Batch test procedures as tools for calibration of the activated sludge model - a pilot scale demonstration

1998 ◽  
Vol 37 (4-5) ◽  
pp. 235-242 ◽  
Author(s):  
Gert Holm Kristensen ◽  
Jes la Cour Jansen ◽  
Per Elberg Jørgensen
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Model Calibration ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Test Procedures ◽  
Process Dynamics ◽  
Analysis System ◽  
Nitrate And Nitrite ◽  
The Impact

Various mathematical models have been developed to facilitate the design and operation of biological nutrient removal plants. Proper calibration of such models can be a difficult task due to the large number of variable process coefficients. The paper describes a strategy for model calibration based on batch characterizations of wastewater and activated sludge biomass and demonstrates its applicability through modelling of the process dynamics in a highly dynamic activated sludge pilot plant. A comprehensive experimental programme was undertaken comprising batch characterizations of readily degradable and easily hydrolysable COD in influent wastewater, maximum and endogenous process rates for functional microorganism groups in the activated sludge, and half-saturation process constants to describe the impact of oxygen on nitrification and denitrification. An on-line measurement of ammonia and nitrate and nitrite using a Flow Injection Analysis System was conducted for two consecutive days to study the process dynamics in a BioDenitro pilot plant for two parallel activated sludge process tanks. It was possible to closely mimic the dynamics of the nitrogen removal processes in the two tanks based on the model calibration strategy using wastewater and biomass characteristics determined in batch experiments.

Nitrification preservation in activated sludge during curative bulking chlorination

2003 ◽  
Vol 47 (11) ◽  
pp. 85-92 ◽  
Author(s):  
E. Cotteux ◽  
P. Duchene
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Oxygen Uptake Rate ◽  
Ammonia Concentration ◽  
Synthetic Wastewater ◽  
Biological Wastewater Treatment ◽  
Simple Method ◽  
Method Of Measurement ◽  
The Impact

The bulking that occurs in biological wastewater treatment plants using activated sludge is very often controlled by the injection of sodium hypochlorite into the return activated sludge (RAS) stream. In the present study undertaken at two pilot plants fed with synthetic wastewater, the impact of the pass frequency of the sludge at the chlorine dosing point on the nitrifying flora is analysed. The pass frequency is one for the pilot plant 1 and two for the pilot plant 2. A dose of chlorine of 4.85 ± 0.05 g/kg/MLVSS per day was applied at both pilots. The preservative effect on nitrifying activity of the lowest concentration of chlorine at the dosing point and therefore of the highest pass frequency was evidenced. Among other tools, a simple method of measurement of the oxygen uptake rate enabled us to monitor the effect of chlorination on nitrification before recording an increase in the ammonia concentration in the bulking.

Membrane bio-reactor for textile wastewater treatment plant upgrading

2005 ◽  
Vol 52 (4) ◽  
pp. 91-98 ◽  
Author(s):  
C. Lubello ◽  
R. Gori
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Experimental Period ◽  
Pilot Scale ◽  
Wastewater Reclamation ◽  
Textile Wastewater Treatment ◽  
Secondary Settling ◽  
Solid Liquid

Textile industries carry out several fiber treatments using variable quantities of water, from five to forty times the fiber weight, and consequently generate large volumes of wastewater to be disposed of. Membrane Bio-reactors (MBRs) combine membrane technology with biological reactors for the treatment of wastewater: micro or ultrafiltration membranes are used for solid-liquid separation replacing the secondary settling of the traditional activated sludge system. This paper deals with the possibility of realizing a new section of one existing WWTP (activated sludge+clariflocculation+ozonation) for the treatment of treating textile wastewater to be recycled, equipped with an MBR (76 l/s as design capacity) and running in parallel with the existing one. During a 4-month experimental period, a pilot-scale MBR proved to be very effective for wastewater reclamation. On average, removal efficiency of the pilot plant (93% for COD, and over 99% for total suspended solids) was higher than the WWTP ones. Color was removed as in the WWTP. Anionic surfactants removal of pilot plant was lower than that of the WWTP (90.5 and 93.2% respectively), while the BiAS removal was higher in the pilot plant (98.2 vs. 97.1). At the end cost analysis of the proposed upgrade is reported.

A pilot-scale study on PVA gel beads based integrated fixed film activated sludge (IFAS) plant for municipal wastewater treatment

2015 ◽  
Vol 73 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Nitin Kumar Singh ◽  
Jasdeep Singh ◽  
Aakansha Bhatia ◽  
A. A. Kazmi
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
16S Rrna Genes ◽  
Volume Index ◽  
Rrna Genes ◽  
Gel Beads

In the present study, a pilot-scale reactor incorporating polyvinyl alcohol gel beads as biomass carrier and operating in biological activated sludge mode (a combination of moving bed biofilm reactor (MBBR) and activated sludge) was investigated for the treatment of actual municipal wastewater. The results, during a monitoring period of 4 months, showed effective removal of chemical oxygen demand (COD), biological oxygen demand (BOD) and NH3-N at optimum conditions with 91%, ∼92% and ∼90% removal efficiencies, respectively. Sludge volume index (SVI) values of activated sludge varied in the range of 25–72 mL/g, indicating appreciable settling characteristics. Furthermore, soluble COD and BOD in the effluent of the pilot plant were reduced to levels well below discharge limits of the Punjab Pollution Control Board, India. A culture dependent method was used to enrich and isolate abundant heterotrophic bacteria in activated sludge. In addition to this, 16S rRNA genes analysis was performed to identify diverse dominant bacterial species in suspended and attached biomass. Results revealed that Escherichia coli, Pseudomonas sp. and Nitrosomonas communis played a significant role in biomass carrier, while Acinetobactor sp. were dominant in activated sludge of the pilot plant. Identification of ciliated protozoa populations rendered six species of ciliates in the plant, among which Vorticella was the most dominant.

Evaluation of the impacts of model-based operation of SBRs on activated sludge microbial community

2006 ◽  
Vol 54 (1) ◽  
pp. 157-166 ◽  
Author(s):  
G. Sin ◽  
R. Govoreanu ◽  
N. Boon ◽  
G. Schelstraete ◽  
P.A. Vanrolleghem
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Pilot Scale ◽  
Optimal Operation ◽  
Community Level ◽  
Molecular Monitoring ◽  
Process Dynamics ◽  
Model Based ◽  
Nutrient Removal Efficiency ◽  
The Stability

Impact of model-based operation of nutrient removing SBRs on the stability of activated sludge population was studied in this contribution. The optimal operation scenario found by the systematic model-based optimisation protocol of Sin et al. (Wat. Sci. Tech., 2004, 50(10), 97–105) was applied to a pilot-scale SBR and observed to considerably improve the nutrient removal efficiency in the system. Further, the process dynamics was observed to change under the optimal operation scenario, e.g. the nitrite route prevailed and also filamentous bulking was provoked in the SBR system. At the microbial community level as monitored by DGGE, a transient shift was observed to gradually take place parallel to the shift into the optimal operation scenario. This implies that the model-based optimisation of a nutrient removing SBR causes changes at the microbial community level. This opens future perspectives to incorporate the valuable information from the molecular monitoring of activated sludge into the model-based optimisation methodologies. In this way, it is expected that model-based optimisation approaches will better cover complex and dynamic aspects of activated sludge systems.

The effect of chemical bulking control on biological nutrient removal in a full scale activated sludge plant

1996 ◽  
Vol 34 (3-4) ◽  
pp. 275-282 ◽  
Author(s):  
G. B. Saayman ◽  
C. F. Schutte ◽  
J. van Leeuwen
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Pilot Scale ◽  
Full Scale ◽  
City Council ◽  
Phosphate Removal ◽  
Biological Nutrient Removal ◽  
Removal Processes ◽  
The City

The use of chemicals for sludge bulking control has a direct effect on the biological nutrient removal processes in activated sludge systems designed for this purpose. Chlorine has been used on full scale but information on the use of ozone and hydrogen peroxide is limited to pilot scale tests. The objective of this study was to investigate the effects of chlorine, ozone and hydrogen peroxide on nutrient removal processes when used on a continuous basis for bulking control in a full scale biological nutrient removal activated sludge plant. The full scale studies were conducted over a period of 39 months at the Daspoort sewage works of the City Council of Pretoria. The results indicate that at low dosages the oxidants have limited effects on the nutrient removal processes but at higher levels chlorine had a detrimental effect resulting in the phosphate limit of 1 mg P.1−1 being exceeded. It is concluded that chlorine is the most effective of the three oxidants for bulking control, but that it should be used with caution in order not to upset the biological phosphate removal processes. Ozone at low levels had a small but consistent positive effect on bulking control as well as on nutrient removal. The effects of hydrogen peroxide were very small except at high dosages.

Test of the Activated Sludge Model's Capabilities as a Prognostic Tool on a Pilot Scale Wastewater Treatment Plant

1992 ◽  
Vol 25 (6) ◽  
pp. 185-194 ◽  
Author(s):  
Jan Pedersen ◽  
Ole Sinkjær
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Prognostic Tool ◽  
Activated Sludge Model ◽  
Simulation Programme ◽  
Positive Results

A newly developed simulation programme, based on the Activated Sludge Model No. 1, was used to investigate the model's abilities to predict variations in a Bio-Denipho pilot plant. The model was tested under both normal conditions and in connection with an inhibition incident on the pilot plant with positive results.

Design of fine-bubble aeration systems for municipal WWTPs with high sea salt concentrations

2017 ◽  
Vol 75 (7) ◽  
pp. 1555-1563 ◽  
Author(s):  
S. Sander ◽  
J. Behnisch ◽  
M. Wagner
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Sea Salt ◽  
Favourable Effect ◽  
Municipal Wastewater Treatment ◽  
Fine Bubble ◽  
Municipal Wastewater Treatment Plants ◽  
The Impact

The impact of sea salt on the aeration coefficient kLa of fine-bubble aeration systems was investigated in clean water and in a model substance for simulating activated sludge. The investigations were carried out at laboratory and pilot scale. Sea salt was dosed in the form of artificial seawater, real seawater or simplified, by adding NaCl. The investigated media showed an increase of kLa with rising sea salt concentrations up to 10 g/L. The ratio between kLa and sea salt concentration is impaired by the air flow rate and the type of applied diffusers. Literature data show that the favourable effect of sea salt on kLa can also be found in the activated sludge of conventional municipal wastewater treatment plants. The results of this study allow the derivation of salt correction equations to be used in the design of fine-bubble aeration systems for taking into account the favourable impact of sea salt on kLa. By that means, a more precise design of respective systems will be enabled.

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