Comparison of Biocenoses from Continuous and Sequencing Batch Reactors

1992 ◽  
Vol 25 (6) ◽  
pp. 239-249 ◽  
Author(s):  
J. Wanner
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Continuous Flow ◽  
Sequencing Batch Reactor ◽  
Flow System ◽  
Batch Reactor ◽  
Continuous Reactor ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Filamentous Microorganisms

Sequencing batch reactors (SBR) are often used for research on nutrient removal systems. A model anaerobic-oxic SBR was compared with a compartmentalized continuous-flow system. The levels of COD, phosphorus, and nitrogen removal in both systems were comparable but the biocenoses differed significantly. The SVI values of activated sludge from the continuous reactor ranged between 100 and 200 ml/g although no significant occurrence of filamentous microorganisms was observed. The sequencing batch reactor produced activated sludge with the SVIs below 100 ml/g and with high settling velocities. Filamentous microorganisms were frequently observed in the biocenosis of the SBR. The differences in settling properties and filamentous growth in both reactors are discussed and explained.

scholarly journals Effect of temperatures and alternating anoxic/oxic sequencing batch reactor (SBR) operating modes on extracellular polymeric substances in activated sludge

2020 ◽  
Author(s):  
Hongwei Sun ◽  
Chenjian Cai ◽  
Jixue Chen ◽  
Chunyu Liu ◽  
Guangjie Wang ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Operating Modes ◽  
Nitrification Process ◽  
Main Component ◽  
Denitrification Process

Abstract In order to investigate the effect of temperatures and operating modes on extracellular polymeric substances (EPS) contents, three sequencing batch reactors (SBRs) were operated at temperatures of 15, 25, and 35 °C (R15 °C, R25 °C, and R35 °C, respectively), with two SBRs operated under alternating anoxic/oxic conditions (RA/O and RO/A, respectively). Results showed that higher contents of tightly bound EPS (TB-EPS) and total EPS appeared in R15 °C, while loosely bound EPS (LB-EPS) dominated in R35 °C. In all three kinds of EPS (LB-EPS, TB-EPS and total EPS) assessed, protein was the main component in R15 °C and R25 °C, while polysaccharides dominated in R35 °C. Moreover, compared with RO/A, RA/O was favorable for the production of the three kinds of EPS. Furthermore, three kinds of EPS and their components were augmented during the nitrification process, while they declined during the denitrification process under all conditions except for R35 °C.

scholarly journals Dynamic control of nutrient-removal from industrial wastewater in a sequencing batch reactor, using common and low-cost online sensors

2015 ◽  
Vol 73 (4) ◽  
pp. 740-745 ◽  
Author(s):  
Jan Dries
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Industrial Wastewater ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Low Cost ◽  
Dynamic Control ◽  
Oxygen Demand ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

On-line control of the biological treatment process is an innovative tool to cope with variable concentrations of chemical oxygen demand and nutrients in industrial wastewater. In the present study we implemented a simple dynamic control strategy for nutrient-removal in a sequencing batch reactor (SBR) treating variable tank truck cleaning wastewater. The control system was based on derived signals from two low-cost and robust sensors that are very common in activated sludge plants, i.e. oxidation reduction potential (ORP) and dissolved oxygen. The amount of wastewater fed during anoxic filling phases, and the number of filling phases in the SBR cycle, were determined by the appearance of the ‘nitrate knee’ in the profile of the ORP. The phase length of the subsequent aerobic phases was controlled by the oxygen uptake rate measured online in the reactor. As a result, the sludge loading rate (F/M ratio), the volume exchange rate and the SBR cycle length adapted dynamically to the activity of the activated sludge and the actual characteristics of the wastewater, without affecting the final effluent quality.

Dynamic mathematical modelling of sequencing batch reactors with aerated and mixed filling period

1997 ◽  
Vol 35 (1) ◽  
pp. 105-112 ◽  
Author(s):  
L. Novák ◽  
M. C. Goronszy ◽  
J. Wanner
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Major Elements ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Nitrogen And Phosphorus ◽  
Sludge Flocs ◽  
Solids Concentration ◽  
A Minor ◽  
Selection Of

Sequencing batch reactors (SBRs) can be successfully operated for both carbon and nutrient removal, including nitrogen and phosphorus. The major elements of design that accomplish population dynamics control to prevent filamentous sludge bulking, cycle time, oxygen supply, biological nitrification, denitrification, phosphorus removal and solids-liquid separation need to be set in such a way that sufficiently optimal conditions are provided to permit the reactions and processes to take place. SBR processing using cyclic activated sludge technology employs biological selectors in the inlet part of the SBR system and a minor sludge recycle stream to ensure influent wastewater is mixed with activated sludge flocs to create favourable conditions for kinetic and metabolic selection of microorganisms producing floccules. Reaction volume, in addition to the designated bottom water level volume, is variable through time fed-batch reactor mode of operation. A mathematical model that describes volume changes and simultaneously the biodegradation kinetics has been developed. The model describes theoretical behaviour of selected parameters of volume, suspended solids concentration, OUR, ammonia and nitrate nitrogen in the selector compartment and the main aerated basin in ideally mixed and filled reactors of the cyclic system during the phase of mixed-fill (selector) and aerated and non-aerated fill (main aeration reactor basin).

Occurrence of Microthrix parvicella in sequencing batch reactors

2014 ◽  
Vol 69 (10) ◽  
pp. 1984-1995 ◽  
Author(s):  
Lana Mallouhi ◽  
Ute Austermann-Haun
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Index ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Municipal Wastewater Treatment ◽  
Nitrogen And Phosphorus ◽  
Microthrix Parvicella

Sequencing batch reactors (SBRs) are known for high process stability and usually have a good sludge volume index (SVI). Nevertheless, in many SBRs in Germany for municipal wastewater treatment, scum and foam problems can occur, and SVI can be larger than 200 mL/g. The microscopic investigations of the activated sludge from plants with nitrogen and phosphorus removal have shown that Microthrix parvicella is dominant in the activated sludge in most of them. Studies showed that the optimum growth of M. parvicella is performed at a high sludge age (>20 d) and low sludge load in the range of 0.05–0.2 kg of biochemical oxygen demand per kg of total suspended solids per day (kg BOD5/(TSS·d)). The investigations in 13 SBRs with simultaneous aerobic sludge stabilization (most of them are operated with a system called differential internal cycle strategy sequential batch reactor (DIC-SBR)) show that M. parvicella is able to grow in sludge loads less than 0.05 kg BOD5/(kg TSS·d) as well. To optimize the operation of those SBRs, long cycle times (8–12 h) and dosing of iron salts to eliminate long-chain fatty acids are both recommended. This leads to better SVI and keeps M. parvicella at a low frequency.

Effects of Different Thiobacillus on Bioleaching of Heavy Metals of Sewage Sludge in a Sequencing Batch Reactor

2013 ◽  
Vol 807-809 ◽  
pp. 1445-1450
Author(s):  
Jun Zhang ◽  
Hui Ping Yang ◽  
Dun Qiu Wang ◽  
Zheng Shi Zhang
Keyword(s):  
Heavy Metals ◽  
Ferrous Sulfate ◽  
Sequencing Batch Reactor ◽  
Loss Rate ◽  
Removal Rate ◽  
Batch Reactor ◽  
Acidithiobacillus Thiooxidans ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Average Loss

A bioleaching experiment was carried out in two sequencing batch reactors (SBR) of 80 L. Acidithiobacillus thiooxidans (A. t) and Acidithiobacillus ferrooxidans (A. f) were enrichment cultured by adding sulfur powder and ferrous sulfate as substrate respectively. Sequential batch leaching ran for three periods in succession. The average removal rate of As, Cd, Cr, Cu, Ni, Pb, Zn was 90.46%, 90.28%, 90.70% and 79.70%, 81.19%, 84.52% respectively. The average loss rate of total nutrient (total account of organic matter, TN, TP and TK) is 35.36%, 33.36% and 35.54% for three runs in sequence. Comparing with A. f, the acidification time of A. t is shortened by 3.0, 6.6 and 4.9 d, with the increase of 13.5 %, 11.2% and 7.3% for the removal rate of heavy metals.

Substrate Removal Mechanism for Sequencing Batch Reactors

1986 ◽  
Vol 18 (6) ◽  
pp. 21-33 ◽  
Author(s):  
D. Orhon ◽  
Y. Cimşit ◽  
O. Tünay
Keyword(s):  
Biological Treatment ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Removal Mechanism ◽  
Factors Affecting ◽  
Substrate Removal ◽  
Reactor Types ◽  
The Many

All factors affecting substrate removal in sequencing batch reactor types of biological treatment systems should be fully explored to benefit from the many flexibilities of operation they offer. In this paper, a growth limited model is proposed for this purpose and verified by experimental observations. Interpretation of the results enabled a broader description of the process. It also indicated a number of interesting issues requiring further exploration.

scholarly journals Finding optimal algal/bacterial inoculation ratio to improve algal biomass growth with wastewater as nutrient source

Water SA ◽  
2019 ◽  
Vol 45 (4 October) ◽  
Author(s):  
Le Anh Pham ◽  
Julien Laurent ◽  
Paul Bois ◽  
Adrien Wanko
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Algal Biomass ◽  
Algal Growth ◽  
Total Biomass ◽  
Batch Reactors ◽  
Biomass Growth ◽  
Sequencing Batch Reactors ◽  
Solids Retention ◽  
Removal Efficiencies

Algal growth, nutrient removal and settling efficiency were quantified while inoculating sequencing batch reactors with a mixture of microalgae and bacteria (activated sludge). Three algae/bacteria inoculation ratios (5:1, 1:1 and 1:5) as well as pure algal biomass (control) were assessed. Algal biomass production increased with the addition of activated sludge. However, the addition of too much activated sludge can cause disturbance to the Al-Bac biomass growth and algal bacterial processes. All reactors including the control with only algae showed similar settling and nutrient removal efficiencies. Good settling was observed in all reactors with only 5% of total biomass found in supernatant after 1 h of settling. Removal efficiencies of COD, TN and PO4-P in all reactors were 79–82%, 61–65% and 15–37%, respectively, with the lowest phosphorus removal efficiency belonging to 1:5 algae/activated sludge ratio. These results may be due to both long hydraulic (7 days) and solids retention times (up to 30 days). Finally, Al-Bac biomass with 1:1 inoculation ratio showed the best enhancement in terms of biomass growth and algal activities.

The effect of upflow air velocity on the structure of aerobic granules cultivated in a sequencing batch reactor

2004 ◽  
Vol 49 (11-12) ◽  
pp. 35-40 ◽  
Author(s):  
J.H. Tay ◽  
Q.S. Liu ◽  
Y. Liu
Keyword(s):  
Shear Force ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Batch Reactors ◽  
Aerobic Granules ◽  
Sequencing Batch Reactors ◽  
Air Velocity ◽  
Hydrodynamic Shear ◽  
Biomass Retention

The effect of upflow air velocity on the formation and structure of aerobic granules was studied in three column sequencing batch reactors. Upflow aeration would be the major cause of hydrodynamic shear force in the column reactor. Results showed that high upflow air velocity resulted in more compact, denser, rounder, stronger and smaller aerobic granules, while high biomass retention in the reactor was achieved. It was found that high upflow air velocity could induce granular sludge to secrete more cell polysaccharides which in turn contributed to the compact and strong structure. It appears from this study that the structure of aerobic granules could be controlled by manipulating the upflow air velocity.

Sequencing Batch Reactors for Nutrient Removal at Small Wastewater Treatment Plants

1993 ◽  
Vol 28 (10) ◽  
pp. 233-242 ◽  
Author(s):  
Bjorn Rusten ◽  
Helge Eliassen
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Biological Phosphorus Removal ◽  
Solids Retention ◽  
Co Precipitation

In order to optimize the sequencing batch reactor (SBR) process for nutrient removal at small wastewater treatment plants, a two year study was carried out at a treatment plant designed for 300 population equivalents. Different operating cycles, solids retention times (SRTs) and periods with co-precipitation were included in the test program. Based on the results, recommendations for achieving nitrification, denitrification and biological phosphorus removal were given. A suitable coagulant (and the optimum dosage) for co-precipitation was found as well.

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