Automatic control of coagulant dosage on the sedimentation and dissolved air flotation(SeDAF) process for enhanced phosphorus removal in sewage treatment facilities

2020 ◽  
Vol 34 (6) ◽  
pp. 411-423
Author(s):  
Yeoju Jang ◽  
◽  
Jinhong Jung ◽  
Weonjae Kim
Keyword(s):  
Automatic Control ◽  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Dissolved Air Flotation ◽  
Coagulant Dosage ◽  
Treatment Facilities ◽  
Air Flotation ◽  
Dissolved Air

scholarly journals Applicability of Al/P (Aluminium/Phosphorus) Ratio in SeDAF Process for Enhanced Phosphorus Removal

2020 ◽  
Vol 42 (11) ◽  
pp. 539-547
Author(s):  
Yeoju Jang ◽  
Jinhong Jung ◽  
Kwangho Ahn ◽  
Hyunman Lim ◽  
Weonjae Kim
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Algal Blooms ◽  
Operating Conditions ◽  
Dissolved Air Flotation ◽  
Treatment Processes ◽  
Coagulant Dosage ◽  
Treatment Facilities ◽  
Operation Characteristics ◽  
Dissolved Air

Objectives : To prevent eutrophication and algal blooms, Ministry of Environment in Korea has reinforced the effluent standards of wastewater treatment facilities. In the last 20 years, various advanced wastewater treatment processes have been introduced nationwide. The sedimentation･dissolved air flotation (SeDAF) process has been developed for efficient enhanced phosphorus removal in the previous researches. In the study, several factors were reviewed to examine the operation characteristics of the SeDAF process. In particular, the applicability of aluminium/phosphorus (Al/P) and aluminium/turbidity (Al/T) ratios were investigated intensively.Methods : To derive the appropriate operating conditions for the SeDAF process, several sets of lab-scale tests were carried out. For each operating condition, Al/P (Al/T-P), Al/PO<sub>4</sub>3--P, and Al/T (Al/Turbidity) ratios were analyzed, compared and reviewed respectively.Results and Discussion : Al/P ratio was revealed as the most prominent factor in terms of stability and feasibility of operation, and Al/P values of the SeDAF process could achieve lower values than those of other processes in the previous researches.Conclusions : It could be expected that the coagulant dosage decision using Al/P ratio has many advantages to reduce coagulant dosage and to decrease the amount of sludge production in the SeDAF process.

Influence of flocculation conditions in the performance of an experimental domestic sewage treatment plant consisting of an anaerobic expanded bed reactor followed by dissolved air flotation

2003 ◽  
Vol 48 (6) ◽  
pp. 285-293
Author(s):  
R.G. Penetra ◽  
M.A.P. Reali ◽  
J.R. Campos
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Domestic Sewage ◽  
Expanded Bed ◽  
Mean Velocity ◽  
Dissolved Air Flotation ◽  
Anaerobic Reactor ◽  
Air Flotation ◽  
Dissolved Air

This paper presents the results of a study performed with an experimental domestic sewage treatment plant (240 m3.d-1 flow) consisting of expanded bed anaerobic reactor (EBAR) followed by dissolved air flotation (DAF) unit. For the flotation step, the anaerobic reactor effluent was previously coagulated with 50 mgFeCl3.l-1 and flocculated under different conditions (mean velocity gradient, Gf, and flocculation time, Tf). The Gf values were from 60 to 100 s-1 associated with 13 and 20 min Tf values. During the tests, the following operational conditions of the flotation unit were maintained: chemical addition (50 mgFeCl3.l-1), 18% recirculation rate associated with a pressure of 450 ± 10 kPa in the saturation chamber and overflow rate of 180 m3.mÐ2.d-1. Temperature ranged from 23.8¡C to 30.01/4C. Best results were achieved for Gf = 80 s-1 and Tf = 20 min. For these conditions, the DAF unit removal efficiencies were: 94.4% for chemical oxygen demand (with 53 mg.l-1 COD residual), 87% for phosphorus (with 0.80 mgP.l-1 residual), 96.7% for total suspended solids (with 9 mg.l-1 TSS residual) and 96.4% for turbidity (with 12.9 NTU residual), when the anaerobic reactor effluents have worst quality during the whole day.

scholarly journals Dissolved air flotation (DAF) for biomass recovery from algal ponds

2017 ◽  
Vol 12 (3) ◽  
pp. 534-540 ◽  
Author(s):  
Dayana Melo Torres ◽  
André Luís Calado Araújo ◽  
Rui de Oliveira ◽  
André Câmara de Brito
Keyword(s):  
Suspended Solids ◽  
Sewage Treatment ◽  
Random Factor ◽  
Dissolved Air Flotation ◽  
Sample Characteristics ◽  
Biomass Recovery ◽  
Air Flotation ◽  
Final Effluent ◽  
Flocculation Time ◽  
Dissolved Air

This work evaluated the performance of a dissolved air flotation (DAF) system for biomass recovery from the effluent of algal ponds used for sewage treatment in Northeast Brazil. Two different coagulants and effluent samples were tested following a random-factor experimental design (34–1–4 factors and 3 levels), in triplicate. Factor analysis showed that coagulant dose was the most important factor, independently of the type of coagulant and sample characteristics. For polyaluminium chloride it is possible to work with the original sample pH at the lower recirculation rate (10%) and flocculation time (10 minutes), being able to recovery an algal masses (dry basis) of around 1,200 kg/day and 550 kg/day from the primary facultative and second maturation pond (final effluent), respectively. DAF was more efficient for ferric chloride, however a pH correction to the value of 5.0 was necessary, leading the process to generate masses of solids (dry basis) of about 1,150 kg/day for the facultative pond and 830 kg/day for the maturation pond. Removals of suspended solids, turbidity, and chlorophyll-a were above 60%, reaching at optimal conditions removals up to 90%.

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.

Sign in / Sign up

Export Citation Format

Share Document