Relationship between solid retention time and phosphorus removal in anaerobic-intermittent aeration process

2007 ◽  
Vol 103 (4) ◽  
pp. 338-344 ◽  
Author(s):  
Doojin Lee ◽  
Moonil Kim ◽  
Jinwook Chung
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Intermittent Aeration ◽  
Solid Retention Time ◽  
Aeration Process

The effect of aeration and non-aeration time on simultaneous organic, nitrogen and phosphorus removal using an intermittent aeration membrane bioreactor

2002 ◽  
Vol 46 (9) ◽  
pp. 193-200 ◽  
Author(s):  
Z. Ujang ◽  
M.R. Salim ◽  
S.L. Khor
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Phosphorus Removal ◽  
Organic Nitrogen ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Intermittent Aeration ◽  
Nitrogen And Phosphorus ◽  
Solid Retention Time ◽  
Aeration Time

A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 mm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.

Factors affecting phosphorus removal in a two-stage intermittent aeration process treating domestic sewage

1998 ◽  
Vol 38 (1) ◽  
pp. 115-122 ◽  
Author(s):  
H. W. Zhao ◽  
D. S. Mavinic ◽  
W. K. Oldham ◽  
F. A. Koch
Keyword(s):  
Phosphorus Removal ◽  
Control Level ◽  
Phosphorus Release ◽  
Intermittent Aeration ◽  
Two Stage ◽  
Factors Affecting ◽  
Stage Ia ◽  
Stage Process ◽  
Anaerobic Zone ◽  
Aeration Process

A bench-scale, continuous-flow, study was conducted to investigate the factors affecting phosphorus removal in a two-stage, intermittent aeration (IA) process. The two-stage process used consisted of an anaerobic zone and an intermittently aerated, completely mixed (IACM) tank, in which intermittent aeration was controlled by absolute ORP. The factors examined were the average ORP control level (used for aeration control), external acetate dosage, and intermittent aeration cycle. The degree of phosphorus removal in the two-stage IA process depended mainly on the presence of acetate in the anaerobic zone. The average ORP control level also affected the phosphorus removal at relatively low external acetate dosages. Small phosphorus release in the presence of nitrate and dissolved oxygen was observed during the air-off period. This suggests that a relatively long aeration cycle should be avoided in the two-stage IA process for preventing significant phosphorus release in the IACM tank.

Basic Studies on Phosphorus Removal by the Contact Aeration Process Using Iron Contactors

1991 ◽  
Vol 23 (4-6) ◽  
pp. 641-650 ◽  
Author(s):  
S. Haruta ◽  
T. Takahashi ◽  
T. Nishiguchi
Keyword(s):  
Corrosion Rate ◽  
Phosphorus Removal ◽  
Domestic Wastewater ◽  
Small Scale ◽  
Combined Method ◽  
Sulfate Reducing ◽  
Biological Sludge ◽  
Aeration Process ◽  
Basic Studies ◽  
Volumetric Loading

The authors have developed what we call the submerged iron contactor process as a simple and inexpensive phosphorus removal method for small-scale plants disposing of domestic wastewater and household wastewater treatment tanks. In this method iron contactors are submerged in biological treatment tanks, where phosphate anions in wastewater are combined with iron cations produced through corrosion of the contactors, and the compound thus produced is precipitated and removed together with biological sludge. In these studies, laboratory experiments were made on the contact aeration process combined with the above-mentioned method, and the following findings were obtained. (1) It is desirable to treat wastewater by making use of corrosion by sulfate-reducing bacteria instead of corrosion by oxygen dissolved in wastewater, to conduct a stable phosphorus removal by this combined method. (2) The corrosion rate of iron contactors is affected by the volumetric loading of BOD in the tanks where they are submerged. (3) Assuming that an iron contactor continues to suffer corrosion evenly all over the surface when our combined method is applied, it is estimated that the corrosion rate is about 1mm or less in 30 years.

Simultaneous removal of nitrogen and phosphorus in a two-biofilter system

2000 ◽  
Vol 41 (12) ◽  
pp. 101-106 ◽  
Author(s):  
D. Pak ◽  
W. Chang
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Aerobic Condition ◽  
Nitrogen Loading ◽  
Simultaneous Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Factors Affecting

A two-biofilter system operated under alternate conditions of anaerobic/aerobic was tested to simultaneously remove nitrogen and phosphorus from sewage. The factors affecting simultaneous removal of nitrogen and phosphorus by the two-biofilter system were investigated. Those factors appeared to be influent COD/T-N and COD/T-P ratio, nitrogen loading rate and hydraulic retention time. Nitrite and nitrate produced in the biofilter in aerobic condition affected phosphorus removal by the two-biofilter system. The amount of biomass wasted during the backwash procedure also affected total nitrogen and phosphorus removal by the system.

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