Long-term performance evaluation of EBPR process in tropical climate: start-up, process stability, and the effect of operational pH and influent C:P ratio

2013 ◽  
Vol 67 (2) ◽  
pp. 340-346 ◽  
Author(s):  
Y. H. Ong ◽  
A. S. M. Chua ◽  
B. P. Lee ◽  
G. C. Ngoh
Keyword(s):  
Phosphorus Removal ◽  
Removal Rate ◽  
Batch Reactor ◽  
Sewage Treatment ◽  
Tropical Climate ◽  
Phosphorus Concentration ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
C:P Ratio ◽  
Tropical Climates

To date, little information is known about the operation of the enhanced biological phosphorus removal (EBPR) process in tropical climates. Along with the global concerns on nutrient pollution and the increasing array of local regulatory requirements, the applicability and compliance accountability of the EBPR process for sewage treatment in tropical climates is being evaluated. A sequencing batch reactor (SBR) inoculated with seed sludge from a conventional activated sludge (CAS) process was successfully acclimatized to EBPR conditions at 28 °C after 13 days' operation. Enrichment of Candidatus Accumulibacter phosphatis in the SBR was confirmed through fluorescence in situ hybridization (FISH). The effects of operational pH and influent C:P ratio on EBPR were then investigated. At pH 7 or pH 8, phosphorus removal rates of the EBPR processes were relatively higher when operated at C:P ratio of 3 than C:P ratio of 10, with 0.019–0.020 and 0.011–0.012 g-P/g-MLVSS•day respectively. One-year operation of the 28 °C EBPR process at C:P ratio of 3 and pH 8 demonstrated stable phosphorus removal rate of 0.020 ± 0.003 g-P/g-MLVSS•day, corresponding to effluent with phosphorus concentration <0.5 mg/L. This study provides the first evidence on good EBPR activity at relatively high temperature, indicating its applicability in a tropical climate.

The bioaugmentation of sequencing batch reactor sludges for biological phosphorus removal

1997 ◽  
Vol 35 (1) ◽  
pp. 19-26 ◽  
Author(s):  
E. Belia ◽  
P. G. Smith
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Pure Culture ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Sewage Treatment Plant ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
Biological Phosphorus

The development of enhanced biological phosphorus removal (EBPR) through the bioaugmentation of a conventional activated sludge was studied. The objectives of the study were to evaluate the phosphorus removal capability of a sequencing batch reactor (SBR) when started with conventional activated sludge and augmented with a pure culture of Acinetobacter lwoffii. The effect of the addition of the pure culture on the reactor start up time, the settling properties of the sludge and on COD and nitrogen removal was also investigated. The effect of the removal of up to 70% of the bioaugmented biomass and its substitution with unconditioned sludge from a conventional sewage treatment plant was determined. This study has demonstrated that bioaugmentation can convert a conventional sewage works activated sludge to an EBPR sludge in 14 days. The sludge produced shows resilience to influent phosphate fluctuations, low D.O. and biomass replacement. The COD and nitrogen removal capabilities of the sludge and its settling properties are not affected by the addition of the pure culture.

Upgrading Wastewater Treatment Plants with Anaerobic Selectors

1990 ◽  
Vol 22 (7-8) ◽  
pp. 35-43
Author(s):  
K. D. Tracy ◽  
S. N. Hong
Keyword(s):  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
High Rate ◽  
Nitrogen Control ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
And Performance ◽  
Activated Sludge Processes ◽  
Biological Phosphorus

The anaerobic selector of the A/0™ process offers many advantages over conventional activated sludge processes with respect to process performance and operational stability. This high-rate, single-sludge process has been successfully demonstrated in full-scale operations for biological phosphorus removal and total nitrogen control in addition to BOD and TSS removal. This process can be easily utilized in upgrading existing treatment plants to meet stringent discharge limitations and to provide capacity expansion. Upgrades of two full-scale installations are described and performance data from the two facilities are presented.

Operation Experiences with Biological Phosphorus Removal at the Sewage Treatment Plants of Berlin (West)

1991 ◽  
Vol 24 (7) ◽  
pp. 133-148 ◽  
Author(s):  
A. Peter ◽  
F. Sarfert
Keyword(s):  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Chemical Precipitation ◽  
Biological Phosphorus Removal ◽  
Treatment Results ◽  
Sewage Treatment Plants ◽  
Research Activities ◽  
Two Stages ◽  
The Given ◽  
Biological Phosphorus

In investigations concerning sludge bulking in Berlin enhanced biological phosphorus removal was first observed unexpectedly. Because since 1986 an officially preset limit of 2 mg TP/l must be kept in all Berlin wastewater discharges it was decided to explore the capabilities of the observed mechanism under the specific circumstances of the exciting two large treatment plants in Ruhleben (240,000 m3/d) and Marienfelde (100,000 m3/d). For this purpose some of the existing units at both plants were equipped with anaerobic zones which were generated mainly by process modifications. Additionally stage one of the Ruhleben plant was altered completely in order to investigate the combination of biological phosphorus and nitrogen removal as a special pilot study in three parallel trains. The research activities and treatment results gained in each of the two stages of the Ruhleben and in the Marienfelde plant are reported in detail. For example BOD-related phosphorus removal rates were obtained ranging from 2.3-4.5 mg TP per 100 mg BOD removed. It must be stressed that all examinations were performed on full-scale conditions. At present the given limit of 2 mg TP/l in the Ruhleben plant is met without any chemical precipitation at least on average. From the beginning biological phosphorus removal will be integrated into further projected extensions.

Biological Phosphorus Removal in a Sequencing Batch Moving Bed Biofilm Reactor

1999 ◽  
Vol 40 (4-5) ◽  
pp. 161-168 ◽  
Author(s):  
H. Helness ◽  
H. Ødegaard
Keyword(s):  
Phosphorus Removal ◽  
Batch Reactor ◽  
Complete Removal ◽  
Biofilm Reactor ◽  
Biological Phosphorus Removal ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Biofilm Carrier ◽  
Biofilm Process ◽  
Biological Phosphorus

Experiments have been carried out with biological phosphorus removal in a sequencing batch moving bed biofilm reactor (SBMBBR) with a plastic biofilm carrier (Kaldnes) suspended in the wastewater. The aim of the research leading to this paper was to evaluate biological phosphorus removal in this type of biofilm process. Biological phosphorus removal can be achieved in a moving bed biofilm reactor operated as a sequencing batch reactor. In order to achieve good and stable phosphorus removal over time, the length of the anaerobic period should be tuned to achieve near complete removal of easily biodegradable COD in the anaerobic period. The total COD-loading rate must at the same time be kept high enough to achieve a net growth of biomass in the reactor. Use of multivariate models based on UV-absorption spectra and measurements of the redox potential show potential for control of such a process.

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.

Impact of cold and dilute sewage on pre-fermentation - a case study

2001 ◽  
Vol 43 (11) ◽  
pp. 109-117 ◽  
Author(s):  
D. Bixio ◽  
P. van Hauwermeiren ◽  
C. Thoeye ◽  
P. Ockier
Keyword(s):  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
High Rate ◽  
Cold Weather ◽  
Biological Nutrient Removal ◽  
Municipal Sewage ◽  
Biological Phosphorus Removal ◽  
Primary Sludge

The municipal sewage treatment plant (STP) of the city of Ghent (Belgium) has to be retrofitted to a 43%-increase in the nitrogen treatment capacity and to phosphorus removal. Cold weather, dilute sewage and a critical COD over N ratio make the retrofit a challenge for full biological nutrient removal. The potential for fermentation of primary sludge to alter those critical feed sewage characteristics was experimentally evaluated. The idea was that the pinpoint introduction of fermentate could optimise the available reactors by achieving high-rate denitrification and enhanced biological phosphorus removal. The fermentation process was evaluated with a bench scale apparatus. At 20°C (heated process), the hydrolysis yield - expressed in terms of soluble COD - varied from 11% to 24% of the total sludge COD. The fermentation yield expressed in VFA COD varied from 8% to 13% of the total sludge COD. The efficiency of heated fermentation of primary sludge was lower during cold and wet weather, due to the different sewage characteristics, as a result of extended dilution periods and low temperature. The raw sewage, the primary effluent and the fermentate were fractionated according to the requirements for the IAWQ Activated Sludge Model No. 2d. The results clearly show that fermentation in the sewer played an important role and temperature was the driving parameter for the characteristics of the dissolved COD. Instead, the weather flow conditions were the driving parameter for the characteristics of the suspended COD. The results of the detailed fractionation were used as background for process evaluation. The final scenario choice for the retrofit depends on a cost-efficiency calculation.

An enhanced biological phosphorus removal (EBPR) control strategy for sequencing batch reactors (SBRs)

2001 ◽  
Vol 43 (3) ◽  
pp. 183-189 ◽  
Author(s):  
C. Y. Dassanayake ◽  
R. L. Irvine
Keyword(s):  
Control Strategy ◽  
Phosphorus Removal ◽  
Batch Reactor ◽  
Past Research ◽  
P Uptake ◽  
Batch Reactors ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Aeration Time ◽  
Biological Phosphorus

A control strategy was developed for enhanced biological phosphorus removal (EBPR) in a Sequencing Batch Reactor (SBR). Unlike past research that focused on maximizing polyhdroxyalkanoate (PHA) formation during the anaerobic period, this study investigated some of the factors that govern aerobic PHA dynamics and its efficient regulation during phosphate (P) uptake. Influent COD, influent P, and the time for aeration were critical factors that governed PHA use and P uptake during aerated react. Unnecessary PHA oxidation (i.e., in the absence of extracellular P) occurred if the time for aerated react exceeded the time required for P uptake. By adjusting the aeration time to that required for P uptake, residual PHA was sustained in the SBR and excess phosphate uptake reaction potential (PRP) was generated for use during transient influent excursions in P. Unlike space oriented systems, the time for react is simply adjusted in the SBR. Because residual PHA is easily maintained once achieved, high influent COD events can be harnessed to increase or sustain excess PRP for management of expected variations in influent P.

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