Nitrogen removal and sludge reduction in a symbiotic activated sludge system between anaerobic archaea and bacteria

2004 ◽  
Vol 50 (6) ◽  
pp. 189-197 ◽  
Author(s):  
H.-B. Jun ◽  
S.-M. Park ◽  
N.-B. Park ◽  
S.-H. Lee
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Biological Activities ◽  
Denitrification Rate ◽  
Nitrification Rate ◽  
Aeration Tank ◽  
Intermittent Aeration ◽  
Conventional Activated Sludge ◽  
Activated Sludge System ◽  
Mineralization Of Organic Matter

The possible symbiosis between bacteria and anaerobic archaea was investigated in intermittent aeration (I/A) systems. Archaea solution added to I/A reactor might play an important role in biological activities as well as in improvement of mineralization of organic matter. I/A reactor with archaea solution (I/A-arch) could increase both nitrification and denitrification rate and also reduce the sludge yield remarkably. These results indicate the possibility of the symbiotic activated sludge system with anaerobic archaea by controlling the DO level in the aeration tank. In this study, DO was controlled by intermittent aeration schemes and a successful symbiotic activated sludge system was achieved to reach the following conclusions. 1) SOUR of I/A-arch system was 2.9 mg-O2/g-VSS·min. SOUR and nitrification rate of the sludge from I/A-arch was higher than those from the I/A and A/S reactors. 2) Removal efficiencies of organic matter (TCODCr) in I/A-arch, I/A and conventional activated sludge (A/S) reactors were 93, 90 and 87%, respectively. 3) Nitrification occurred successfully in each reactor, while denitrification rate was much higher in the I/A-arch reactor. Efficiencies of TN removal in A/I-arch, I/A and A/S reactors were 75, 63 and 33%, respectively. 4) Observed yield coefficients of I/A-arch, I/A and A/S reactors were 0.28, 0.41 and 0.37 g-VSS/g-COD.

Performance of coarse pore filtration activated sludge system

2002 ◽  
Vol 46 (11-12) ◽  
pp. 71-76 ◽  
Author(s):  
M.R. Alavi Moghaddam ◽  
H. Satoh ◽  
T. Mino
Keyword(s):  
Activated Sludge ◽  
Pore Size ◽  
Small Scale ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Trickling Filter ◽  
Conventional Activated Sludge ◽  
Activated Sludge System ◽  
Scale Reactor

A coarse pore filter can be applied inside the aeration tank to facilitate the separation of sludge from liquid instead of sedimentation. This filter has pores, which are irregular in shape, and the pore size is bigger than those of MF. The objectives of the study were to maintain as much as MLSS in the activated sludge process with coarse pore filter and to investigate the performance under high MLSS condition. Small-scale reactor results so far show good quality of effluent specially after starting the sludge bulking in the system in terms of SS, TOC, DOC and turbidity. The average carbon removal for 62 days operation of this system was about 94% (based on effluent DOC) and 87% (based on effluent TOC). The average sludge yield in this system is about 0.44 kg MLSS/kg TOC which is about 0.24 kg MLSS/kg BOD. This amount is less than those of conventional activated sludge and trickling filter.

Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor

2011 ◽  
Vol 63 (4) ◽  
pp. 733-740 ◽  
Author(s):  
E. Sahar ◽  
M. Ernst ◽  
M. Godehardt ◽  
A. Hein ◽  
J. Herr ◽  
...  
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Macrolide Antibiotics ◽  
Organic Micropollutants ◽  
Removal Rates ◽  
Conventional Activated Sludge

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8–10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin – at an MLSS of 6–9 g/L – showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.

Inhibition of sulfide generation by dosing formaldehyde and its derivatives in sewage under anaerobic conditions

2008 ◽  
Vol 57 (6) ◽  
pp. 915-919 ◽  
Author(s):  
L. Zhang ◽  
L. Mendoza ◽  
M. Marzorati ◽  
W. Verstraete
Keyword(s):  
Hydrogen Sulfide ◽  
Oxygen Uptake ◽  
Activated Sludge ◽  
Oxygen Uptake Rate ◽  
Urea Formaldehyde ◽  
Nitrification Rate ◽  
Economic Aspects ◽  
Anaerobic Conditions ◽  
Activated Sludge System ◽  
The Impact

Hydrogen sulfide emission in sewers is associated with toxicity, corrosion, odor nuisance and a lot of costs. The possibility to inhibit sulfide generation by formaldehyde and its derivatives (paraformaldehyde and urea formaldehyde) has been evaluated under anaerobic conditions. The impact of formaldehyde on an activated sludge system and an appraisal of the economic aspects are also presented. The optimum dosage to inhibit sulfide generation in sewage was 12–19 mg L−1 formaldehyde. The dosages of 32 mg L−1 paraformaldehyde or 100 mg L−1 urea formaldehyde were not capable of inhibiting sulfide generation in sewage. The impact of 19 mg L−1 formaldehyde on activated sludge system was negligible in terms of COD removal, nitrification rate and oxygen uptake rate.

Evaluation of ozonation and cryptic growth for biosolids management in wastewater treatment

1999 ◽  
Vol 39 (10-11) ◽  
pp. 155-158 ◽  
Author(s):  
E. Egemen ◽  
J. Corpening ◽  
J. Padilla ◽  
R. Brennan ◽  
N. Nirmalakhandan
Keyword(s):  
Activated Sludge ◽  
Continuous Flow ◽  
Growth Conditions ◽  
Aeration Tank ◽  
Biomass Growth ◽  
Waste Sludge ◽  
Process Configuration ◽  
Activated Sludge System ◽  
Expensive Problems ◽  
Cryptic Growth

The ultimate disposal of biosolids has been and continues to be one of the most expensive problems faced by wastewater utilities. The objective of this research is to develop a process configuration for reducing the waste sludge generation in an activated sludge plant by promoting cryptic growth conditions (i.e., biomass growth on intracellular products). For this purpose, excess biosolids from a continuous flow activated sludge system were solubilized using ozone as the cell lysis agent, and then returned to the aeration tank. It is hypothesized that growth under such cryptic conditions will result in low net microbial yields, and hence, minimal net solids wastage. The results of these preliminary studies indicate that the proposed process configuration has the potential to reduce the waste sludge production by 40% to 60%.

scholarly journals Nitrous oxide emissions from an intermittent aeration activated sludge system of an urban wastewater treatment plant

Química Nova ◽  
2013 ◽  
Vol 36 (1) ◽  
pp. 16-20 ◽  
Author(s):  
William Z. de Mello ◽  
Renato P. Ribeiro ◽  
Ariane C. Brotto ◽  
Débora C. Kligerman ◽  
Andrezza de S. Piccoli ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Nitrous Oxide Emissions ◽  
Intermittent Aeration ◽  
Urban Wastewater ◽  
Activated Sludge System ◽  
Urban Wastewater Treatment

Molecular Weight Distributions of Soluble Organic Matter in Various Secondary and Tertiary Effluents

1987 ◽  
Vol 19 (3-4) ◽  
pp. 529-538 ◽  
Author(s):  
Gary L. Amy ◽  
Curtis W. Bryant ◽  
Mosen Belyani
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Activated Sludge ◽  
Water Reuse ◽  
Treatment Process ◽  
Apparent Molecular Weight ◽  
Pure Oxygen ◽  
Soluble Organic Matter ◽  
Conventional Activated Sludge ◽  
Absorbing Material

Differences in the nature of soluble organic matter were measured for various full-scale wastewater treatment processes. Conventional activated sludge, pure oxygen activated sludge, biofiltration, granular activated carbon, and tertiary sand filtration were evaluated. Effluent soluble organic matter was analyzed by ultrafiltration for the apparent molecular weight distribution of soluble organic carbon and UV-absorbing material. The effects of annual season, secondary treatment process, and tertiary treatment process upon the properties of the effluent soluble organic matter were statistically significant at the 99% level. Effluent properties from the various treatments were sufficiently different to support the concept of the selection of appropriate treatments to minimize the effluent concentration of specific fractions of the soluble organic material as required for specific water reuse applications.

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