Evaluating upgrade possibilities of activated sludge wastewater treatment plants utilizing biofilm-based treatment technologies – an experimental study at the South Pest WWTP

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
N. Szilágyi ◽  
R. Kovács ◽  
I. Kenyeres ◽  
B. Törő ◽  
Zs. Csikor ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Plant Root ◽  
Pilot Scale ◽  
Load Reduction ◽  
The South ◽  
Treatment Technologies ◽  
Biofilm Carriers

As more and more wastewater treatment plants (WWTPs) arrive to a point in their lifecycles when their original capacities are not sufficient anymore, the demand for good WWTP retrofitting solutions becomes increasingly critical. One of the typical problems is the suspended solids overload of secondary clarifiers, which is one of the main concerns at the South Pest WWTP as well. Pilot scale studies were carried out at the WWTP with a biofilm based technology applying biofilm carriers imitating plant root structures in order to characterize the potentials of clarifier TSS load reduction while maintaining the existing biodegradation performance of the activated sludge stage. The research demonstrated that the clarifier load can be reduced by more than 90%, while the original biodegradation performance of the system does not decrease. In addition to this, it was demonstrated that the biomass amount in the reactors can be increased substantially opening potentials for further biodegradation capacity.

Performance of activated sludge diffusion for biological treatment of hydrogen sulphide gas emissions

2013 ◽  
Vol 68 (9) ◽  
pp. 1932-1939 ◽  
Author(s):  
Vera L. Barbosa ◽  
Richard M. Stuetz
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Hydrogen Sulphide ◽  
Biological Treatment ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Broad Application ◽  
H2s Removal ◽  
Treatment Performance ◽  
Solids Concentration

Odours from wastewater treatment plants are comprised of a mixture of various gases with hydrogen sulphide (H2S) often being the dominant constituent. Activated sludge diffusion (ASD) as a biotreatment system for odour abatement has been conducted for over 30 years but has limited broad application due to disagreement in the literature regarding the effect that ASD may have on wastewater treatment performance. The effects of continuous H2S diffusion at 25 ppmv, with weekly peaks of approximately 100 ppmv, on H2S removal efficiency and wastewater treatment performance was evaluated over a 2-month period using an activated sludge pilot plant. H2S removal averaged 100% during diffusion at 25 ppmv, and 98.9% during the 100 ppmv peak periods. A significant increase in mixed liquor volatile suspended solids concentration (P < 0.01) was observed during H2S diffusion, which may be due to an increase in H2S-degrading microorganisms. There was no adverse effect of H2S on nitrification throughout the ASD trials. Ammonia (NH3) removal was slightly better in the test receiving H2S diffusion (87.6%) than in the control (85.4%). H2S diffusion appeared to improve robustness of the AS biomass to operational upsets.

scholarly journals Reliability of removal of selected pollutants in different technological solutions of household wastewater treatment plants

2017 ◽  
Vol 35 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michał Marzec
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Total Suspended Solids ◽  
Hybrid Reactor ◽  
Limit Values

AbstractThe reliability of removal of selected contaminants in three technological solutions of the household sewage treatment plants was analysed in this paper. The reliability of the sewage treatment plant with activated sludge, sprinkled biological deposit and hybrid reactor (activated sludge and immersed trickling filter) was analyzed. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, COD and total suspended solids. The technological reliability of the active sludge treatment plant was 70% for BOD5, 87% for COD and 66% for total suspended solids. In the sewage treatment plant with a biological deposit, the reliability values determined were: 30% (BOD5), 60% (COD) and 67% (total suspended solids). In a treatment plant with a hybrid reactor, 30% of the BOD5and COD limit values were exceeded, while 30% of the total suspended solids were exceeded. The reliability levels are significantly lower than the acceptable levels proposed in the literature, which means that the wastewater discharged from the analysed wastewater treatment plants often exceeds the limit values of indicators specified in currently valid in Poland Regulation of the Minister of Environment for object to 2000 population equivalent.

Oxidation-reduction potential (ORP) regulation of nutrient removal in activated sludge wastewater treatment plants

2002 ◽  
Vol 46 (1-2) ◽  
pp. 35-39 ◽  
Author(s):  
B. Li ◽  
P. Bishop
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Redox Status ◽  
Organic Substrate ◽  
Microbial Biodegradation ◽  
Scale Experiment ◽  
One Year

Redox potential (ORP) regulation of nutrient removal in aeration tanks was tested for one year in three activated sludge wastewater treatment plants in Cincinnati, OH. The experiment results show a good relationship between ORP values and nutrient removal. Macro-biodegradation and sorption of substrate by activated sludge can significantly increase wastewater ORP, indicating the improvement of redox status of the bulk liquor. DO higher than 1.0 mg/L is necessary for good biodegradation and the improvement of liquid redox status. ORP values at higher temperatures (Twater=20–26°C) were lower than ORP values at lower temperatures (Twater=14–19°C), caused by the lower oxygen saturation capacity in wastewater and the more rapid oxygen consumption by microorganism under warmer conditions. Nitrification occurred at higher ORP values (380 mV) than did organic substrate oxidation (250mV). This verifies that different metabolic processes dominate in different ORP ranges. The pilot-scale experiment results demonstrate that the wastewater ORP values continued to increase throughout the whole 6-hour cycle when the influent COD was higher than 1,000 mg/L. For influent with low COD (40–120 mg/L), the wastewater ORP values did not increase in the second 3 hours of the cycle, during which time the microbial-biodegradation within the activated sludge floc dominated. High DO concentrations (6–8 mg/L) did not help improve the redox status. In fully-aerated wastewater, oxygen deeply penetrated into the activated sludge flocs, and microorganisms biodegraded the substrates within the flocs. Endogenous metabolism predominated.

Microsieving in primary treatment: effect of chemical dosing

2016 ◽  
Vol 74 (2) ◽  
pp. 438-447 ◽  
Author(s):  
J. Väänänen ◽  
M. Cimbritz ◽  
J. la Cour Jansen
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Municipal Wastewater Treatment ◽  
Chemically Enhanced Primary Treatment ◽  
Municipal Wastewater Treatment Plants

Primary and chemically enhanced primary wastewater treatment with microsieving (disc or drum filtration) was studied at the large pilot scale at seven municipal wastewater treatment plants in Europe. Without chemical dosing, the reduction of suspended solids (SS) was (on average) 50% (20–65%). By introducing chemically enhanced primary treatment and dosing with cationic polymer only, SS removal could be controlled and increased to >80%. A maximum SS removal of >90% was achieved with a chemical dosing of >0.007 mg polymer/mg influent SS and 20 mg Al3+/L or 30 mg Fe3+/L. When comparing sieve pore sizes of 30–40 μm with 100 μm, the effluent SS was comparable, indicating that the larger sieve pore size could be used due to the higher loading capacity for the solids. Phosphorus removal was adjusted with the coagulant dose, and a removal of 95–97% was achieved. Moreover, microsieving offers favourable conditions for automated dosing control due to the low retention time in the filter.

Tracking influent inorganic suspended solids through wastewater treatment plants

2006 ◽  
Vol 54 (8) ◽  
pp. 101-109 ◽  
Author(s):  
G.A. Ekama ◽  
M.C. Wentzel ◽  
S.W. Sötemann
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Settling Tank ◽  
Treatment Plant ◽  
Primary Sludge ◽  
Unit Operations ◽  
Sludge Digestion ◽  
N Removal

From an experimental and theoretical investigation of the continuity of influent inorganic suspended solids (ISS) along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) and anaerobic and aerobic sludge digestion unit operations, it was found that the influent wastewater (fixed) ISS concentration is conserved through primary sludge anaerobic digestion, activated sludge and aerobic digestion unit operations. However, the measured ISS flux at different stages through a series of wastewater treatment plant (WWTP) unit operations is not equal to the influent ISS flux, because the ordinary heterotrophic organisms (OHO) biomass contributes to the ISS flux by differing amounts depending on the active fraction of the VSS solids at that stage.

Modelling of wastewater treatment plants – how far shall we go with sophisticated modelling tools?

2006 ◽  
Vol 53 (3) ◽  
pp. 79-89 ◽  
Author(s):  
G.C. Glover ◽  
C. Printemps ◽  
K. Essemiani ◽  
J. Meinhold
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Full Scale ◽  
Structure Identification ◽  
Oxidation Ditch ◽  
Computational Fluid Dynamics Analysis

Several levels of complexity are available for modelling of wastewater treatment plants. Modelling local effects rely on computational fluid dynamics (CFD) approaches whereas activated sludge models (ASM) represent the global methodology. By applying both modelling approaches to pilot plant and full scale systems, this paper evaluates the value of each method and especially their potential combination. Model structure identification for ASM is discussed based on a full-scale closed loop oxidation ditch modelling. It is illustrated how and for what circumstances information obtained via CFD (computational fluid dynamics) analysis, residence time distribution (RTD) and other experimental means can be used. Furthermore, CFD analysis of the multiphase flow mechanisms is employed to obtain a correct description of the oxygenation capacity of the system studied, including an easy implementation of this information in the classical ASM modelling (e.g. oxygen transfer). The combination of CFD and activated sludge modelling of wastewater treatment processes is applied to three reactor configurations, a perfectly mixed reactor, a pilot scale activated sludge basin (ASB) and a real scale ASB. The application of the biological models to the CFD model is validated against experimentation for the pilot scale ASB and against a classical global ASM model response. A first step in the evaluation of the potential of the combined CFD-ASM model is performed using a full scale oxidation ditch system as testing scenario.

Operational and control practices to improve the performance of small wastewater treatment plants in Catalonia

2000 ◽  
Vol 41 (1) ◽  
pp. 53-56 ◽  
Author(s):  
C. Camos ◽  
S. Martorell ◽  
A. Rey ◽  
D. Güell ◽  
J. Robusté ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Solids Separation ◽  
And Control ◽  
Separation Problems

Observations during routine wastewater treatment plants (WWTP) controls in Catalonia suggest that in small Activated Sludge (AS) plants suspended solids separation problems could reach a special intensity. In order to evaluate their incidence, filamentous scums, clarifier floating solids, rising sludge, deflocculation and bulking incidences occurring in 34 small WWTP were controlled for a year. To improve the efficiency of these plants, analyses of mainly suspended solids separation problems were systematically performed.

scholarly journals Metagenomic analysis of an ecological wastewater treatment plant’s microbial communities and their potential to metabolize pharmaceuticals

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 1881 ◽  
Author(s):  
Ian N. Balcom ◽  
Heather Driscoll ◽  
James Vincent ◽  
Meagan Leduc
Keyword(s):  
Drinking Water ◽  
Wastewater Treatment ◽  
Microbial Communities ◽  
Agricultural Soils ◽  
Wastewater Treatment Plants ◽  
Plant Root ◽  
Cost Effective ◽  
Treatment Tank ◽  
Treatment Technologies ◽  
Visitor Center

Pharmaceuticals and other micropollutants have been detected in drinking water, groundwater, surface water, and soil around the world. Even in locations where wastewater treatment is required, they can be found in drinking water wells, municipal water supplies, and agricultural soils. It is clear conventional wastewater treatment technologies are not meeting the challenge of the mounting pressures on global freshwater supplies. Cost-effective ecological wastewater treatment technologies have been developed in response. To determine whether the removal of micropollutants in ecological wastewater treatment plants (WWTPs) is promoted by the plant-microbe interactions, as has been reported for other recalcitrant xenobiotics, biofilm microbial communities growing on the surfaces of plant roots were profiled by whole metagenome sequencing and compared to the microbial communities residing in the wastewater. In this study, the concentrations of pharmaceuticals and personal care products (PPCPs) were quantified in each treatment tank of the ecological WWTP treating human wastewater at a highway rest stop and visitor center in Vermont. The concentrations of detected PPCPs were substantially greater than values reported for conventional WWTPs likely due to onsite recirculation of wastewater. The greatest reductions in PPCPs concentrations were observed in the anoxic treatment tank where Bacilli dominated the biofilm community. Benzoate degradation was the most abundant xenobiotic metabolic category identified throughout the system. Collectively, the microbial communities residing in the wastewater were taxonomically and metabolically more diverse than the immersed plant root biofilm. However, greater heterogeneity and higher relative abundances of xenobiotic metabolism genes was observed for the root biofilm.

Relationship for Clarification Efficiency of Circular Secondary Clarifiers

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2539-2542 ◽  
Author(s):  
N. S. Voutchkov
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Solids Concentration

This paper discusses a regression-based model describing clarification efficiency of circular activated sludge secondary clarifiers. Surface overflow rate was found to be well correlated with effluent suspended solids, sidewater depth and settled sludge volume at three full scale wastewater treatment plants during a six month study. Relationship was verified to be sufficiently accurate for prediction of effluent suspended solids concentration over a six month period at another three treatment plants.

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