scholarly journals The Effect of Stepwise Changes of Influent Organic Matter Concentration and Operational Mode on Population Dynamics of Bacteria for Phosphorus Removal in Sequencing Batch Reactor(SBR) Activated Sludge Processes.

1993 ◽  
Vol 16 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Chi-Kang LIN ◽  
Youko KATAYAMA ◽  
Mitsumasa OKADA ◽  
Akihiko MURAKAMI
Keyword(s):  
Population Dynamics ◽  
Organic Matter ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Operational Mode ◽  
Organic Matter Concentration ◽  
Activated Sludge Processes ◽  
Matter Concentration

Stability of Phosphorus Removal and Population of Bio-P-Bacteria under Short Term Disturbances in Sequencing Batch Reactor Activated Sludge Process

1992 ◽  
Vol 26 (3-4) ◽  
pp. 483-491 ◽  
Author(s):  
M. Okada ◽  
C. K. Lin ◽  
Y. Katayama ◽  
A. Murakami
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Bacterial Population ◽  
Batch Reactor ◽  
Slow Recovery ◽  
Short Term ◽  
Removal Capacity ◽  
Species Succession ◽  
Activated Sludge Processes

Laboratory-scale sequencing batch reactor(SBR) activated sludge processes were operated to investigate the stability of phosphorus removal capacity and population of bio-P-bacteria under short term disturbances (2 to 5 days) and to characterize the structure and dynamics of bacterial population of activated sludge for phosphorus removal. The performance on phosphorus removal deteriorated in 3 days, whereas it took more than 1 week for the recovery and the time for the recovery prolonged with the length of disturbances. The responses of phosphorus removal activity and quinone profiles suggested that the deterioration and the slow recovery were dependent not on the decrease in the activity of each bio-P-bacteria but on the decrease in their population, i.e. species succession of bacteria. The isolated strains of Acinetobacter and Pseudomonas were seen to be predominant species in the total bacterial population in the activated sludge. These strains showed high activity of phosphorus removal and low specific growth rate indicating also the slow recovery.

Bacteria and Protozoa Population Dynamics in Biological Phosphate Removal Systems

1994 ◽  
Vol 29 (7) ◽  
pp. 109-117 ◽  
Author(s):  
J. S. Čech ◽  
P. Hartman ◽  
M. Macek
Keyword(s):  
Population Dynamics ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Sole Source ◽  
Phosphate Removal ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
System Collapse ◽  
Biological Phosphorus

Population dynamics of polyphosphate-accumulating bacteria (PP bacteria) was studied in a laboratory sequencing batch reactor simulating anaerobic-oxic sludge system. The competition between PP bacteria and another microorganism (“G bacteria”) for anaerobic-oxic utilization of acetate as the sole source of organic carbon was observed. The competition was found to be seriously influenced by protozoan and metazoan grazing: Predation-resistant “G bacteria” forming large compact flocs outcompeted PP bacteria. Several breakdowns of enhanced biological phosphorus removal were observed. The first one was related to the development of an euglenid flagellate Entosiphon sulcatus and attached ciliates Vorticella microstoma and V. campanula. The second system collapse was connected with a rapid proliferation of rotifers. An alternative-prey predation was thought to be a mechanism of PP bacteria elimination.

Simultaneous Removal of Phosphorus and Nitrogen by Sequencing Batch Reactor Activated Sludge Process

1985 ◽  
Vol 17 (11-12) ◽  
pp. 315-316
Author(s):  
Mitsumasa Okada ◽  
Ryuichi Sudo
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Batch Reactor ◽  
Simultaneous Removal ◽  
Activated Sludge Process ◽  
Nitrogen Concentrations ◽  
Stage 1 ◽  
Activated Sludge Processes

Abstract–Phosphorus removal by biological means in continuous-flow aerobic/ anaerobic activated sludge processes is now in a stage of full-scale operations. The similar aerobic/anaerobic treatment is also found in biological processes for nitrogen removal by nitrification followed by denitrification. These processes are successfully applied not only to continuous-flow system but also to sequencing batch reactor (SBR) activated sludge processes, whereas little attempts have been reported on phosphorus removal in SBR activated sludge processes. It is most probable that both phosphorus and nitrogen in addition to organic matter can be removed by the SBR activated sludge processes if aerobic and anaerobic treatments were properly incorporated into a cycle of batch operation. Laboratory scale experiments on aerobic/anaerobic operations of the SBR processes were conducted aiming at simultaneous removal of phosphorus, nitrogen, and organic matter without any addition of chemicals. SBR of 5 1 in working volume was fed with synthetic wastewater in which TOC = 120-200 mg/l, BOD = 200-400 mg/l, total phosphorus = 6-12 mg/1 and total nitrogen = 36-60 mg/1. The following sequence of operations were conducted in a batch cycle; 1) mixing and inflow of wastewater, 2) aeration and mixing, 3) mixing, 4) aeration and mixing, 5) settling and 6) decanting. It was secured from continuous monitoring of dissolved oxygen concentration in the mixed liquor that both anaerobic (stages 1 and 3) and aerobic (stages 2 and 4) treatments were repeated twice in a cycle. In some operations, stages 3 and 4 were omitted for comparison, i.e. anaerobic and aerobic treatments were conducted only once per cycle. The volume of mixed liquor before the inflow of wastewater at the beginning of a cycle (low level) ranged from 33 % to 50 % of that during full volume stages from 2 to 5 (high level). In stage 6, the supernatant was discharged down to the low level and followed by the next cycle of operation. The length of time for a cycle of operation was β h or 9.5 h. Among various types of operations tried, the following sequence was the best in the quality of effluent; 1) 2 h for mixing and inflow, 2) 3 h for aeration and mixing, 3) 3 h for mixing, 4) 20 min for aeration and mixing, 5) 1 h for settling, and 6) 10 min for decanting in a cycle of 9.5 h if influent BOD, total phosphorus and total nitrogen concentrations were 400 mg/1, 12 mg/1 and 60 mg/1, respectively, and BOD loading was 0.68 kg/cu m/d. Total phosphorus and nitrogen concentrations in the effluent were 1.2 mg/1 and 8.0 mg/1, respectively. Similar results were obtained in operations where anaerobic and aerobic treatments were repeated twice in a cycle. In operations where effluent quality was satisfactory, release of phosphorus from the sludge was observed in stage 1. The reactor concentration of filterable total phosphorus (FTP) increased rapidly and its maximum value observed at the end of the stage was ca. 50 mg/1. Phosphorus uptake under aerobic condition (stage 2) decreased FTP to the level of effluent FTP. The luxury uptake of phosphorus by the sludge was noted, i.e. phosphorus content in the sludge ranged from 2.0 % to 4.0 %(w/w). The release of phosphorus from the sludge and subsequent luxury uptake were not significant during stages 3 to 4, hence, further removal of phosphorus was not remarkable. Nitrate nitrogen concentration increased during stage 2 by nitrification. Denitrification was noted both in stages 1 and 3. In stage 1, filterable total organic carbon (FTOC) increased by the inflow of wastewater. It should be, therefore, utilized for denitrification as hydrogen donor. FTOC decreased rapidly after the initiation of aeration in stage 2 and little FTOC remained after the latter half of stage 2. Intracellular organic substances of the sludge, therefore, were regarded to be utilized for denitrification without any addition of chemicals at stage 3. In the best operation, from 50% to 70% out of total nitrogen inflow was removed by denitrification. Effluent BOD was less than 10 mg/l. Although further investigations would be required to determine optimum scheduling in a cycle such as the combination of anaerobic and aerobic periods, the ratio between low and high levels in the reactor, the length of a cycle, and etc. for a given wastewater, the SBR activated sludge process would be a promising wastewater treatment process for simultaneous removal of phosphorus, nitrogen and organiC matter by a single reactor. In spite of complicated operational sequence, full scale automatic operations of SBR activated sludge process would be possible economically even in small-scale plants by using recently advanced microcomputer technology.

Population Dynamics of Bacteria for Phosphorus Removal in Sequencing Batch Reactor (SBR) Activated Sludge Processes

1991 ◽  
Vol 23 (4-6) ◽  
pp. 755-763 ◽  
Author(s):  
M. Okada ◽  
A. Murakami ◽  
C. K. Lin ◽  
Y. Ueno ◽  
T. Okubo
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Growth Rates ◽  
Sodium Acetate ◽  
Sequencing Batch Reactor ◽  
Specific Growth ◽  
Batch Reactor ◽  
Organic Substrates ◽  
Specific Growth Rates ◽  
Activated Sludge Processes

Laboratory-scale sequencing batch reactor (SBR) activated sludge processes were operated using synthetic wastewater to clarify the effects of sludge retention time(SRT) and organic substrates on the accumulation of bio-P-bacteria. The accumulation of bio-P-bacteria could be enhanced by wide variation in concentration of organic substrates by giving a short fill period and sufficient anaerobic conditions. However, the accumulation could not be enhanced in the reactor operated with SRT less than 25 d in spite of the higher, more than 0.1 d−1, specific growth rates observed in the isolated strains of bio-P-bacteria. The specific growth rates of bio-P-bacteria were estimated at 0.040 d−1, 0.030 d−1 and 0.035 d−1 in the SBR activated sludge processes fed with sodium acetate (A), glucose and polypeptone (GP) and polypeptone (P), respectively. Therefore, a large sludge retention time would be necessary for the accumulation of bio-P-bacteria. Volatile fatty acids (VFA), such as sodium acetate (A), seemed to be more effective than other organic substrates (GP and P) for the accumulation of bio-P-bacteria in activated sludge ecosystems.

Organic and nitrogen removal with minimal COD requirement by integration of sequestered denitrification and separate nitrification in a low-loaded activated sludge process

2000 ◽  
Vol 42 (12) ◽  
pp. 65-72 ◽  
Author(s):  
H.-S. Shin ◽  
S.-Y. Nam
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Electron Donor ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Contact Process ◽  
Oxygen Demand ◽  
Specific Mass ◽  
Film Reactor ◽  
Soluble Chemical Oxygen Demand

A separate sludge system incorporating sequencing batch reactor (SBR) for sequestered denitrification and an immobilized fixed-film reactor for nitrification was investigated in this study. Emphases were placed on the preservation of organic matter as an electron donor for denitrification and the improvement of nitrification efficiency by using an immobilization technique with alginate coating. To preserve organic materials in the sludge required for denitrification, a study was made with a contact process. The contactor, when operated with a short detention time, gave incomplete metabolism of organic matter. With 64% of the influent soluble chemical oxygen demand (SCOD) was adsorbed to activated sludge within 30 min. The specific mass of organic matter uptaken was 55 mg SCOD/g mixed liquor suspended solids (MLSS), which enhanced the denitrification efficiency up to 63% in the following denitrification step. Thus, the required COD in the proposed system can be saved up to 63% as an available electron donor for the conventional aerobic process. The immobilized nitrification unit showed over 90% of nitrate production rate up to 50 mg/l of influent ammonia load.

pH: Keyfactor in the Biological Phosphorus Removal Process

1994 ◽  
Vol 29 (7) ◽  
pp. 71-74 ◽  
Author(s):  
G. J. F. Smolders ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Glycogen Metabolism ◽  
Activated Sludge Process ◽  
Biological Phosphorus Removal ◽  
Anaerobic Conditions ◽  
Biochemical Mechanisms ◽  
Biological Phosphorus

Experiments have been performed, using a sequencing batch reactor, to examine the effect of pH on biological phosphorus removal in the activated sludge process. The results, which indicate that glycogen metabolism occurs during anaerobic conditions, are useful in elucidating the biochemical mechanisms involved in phosphorus-removal, and have potential implications for systems such as Phostrip.

Photo-Fenton processes assisted by solar light used as preliminary step to biological treatment applied to winery wastewaters

2007 ◽  
Vol 56 (2) ◽  
pp. 89-94 ◽  
Author(s):  
R. Mosteo ◽  
M.P. Ormad ◽  
J.L. Ovelleiro
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Research Work ◽  
Biological Processes ◽  
Activated Sludge Process ◽  
Fenton Process ◽  
Organic Matter Concentration ◽  
Pre Treatment ◽  
Matter Concentration

Winery wastewaters are difficult to treat by conventional biological processes, because they are seasonal and experience substantial flow variations. Photocatalytic advanced oxidation is a promising technology for wastewaters containing high amounts of organic matter. In this research work, solar assisted photo-Fenton processes of both heterogeneous and homogeneous phase are used in the pre-treatment of winery wastewaters. The results of these experiments have confirmed the suitability of the photo-Fenton processes, due to these treatments achieving purification levels of up to 50% (measured as total organic carbon). The intermediate effluents are treated adequately by aerobic biological treatment (activated sludge process), due to the decrease in organic matter concentration present in winery wastewaters. The possibility of a combined photo-Fenton process, based on the use of sunlight, and aerobic biological treatment (activated sludge) is suggested.

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