scholarly journals Efficiency studies of modified IFAS-OSA system upgraded by an anoxic sludge holding tank

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mansour Fazelipour ◽  
Afshin Takdastan ◽  
Seyed Mehdi Borghei ◽  
Neda Kiasat ◽  
Marcin Glodniok ◽  
...  
Keyword(s):  
Control System ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biomass Yield ◽  
New Technology ◽  
Cod Removal ◽  
Yield Coefficient ◽  
Excess Sludge ◽  
Fixed Film ◽  
P Removal

AbstractAn upgraded integrated fixed-film activated sludge-oxic settling anoxic (IFAS-OSA) system is a new technology for reducing nutrients and excess sludge. The results showed that the average TN removal efficiency of the IFAS-OSA system was gradually increased up to 7.5%, while the PO4–3-P removal efficiency increased up-to 27%, compared with that of the IFAS system. The COD removal efficiency of the IFAS-OSA system was slightly increased up-to 5.4% and TSS removal efficiency increased up to 10.5% compared with the control system. Biomass yield coefficient (Yobs) in the IFAS and IFAS-OSA systems were 0.44 and 0.24 (gr MLSS/ gr COD). Hence, sludge production decreased by 45%. The average SVI was decreased by 48% in IFAS-OSA system compared with IFAS. This study demonstrated the better performance of the IFAS-OSA system compared to that of the IFAS system.

Pond Treatment of Rettery Wastewaters

1987 ◽  
Vol 19 (12) ◽  
pp. 79-83
Author(s):  
K. Bartoszewski ◽  
A. Bilyk
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
New Technology ◽  
Treatment Plant ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Experimental Results ◽  
Aerobic Conditions ◽  
Aerobic Stabilization ◽  
In Series

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.

scholarly journals Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Cod Removal ◽  
Septic Tank ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Cod Removal Efficiency

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

Enhancing nitrogen removal efficiency and reducing nitrate liquor recirculation ratio by improving simultaneous nitrification and denitrification in integrated fixed-film activated sludge (IFAS) process

2015 ◽  
Vol 73 (4) ◽  
pp. 827-834 ◽  
Author(s):  
Yang Bai ◽  
Yaobin Zhang ◽  
Xie Quan ◽  
Shuo Chen
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Electricity Consumption ◽  
Simultaneous Nitrification And Denitrification ◽  
Recirculation Flow ◽  
Fixed Film ◽  
Gradient Gel Electrophoresis ◽  
Nitrification And Denitrification

An integrated fixed-film activated sludge (IFAS) process (G1) and an activated sludge anoxic–oxic process (G2) were operated at nitrate liquor recirculation ratio (R) of 100, 200 and 300% to investigate the feasibility of enhancing nitrogen removal efficiency (RTN) and reducing R by improving simultaneous nitrification and denitrification (SND) in the IFAS process. The results showed that the effluent NH4+-N and total nitrogen (TN) of G1 at R of 200% were less than 1.5 and 14.5 mg/L, satisfying the Chinese discharge standard (NH4+-N < 5 mg/L; TN < 15 mg/L). However, the effluent NH4+-N and TN of G2 at R of 300% were higher than 8.5 and 15.3 mg/L. It indicated that better RTN could be achieved at a lower R in the IFAS process. The polymerase chain reaction–denaturing gradient gel electrophoresis results implied that nitrifiers and denitrifiers co-existed in one microbial community, facilitating the occurrence of SND in the aerobic reactor of G1, and the contribution of SND to TN removal efficiency ranged 15–19%, which was the main reason that the RTN was improved in the IFAS process. Therefore, the IFAS process was an effective method for improving RTN and reducing R. In practical application, this advantage of the IFAS process can decrease the electricity consumption for nitrate liquor recirculation flow, thereby saving operational costs.

scholarly journals Bioaugmentation as a Tool To Protect the Structure and Function of an Activated-Sludge Microbial Community against a 3-Chloroaniline Shock Load

2003 ◽  
Vol 69 (3) ◽  
pp. 1511-1520 ◽  
Author(s):  
Nico Boon ◽  
Eva M. Top ◽  
Willy Verstraete ◽  
Steven D. Siciliano
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Real Time ◽  
Removal Efficiency ◽  
Real Time Pcr ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Cod Removal ◽  
Shock Load ◽  
Volume Index ◽  
Cod Removal Efficiency

ABSTRACT Bioaugmentation of bioreactors focuses on the removal of xenobiotics, with little attention typically paid to the recovery of disrupted reactor functions such as ammonium-nitrogen removal. Chloroanilines are widely used in industry as a precursor to a variety of products and are occasionally released into wastewater streams. This work evaluated the effects on activated-sludge reactor functions of a 3-chloroaniline (3-CA) pulse and bioaugmentation by inoculation with the 3-CA-degrading strain Comamonas testosteroni I2 gfp. Changes in functions such as nitrification, carbon removal, and sludge compaction were studied in relation to the sludge community structure, in particular the nitrifying populations. Denaturing gradient gel electrophoresis (DGGE), real-time PCR, and fluorescent in situ hybridization (FISH) were used to characterize and enumerate the ammonia-oxidizing microbial community immediately after a 3-CA shock load. Two days after the 3-CA shock, ammonium accumulated, and the nitrification activity did not recover over a 12-day period in the nonbioaugmented reactors. In contrast, nitrification in the bioaugmented reactor started to recover on day 4. The DGGE patterns and the FISH and real-time PCR data showed that the ammonia-oxidizing microbial community of the bioaugmented reactor recovered in structure, activity, and abundance, while the number of ribosomes of the ammonia oxidizers in the nonbioaugmented reactor decreased drastically and the community composition changed and did not recover. The settleability of the activated sludge was negatively influenced by the 3-CA addition, with the sludge volume index increasing by a factor of 2.3. Two days after the 3-CA shock in the nonbioaugmented reactor, chemical oxygen demand (COD) removal efficiency decreased by 36% but recovered fully by day 4. In contrast, in the bioaugmented reactor, no decrease of the COD removal efficiency was observed. This study demonstrates that bioaugmentation of wastewater reactors to accelerate the degradation of toxic chlorinated organics such as 3-CA protected the nitrifying bacterial community, thereby allowing faster recovery from toxic shocks.

Effects of Ce3+ Addition on Granulation of Activated Sludge

2014 ◽  
Vol 1004-1005 ◽  
pp. 990-995
Author(s):  
Yu Xiao Zhao ◽  
Min Tian Gao ◽  
Xiao Hui Liang ◽  
Hui Mu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Activated Sludge ◽  
Protein Content ◽  
Removal Efficiency ◽  
Extracellular Polymeric Substances ◽  
Cod Removal ◽  
Aerobic Granules ◽  
Sludge Granulation ◽  
Scanning Electron

In this study the effect of Ce3+ on activated sludge granulation were first studied. It was found that 50 mg/l Ce3+ significantly promotes the granulation of activated sludge and more compacted smaller aerobic granules are formed. Additional Ce3+ has no influences on COD removal efficiency, but improved the SOP removal efficiency significantly. Although protein contents in extracellular polymeric substances increased along with granulation in both reactors, protein content in EPS of Ce3+-fed granules was higher than that without Ce3+ addition. Polysaccharide contents in extracellular polymeric substances decreased slightly through the experiment in the two reactors. Scanning electron microscopy showed that bacilli and cocci were dominant on surface of granules in both reactors. But there were more and longer rod-shaped bacteria on surface of Ce3+-fed granules.

scholarly journals A comparative study of an up-flow aerobic/anoxic sludge fixed film bioreactor and sequencing batch reactor with intermittent aeration in simultaneous nutrients (N, P) removal from synthetic wastewater

2017 ◽  
Vol 76 (5) ◽  
pp. 1044-1058 ◽  
Author(s):  
Amir Mohammad Mansouri ◽  
Ali Akbar Zinatizadeh
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Intermittent Aeration ◽  
Fixed Film ◽  
Removal Efficiencies ◽  
P Removal

The performance of two bench scale activated sludge reactors with two feeding regimes, continuous fed (an up-flow aerobic/anoxic sludge fixed film (UAASFF) bioreactor) and batch fed (sequencing batch reactor (SBR)) with intermittent aeration, were evaluated for simultaneous nutrients (N, P) removal. Three significant variables (retention/reaction time, chemical oxygen demand (COD): N (nitrogen): P (phosphorus) ratio and aeration time) were selected for modeling, analyzing, and optimizing the process. At high retention time (≥6 h), two bioreactors showed comparable removal efficiencies, but at lower hydraulic retention time, the UAASFF bioreactor showed a better performance with higher nutrient removal efficiency than the SBR. The experimental results indicated that the total Kjeldahl nitrogen removal efficiency in the UAASFF increased from 70.84% to 79.2% when compared to SBR. It was also found that the COD removal efficiencies of both processes were over 87%, and total nitrogen and total phosphorus removal efficiencies were 79.2% and 72.98% in UAASFF, and 71.2% and 68.9% in SBR, respectively.

Anaerobic Treatment of a Petrochemical Wastewater from a Terephthalic Acid Plant

1992 ◽  
Vol 25 (7) ◽  
pp. 223-235 ◽  
Author(s):  
H. Macarie ◽  
A. Noyola ◽  
J. P. Guyot
Keyword(s):  
Activated Sludge ◽  
Terephthalic Acid ◽  
Treatment Plant ◽  
Tubular Reactor ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Acid Plant ◽  
Aerobic Process ◽  
Fixed Film ◽  
Film Reactor

Anaerobic treatment of terephthalic acid plant wastewater was tested using two UASB reactors (T and U) and a downflow tubular fixed film reactor. UASB T was inoculated with sludge sampled from an anaerobic stabilization pond receiving waste activated sludge from a petrochemical industry treatment plant. UASB U and the fixed film reactor were inoculated with anaerobically adapted activated sludge from a municipal plant. Raw effluent had to be settled and neutralized before reactor feeding. Sedimentation resulted in 70% TSS and 37% COD removal. UASB digesters presented comparable treatment efficiencies with rather low COD removals: the best results were 46.4% for UASB T at 2.6 kg COD/m3.d and a hydraulic retention time (θ) of 2.7 days and 43.9% for UASB U at 2.2 kg COD/m3.d and θ of 3.2 days. The performance of the tubular reactor was much higher, 74.5% COD removal at 1.89 kg/m3.d and θ of 3.4 days. The better efficiencies of this last digester are explained mainly by a higher VSS content and a better resistance to toxicity caused by the aromatics present in the wastewater. A primary settling-anaerobic-aerobic process is proposed as an alternative to the conventional aerobic process for treating terephthalic wastewater, but disposal of solids from primary sedimentation and cost of neutralization have to be considered before application.

Treatability of cefazolin antibiotic formulation effluent with O3 and O3/H2O2 processes

2007 ◽  
Vol 55 (10) ◽  
pp. 217-225 ◽  
Author(s):  
G. Iskender ◽  
A. Sezer ◽  
I. Arslan-Alaton ◽  
F. Germirli Babuna ◽  
O.S. Okay
Keyword(s):  
Acute Toxicity ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Inhibition Test ◽  
Cod Removal ◽  
Cod Removal Efficiency

The effect of applying ozonation and perozonation to antibiotic cefazolin-Na formulation effluents were investigated in this study. Twenty minutes of ozonation at a rate of 1,500 mg/L-h was observed to remove COD by 38%, whereas a COD removal efficiency of 40% was achieved via H2O2 enhanced ozonation (same conditions + 31.25 mM H2O2). Both of the pretreatment alternatives were monitored to elevate the BOD5/COD ratio from 0.01 to 0.08. The initially inert COD was reduced by 38% using ozonation and by 60% employing H2O2 enhanced ozonation. In terms of the lowest achievable effluent COD levels after bio-treatment, ozonation was observed to yield a residual COD of 205 mg L−1, while a residual COD of 135 mg L−1 was involved for perozonation. According to the results of acute toxicity on Phaedactylum tricornutum, ozonated and perozonated samples exhibited more toxicity than the untreated effluent after 4 days. The activated sludge inhibition test demonstrated that both of the pretreatment alternatives efficiently eliminated the inhibition of investigated formulation effluent.

scholarly journals Efficiency of the work of almond shells as biological carriers in activated sludge aeration tanks: كفاءة عمل قشور اللوز كحوامل بيولوجية في أحواض التهوية بالحمأة المنشطة

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Raghad Salim Al-Shalabi, Naeima Ajib, Mahmoud Fattamah
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Retention Time ◽  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Aeration Tank ◽  
Sludge Treatment ◽  
Mixed Liquor ◽  
Conventional Activated Sludge ◽  
Fixed Film

Based on the interest in environmentally friendly materials for wastewater treatment, this research is aimed at evaluating the efficiency of almond shells work as biological carriers in activated sludge aeration tanks, known as the integrated fixed-film activated sludge treatment, a hybrid tank with attached growth and suspended growth is obtained. Almond shells were placed at 7% of the size of the aeration tank throughout the experiment period for about 4 months with a number of indicators such as hydraulic retention time and mixed liquor suspended solids. Two sets of experiments were performed, the first group with a constant hydraulic retention time ( HRT= 4 hours), and mixed liquor suspended solids was changed (500-1000-2000-3000 mg/ L), with the best removal efficiency at MLSS = 2000 mg/ l, by 91.3% and 92.1% for COD and SS respectively. The optimal MLSS concentration was adopted for the second group of experiments where HRT was increased to 5 and 6 hours. As a result, the best chain was found to be MLSS = 2000 mg/ l and HRT = 5 hours, with a removal efficiency of 93.4% and 93.9% for COD and SS respectively. As a result, the rate of return activated sludge was reduced from 100% to 60% and the rate of inflow into the aeration tank was increased due to the reduction HRT from 6 hours to 5 hours compared to conventional activated sludge treatment.

Performance evaluation of various aerobic biological systems for the treatment of domestic wastewater at low temperatures

2008 ◽  
Vol 58 (4) ◽  
pp. 819-830 ◽  
Author(s):  
N. Sundaresan ◽  
L. Philip
Keyword(s):  
Performance Evaluation ◽  
Activated Sludge ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Biological Systems ◽  
Domestic Wastewater ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Activated Sludge Process ◽  
Cod Removal Efficiency

Studies were undertaken on the performance evaluation of three different types of aerobic reactors, namely, activated sludge process, fluidized bed reactor and submerged bed reactor. Initially synthetic wastewater was used for stabilizing the system and later domestic wastewater of IIT Madras was used as the feed for the biological systems. The hydraulic retention time was maintained as 24 h. The seed sludge was collected from IIT Madras sewage treatment plant. The inlet COD to the reactors with synthetic wastewater was 1,000±20 mg/L and with real wastewater, it was 150 to 350 mg/L. The performance of the reactors was evaluated based on the soluble COD and nitrogen removal efficiency. The pH, temperature, dissolved oxygen (DO) and mixed liquid suspended solid (MLSS) concentration were measured periodically. The reactors were acclimatized at 35°C in batch mode and changed to continuous mode at 30°C. After the systems attained its steady state at a particular temperature, the temperature was reduced from 35°C to 5°C stepwise, with each step of 5°C. The start-up time for submerged bed reactor was slightly more than fluidized and conventional activated sludge process. The COD removal efficiency of the three reactors was higher with synthetic wastewaters as compared to actual domestic wastewater. Submerged bed reactor was more robust and efficient as compared to activated sludge and fluidized bed reactors. The COD removal efficiency of the reactors was relatively good until the operating temperature was maintained at 15°C or above. At 10°C, submerged bed reactor was able to achieve 40% COD removal efficiency whereas; the fluidized bed and conventional ASP reactors were showing only 20% COD removal efficiency. At 5°C, almost all the systems failed. Submerged bed reactor showed around 20% COD removal efficiency. However, this reactor was able to regain its 90% of original efficiency, once the temperature was raised to 10°C. At higher temperatures, the nitrification efficiency of the reactors was above 80–90%. As the temperature reduced the nitrification efficiency has reduced drastically. In summary, submerged bed reactors seems to be a better option for treating domestic wastewaters at low temperature regions.

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