Advanced Wastewater Treatment under Different Dissolved Oxygen Conditions in an Innovative Step-Feed Process

2011 ◽  
Vol 383-390 ◽  
pp. 3707-3712
Author(s):  
L M Yuan ◽  
C Y Zhang ◽  
R Yan ◽  
G Z Zhao ◽  
L J Tian ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Removal Efficiency ◽  
Phosphorus Uptake ◽  
Great Influence ◽  
Domestic Wastewater ◽  
Phosphorus Release ◽  
Carbon Substrate ◽  
Nitrogen And Phosphorus ◽  
Oxygen Conditions ◽  
Do Concentration

An innovative step-feed Anaerobic-multiple Anoxic/Oxic-Membrane Bioreactor [An-M(A/O-MBR] process was developed to treat synthetic domestic wastewater. Performance of the lab-scale system was investigated at different dissolved oxygen (DO) concentration (0.4-2.4mg/L) in the aerobic tank of the multiple A/O zone. The results showed that, under the conditions imposed, the DO level has no obvious influence on COD removal and the removal efficiency was more than 94% throughout the operation. However, DO levels have great influence on nitrogen and phosphorus removal. Better nitrification performance(>99%) could be obtained when DO was in the range of 0.8~2.4mg/L. High total nitrogen (TN) and total phosphorus (TP) removal performance can be obtained when DO was in the range of 0.8~1.2mg/L, the average removal efficiency was 74.81% and 71.41%, respectively. In this condition, DO can meet the demand of nitrification and phosphorus uptake simultaneously, and the simultaneous nitrification and denitrification (SND) occurred in the aerobic tanks under 1ower DO concentration. Meanwhile, since the DO circulated from the aerobic tank to the anoxic tank decreased, denitrification was enhanced and the nitrate quantity in the sludge recycle system decreased, resulting in the decrease of carbon substrate competition between denitrifcation and phosphorus release in the anaerobic zone. Ultimately, the performance of TN and TP removal was enhanced.

Effect of Dissolved Oxygen on Nitrogen and Phosphorus Removal Rate in Biolak Process

2013 ◽  
Vol 779-780 ◽  
pp. 1629-1633
Author(s):  
Yu Kun Ju ◽  
He Li Wang ◽  
Qiang Zhang ◽  
Jia Le Xing
Keyword(s):  
Dissolved Oxygen ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Nitrogen Efficiency ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Oxic Zone

In this research, the domestic wastewater was treated by full-scale Biolak/A2O process. The effects of dissolved oxygen (DO) on nitrogen and phosphorus removal of the system in oxic zone were investigated. Controlling to DO at 0.8-1.5 mg/L, the treatment efficiency of system was near optimal with the total nitrogen efficiency of 69.45%. The simultaneous nitrification and denitrification could be achieved under this condition. Based on the calculation equations and transformation pathways of nutrients, about 23.71% total nitrogen (TN) was removed by multistage A/O system in the oxic tank. When DO was 1.0-3.0mg/L, the total phosphorus (TP) removal efficiency was the highest at 73.97%. DO in the range of 1.0-1.5mg/L was optimal for the nutrient removal in Biolak/A2O process, removal efficiency of TN and TP were 68.87% and 73.68%. TN and TP of the effluent were 12.02mg/L and 0.95mg/L, respectively.

Start-Up of A2/O Humic Activated Sludge Systemphosphorus Removal Efficiency Analysis

2010 ◽  
Vol 113-116 ◽  
pp. 2201-2207 ◽  
Author(s):  
Jun Yin ◽  
Lei Wu ◽  
Ke Zhao ◽  
Yu Juan Yu
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Removal Rate ◽  
Phosphorus Uptake ◽  
Phosphorus Release ◽  
Activated Sludge System ◽  
Start Up ◽  
Article Analysis ◽  
Sludge Activity

In this article, analysis the start-up of A2/O humic activated sludge system phosphorus removal efficiency and the characteristics of anaerobic phosphorus release, aerobic phosphorus uptake, sludge activity and their change in the Series Technologies process. The results show that A2/O humic activated sludge system phosphorus removal rate stabilized at 90.7% ~ 97.6%. Sludge activity except for anoxic zone 2 increased, along the process showed a gradual decrease trend.

Simultaneous Removal of Nitrogen and Phosphorus in Intermittently Aerated 2-Tank Activated Sludge Process Using DO and ORP-Bending-Point Control

1993 ◽  
Vol 28 (11-12) ◽  
pp. 513-521 ◽  
Author(s):  
Kousei Sasaki ◽  
Yasuji Yamamoto ◽  
Kazushi Tsumura ◽  
Shigeru Hatsumata ◽  
Masahiro Tatewaki
Keyword(s):  
Control System ◽  
Activated Sludge ◽  
Phosphorus Uptake ◽  
Material Balance ◽  
Phosphorus Release ◽  
Test Plant ◽  
Activated Sludge Process ◽  
Time Sharing ◽  
Nitrogen And Phosphorus ◽  
Time Control

The 2-tank intermittent aeration method is an anaerobic-aerobic activated sludge process of time-sharing type in which 2 complete mixing reaction tanks are connected in series, and aeration and agitation are periodically repeated in each tank. We have developed a new control system for the process which can secure anaerobic, anoxic and aerobic conditions through a combination of DO and ORP-Bending-point (corresponding to termination of denitrification) emergence time control. In the 1st tank, nitrification and phosphorus uptake occur in the aeration period, followed by denitrification and phosphorus release in the agitation. The 2nd tank performs nitrification and phosphorus uptake in the aeration and denitrification in the agitation. One cycle of aeration and agitation is approximately 2 hours. This control system was applied to the test plant (influent flow rate: 225 I/day) for two months under the conditions of HRT 16 hours and temperature 20 ±2 °C. We achieved stable and high removal ratios: TOC 94.9 %, T-N 89.4 %, and T-P 95.5 %. We also investigated the mechanisms of nitrogen and phosphorus removal and their material balance.

Influence of denitrification reactor retention time distribution (RTD) on dissolved oxygen control and nitrogen removal efficiency

2015 ◽  
Vol 72 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Massimo Raboni ◽  
Renato Gavasci ◽  
Paolo Viotti
Keyword(s):  
Dissolved Oxygen ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Plug Flow ◽  
Oxygen Control ◽  
Low Concentrations ◽  
Dissolved Oxygen Control ◽  
Denitrification Reactor ◽  
Do Concentration ◽  
Mixed Reactor

Abstract Low concentrations of dissolved oxygen (DO) are usually found in biological anoxic pre-denitrification reactors, causing a reduction in nitrogen removal efficiency. Therefore, the reduction of DO in such reactors is fundamental for achieving good nutrient removal. The article shows the results of an experimental study carried out to evaluate the effect of the anoxic reactor hydrodynamic model on both residual DO concentration and nitrogen removal efficiency. In particular, two hydrodynamic models were considered: the single completely mixed reactor and a series of four reactors that resemble plug-flow behaviour. The latter prove to be more effective in oxygen consumption, allowing a lower residual DO concentration than the former. The series of reactors also achieves better specific denitrification rates and higher denitrification efficiency. Moreover, the denitrification food to microrganism (F:M) ratio (F:MDEN) demonstrates a relevant synergic action in both controlling residual DO and improving the denitrification performance.

Utilization of a hybrid sequencing batch reactor (HSBR) as a decentralized system of domestic wastewater treatment

2008 ◽  
Vol 57 (12) ◽  
pp. 1951-1956 ◽  
Author(s):  
R. H. R. da Costa ◽  
V. S. Souto ◽  
A. T. S. Prelhaz ◽  
L. G. L. Neto ◽  
D. B. Wolff
Keyword(s):  
Removal Efficiency ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Domestic Wastewater ◽  
Ammonium Concentration ◽  
Cylindrical Shape ◽  
Nitrogen And Phosphorus ◽  
Decentralized System ◽  
Treated Effluent ◽  
Domestic Wastewater Treatment

This paper presents the experiments carried out in a hybrid sequencing batch reactor (HSBR), used for biological treatment of sewage. The HSBR was built in a cylindrical shape and made of stainless steel, with a volume of 1.42 m3. Besides the biomass in suspension, the reactor also carried fixed biomass (hybrid process), adhered in the support material. This consisted of a nylon net disposed in a grille for biofilm biomass adhesion. The reactor worked fully automated in operational cycles of maximum 8 hours each, presenting the following phases: filling, anoxic, aerobic, settle and draw of treated effluent, with 3 fillings per cycle. Increasing organic loads (0.14 to 0.51 kg TCOD/m3 day) and ammonium loads (0.002 to 0.006 kg NH4-N/m3·day) were tested. We monitored the reactor's performance by measuring the liquid phase (COD, pH, temperature, DO, nitrogen and phosphorus) during the cycles and by measuring the sludge through respirometric tests. The results obtained demonstrated TCOD removal efficiency between 73 and 96%, and ammonium removal efficiency between 50 and 99%. At the end of the cycles, the effluent presented ammonium concentration <20 mg/L, meeting the Brazilian environmental legislation standards (CONAMA 357/2005) regarding discharges into the water bodies. Respirometric tests showed biomass dependency on FCOD concentrations. Results have demonstrated the potential of this type of reactor for decentralized treatment of domestic wastewater.

Effects of Environmental Factors on Phosphorus Release in Sediment from Baihua Lake, China

2012 ◽  
Vol 260-261 ◽  
pp. 912-916 ◽  
Author(s):  
Mei Jin ◽  
Ji Wei Hu ◽  
Xian Fei Huang ◽  
Li Ya Fu ◽  
Jin Luo ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Dissolved Oxygen ◽  
Total Phosphorus ◽  
Sharp Increase ◽  
Ph Value ◽  
Aerobic Condition ◽  
Phosphorus Release ◽  
Anoxic Condition ◽  
Do Concentration ◽  
Effects Of Temperature

This paper reports an investigation regarding the effects of temperature, pH, dissolved oxygen (DO) concentration and agitation on total phosphorus (TP) release in sediment form Baihua Lake. The results showed that an increase in the temperature led to a sharp increase in the TP release in the examined sediment. The TP release from the sediment decreased as the pH value increased until approximately pH = 7, and increased when pH > 7. There was phosphorus release in both aerobic and anoxic conditions, although the release quantities of TP were significantly higher in the anoxic condition than those in the aerobic condition. In addition, the TP release increased with agitation.

Nitrate Removal from Domestic Wastewater by Using Denitrification Limestone Filter

2014 ◽  
Vol 1051 ◽  
pp. 578-582
Author(s):  
Rafidah binti Hamdan ◽  
Tengku Nur Zulaikha ◽  
Izzati Izwani Ibrahim
Keyword(s):  
Dissolved Oxygen ◽  
Filter Design ◽  
Nitrate Removal ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
Maintenance Cost ◽  
Wastewater Sample ◽  
Filter System ◽  
Do Concentration ◽  
Denitrification Process

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, in the previous works in the UK the system was outperformed in removing ammonia nitrogen with limited nitrate removal. Hence, the present study was carried out to investigate the removal of nitrate from domestic wastewater through denitrification process using a lab-scale 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 treatments were run in lab-scale limestone denitrification filter for 10 weeks. Effluent from nitrification filter was passing through the limestone denitrification filter as influent for further treatment. The in fluent and effluent of the filter system have been sampled and analyzed on biweekly basis for selected parameters including pH, alkalinity, temperature, dissolved oxygen, nitrate and ammonia nitrogen to monitor the effectiveness of the filter. Results from this study show that denitrification process has took place even the percentages of nitrate removal were considerably low but it seems promising with some modification of designing the the limestone filter to enhance denitrification process. The highest removal rate was 17.66%. Low removal of nitrate was inhibited within the filter system might be due to the high DO concentration as it was found that the range of DO was 4.75-7.78 mg/L. To permit the denitrification process to take place within the filter system, it is required an anoxic condition in the presence of nitrate with minimum DO concentration. Consequently, some modifications to the filter design will be considered in the future research in order to enhance the removal of nitrate through denitrification process.

Effects of Primary Settling Tank on Denitrifying Phosphorus Removal in a Full-Scale AAO Process

2013 ◽  
Vol 860-863 ◽  
pp. 506-509
Author(s):  
Zhen Zhou ◽  
Wei Min Qiao ◽  
Rezihan Muhemaiti ◽  
Zhen Li ◽  
Ling Yan Jiang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Field Survey ◽  
Settling Tank ◽  
Phosphorus Uptake ◽  
Phosphorus Release ◽  
Full Scale ◽  
Batch Test ◽  
Microbial Activities ◽  
Denitrifying Phosphorus Removal

Effects of primary settling tank (PST) on phosphorus removal and the ratio of denitrifying phosphorus removing bacteria (DPB) to phosphorus accumulating organisms (PAOs) in a full-scale anaerobic/anoxic/aerobic (AAO) process were investigated by field survey and batch test. The AAO process without PST showed higher phosphorus removal efficiency than that with PST. In the anoxic tank, the phenomenon of anoxic phosphorus uptake and anaerobic phosphorus release were observed in the AAO process without and with PST, respectively. The DBP/PAOs ratio was 46% and 39% in the AAO process with and without PST, respectively. The AAO process with PST yielded higher microbial activities than that without PST.

On-line titrimetric monitoring of anaerobic–anoxic EBPR processes

2008 ◽  
Vol 57 (8) ◽  
pp. 1149-1154 ◽  
Author(s):  
M. Vargas ◽  
A. Guisasola ◽  
J. Lafuente ◽  
C. Casas ◽  
J. A. Baeza
Keyword(s):  
Control Strategies ◽  
Low Frequency ◽  
Phosphorus Release ◽  
Indirect Measurement ◽  
Carbon Substrate ◽  
Batch Reactors ◽  
Data Sampling ◽  
Nitrogen And Phosphorus ◽  
Nitrite Uptake ◽  
On Line

Denitrifying phosphorus accumulating organisms (DPAO) are able to remove nitrogen and phosphorus simultaneously. The use of DPAO in EBPR systems results in a substantial saving on aeration cost and a lower sludge production when compared to anaerobic–aerobic EBPR systems. This process is usually studied in sequencing batch reactors (SBR) and monitored with off-line measurements. However, off-line monitoring implies low frequency data sampling and delay between sampling and obtainment of the results. For this reason, an online measurement such as titrimetry is strongly recommended to improve the daily management of the lab-scale SBR. This paper shows different applications of titrimetric measurements for on-line monitoring of DPAO lab-scale SBR cycles. The results demonstrate that titrimetry is a suitable tool for detecting the end of phosphorus release and carbon substrate depletion point in the anaerobic phase. Moreover, this paper proposes the indirect measurement of nitrate/nitrite uptake rate with titrimetric measurements, which allows the on-line estimation of its concentration during the anoxic phase. Therefore, titrimetry is an on-line measurement with a high potential to implement new control strategies in DPAO lab-scale SBR systems.

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