents the results of a study performed with a lab-scale dissolved-air flotation (LSDAF) unit fed with previously coagulated effluent from a pilot scale up-flow anerobic sludge blanket (UASB) reactor treating domestic sewage. Physical operational conditions for coagulation (rapid mix) and flocculation/flotation were maintained constant. Chemical (FeCl3) dosages ranged from 30 to 110 mg.l−1. The effect of pH was also verified in the range of 5.1 to 7.6 for each dosage. Best results were achieved for 65 mg.l−1 of FeCl3 and pH values between 5.3 and 6.1. For these conditions, the removal efficiencies obtained in the LSDAF unit were: between 87% and 91% for chemical oxygen demand (COD), between 95% and 96% for total phosphate (TP), 94% for total suspended solids (TSS), between 96% and 97% for turbidity (TU), between 90% and 93% for apparent color (AC) and more than 96% for sulfide (S). For the UASB-DAF system, global efficiencies would be around 98% for COD, 98% for TP, 98.4% for TSS, 99.3% for TU and 98% for AC. The stripped gases treatment is desirable.

Optimization of Solids Separation in Dissolved Air Flotation

2008 ◽  
Vol 43 (2-3) ◽  
pp. 239-247 ◽  
Author(s):  
Beata Gorczyca ◽  
Paul Klassen
Keyword(s):  
Bubble Formation ◽  
Particle Removal ◽  
Dissolved Air Flotation ◽  
Particle Counter ◽  
Floc Size ◽  
Treated Effluent ◽  
Air Flotation ◽  
Average Size ◽  
Solid Liquid ◽  
Dissolved Air

Abstract Sizes of flocs were analyzed to identify characteristics of the particle size distribution optimal for separation by dissolved air flotation (DAF). Optical microscopes and two particle counters were used for floc sizing. A Brightwell Technologies particle counter was found to provide floc size measurements in agreement with improved microscopic methods. The particle counter provided distribution of flocs with sizes down to 1 micron (µm). This allowed for inclusion of flocs with size ranging from 5 to 1 µm, which were excluded from the analyses in the earlier study. Four alum dosages were applied: 15, 25, 40, and 60 mg/L. The turbidity and colour of the DAF effluent at alum dosages of 25, 40, and 60 mg/L were very similar. However, the analysis of the flocs in the treated effluent revealed that, at the alum dose of 60 mg/L, particle removal was the best. Therefore, this dosage was selected as optimal for the solid/liquid separation process. The average size of coagulation flocs at 60 mg/L was approximately 30 µm, and was equal to the estimated size of air bubbles produced by the saturator. Therefore, this study confirms the finding of the earlier work claiming that the optimum DAF performance is attained when the mean floc size and the bubble size are equal. Similar size of floc and bubble indicates that flocs act predominantly as nuclei for bubble formation. This finding contributes to the knowledge of mechanisms of floc air bubble attachment in DAF.

Evaluation of Treatment Efficiency of Processes for Petroleum Refinery Wastewater

1994 ◽  
Vol 29 (8) ◽  
pp. 47-50 ◽  
Author(s):  
Kee Kean Chin
Keyword(s):  
Petroleum Refinery ◽  
Refinery Wastewater ◽  
Residual Oil ◽  
Oil And Grease ◽  
Dissolved Air Flotation ◽  
Petroleum Refinery Wastewater ◽  
Aeration System ◽  
Air Flotation ◽  
Final Effluent ◽  
Dissolved Air

Processes used in the treatment of a petroleum refinery wastewater included initial API oil separator to be followed by dissolved air flotation and an extended aeration system. The API oil separator removed most of the settleable solids and oil. The residual oil varied from around 680 mg/l to 104 mg/l and was further treated with chemical coagulation, flocculation and dissolved air flotation which remove more than 80 % of the oil and grease. Mean COD after dissolved air flotation was around 970 mg/l and it was lowered to around 378 mg/l using the extended aeration biological system at 15-day HRT. The final effluent COD/BOD ratio was high indicating the presence of a high percentage of refractory organic compounds.

Impact of salinity on coagulation and dissolved air flotation treatment for oil and gas produced water

2013 ◽  
Vol 49 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Jessica M. Younker ◽  
Margaret E. Walsh
Keyword(s):  
Water Samples ◽  
Oil And Gas ◽  
Produced Water ◽  
Oil And Grease ◽  
Dissolved Air Flotation ◽  
Coagulation Process ◽  
Dispersed Oil ◽  
Air Flotation ◽  
The Impact ◽  
Dissolved Air

Produced water is a major wastewater stream in the oil and gas industry which typically consists of dispersed and dissolved oils, and high levels of salinity. Despite concerns that dissolved aromatics in produced water may be detrimental to marine life, discharge regulations and treatment technologies for produced water largely focus on dispersed oil and grease removal. The purpose of this research project was to investigate coagulation with ferric chloride (FeCl3) and dissolved air flotation (DAF) at bench-scale for the removal of both dispersed and dissolved oils from synthetic and offshore produced water samples, with a specific focus on the impact of salinity on the coagulation process. Coagulation and DAF treatment of the produced water samples achieved high removals of dispersed oil and grease, but had limited impact on dissolved aromatics. The coagulation process in the saline produced water samples reduced dispersed oil and grease concentrations from 100 mg/L to below North American discharge limits (i.e. 30 mg/L in Canada, 29 mg/L in the USA) under all conditions tested, while the effectiveness of coagulation treatment in the fresh water synthetic samples was highly dependent on coagulation pH.

scholarly journals Sludge Production Characteristics of SedimentationㆍDissolved Air Flotation (SeDAF) Process for Enhanced Phosphorus Removal

2020 ◽  
Vol 42 (11) ◽  
pp. 529-538
Author(s):  
Yeoju Jang ◽  
Jinhong Jung ◽  
Hyangyoun Chang ◽  
Nari Park ◽  
Miratul Maghfiroh ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Algal Blooms ◽  
Dissolved Air Flotation ◽  
Quality Item ◽  
Operation Conditions ◽  
Coagulant Dosage ◽  
Removal Efficiencies ◽  
Air Flotation ◽  
Dissolved Air ◽  
Sludge Production

Objectives : In order to prevent eutrophication and algal blooms, Ministry of Environment in Korea reinforced the effluent standards of wastewater treatment facilities. As a result, many advanced wastewater treatment processes have been implemented nationwide. Current conventional treatment systems have usually been facing high operational costs and large sludge production problems. Therefore, it is essential to develop more economic and efficient process to cope with these issues.Methods : The sedimentation and dissolved air flotation (SeDAF) process has been developed, that integrates sedimentation and dissolved air flotation. Several simulation experiments were carried out to verify and optimize the operation conditions of the SeDAF process. Removal efficiencies of each water quality item and sludge mass balance were analyzed intensively in the SeDAF process using the modified jar-test.Results and Discussion : Removal efficiencies of the SeDAF process were higher and more stable than those of sedimentation process. Several ‘sludge production / coagulant dosage’ ratios were analyzed and the representative value of 4 mg･L-1 as SS / mg･L-1 as Al<sub>2</sub>O<sub>3</sub> was obtained in the SeDAF process. Fractions of suspended solids (SS) and total phosphorus (T-P) in sludge were measured; the ratios of flotation sludge to sedimentation sludge and fractions of flotation sludge in total sludge had their typical convergence ranges for the conditions of optimal coagulant dosage.Conclusions : The ratios or fractions of SS and T-P in sludge could be applied as the evaluation indicators of the SeDAF process. The reduction of coagulant dosage could be corresponded directly to the reduction of sludge production.

scholarly journals Full-scale dissolved air flotation (DAF) equipment for emergency treatment of eutrophic water

2018 ◽  
Vol 77 (7) ◽  
pp. 1802-1809 ◽  
Author(s):  
Zhuang Tian ◽  
Can Wang ◽  
Min Ji
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Demand ◽  
River System ◽  
Dissolved Air Flotation ◽  
Coagulant Dosage ◽  
Eutrophic Water ◽  
Air Flotation ◽  
Control Technologies ◽  
Point And Diffuse Sources ◽  
Dissolved Air

Abstract Eutrophication of urban rivers has caused severe environmental problems due to the pollution from point and diffuse sources. Although eutrophication can be alleviated by reducing the input to the river system, fast-treating terminal control technologies, especially under emergent situations, should be developed to reduce risks induced by eutrophication. The present study developed an emergency purification device based on dissolved air flotation (DAF) technology. After equipment commissioning and parameter optimization for applications in the field of engineering, the device was found to effectively remove total phosphorus, chlorophyll a, chemical oxygen demand, and turbidity in water by controlling the coagulant dosage and adjusting the gas-liquid mixing pump parameters. Dissolved air in water could enhance dissolved oxygen, and dissolved oxygen in polluted rivers could be raised from 0.2–2 mg/L to 3–3.5 mg/L. Removal of total nitrogen was poor because the majority of nitrogen contents were dissolved. Finally, DAF has been proven to be a promising technology due to its ease of implementation, low equipment investment requirement, and low operation cost.

Stormwater treatment by dissolved air flotation: first results from a pilot project

1995 ◽  
Vol 32 (1) ◽  
pp. 137-143 ◽  
Author(s):  
C. Bernard ◽  
P. Herviou ◽  
T. Poujol
Keyword(s):  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Project ◽  
Process Efficiency ◽  
Stormwater Treatment ◽  
Dissolved Air Flotation ◽  
First Results ◽  
Important Input ◽  
Air Flotation ◽  
Dissolved Air

A stormwater treatment plant using dissolved air flotation was operated in 1993, at the outlet of the Chelles River catchment area (Seine-et-Marne, France). The process was divided into two different stages. Firstly, a coagulation/flocculation stage, secondly a flotation stage in a flotation tank. The flow rate was set at 13 m3/h. Stormwater was the main part of the effluent but with some urban wastewater as the network is not strictly separate. The process efficiency was tested for suspended solids, chemical oxygen demand and hydrocarbons. A total hydrocarbon removal was observed. Finally, constant output concentrations were observed in spite of important input roughwater concentration variations.

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