scholarly journals Comparison of Organic Substances in the Contact Aeration Process and the Activated Sludge Process.

2001 ◽  
Vol 24 (10) ◽  
pp. 693-698
Author(s):  
Takeshi YAHASHI ◽  
Youmei KUSHIDA ◽  
Takao WATANABE ◽  
Hideaki OHMORI ◽  
Yoshio INOUE
Keyword(s):  
Activated Sludge ◽  
Activated Sludge Process ◽  
Organic Substances ◽  
Aeration Process

An activated sludge process without excess sludge production

1997 ◽  
Vol 36 (11) ◽  
pp. 163-170 ◽  
Author(s):  
Yoshio Sakai ◽  
Tetsuro Fukase ◽  
Hidenari Yasui ◽  
Masahide Shibata
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
The Other ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Organic Substances ◽  
Complete Elimination ◽  
Excess Sludge ◽  
Effluent Quality ◽  
Inorganic Substances

An activated sludge process which produces no excess sludge was developed. The process is very simple as a small amount of return sludge is ozonated and then returned to the aeration tank. The ozonation enhances biodegradability of activated sludge, which is biologically oxidized in the aeration tank. A full-scale plant for treating 450m3/d of municipal wastewater was constructed and has been operated successfully for 9 months. The amount of excess sludge eliminated is directly proportional to the amount of ozone dosed to the sludge. At the ozone dosing rate of 0.034 kg/kg-SS, complete elimination of excess sludge has been achieved when 4 times more amount of sludge is ozonated than that of the excess sludge expected in the treatment without ozonation. After 5 months of operation without any withdrawal of excess sludge, small amount of inorganic substances like sand and silt accumulated in the sludge. On the other hand, inert organic substances does not seem to accumulate. As for effluent quality, BOD and nitrogen were kept good. Although effluent SS was 2–15 mg/l higher compared to a control without ozonation, it has been well below the discharge limit.

scholarly journals Effect of Primary Variables on A Confined Plunging Liquid Jet Reactor

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 764 ◽  
Author(s):  
Bader S. Al-Anzi
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Air Entrainment ◽  
Operating Conditions ◽  
Liquid Jet ◽  
Entrainment Rate ◽  
Activated Sludge Process ◽  
Gas Entrainment ◽  
Air Entrainment Rate ◽  
Aeration Process

The effects of operating conditions including a novel downcomer geometry on the gas/air entrainment rate, Qa, were investigated for a local vertical confined plunging liquid jet reactor (CPLJR) as an alternative aeration process that is of interest to Kuwait and can be used in various applications, such as in wastewater treatment as an aerobic activated sludge process, fermentation, brine dispenser, and gas–liquid reactions. Operating conditions, such as various downcomer diameters (Dc = 45−145 mm), jet lengths (Lj = 200–500 mm), nozzle diameters (dn = 3.5–15 mm), and contraction angles (Ɵ =20–80°), were investigated. A newly designed downcomer with various mesh openings/pores (Dm = 0.25ʺ (6.35 mm)–1ʺ (25.4 mm)) was also investigated in the current study. The air entrainment results showed that these were the primary parameters for the measured air entrainment rate in confined systems. The highest gas entrainment rates were achieved when the ratio of the downcomer diameter (Dc) to the nozzle diameter (dn) was greater than approximately 5, as long as the liquid superficial velocity was sufficient to carry bubbles downward. Furthermore, a downcomer with mesh openings (Dm) less or equal to 0.5ʺ (12.7 mm) provided a higher entrainment rate than that of conventional downcomer (without a mesh).

Effect of biosorption on the damping of influent fluctuation in activated sludge aeration tanks

1997 ◽  
Vol 35 (7) ◽  
pp. 79-87 ◽  
Author(s):  
Koichi Fujie ◽  
Hong-Ying Hu ◽  
Byung-Ran Lim ◽  
Huang Xia
Keyword(s):  
Activated Sludge ◽  
Organic Pollutants ◽  
Control Strategies ◽  
Domestic Wastewater ◽  
Activated Sludge Process ◽  
Organic Substances ◽  
Effluent Water ◽  
Organic Removal ◽  
Set Up ◽  
The Mathematical Model

To describe the organic removal performance in an activated sludge process, the effect of biological adsorption (biosorption, hereinafter) of both soluble and particulate organic substances (SOS and POS, respectively, hereinafter) on the rate of organic removal must be taken into account. This study quantitatively investigated the biosorption of organic pollutants in the domestic wastewater by the activated sludge. The capability of biosorption and the rate of bio-oxidation of organic pollutants were formulated based on the experimental results as functions of both COD concentration and temperature. The biosorption capacity of activated sludge was proportional to COD concentration in the mixed liquor originated from the influent. The kinetic expressions were combined with the equation of longitudinal liquid mixing to set up the mathematical model to predict the effluent COD, and thus to clarify the effect of biosorption on the damping of influent fluctuations of both COD concentration and the inflow rate. The model was also successfully applied to assessing the effectiveness of MLSS control strategies in equalizing the effluent water quality.

Operation and Performance of a New Activated Sludge Process: The Contact Stabilization Extended Aeration Hybrid

1982 ◽  
Vol 14 (1-2) ◽  
pp. 367-380
Author(s):  
B H Paepcke ◽  
P H Jones
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Lower Cost ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Process Stability ◽  
Aeration Process ◽  
And Performance

In this study the operation and performance of a contact stabilization process operating under the extended aeration mode is examined. Data was obtained during a detailed plant study carried out at a full scale municipal wastewater treatment plant. This new hybrid activated sludge process has good process stability like the conventional extended aeration process, but achieves this with a significantly smaller aeration tank volume and therefore lower cost.

scholarly journals Treatment of slaughterhouse wastewater using an activated sludge/contact aeration process

2003 ◽  
Vol 47 (12) ◽  
pp. 285-292 ◽  
Author(s):  
C.-K. Chen ◽  
S.-L. Lo
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Two Phase ◽  
Slaughterhouse Wastewater ◽  
Aeration Process ◽  
Biological Treatment System

This study combines a two-phase biological treatment system of activated sludge/contact aeration process by adding biological contact filters into the rear sector of the activated sludge aeration tank of the slaughterhouse wastewater treatment plant. This system keeps the advantages of complete mixing of substrates and microorganisms and flexible operation of the activated sludge process, and increased biological phase, less sludge, process stability and good settleability of sludge of the contact aeration process. This system could avoid the defects of sludge bulking, increased sludge production and difficult operation of the activated sludge process, and system clogging and rigid operation of the contact aeration process. Because suspended microorganisms are flowing into the contact aeration system, which then degrade or suspend within the biological contact filters after being adsorbed by the fixed biological film, on which partial bio-solids will act as seeding microorganisms. Suspended microorganisms and the dropped biological film will settled in the secondary settling tank, then reflux into the activated sludge aeration tank. The partial dropped biological film will decompose in the activated sludge aeration tank to achieve the function of decreasing sludge. Large specific gravity and good settling ability of biofilm sludge will provide better effluent quality. It has been proven through a practical experiment at a slaughterhouse wastewater treatment plant in Taiwan, that the activated sludge process effluent COD value of 150-200 mg/L and SS value of 80-100 mg/L were decreased to around 40 mg/L and 22 mg/L, respectively, after changing its system to the two-phase biological treatment system of activated sludge/contact aeration process.

Sign in / Sign up

Export Citation Format

Share Document