Enhanced reduction of excess sludge and nutrient removal in a pilot-scale A2O-MBR-TAD system

2011 ◽  
Vol 63 (8) ◽  
pp. 1547-1556 ◽  
Author(s):  
J. S. Ventura ◽  
S. Seo ◽  
I. Chung ◽  
I. Yeom ◽  
H. Kim ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Nutrient Removal ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Excess Sludge ◽  
E Coli ◽  
Effluent Quality ◽  
Cryptic Growth ◽  
A2o Process ◽  
Sludge Production

In this study, a pilot scale anaerobic-anoxic-oxic (A2O) process with submerged membrane (MBR) in the oxic tank was coupled with thermophilic aerobic digestion (TAD) reactor and was operated for longer than 600 days to treat real domestic wastewater. Regardless of the varying conditions of the system, the A2O-MBR-TAD process removed MLSS, TCOD, BOD, TN, TP, and E. coli about 99%, 96%, 96%, 70%, 83%, and 99%, respectively. The additional TP removal of the system was due to the precipitating agent directly added in the oxic reactor, without which TP removal was about 56%. In the TAD reactor, receiving MLSS from the oxic tank (MBR), about 25% of TSS and VSS were solubilized during 2 days of retention. The effluent of the TAD reactor was recycled into the anoxic tank of A2O-MBR to provide organic carbon for denitrification and cryptic growth. By controlling the flowrate of wasting stream from the MBR, sludge production decreased to almost zero. From these results, it was concluded that the A2O-MBR-TAD process could be a reliable option for excellent effluent quality and near zero-sludge production.

Integrated side-stream reactor for biological nutrient removal and minimization of sludge production

2015 ◽  
Vol 71 (7) ◽  
pp. 1056-1064 ◽  
Author(s):  
M. Coma ◽  
S. Rovira ◽  
J. Canals ◽  
J. Colprim
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Slight Reduction ◽  
Nitrogen And Phosphorus ◽  
Effluent Quality ◽  
Side Stream ◽  
Sludge Production

Integrated processes to reduce in situ the sludge production in wastewater treatment plants are gaining attention in order to facilitate excess sludge management. In contrast to post-treatments, such as anaerobic digestion which is placed between the activated sludge system and dewatering processes, integrated technologies are placed in the sludge return line. This study evaluates the application of an anoxic side-stream reactor (SSR) which creates a physiological shock and uncouples the biomass metabolism and diverts the activity from assimilation for biosynthesis to non-growth activities. The effect of this system in biological nutrient removal for both nitrogen and phosphorus was evaluated for the anaerobic, anoxic and aerobic reactors. The RedOx potential within the SSR was maintained at −150 mV while the sludge loading rate was modified by increasing the percentage of recycled activated sludge feed to the SSR (0 and 40% at laboratory scale and 0, 10, 50 and 100% at pilot scale). The use of the SSR presented a slight reduction of phosphorus removal but maintained the effluent quality to the required discharge values. Nitrogen removal efficiency increased from 75 to 86% while reducing the sludge production rate by 18.3%.

Removal of Ammonia Nitrogen from Domestic Wastewater Using Vertical Aerated Limestone Filter

2015 ◽  
Vol 752-753 ◽  
pp. 232-237
Author(s):  
Rafidah binti Hamdan ◽  
Izzati Izwani Ibrahim ◽  
Ain Nabila Abdul Talib
Keyword(s):  
Dissolved Oxygen ◽  
Water Body ◽  
Nutrient Removal ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
Maintenance Cost ◽  
Effluent Quality ◽  
Filter System ◽  
Nitrification Process ◽  
Final Effluent

Nitrogen is a naturally occurring element that is essential for growth and reproduction in both plants and animals. Excessive concentrations in the water body can cause excessive growth of algae and other plants, leading to accelerate eutrophication of lakes, and occasional depletion of dissolved oxygen. To remove nitrogen conventionally from domestic wastewater requires a high cost technology due to consumption of chemicals, high operational and maintenance cost. Therefore, an alternative low cost treatment technology particularly for nutrient removal including nitrogen removal system has been developed to improve the final effluent quality that is an aerated rock filter system. However, the optimization study under warm climate has not yet been developed. Hence, the present study was carried out to investigate the removal of ammonia nitrogen (AN) from domestic wastewater through nitrification process using a lab-scale vertical aerated limestone filter. Domestic wastewater sample used in this study was collected from Taman Bukit Perdana Wastewater Treatment Plant (WWTP), Batu Pahat, Johor owned by IWK. The experiment has been carried out for 10 weeks. The influent and effluent of the vertical aerated limestone filter system have been sampled and analyzed on biweekly basis for selected parameters including AN, Total Kjedhal Nitrogen (TKN), pH, alkalinity, temperature and dissolved oxygen to monitor the effectiveness of the filter. Results from this study show that nitrification process has took place within the aerated limestone filter as the results from laboratory experiments show that AN in wastewater was oxidized to nitrate and efficiently removed as the removal of AN was ranged from 85 % to 92 % and the removal percentage of TKN was ranged from 83.52 % - 91.67 %. The temperature was in the average of 26.3oC±0.75, pH value average of , DO was from 6.64 mg/L to 7.75 mg/L , and the alkalinity was from 15 to 110 mg / l as CaCO3 . Therefore, from this study it can be concluded that aerated rock filter system has high potential in removing AN and TKN. It is also able to produce a good final effluent quality which is comply with the effluent requirement for nutrient removal in wastewater under the Environmental Quality Act (Sewage) Regulations, 2009 that is safe to be released to the water body.

Decreased sludge production strategy for domestic wastewater treatment

1994 ◽  
Vol 30 (8) ◽  
pp. 97-106 ◽  
Author(s):  
Angel Canales ◽  
Alain Pareilleux ◽  
Jean Luc Rols ◽  
Ge´rard Goma ◽  
Alain Huyard
Keyword(s):  
Wastewater Treatment ◽  
Thermal Treatment ◽  
Cell Lysis ◽  
Production Yield ◽  
Biomass Growth ◽  
Excess Sludge ◽  
Cell Content ◽  
Content Ratio ◽  
Cryptic Growth ◽  
Sludge Production

With new EEC regulations, alternative treatment and disposal techniques of the excess sludge produced by Activated Sludge (AS) wastewater treatment plants have to be performed. In order to reduce the excess sludge produced, experiments have been carried out with a Membrane BioReactor (MBR) to study the maintenance and cryptic growth phenomena of Pseudomonas fluorescens culture taken as a model when grown on a limiting substrate complex medium similar to a synthetic urban wastewater. Experiments with various imposed wasting rates showed that viability and sludge production yield decreased when sludge age increased. Same variations were observed on the cell content ratio protein/polysaccharide by analysis of the cell lysis products released after discontinuous thermal treatment. Biomass growth on these cell lysis products was achieved to characterize cryptic growth and its impact on sludge production yield. Finally, a continuous sludge thermal treatment system was operating with MBR to amplify sludge breakage and consequently biomass growth on the lysis products. With the promising results obtained, this work gives a new outlook on the AS process and leads to the development of processes with control and reduction of sludge production.

Evaluation of influent prefermentation as a unit process upon biological nutrient removal

2003 ◽  
Vol 47 (11) ◽  
pp. 9-15 ◽  
Author(s):  
T. McCue ◽  
R. Shah ◽  
I. Vassiliev ◽  
Y.-H. Liu ◽  
F.G. Eremektar ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
P Availability ◽  
Unit Process ◽  
Design Engineers ◽  
N Removal ◽  
Technical Basis ◽  
P Removal

The objective of this NSF sponsored research was to provide a controlled comparison of identical continuous flow biological nutrient removal (BNR) processes both with and without prefermentation in order to provide a stronger, more quantitative, technical basis for design engineers to determine the potential benefits of prefermentation to EBPR in treating domestic wastewater. Specifically, this paper focused upon the potential impacts of primary influent prefermentation upon BNR processes treating septic domestic wastewater. This study can be divided into two distinct phases - an initial bench-scale phase which treated septic P-limited (TCOD:TP>40) wastewater and a subsequent pilot-scale phase which treated septic COD-limited (TCOD:TP<40) wastewater. The following conclusions can be drawn from the results obtained to date.•Prefermentation increased both RBCOD, SBCOD and VFA content of septic domestic wastewater.•Prefermentation resulted in increased biological P removal for a highly septic, non-P limited (TCOD:TP<40:1) wastewater. However, in septic, P-limited (TCOD:TP>40:1) wastewater, changes in net P removal due to prefermentation were suppressed by limited P availability, even though P release and PHA content were affected.•Prefermentation increased specific anoxic denitrification rates for both COD and P-limited wastewaters, and in the pilot (COD-limited) study also coincided with greater system N removal.

Comparative study of membrane bioreactor (MBR) and activated sludge processes in the treatment of Moroccan domestic wastewater

2018 ◽  
Vol 78 (5) ◽  
pp. 1129-1136 ◽  
Author(s):  
S. Kitanou ◽  
M. Tahri ◽  
B. Bachiri ◽  
M. Mahi ◽  
M. Hafsi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Quality Parameters ◽  
Effluent Quality ◽  
Conventional Activated Sludge ◽  
Activated Sludge Processes

Abstract The study was based on an external pilot-scale membrane bioreactor (MBR) with a ceramic membrane compared to a conventional activated sludge process (ASP) plant. Both systems received their influent from domestic wastewater. The MBR produced an effluent of much better quality than the ASP in terms of total suspended solids (TSS), 5-day biological oxygen demand (BOD5) and chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN). Other effluent quality parameters also indicated substantial differences between the ASP and the MBR. This study leads to the conclusion that in the case of domestic wastewater, MBR treatment leads to excellent effluent quality. Hence, the replacement of ASP by MBR may be justified on the basis of the improved removal of solids, nutrients, and micropollutants. Furthermore, in terms of reuse the high quality of the treated water allows it to be reused for irrigation.

A strategy in wastewater treatment process for significant reduction of excess sludge production

2002 ◽  
Vol 45 (12) ◽  
pp. 127-134 ◽  
Author(s):  
N. Shiota ◽  
A. Akashi ◽  
S. Hasegawa
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Pilot Scale ◽  
Aeration Tank ◽  
Excess Sludge ◽  
Wastewater Treatment Process ◽  
Conventional Activated Sludge ◽  
New Process ◽  
Treatment Step ◽  
Sludge Production

A novel wastewater treatment process (S-TE PROCESS®) with significantly reduced production of excess sludge has been developed. The process consists of two different stages, one for a biological wastewater treatment and the other for a thermophilic aerobic digestion of the resulting sludge. A portion of return sludge from the wastewater treatment step is injected into a thermophilic aerobic sludge digester (TASD), in which the injected sludge is solubilized by the action of thermophilic aerobic bacteria. The solubilized sludge is returned to the aeration tank in the wastewater treatment step for its further degradation. Pilot-scale facilities of the S-TE process and the conventional activated sludge process as a control, both treating the same industrial wastewater, were comparatively operated for totally 270 days. As a result, 93% reduction in overall excess sludge production was achieved in the S-TE operation. The SS solubilization rate in TASD was stable at around 30%. Only a slight increase in the effluent SS and TOC concentrations was observed compared with those of the control facility. Otherwise the removal efficiency of TOC was approximately 95% for both plants. A full-scale plant treating domestic sewage was operated for three years, showing 75% reduction of overall excess sludge production. It was concluded that the new process was feasible.

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