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.

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.

The feasibility of electro-osmotic belt filter dewatering technology at pilot scale

2000 ◽  
Vol 41 (8) ◽  
pp. 137-144 ◽  
Author(s):  
H. G. Snyman ◽  
P. Forssman ◽  
A. Kafaar ◽  
M. Smollen
Keyword(s):  
Applied Voltage ◽  
Feed Rate ◽  
Cost Effective ◽  
Pilot Scale ◽  
Filter Press ◽  
Digested Sludge ◽  
Dissolved Air Flotation ◽  
Anaerobically Digested Sludge ◽  
Air Flotation ◽  
Dissolved Air

Sewage sludge is typically dewatered using drying beds, belt filter presses or centrifuges. Mechanical dewatering of sludge is costly in terms of capital and running costs, especially the flocculent. In an attempt to address the need for more cost-effective dewatering technologies, electro-osmotic belt filtering was developed by Smollen and Kafaar in 1995. Themechanical equipment resembles a belt filter press but the belts are stainless steel, woven belts, which act as the electrodes. In this study, thefeasibility of the technology was tested at pilot scale using wasteactivated-, anaerobically digested- and dissolved air flotation sludge. The parameters which were investigated includes the applied voltage, polyelectrolyteusage and sludge feed rate. Applied voltage of between 15 and 25 volts increased the dewatering significantly in the waste activated- and anaerobically digested sludge. Applying a voltage in dissolved air flotation sludge could not enhance the efficiency of dewatering, unless stored to de-air. The technology was found as sensitive to polyelectrolyte dosages as belt presses. The performance of the electro-osmotic belt filter was sensitive to feed rate, but performed well with non-thickened waste activated sludge (0.61% solids), resulting in cake solids above 20%.

Ozonation followed by coagulation/flocculation and flotation as post-treatment of the effluent from an anaerobic baffled reactor treating domestic sewage

2001 ◽  
Vol 43 (8) ◽  
pp. 99-106 ◽  
Author(s):  
M. M. Marchioretto ◽  
M. A. Reali
Keyword(s):  
Ph Value ◽  
Domestic Sewage ◽  
Post Treatment ◽  
Dissolved Air Flotation ◽  
Anaerobic Baffled Reactor ◽  
Ozone Dose ◽  
Apparent Color ◽  
Consequent Reduction ◽  
High Degree ◽  
Dissolved Air

This paper reports on the use of ozonation and dissolved air flotation as a post-treatment of the effluent from an anaerobic baffled reactor treating domestic sewage. After preliminary essays, the present experiment was performed fixing coagulant doses and, to all of them, some ozone doses were investigated. Later, the pH value and the ozone dose which provided the best removal efficiencies of all the parameters involved were tested, changing the coagulant dose and varying, for each of them, two ozone doses: the zero one and the optimum. Considering the best conditions of coagulation/flotation (ferric chloride dose of 65 mg.L−1: and pH around 5.5), the ozone dose application of 6 mg.L−1 led to a significant level in the removal efficiency of COD (80.4%), BOD (79.0%), total phosphate (93.4%), apparent color (91.9%) and turbidity (97.0%), demonstrating that the system seems to be efficient and capable of promoting a high degree of sewage post-treatment, reducing the coagulant dose until 30%, with a consequent reduction in the sludge generation.

Sewage treatment by anaerobic biological process associated with dissolved air flotation

2001 ◽  
Vol 43 (8) ◽  
pp. 91-98 ◽  
Author(s):  
M. A. P. Reali ◽  
J. R. Campos ◽  
R. G. Penetra
Keyword(s):  
Scale Up ◽  
Sewage Treatment ◽  
Pilot Scale ◽  
Cationic Polymer ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Mean Velocity ◽  
Dissolved Air Flotation ◽  
Flotation Process ◽  
Anaerobic Sludge Blanket

This paper presents the results of a study performed with a lab-scale batch DAF unit fed with previously coagulated (with FeCl3 or cationic polymer) effluent from a pilot scale up-flow anaerobic sludge blanket (UASB) reactor treating domestic sewage. The adequate coagulation/flocculation conditions – chemical dosage, time (Tf) and mean velocity gradient (Gf) in the flocculation step – and air requirements for flotation process were investigated. Best results were achieved for 65 mg.l−1 of FeCl3 at Tf around 15 min and Gf of 80 s−1. In the assays where only polymer was applied, 7 mg.l−1 of cationic polymer dosage gave optimum removals with Tf around 15 min and Gf of 30 s−1. Air requirements ranged from 9.5 to 19.0 g of air.m−1 wastewater. Best TSS (95% and residual of 2 mg.l−1), COD (85% and residual of 20 mg.l−1) and total phosphate (95% and residual of 0.6 mg.l−1) removals were obtained when applying FeCl3, although the use of cationic polymer also produced good level of TSS (74% and residual of14 mg.l−1) and COD (75% and residual of 45 mg.l−1) removals. For the UASB-DAF (batch) system and FeCl3, global efficiencies would be 97.2% for COD, 97.9% for phosphate and 98.9% for TSS.

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.

Post-treatment of UASB effluent in an expanded granular sludge bed reactor type using flocculent sludge

2003 ◽  
Vol 48 (6) ◽  
pp. 279-284 ◽  
Author(s):  
M.T. Kato ◽  
L. Florencio ◽  
R.F.M. Arantes
Keyword(s):  
Oxygen Demand ◽  
Granular Sludge ◽  
Total Suspended Solid ◽  
Experimental Period ◽  
Pilot Scale ◽  
Suspended Solid ◽  
Domestic Sewage ◽  
Post Treatment ◽  
Uasb Reactor ◽  
Reactor Type

The performance of an EGSB (expanded granular sludge bed) reactor type using flocculent sludge was evaluated for the post-treatment of effluent from UASB reactor treating domestic sewage. A pilot-scale 157.5-L EGSB reactor was monitored during a 331-day period. The original concept of the EGSB reactor was based on granular sludge use and by applying of high upflow liquid velocities (Vup). However, even using flocculent sludge from a UASB full-scale (Mangueira Plant, Recife, Brazil), good mixing conditions and high retention of biomass were achieved. By applying a 4-h hydraulic retention time and Vup values up to 3.75 m/h, effluent chemical oxygen demand concentrations in the EGSB were below 87 mg/L and 55 mg/L, for total and filtered samples, respectively. Total suspended solid (TSS) concentrations in the effluent were below 32 mg/L. Good performance and stable reactor operation during the whole experimental period were observed. Therefore, the EGSB reactor type using flocculent sludge can also be used for post-treatment of very dilute anaerobic effluent from reactors treating domestic sewage.

Effect of Biosurfactant Addition in a Pilot Scale Dissolved Air Flotation System

2014 ◽  
Vol 50 (4) ◽  
pp. 618-625 ◽  
Author(s):  
Fernanda C. Padilha da Rocha e Silva ◽  
Nathália M. Padilha da Rocha e Silva ◽  
Alex Elton de Moura ◽  
Rodrigo Almeida Galdino ◽  
Juliana Moura Luna ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Dissolved Air Flotation ◽  
Air Flotation ◽  
Dissolved Air

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 %

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