Optimization of a mainstream nitritation-denitritation process and anammox polishing

2015 ◽  
Vol 72 (4) ◽  
pp. 632-642 ◽  
Author(s):  
Pusker Regmi ◽  
Becky Holgate ◽  
Dana Fredericks ◽  
Mark W. Miller ◽  
Bernhard Wett ◽  
...  
Keyword(s):  
Retention Time ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
High Rate ◽  
Anammox Bacteria ◽  
Tin Removal

This paper deals with an almost 1-year long pilot study of a nitritation-denitritation process that was followed by anammox polishing. The pilot plant treated real municipal wastewater at ambient temperatures. The effluent of high-rate activated sludge process (hydraulic retention time, HRT = 30 min, solids retention time = 0.25 d) was fed to the pilot plant described in this paper, where a constant temperature of 23 °C was maintained. The nitritation-denitritation process was operated to promote nitrite oxidizing bacteria out-selection in an intermittently aerated reactor. The intermittent aeration pattern was controlled using a strategy based on effluent ammonia and nitrate + nitrite concentrations. The unique feature of this aeration control was that fixed dissolved oxygen set-point was used and the length of aerobic and anoxic durations were changed based on the effluent ammonia and nitrate + nitrite concentrations. The anaerobic ammonia oxidation (anammox) bacteria were adapted in mainstream conditions by allowing the growth on the moving bed bioreactor plastic media in a fully anoxic reactor. The total inorganic nitrogen (TIN) removal performance of the entire system was 75 ± 15% during the study at a modest influent chemical oxygen demand (COD)/NH4+-N ratio of 8.9 ± 1.8 within the HRT range of 3.1–9.4 h. Anammox polishing contributed 11% of overall TIN removal. Therefore, this pilot-scale study demonstrates that application of the proposed nitritation-denitritation system followed by anammox polishing is capable of relatively high nitrogen removal without supplemental carbon and alkalinity at a low HRT.

A pilot-scale study on PVA gel beads based integrated fixed film activated sludge (IFAS) plant for municipal wastewater treatment

2015 ◽  
Vol 73 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Nitin Kumar Singh ◽  
Jasdeep Singh ◽  
Aakansha Bhatia ◽  
A. A. Kazmi
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
16S Rrna Genes ◽  
Volume Index ◽  
Rrna Genes ◽  
Gel Beads

In the present study, a pilot-scale reactor incorporating polyvinyl alcohol gel beads as biomass carrier and operating in biological activated sludge mode (a combination of moving bed biofilm reactor (MBBR) and activated sludge) was investigated for the treatment of actual municipal wastewater. The results, during a monitoring period of 4 months, showed effective removal of chemical oxygen demand (COD), biological oxygen demand (BOD) and NH3-N at optimum conditions with 91%, ∼92% and ∼90% removal efficiencies, respectively. Sludge volume index (SVI) values of activated sludge varied in the range of 25–72 mL/g, indicating appreciable settling characteristics. Furthermore, soluble COD and BOD in the effluent of the pilot plant were reduced to levels well below discharge limits of the Punjab Pollution Control Board, India. A culture dependent method was used to enrich and isolate abundant heterotrophic bacteria in activated sludge. In addition to this, 16S rRNA genes analysis was performed to identify diverse dominant bacterial species in suspended and attached biomass. Results revealed that Escherichia coli, Pseudomonas sp. and Nitrosomonas communis played a significant role in biomass carrier, while Acinetobactor sp. were dominant in activated sludge of the pilot plant. Identification of ciliated protozoa populations rendered six species of ciliates in the plant, among which Vorticella was the most dominant.

scholarly journals A pilot-scale anaerobic membrane bioreactor under short hydraulic retention time for municipal wastewater treatment: performance and microbial community identification

2017 ◽  
Vol 8 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Xiaojie Mei ◽  
Zhiwei Wang ◽  
Yan Miao ◽  
Zhichao Wu
Keyword(s):  
Microbial Community ◽  
Retention Time ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Municipal Wastewater Treatment ◽  
Term Operation ◽  
Anaerobic Membrane Bioreactor

Abstract Anaerobic membrane bioreactor (AnMBR) processes are a promising method of recovering energy from municipal wastewater. In this study, a pilot-scale AnMBR with extremely short hydraulic retention time (HRT = 2.2 h) was operated at a flux of 6 L/(m2h) for 340 days without any membrane cleaning. The average value achieved for chemical oxygen demand (COD) removal was 87% and for methane yield was 0.12 L CH4/gCODremoved. Based on mass balance analysis, it was found that about 30% of total influent COD was used for methane conversion, 15% of COD for sulfate reduction, 10% for biomass growth and 10–20% of COD remained in the effluent. Microbial community analyses indicated that seasonal changes of feedwater (in terms of organic components and temperature) led to the variations of microbial community structures. Among the bacterial communities, Chloroflexi, Proteobacteria and Bacteroidetes were the three most predominant phyla. In the archaeal consortia, WCHA1-57 and Methanobacterium surpassed Methanosaeta and Methanolinea to become the predominant methanogens during the long-term operation of short HRT. The sulfate-reducing bacteria, accounting for less than 2% of total abundance of bacteria, might not be the dominant competitor against methanogens.

Algal-Bacterial Ponding Systems for Municipal Wastewater Treatment in Arid Regions

1987 ◽  
Vol 19 (12) ◽  
pp. 341-343 ◽  
Author(s):  
I. I. Esen ◽  
K. Puskas ◽  
I. Banat ◽  
R. Al-Daher
Keyword(s):  
Pilot Plant ◽  
Arid Regions ◽  
Large Scale ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
High Rate ◽  
Experimental Program ◽  
Design Parameters ◽  
Municipal Wastewater Treatment ◽  
A Site

A pilot plant was constructed to investigate the use of algal-bacterial systems to treat municipal wastewaters in arid regions. The pilot plant consists of sand and oil traps, weir tanks, two facultative ponds (250 m3 holding capacity each), two high-rate ponds (25 m3 holding capacity each), four sedimentation tanks, a sludge digestor, and such auxiliary facilities as a pumping station for wastewater supply, drainage systems, and a site laboratory. The main objectives of the study are to determine the design parameters needed for large-scale algal-bacterial ponds in hot climates and to determine the degree of treatment and disinfection attained in the system by operating the pilot plant. After the algae is separated from the treated water, the final effluent will be used for irrigation, and algae will be used as a soil conditioner. Investigations during start-up, test runs and experiments completed so far focused on the growth of algae and removal of biochemical oxygen demand, chemical oxygen demand, and suspended solids. During the 20-month experimental program, various operating patterns, including series operation of facultative and high-rate ponds, will be investigated. Results obtained so far indicate significant reductions in pollution concentrations.

Deep Shaft High Rate Aerobic Digestion: Laboratory and Pilot Plant Performance

1981 ◽  
Vol 16 (1) ◽  
pp. 71-90 ◽  
Author(s):  
F. Tran ◽  
D. Gannon
Keyword(s):  
Retention Time ◽  
Oxygen Transfer ◽  
Pilot Plant ◽  
High Rate ◽  
Plant Performance ◽  
High Solids ◽  
Aerobic Digestion ◽  
Volatile Solids ◽  
Solids Content ◽  
High Solids Content

Abstract The Deep Shaft process, originating from ICI Ltd. in the U.K., has been further developed by C-I-L Inc., Eco-Technology Division into an extremely energy efficient, high rate biological treatment process for industrial and municipal wastewaters. The Deep Shaft is essentially an air-lift reactor, sunk deep in the ground (100 - 160 m): the resulting high hydrostatic pressure together with very efficient mixing in the shaft provide extremely high oxygen transfer efficiencies (O.T.E.) of up to 90% vs 4 to 20% in other aerators. This high O.T.E. suggests real potential for Deep Shaft technology in the aerobic digestion of sludges and animal wastes: with conventional aerobic digesters an O.T.E. over 8% is extremely difficult to achieve. This paper describes laboratory and pilot plant Deep Shaft aerobic digester (DSAD) studies carried out at Eco-Research's Pointe Claire, Quebec laboratories, and at the Paris, Ontario pilot Deep Shaft digester. An economic pre-evaluation indicated that DSAD had the greatest potential for treating high solids content primary or secondary sludge (3-7% total solids) in the high mesophilic and thermophilic temperature range (25-60°C) i.e. in cases where conventional digesters would experience severe limitations of oxygen transfer. Laboratory and pilot plant studies have accordingly concentrated on high solids content sludge digestion as a function of temperature. Laboratory scale daily draw and fill DSAD runs with a 5% solids sludge at 33°C with a 3 day retention time have achieved 34% volatile solids reduction and a stabilized sludge exhibiting a specific oxygen uptake rate (S.O.U.R.) of less than 1 mgO2/gVSS/hour, measured at 20°C. This digestion rate is about four times faster than the best conventional digesters. Using Eco-Research's Paris, Ontario pilot scale DSAD (a 160 m deep 8 cm diameter u-tube), a 40% reduction in total volatile solids, (or 73% reduction of biodegradable VS) and a final SOUR of 1.2 mg02/gVSS/hour have been achieved for a 4.6% solids sludge in 4 days at 33°C, with loading rates of up to 7.9 kg VSS/m3-day. Laboratory runs at thermophilic temperatures (up to 60°C) have demonstrated that a stabilized sludge (24-41% VSS reduction) can be produced in retention time of 2 days or less, with a resulting loading rate exceeding 10 kg VSS/m3-day.

Tilapia rearing with high rate algal pond effluent: ammonia surface loading rates and stocking densities effects

2018 ◽  
Vol 78 (1) ◽  
pp. 49-56
Author(s):  
I. A. Sánchez ◽  
R. K. X. Bastos ◽  
E. A. T. Lana
Keyword(s):  
Weight Gain ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
High Rate ◽  
Surface Loading ◽  
Loading Rates ◽  
Total Weight Gain ◽  
Low Weight ◽  
Total Ammonia

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.

Novel biofilm reactor for denitrification of municipal wastewater

2018 ◽  
Vol 78 (7) ◽  
pp. 1566-1575 ◽  
Author(s):  
S. S. Rathnaweera ◽  
B. Rusten ◽  
K. Korczyk ◽  
B. Helland ◽  
E. Rismyhr
Keyword(s):  
Carbon Source ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Removal Rates ◽  
Good Filter ◽  
Solids Removal

Abstract A pilot-scale CFIC® (continuous flow intermittent cleaning) reactor was run in anoxic conditions to study denitrification of wastewater. The CFIC process has already proven its capabilities for biological oxygen demand removal with a small footprint, less energy consumption and low cost. The present study focused on the applicability for denitrification. Both pre-denitrification (pre-DN) and post-denitrification (post-DN) were tested. A mixture of primary treated wastewater and nitrified wastewater was used for pre-DN and nitrified wastewater with ethanol as a carbon source was used for post-DN. The pre-DN process was carbon limited and removal rates of only 0.16 to 0.74 g NOx-N/m²-d were obtained. With post-DN and an external carbon source, 0.68 to 2.2 g NO3-Neq/m²-d removal rates were obtained. The carrier bed functioned as a good filter for both the larger particles coming with influent water and the bio-solids produced in the reactor. Total suspended solids removal in the reactor varied from 20% to 78% (average 45%) during post-DN testing period and 9% to 70% (average 29%) for pre-DN. The results showed that the forward flow washing improves both the DN function and filtration ability of the reactor.

scholarly journals Municipal Wastewater Treatment Using a Packed Bio-tower Approach

2020 ◽  
pp. 42-50
Author(s):  
Klaus Doelle ◽  
Qian Wang
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Continuous Operation ◽  
Growth Media ◽  
Municipal Wastewater Treatment ◽  
Bacteria Growth ◽  
Tower System

The study tested a designed and built pilot scale packed bio-tower system under continuous operation using pre-clarified municipal wastewater. Performance was evaluated by measuring the removal of chemical oxygen demand and nitrogen ammonia. The pilot scale packed bio-tower system had a diameter of 1209 mm (4 ft.) and a height of 3,962 mm (13 ft.) and contained Bentwood CF-1900 bacteria growth media with a surface area of 6,028.80 ft² (560.09 m²). The municipal residential sewage was fed into a 1,481 l (375 gal.) recirculation reservoir at a temperature of 15°C (59.0°F) and a flow rate between 7,571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d) and recirculated through the bio-tower with a fixed recirculation rate of 75.7 l/min (20 gal/min). The influent COD value reduction achieved is between 63.4% and 84.8%, whereas the COD influent value varied between 87 mg/l and 140 mg/l. The influent NH3-N reduction achieved was between 99.8% and 91.8% whereas the influent NH3-N value was between 28.8 mg/l and 18.6 mg/l  at a flow rate between 7571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d).

scholarly journals Optimising the Hydraulic Retention Time in a Pilot-Scale Microbial Electrolysis Cell to Achieve High Volumetric Treatment Rates Using Concentrated Domestic Wastewater

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2945 ◽  
Author(s):  
Daniel D. Leicester ◽  
Jaime M. Amezaga ◽  
Andrew Moore ◽  
Elizabeth S. Heidrich
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Direct Analysis ◽  
Pilot Scale ◽  
Electrolysis Cell ◽  
Treatment Technique ◽  
Microbial Electrolysis Cell ◽  
Microbial Electrolysis

Bioelectrochemical systems (BES) have the potential to deliver energy-neutral wastewater treatment. Pilot-scale tests have proven that they can operate at low temperatures with real wastewaters. However, volumetric treatment rates (VTRs) have been low, reducing the ability for this technology to compete with activated sludge (AS). This paper describes a pilot-scale microbial electrolysis cell (MEC) operated in continuous flow for 6 months. The reactor was fed return sludge liquor, the concentrated filtrate of anaerobic digestion sludge that has a high chemical oxygen demand (COD). The use of a wastewater with increased soluble organics, along with optimisation of the hydraulic retention time (HRT), resulted in the highest VTR achieved by a pilot-scale MEC treating real wastewater. Peak HRT was 0.5-days, resulting in an average VTR of 3.82 kgCOD/m3∙day and a 55% COD removal efficiency. Finally, using the data obtained, a direct analysis of the potential savings from the reduced loading on AS was then made. Theoretical calculation of the required tank size, with the estimated costs and savings, indicates that the use of an MEC as a return sludge liquor pre-treatment technique could result in an industrially viable 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.

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