Filtration characteristics of immersed coarse pore filters in an activated sludge system for domestic wastewater reclamation

2007 ◽  
Vol 55 (1-2) ◽  
pp. 51-58 ◽  
Author(s):  
G.T. Seo ◽  
B.H. Moon ◽  
Y.M. Park ◽  
S.H. Kim
Keyword(s):  
Activated Sludge ◽  
Domestic Wastewater ◽  
Woven Fabric ◽  
Wastewater Reclamation ◽  
Fabric Filter ◽  
Tubular Type ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
Filtration Area ◽  
Plate Type

The filtration characteristics of two different module configurations with coarse pore filter (non-woven fabric) were investigated for sludge floc separation in an activated sludge reactor for domestic wastewater reclamation. A polypropylene non-woven fabric filter (35 g/m2) was used for the two different module configurations, one flat and one tubular type, each with a filtration area of 0.052 m2. The different module types, submerged in the oxic compartment of A/O (anaerobic/oxic) type reactors, were operated simultaneously. The filtration fluxes were gradually increased from 0.5 to 1.2 and 1.73 m/d. The filtration pressures were more stably maintained for the tubular type module than the plate type. The tubular type module installed horizontally with two-side suction showed less filtration pressures than the tubular type module installed vertically with one-side suction. The solid separation was significantly high showing less than 5 mg/L effluent solids. The organic and T-N removal efficiencies were around 95 and 50%, respectively. The 85% removal of T-P was achieved with 20 mg/L injection of PAC (poly-aluminum chloride).

Non-woven fabric filter separation activated sludge reactor for domestic wastewater reclamation

2003 ◽  
Vol 47 (1) ◽  
pp. 133-138 ◽  
Author(s):  
G.T. Seo ◽  
B.H. Moon ◽  
T.S. Lee ◽  
T.J. Lim ◽  
I.S. Kim
Keyword(s):  
Activated Sludge ◽  
Domestic Wastewater ◽  
Woven Fabric ◽  
Wastewater Reclamation ◽  
Permeate Flux ◽  
Liquid Separation ◽  
Fabric Filter ◽  
Activated Sludge Reactor ◽  
Solid Liquid ◽  
Solid Liquid Separation

A non-woven fabric filter was experimentally evaluated for solid-liquid separation in an activated sludge reactor as an alternative membrane. A polypropylene fabric filter (70, 50 and 35 g/m2) was used for the experiment. The pilot system was operated in A/O (Anaerobic/Oxic) type in which the filter module was submerged into the oxic compartment. The filtration module consists of 10 plate type rectangular filter elements with effective filtration area, 2 m2. Gravity filtration was carried out for solid-liquid separation by changing the water head 0.05–0.5 m without backwashing during the system operation. Initial permeate flux was set at 0.4 m/d. C/N ratio of raw wastewater was controlled at 4.5 in terms of BOD/T-N. The fabric filter system showed a good performance enough for domestic wastewater treatment. Effluent solid concentration was 3.2 mg/L (93.5% removal). COD removal efficiency was 91.6% producing an effluent concentration around 13 mg/L. 66% of total nitrogen removal could be obtained at the adjusted C/N ratio of influent wastewater. However phosphorus removal was very low at 23%. It was found that the initial flux of 0.4 m/d should be maintained for stable performance of the system.

A comparison of NH4/NO3 control strategies for alternating activated sludge processes

1999 ◽  
Vol 39 (4) ◽  
pp. 93-102 ◽  
Author(s):  
L. J. S. Lukasse ◽  
K. J. Keesman ◽  
A. Klapwijk ◽  
G. van Straten
Keyword(s):  
Activated Sludge ◽  
Time Delays ◽  
Control Strategies ◽  
Treatment Plant ◽  
Biological Processes ◽  
Effluent Quality ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
The Difference ◽  
Activated Sludge Processes

Four control strategies for N-removal in alternating activated sludge plants (ASP's) are compared: 1. timer-based, 2. switching the aeration on/off when depletion of nitrate/ammonium is detected, 3. switching the aeration on/off when ammonium crosses an upper/lower-bound, 4. the newly developed adaptive receding horizon optimal controller (ARHOC) as presented in Lukasse et al. (1997). The comparison is made by simulating the controllers' application to an alternating continuously-mixed activated sludge reactor preceded by a small anoxic reactor for predenitrification. The biological processes in the reactors are modelled by the activated sludge model no. 1. Realistic influent patterns, measured at a full-scale wastewater treatment plant, are used. The results show that three totally different controllers (timer-based, NH4-bounds based and ARHOC) can achieve a more or less equal effluent quality, if tuned optimally. The difference mainly occurs in the sensitivity to suboptimal tunings. The timer-based strategy has a higher aeration demand. The sensitivity of the ARHOC controller to sub-optimal tuning, known measurement time delays and changing plant loads is significantly less than that of the other controllers. Also its tuning is more natural and explicit.

Simultaneous biological removal of sulphide and nitrate by autotrophic denitrification in an activated sludge system

2006 ◽  
Vol 53 (12) ◽  
pp. 91-99 ◽  
Author(s):  
I. Manconi ◽  
A. Carucci ◽  
P. Lens ◽  
S. Rossetti
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Electron Donor ◽  
Product Formation ◽  
Fish Analysis ◽  
Autotrophic Denitrification ◽  
Biological Removal ◽  
N Removal ◽  
Activated Sludge Reactor ◽  
Denitrification Process

The feasibility of an autotrophic denitrification process in an activated sludge reactor, using sulphide as the electron donor, was tested for simultaneous denitrification and sulphide removal. The reactor was operated at nitrate (N) to sulphide (S) ratios between 0.5 and 0.9 to evaluate their effect on theN-removal efficiency, the S-removal efficiency and the product formation during anoxic oxidation of sulphide. One hundred per cent removal of both nitrate and sulphide was achieved at a NLR of 7.96 mmol N·L−1·d−1 (111.44 mg NO3−-N·L−1·d−1) and at a N/S ratio of 0.89 with complete oxidation of sulphide to sulphate. The oxygen level in the reactor (10%) was found to influence the N-removal efficiency by inhibiting the denitrification process. Moreover, chemical (or biological) oxidation of sulphide with oxygen occurred, resulting in a loss of the electron donor. FISH analysis was carried out to study the microbial population in the system.

scholarly journals Comparison Between Continuous and Batch Flow Activated Sludge Reactor to Remove Nitrate and Phosphate From Domestic Wastewater

2012 ◽  
Vol 9 (1) ◽  
pp. 37-42
Author(s):  
Waleed Sheet ◽  
Afaf Obed ◽  
Masuod Hazaa ◽  
Safa Badeaa ◽  
Manolea Aiden
Keyword(s):  
Activated Sludge ◽  
Domestic Wastewater ◽  
Activated Sludge Reactor

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

A Batch Activated Sludge Study of Pineapple Wastewater Using a Bioaugmentation Process

1991 ◽  
Vol 24 (5) ◽  
pp. 233-240 ◽  
Author(s):  
Nik Fuaad Nik Abllah ◽  
Aik Heng Lee
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
Batch Reactors ◽  
Organic Loading ◽  
Suitable Alternative ◽  
Organic Removal ◽  
Sludge Production

A laboratory study was conducted to determine the feasibility of batch activated sludge reactor for treating pineapple wastewater and to examine the effects of bioaugmentation on treatment performance. The experimental set-up consists of eleven batch reactors. Activated sludge obtained from a wastewater treatment plant treating domestic wastewater was used as seed for the reactors. Synthetic pineapple wastewater was used as feed for the reactors. The eleven reactors were arranged to evaluate the total organic removal, nitrification, and sludge production by bioaugmentation process. Three major factors considered were influent organic loading, ammonia-nitrogen, and dosage of bacterial-culture-product addition. Removal of TOG (total organic carbon), sludge production in terms of SS(suspended solids), and ammonia-nitrogen removal variation are used as evaluation parameters. The TOC removal efficiency after the end of a 48 hour reactor run, for influent TOC of 350.14 to 363.30 mg/l, and 145.92 to 169.66 mg/l, was 94.41 to 95.89%, and 93.72 to 94.73% respectively. Higher organic removal was observed in the bioaugmented reactors with higher organic loading. The better organic removal efficiency in the bioaugmented reactors was probably due to activities of bacteria added. The test results also indicated that sludge yield was enhanced by the bacteria additive and high bacteria dosage produced less sludge. Bioaugmentation was observed to be a suitable alternative for enhancing the biological treatment of pineapple wastewater.

scholarly journals Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge

2021 ◽  
Vol 11 (4) ◽  
pp. 1889 ◽  
Author(s):  
Agnieszka Micek ◽  
Krzysztof Jóźwiakowski ◽  
Michał Marzec ◽  
Agnieszka Listosz ◽  
Tadeusz Grabowski
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Treated Wastewater ◽  
Contaminant Removal ◽  
Nitrogen And Phosphorus ◽  
Wastewater Samples ◽  
Polish Law

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

scholarly journals Simultaneous removal of BOD, N and P in a single continuous flow real scale activated sludge reactor with cyclic aeration

2020 ◽  
Vol 15 (1) ◽  
pp. 201-212
Author(s):  
Álvaro Orozco-Jaramillo ◽  
Santiago Vélez-Velásquez
Keyword(s):  
Continuous Flow ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Aeration Tank ◽  
Domestic Wastewater Treatment ◽  
Stable Conditions ◽  
Activated Sludge Reactor ◽  
Anoxic Environment ◽  
Real Scale ◽  
Composite Samples

Abstract The present study evaluates the performance of a real scale domestic wastewater treatment plant (WWTP), operating under continuous flow conditions with ‘extremely high sludge age’, designed to remove organic matter and perform nitrification-denitrification within a single reactor under cyclic aeration. Composite samples were withdrawn from the reactor for one week and their analysis results compared satisfactorily with the calculations of the design models. The WWTP is operating under stable conditions with a BOD5 removal of 86%, COD removal of 87%, TKN removal of 73% and, unexpectedly, a stable removal of 55% of total phosphorus. The design of the WWTP is simple and consists of a single aeration tank with a kinetic selector and a secondary sedimentation tank, operating under cyclic conditions in the aeration tank, with 45-minute aeration on (oxic environment) and 15 minutes aeration off (anoxic environment). The system can be applied to upgrade WWTP from secondary to tertiary treatment with only small modifications. A phosphorus removal mechanism is also proposed.

Nitrite reduction and methanogenesis in a single-stage UASB reactor

2015 ◽  
Vol 72 (12) ◽  
pp. 2236-2242 ◽  
Author(s):  
L. I. Borges ◽  
C. M. López-Vazquez ◽  
H. García ◽  
J. B. van Lier
Keyword(s):  
Domestic Wastewater ◽  
High Strength ◽  
Single Stage ◽  
Nitrite Reduction ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
N Removal

In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO2−-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO2−-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO2−-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO2− reduction to N2. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

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