Performance of coarse pore filtration activated sludge system

2002 ◽  
Vol 46 (11-12) ◽  
pp. 71-76 ◽  
Author(s):  
M.R. Alavi Moghaddam ◽  
H. Satoh ◽  
T. Mino
Keyword(s):  
Activated Sludge ◽  
Pore Size ◽  
Small Scale ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Trickling Filter ◽  
Conventional Activated Sludge ◽  
Activated Sludge System ◽  
Scale Reactor

A coarse pore filter can be applied inside the aeration tank to facilitate the separation of sludge from liquid instead of sedimentation. This filter has pores, which are irregular in shape, and the pore size is bigger than those of MF. The objectives of the study were to maintain as much as MLSS in the activated sludge process with coarse pore filter and to investigate the performance under high MLSS condition. Small-scale reactor results so far show good quality of effluent specially after starting the sludge bulking in the system in terms of SS, TOC, DOC and turbidity. The average carbon removal for 62 days operation of this system was about 94% (based on effluent DOC) and 87% (based on effluent TOC). The average sludge yield in this system is about 0.44 kg MLSS/kg TOC which is about 0.24 kg MLSS/kg BOD. This amount is less than those of conventional activated sludge and trickling filter.

A full-scale operation of a novel activated sludge process without excess sludge production

1996 ◽  
Vol 34 (3-4) ◽  
pp. 395-404 ◽  
Author(s):  
H. Yasui ◽  
K. Nakamura ◽  
S. Sakuma ◽  
M. Iwasaki ◽  
Y. Sakai
Keyword(s):  
Activated Sludge ◽  
Inorganic Compounds ◽  
Material Balance ◽  
Full Scale ◽  
Aeration Tank ◽  
Total Biomass ◽  
Activated Sludge Process ◽  
Excess Sludge ◽  
Conventional Activated Sludge ◽  
Operation Costs

The authors have presented a new concept of excess sludge elimination treatment with recirculation of sludge via ozonation in the activated sludge process. This paper is intended to clarify the potential application of the process to municipal and industrial wastewater treatments. In a full-scale operational experiment lasting 10 months under 550 kg/d of BOD loading, no excess sludge was needed to be withdrawn and no significant accumulation of inorganic solids occurred in the aeration tank. Most of the inorganic compounds in the sludge were released to the soluble phase. Material balance indicated that one-third of ozonated sludge was mineralized via the recirculation treatment, and thereby the requirement of sludge mass to be treated was 3.3 times as much as sludge to be eliminated. Effluent TOC was slightly higher than under the conventional activated sludge process, indicating that refractory TOC was released from the sludge eliminated by treatment. The amount of released TOC corresponded to less than 2 weight % of eliminated sludge under recirculation rates below 30% of total biomass in the aeration tank in a day, but increased at higher recirculation rates. The operation costs associated with the process were estimated to be lower than those of conventional dewatering and disposal.

New Trickling Filter Applications in the U.S.A.

1990 ◽  
Vol 22 (1-2) ◽  
pp. 215-226 ◽  
Author(s):  
D. S. Parker ◽  
M. P. Lutz ◽  
A. M. Pratt
Keyword(s):  
Activated Sludge ◽  
Poor Quality ◽  
Trickling Filter ◽  
Trickling Filters ◽  
The Poor ◽  
Activated Sludge System ◽  
New Applications ◽  
The U.S

After falling in disfavor in the U.S. in the 1970s, trickling filters are now reappearing in new applications. The Trickling Filter/Solids Contact (TF/SC) process uses physical and biological flocculation features to transform the poor quality of the trickling filter effluent into an effluent equal to the best activated sludge system. Over 50 TF/SC plants have been built since the process was introduced in 1979. The recent development (1988) of the Biofilm-Controlled Nitrifying Trickling Filter (BCNTF) has permitted higher rate operation and rendered the process less costly than the activated sludge system for nitrification. Three BCNTF projects are now underway in the U.S.

An innovative approach to reduce excess sludge production in the activated sludge process

1994 ◽  
Vol 30 (9) ◽  
pp. 11-20 ◽  
Author(s):  
H. Yasui ◽  
M. Shibata
Keyword(s):  
Activated Sludge ◽  
Biomass Concentration ◽  
Experimental Period ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Biological Degradation ◽  
Excess Sludge ◽  
Conventional Activated Sludge ◽  
New Process ◽  
Sludge Production

A new process has been developed to reduce excess sludge production, in which both excess sludge digestion and wastewater treatment are conducted simultaneously in the same aeration tank. The ozonation enhances biological degradation of the activated sludge, which is decomposed in a subsequent biological treatment. A considerable amount of biomass is mineralized biologically in proportion to the amount of recirculated biomass from the ozonation stage to the biological stage. It was observed that the amount of excess sludge is reduced to nearly zero when 1.2 kg/m3-aeration tank volume of biomass is recirculated in a day from the biological stage to the ozonation stage at a BOD loading of 1.0 kg/m3/d. A biomass concentration of 4200 mg/L was maintained at 1.0 kg-BOD/m3/d without drawing excess sludge for 6 weeks of experimental period under ozone dose of 0.05 g-O3/g-SS and recirculation rate at 0.3 d−1. Only a limited difference in the effluent quality was observed between the new process and the conventional activated sludge process.

Nitrogen removal and sludge reduction in a symbiotic activated sludge system between anaerobic archaea and bacteria

2004 ◽  
Vol 50 (6) ◽  
pp. 189-197 ◽  
Author(s):  
H.-B. Jun ◽  
S.-M. Park ◽  
N.-B. Park ◽  
S.-H. Lee
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Biological Activities ◽  
Denitrification Rate ◽  
Nitrification Rate ◽  
Aeration Tank ◽  
Intermittent Aeration ◽  
Conventional Activated Sludge ◽  
Activated Sludge System ◽  
Mineralization Of Organic Matter

The possible symbiosis between bacteria and anaerobic archaea was investigated in intermittent aeration (I/A) systems. Archaea solution added to I/A reactor might play an important role in biological activities as well as in improvement of mineralization of organic matter. I/A reactor with archaea solution (I/A-arch) could increase both nitrification and denitrification rate and also reduce the sludge yield remarkably. These results indicate the possibility of the symbiotic activated sludge system with anaerobic archaea by controlling the DO level in the aeration tank. In this study, DO was controlled by intermittent aeration schemes and a successful symbiotic activated sludge system was achieved to reach the following conclusions. 1) SOUR of I/A-arch system was 2.9 mg-O2/g-VSS·min. SOUR and nitrification rate of the sludge from I/A-arch was higher than those from the I/A and A/S reactors. 2) Removal efficiencies of organic matter (TCODCr) in I/A-arch, I/A and conventional activated sludge (A/S) reactors were 93, 90 and 87%, respectively. 3) Nitrification occurred successfully in each reactor, while denitrification rate was much higher in the I/A-arch reactor. Efficiencies of TN removal in A/I-arch, I/A and A/S reactors were 75, 63 and 33%, respectively. 4) Observed yield coefficients of I/A-arch, I/A and A/S reactors were 0.28, 0.41 and 0.37 g-VSS/g-COD.

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Shock Load ◽  
Economic Evaluations ◽  
Activated Sludge Process ◽  
Trickling Filter

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.

High rate and compact single sludge pre-denitrification process for retrofit

1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
High Rate ◽  
Activated Sludge Process ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Treatment Techniques ◽  
Conventional Activated Sludge Process ◽  
Denitrification Process

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.

Advanced Treatment of Domestic Wastewater Using Sequencing Batch Reactor Activated Sludge Process

1993 ◽  
Vol 28 (10) ◽  
pp. 267-274 ◽  
Author(s):  
M. Imura ◽  
E. Suzuki ◽  
T. Kitao ◽  
S. Iwai
Keyword(s):  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Domestic Wastewater ◽  
Experimental Period ◽  
Small Scale ◽  
Experimental Plant ◽  
Activated Sludge Process ◽  
Nitrogen And Phosphorus ◽  
Experimental Apparatus

In order to apply a sequencing batch reactor activated sludge process to small scale treatment facilities, various experiments were conducted by manufacturing an experimental apparatus made of a factory-produced FRP cylinder transverse tank (Ø 2,500mm). Results of the verification test conducted for one year by leading the wastewater discharged from apartment houses into the experimental apparatus were as follows. Excellent performance was achieved without any addition of carbon source, irrespective of the organic compound concentration and the temperature of raw wastewater. Organic substances, nitrogen and phosphorus were removed simultaneously. Due to the automated operation format, stable performance was obtained with only periodic maintenance. Though water depth of the experimental plant was shallow, effective sedimentation of activated sludge was continued during the experimental period. Regarding the aerobic and anaerobic process, nitrification and denitrification occurred smoothly.

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