Performance evaluation of a UASB - activated sludge system treating municipal wastewater

2001 ◽  
Vol 43 (11) ◽  
pp. 323-328 ◽  
Author(s):  
M. von Sperling ◽  
V. H. Freire ◽  
C. A. de Lemos Chernicharo
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Large City ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Warm Climate ◽  
Conventional Activated Sludge ◽  
Activated Sludge System ◽  
Solids Concentration ◽  
Sufficient Detail

Recent research has indicated the advantages of combining anaerobic and aerobic processes for the treatment of municipal wastewater, especially for warm-climate countries. Although this configuration is seen as an economical alternative, is has not been investigated in sufficient detail on a worldwide basis. This work presents the results of the monitoring of a pilot-scale plant comprising of an UASB reactor followed by an activated sludge system, treating actual municipal wastewater from a large city in Brazil. The plant was intensively monitored and operated for 261 days, divided into five different phases, working with constant and variable inflows. The plant showed good COD removal, with efficiencies ranging from 69% to 84% for the UASB reactor, from 43% to 56% for the activated sludge system only and from 85% to 93% for the overall system. The final effluent suspended solids concentration was very low, with averages ranging from 13 to 18 mg/l in the typical phases of the research. Based on the very good overall performance of the system, it is believed that it is a better alternative for warm-climate countries than the conventional activated sludge system, especially considering the total low hydraulic detention time (4.0 h UASB; 2.8 h aerobic reactor; 1.1 h final clarifier), the savings in energy consumption, the absence of primary sludge and the possibility of thickening and digesting the aerobic excess sludge in the UASB reactor itself.

Municipal wastewater treatment targeting pharmaceuticals by a pilot-scale hybrid attached biofilm and activated sludge system (Hybas™)

Chemosphere ◽  
2020 ◽  
Vol 259 ◽  
pp. 127397 ◽  
Author(s):  
Kai Tang ◽  
Gordon T.H. Ooi ◽  
Elena Torresi ◽  
Kamilla M.S. Kaarsholm ◽  
Adam Hambly ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Municipal Wastewater Treatment ◽  
Activated Sludge System ◽  
Treatment Targeting

Operation of different membrane bioreactors: experimental results and physiological state of the micro-organisms

2000 ◽  
Vol 41 (10-11) ◽  
pp. 269-277 ◽  
Author(s):  
S. Rosenberger ◽  
R. Witzig ◽  
W. Manz ◽  
U. Szewzyk ◽  
M. Kraume
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Physiological State ◽  
High Strength ◽  
Dry Weight ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Conventional Activated Sludge ◽  
Consumption Rates ◽  
Microfiltration Membranes

Lab-scale and pilot-scale activated sludge bioreactors with integrated microfiltration membranes were operated over a period of up to three years. During the entire operation period no excess sludge was removed from the bioreactors apart from sampling, resulting in highly concentrated biomass in the reactors. The dry weight of the sludge ranged from 15 to 23 g MLSS l–1 for a plant fed with municipal wastewater and up to 60 g ll–1 for a lab-scale plant fed with high strength molasses. Stable biomass concentrations were reached at F/M ratios as low as approximately 0.07 kg COD (kg MLSS)–1 d–1. The degradation performance of the analyzed reactors was high and stable. Direct microscopical studies revealed high amounts of free suspended cells and at various times also high numbers of filamentous bacteria. Surprisingly only low numbers of protozoa were observed during most of the time. By use of fluorescent in situ hybridization (FISH) only about 40% to 50% of all bacteria emitted probe conferred fluorescence signals sufficient for detection, compared to around 80% cells detectable in conventional activated sludge. Studies on oxygen consumption rates indicated that the biomass in the bioreactor was substrate limited. These data suggest that substrate is mainly oxidized and not used for growth purposes which offers the possibility to operate membrane bioreactors with significantly reduced secondary sludge production.

Effectiveness of the membrane bioreactor in the biodegradation of high molecular-weight compounds

1996 ◽  
Vol 34 (9) ◽  
pp. 197-203 ◽  
Author(s):  
H. Winnen ◽  
M. T. Suidan ◽  
P. V. Scarpino ◽  
B. Wrenn ◽  
N. Cicek ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Extended Period ◽  
Membrane System ◽  
Pilot Scale ◽  
Synthetic Wastewater ◽  
Activated Sludge Process ◽  
Conventional Activated Sludge ◽  
Heterotrophic Microorganisms

The activated sludge process has been used extensively to treat municipal wastewater. The membrane bioreactor (MBR) process is a modification of the conventional activated sludge process where the clarifier is replaced with a membrane system for separation between the mixed liquor and the effluent. This paper presents the biological and physical performance data of a pilot-scale membrane bioreactor system, fed with a synthetic wastewater. At steady state, particularly high effluent quality was obtained and maintained for an extended period of time. Heterotrophic plate counting showed that the membrane retains heterotrophic microorganisms. Bacteriophage MS-2 was used to determine the retention of viruses. The membrane proved to retain the MS-2 virus.

Treatment of municipal wastewater in a CIRCOX® airlift reactor with integrated denitrification

1997 ◽  
Vol 36 (1) ◽  
pp. 173-181 ◽  
Author(s):  
C. T. M. J. Frijters ◽  
D. H. Eikelboom ◽  
A. Mulder ◽  
R. Mulder
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Loading Rate ◽  
Airlift Reactor ◽  
Loading Rates ◽  
Activated Sludge System ◽  
Conversion Rates ◽  
Substrate Conversion ◽  
Airlift Pump ◽  
Interesting Alternative

In this study it was investigated whether the CIRCOX® airlift technology with integrated denitrification was suitable to treat municipal wastewater. The standard CIRCOX® reactor was extended with an anoxic compartment. The sludge on carrier is circulated alternately over the anoxic and oxic compartments by means of an airlift pump. The study was performed in two pilot reactors, a standard CIRCOX® reactor and a CIRCOX® reactor with integrated denitrification. Concerning BOD conversion and nitrification, no differences between the two systems were observed. It was shown that both BOD and nitrogen were removed efficiently. In the effluent, mean soluble BOD concentrations of 7 mg/l were attained at varying COD loading rates. Nitrification was complete in both reactors at temperatures above 15°C and at COD conversion rates of more than 2.5 kg COD/m3/d. Nitrification rates below 15°C were higher as compared to a low loaded activated sludge system. Substrate conversion rates were found to be constant throughout the denitrifying reactor. Denitrification matched the rates theoretically feasible. This could be achieved by controlling the recirculation and the aeration in relation to the loading rate. It can be concluded that the denitrifying CIRCOX® airlift technology seems to be an interesting alternative to treat municipal wastewater.

scholarly journals LCA of a Membrane Bioreactor Compared to Activated Sludge System for Municipal Wastewater Treatment

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas
Keyword(s):  
Wastewater Treatment ◽  
Life Cycle ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Municipal Wastewater Treatment ◽  
Conventional Activated Sludge

Membrane bioreactor (MBR) systems are connected to several advantages compared to the conventional activated sludge (CAS) units. This work aims to the examination of the life cycle environmental impact of an MBR against a CAS unit when treating municipal wastewater with similar influent loading (BOD = 400 mg/L) and giving similar high-quality effluent (BOD < 5 mg/L). The MBR unit contained a denitrification, an aeration and a membrane tank, whereas the CAS unit included an equalization, a denitrification, a nitrification, a sedimentation, a mixing, a flocculation tank and a drum filter. Several impact categories factors were calculated by implementing the Life Cycle Assessment (LCA) methodology, including acidification potential, eutrophication potential, global warming potential (GWP), ozone depletion potential and photochemical ozone creation potential of the plants throughout their life cycle. Real data from two wastewater treatment plants were used. The research focused on two parameters which constitute the main differences between the two treatment plants: The excess sludge removal life cycle contribution—where GWPMBR = 0.50 kg CO2-eq*FU−1 and GWPCAS = 2.67 kg CO2-eq*FU−1 without sludge removal—and the wastewater treatment plant life cycle contribution—where GWPMBR = 0.002 kg CO2-eq*FU−1 and GWPCAS = 0.14 kg CO2-eq*FU−1 without land area contribution. Finally, in all the examined cases the environmental superiority of the MBR process was found.

scholarly journals Clustering, morphology, and treatment resistance of Bacillus globigii spores recovered from a pilot-scale activated sludge system

Chemosphere ◽  
2020 ◽  
Vol 260 ◽  
pp. 127591
Author(s):  
Yun Xing ◽  
Jeff Szabo ◽  
Matthew Magnuson ◽  
Willie F. Harper
Keyword(s):  
Activated Sludge ◽  
Treatment Resistance ◽  
Pilot Scale ◽  
Activated Sludge System

Environmental performance of an integrated fixed-film activated sludge (IFAS) reactor treating actual municipal wastewater during start-up phase

2015 ◽  
Vol 72 (10) ◽  
pp. 1840-1850 ◽  
Author(s):  
Nitin Kumar Singh ◽  
Absar Ahmad Kazmi ◽  
Markus Starkl
Keyword(s):  
Activated Sludge ◽  
Pathogenic Bacteria ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Lessons Learned ◽  
Present System ◽  
Salmonella Spp ◽  
Start Up ◽  
Fixed Film

The present study summarizes the start-up performance and lessons learned during the start-up and optimization of a pilot-scale plant employing integrated fixed film activated sludge (IFAS) process treating actual municipal wastewater. A comprehensive start-up was tailored and implemented to cater for all the challenges and problems associated with start-up. After attaining desired suspended biomass (2,000–3,000 mg/L) and sludge age (∼7 days), the average biological oxygen demand (BOD) and chemical oxygen demand (COD) removals were observed as 77.3 and 70.9%, respectively, at optimized conditions, i.e. hydraulic retention time (HRT), 6.9 h; return sludge rate, 160%. The influent concentrations of COD, BOD, total suspended solids, NH3-N, total nitrogen and total phosphorus were found to be in the range of 157–476 mg/L, 115–283 mg/L, 152–428 mg/L, 23.2–49.3 mg/L, 30.1–52 mg/L and 3.6–7.8 mg/L, respectively, and the minimum effluent concentrations were achieved as ∼49 mg/L, 23 mg/L, 35 mg/L, 2.2 mg/L, 3.4 mg/L and 2.8 mg/L, respectively, at optimum state. The present system was found effective in the removal of pathogenic bacteria (Escherichia coli, 79%; Salmonella spp., 97.5%; Shigella spp., 92.9%) as well as coliforms (total coliforms, 97.65%; faecal coliforms, 80.35%) without any disinfection unit. Moreover it was observed that the time required for the stabilization of the plant was approximately 3 weeks if other parameters (sludge age, HRT and dissolved oxygen) are set to optimized values.

Removal Efficiency of Environmental Endocrine Disrupting Chemicals Pollutants-Phthalate Esters in Northern WWTP

2013 ◽  
Vol 807-809 ◽  
pp. 694-698
Author(s):  
Rong Xin Huang ◽  
Zhen Xing Wang ◽  
Gang Liu ◽  
Qi Jin Luo
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Phthalate Esters ◽  
Endocrine Disrupting Chemicals ◽  
Treatment Plant ◽  
Activated Sludge Process ◽  
Wastewater Reclamation ◽  
Conventional Activated Sludge

In order to guarantee the reliability and security of reclaiming water, research on the removal efficiency of the environmental endocrine chemicals (EDCs) --the Phthalate Esters (PAEs) in conventional secondary activated sludge and wastewater reclamation and reuse process was undergoing at Harbin wastewater treatment plant (WWTP). The wastewater samples were colleted from every unit effluent of WWTP. The results showed that contamination of EDCs were presented in municipal wastewater at Harbin and the concentrations of the four PAEs were 21.01μg/L for Di-n-butyl Phthalate (DBP); 9.63μg/L for Di-n-octyl Phthalate (DnOP); 4.56μg/L for Diethyl Phthalate (DEP); 1.96μg/L for Dimethyl Phthalate (DMP) respectively in the influent. The conventional activated sludge has good removal efficiencies performance on DMP, DEP and DBP. With the increasing of molecular weight and branch chains of PAEs contaminations, the removal rate of the four PAEs in the conventional activated sludge process decreased from 99.82%(DMP)，90.60%(DEP)，90.10%(DBP) to the only 45.13% removal rate for DnOP, which was mostly removed from primary treatment but no from secondary activated sludge process; Coagulation-air flotation plus filtration process was not a feasible way to remove PAEs from reclaiming treatment units.

Fate of selected RCRA compounds in a pilot-scale activated sludge system

1996 ◽  
Vol 68 (3) ◽  
pp. 260-269 ◽  
Author(s):  
S. K. Bhattacharya ◽  
R. L. Madura ◽  
R. A. Dobbs ◽  
R. V. R. Angara ◽  
H. Tabak
Keyword(s):  
Activated Sludge ◽  
Pilot Scale ◽  
Activated Sludge System
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