scholarly journals Rapid Start-Up of the Aerobic Granular Reactor under Low Temperature and the Nutriment Removal Performance of Granules with Different Particle Sizes

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3590
Author(s):  
Dongbo Liang ◽  
Jun Li ◽  
Zhaoming Zheng ◽  
Jing Zhang ◽  
Yaodong Wu ◽  
...  

The start-up of the aerobic granular sludge (AGS) process under low temperature is challenging. In this study, the sequencing batch reactor (SBR) was fed with synthetic wastewater and the temperature was controlled at 15 ℃. The main components in the synthetic wastewater were sodium acetate and ammonium chloride. The influent chemical oxygen demand (COD) and NH4+-N concentrations were 300 and 60 mg/L, respectively. The AGS was successfully cultivated in 60 days by gradually shortening the settling time. During the stable operation stage (61–100 d), the average effluent COD, NH4+-N, NO2−-N, and NO3−-N concentrations were 47.2, 1.0, 47.2, and 5.1 mg/L, respectively. Meanwhile, the nitrite accumulation rate (NAR) reached 90.6%. Batch test showed that the smaller AGS had higher NH4+-N removal rate while the larger AGS performed higher NAR. The NH4+-N removal rates of R1 (1.0–2.0 mm), R2 (2.0–3.0 mm), and R3 (>3 mm) granules were 0.85, 0.61, and 0.45 g N/(kg VSS·h), respectively. Meanwhile, the NAR of R1, R2, and R3 were 36.2%, 77.2%, and 94.9%, respectively. The obtained results could provide important guidance for the cultivation of AGS in low-temperature wastewater treatment.

2021 ◽  
Vol 43 (6) ◽  
pp. 419-427
Author(s):  
Sukru Aslan ◽  
Burhanettin Gurbuz

Objectives : Effects of various Cu2+ concentrations in the synthetic wastewater on nitrite accumulation was investigated in a submerged partial biofilter reactor (SPBNR).Methods : Experiments were carried out at the constant operational conditions (T=35℃; pH=9.0 and DO=2.0 mg O2/L) by varying the concentrations between 5-50 mg Cu2+/L. The SPBNR, which was operated in an upward flow mode, set-up consisted of a cylindrical stainless steel. The support materials filling ratio was about 23% of the total reactor volume. The SPBNR was inoculated with microorganism drawn from a batch experimental biological reactor operated about one month by using the synthetic wastewater composition.Results and Discussion : Before exposure to Cu2+, the highest loading rate of 1.3 g NH4-N/(m2.day) was determined under the operational conditions. Addition of 5 µg Cu2+/L into the waters promoted the activity of organisms and the loading rate achieved to 1.6 g NH4-N/(m2.day). At the control operational condition, the ratio of NO2-N/NOx-N was determined as 0.74, while the ratio increased to 0.78 at the Cu2+ concentration of 5 µg/L.Conclusions : Results indicated that the ammonium oxidizing bacteria (AOB) is more stimulated than the nitrite oxidizing bacteria (NOB) at the concentration of 5 µg Cu2+/L. However, approximately equal NH4-N removal rate (ANRR) and NO2-N accumulation rate (NiAR) losses indicated that the AOB and NOB are approximately equally effected at the inlet concentrations of 35 and 50 µg Cu2+/L.


2012 ◽  
Vol 65 (3) ◽  
pp. 581-588 ◽  
Author(s):  
Naohiro Kishida ◽  
Goro Saeki ◽  
Satoshi Tsuneda ◽  
Ryuichi Sudo

In this study, the effectiveness of aerobic granular sludge as seed sludge for rapid start-up of nitrifying processes was investigated using a laboratory-scale continuous stirred-tank reactor (CSTR) fed with completely inorganic wastewater which contained a high concentration of ammonia. Even when a large amount of granular biomass was inoculated in the reactor, and the characteristics of influent wastewater were abruptly changed, excess biomass washout was not observed, and biomass concentration was kept high at the start-up period due to high settling ability of the aerobic granular sludge. As a result, an ammonia removal rate immediately increased and reached more than 1.0 kg N/m3/d within 20 days and up to 1.8 kg N/m3/d on day 39. Subsequently, high rate nitritation was stably attained during 100 days. However, nitrite accumulation had been observed for 140 days before attaining complete nitrification to nitrate. Fluorescence in situ hybridization analysis revealed the increase in amount of ammonia-oxidizing bacteria which existed in the outer edge of the granular sludge during the start-up period. This microbial ecological change would make it possible to attain high rate ammonia removal.


2015 ◽  
Vol 73 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Yangfan Deng ◽  
Xiaoling Zhang ◽  
Ying Miao ◽  
Bo Hu

In this study, a laboratory-scale sequencing biofilm batch reactor (SBBR) was employed to explore a fast start-up of completely autotrophic nitrogen removal over nitrite (CANON) process. Partial nitrification was achieved by controlling free ammonia concentration and operating at above 30 °C; then the reactor was immediately operated with alternating periods of aerobiosis and anaerobiosis to start the anammox process. The CANON process was successfully achieved in less than 50 d, and the total-nitrogen removal efficiency and the nitrogen removal rate were 81% and 0.14 kg-N m−3 d−1 respectively. Afterwards, with the increasing of ammonium loading rate a maximum nitrogen removal rate of 0.39 kg-N m−3 d−1 was achieved on day 94. DNA analysis showed that ‘Candidatus Brocadia’ was the dominant anammox species and Nitrosomonas was the dominant aerobic ammonium-oxidizing bacteria in the CANON reactor. This study revealed that due to shortening the persistent and stable nitrite accumulation period the long start-up time of the CANON process can be significantly reduced.


2019 ◽  
Vol 79 (4) ◽  
pp. 753-758 ◽  
Author(s):  
Jianfei Chen ◽  
Shujun Zhang ◽  
Xiaoyu Han ◽  
Liang Zhang ◽  
Yongzhen Peng

Abstract In this study, the side-stream heat-shock treatment was used to start up and maintain the nitritation of real sewage. Complete nitrification was obtained when the real sewage was treated in a sequencing batch reactor (SBR). Then, about 50% of the mixed sludge was collected from the SBR and treated with the heat-shock treatment at 60 °C for 40 min in another reactor every 2 weeks. After providing the heat-shock treatment for four times, the effluent nitrate in the SBR gradually decreased from 22.5 to 3.2 mg/L, while the nitrite accumulation rate increased from 4.4% to 81.8%, indicating a successful start-up of nitritation. Further, the sewage nitritation was stable with the regular side-steam heat-shock treatment for 91 days, and the ammonium removal efficiency of 80.6% and nitrite accumulation rate of 91.2% were achieved. This study suggests that the side-stream heat-shock treatment could be used to start up sewage nitritation and maintain stability for a long-term operation.


2016 ◽  
Vol 1 (2) ◽  
pp. 10 ◽  
Author(s):  
Hong Liang ◽  
Xue Li ◽  
Shanshan Wang ◽  
Dawen Gao

A sequencing batch reactor (SBR) was used to study the effect of carbon source (C6H12O6 and CH3COONa) and C/N ratio (C/N=4:1 and C/N=7:1) on the production of nitrous oxide (N2O) in the process of simultaneous nitrifica-tion and denitrification via nitrite (short-cut SND) by aerobic granular sludge and the removal efficiency of nitrogen under low dissolved oxygen (DO). The results showed that short-cut SND occurred in this system, and the removal ef-ficiency of total nitrogen (TN) at C6H12O6 and CH3COONa were 28.93 % and 41.19 %, respectively. However, the production of N2O significantly increased when CH3COONa was used as a carbon source. In addition, the rate of N2O release when CH3COONa was a carbon source was 8.34 times the rate when C6H12O6 was the carbon source. With the increase of C/N, removal rate of TN and the efficiency of the short-cut SND were increased. The removal efficiency of TN at C/N=7:1 was 90.33%, which was 2.19 times at C/N=4:1. The percentage of short-cut SND at C/N=4:1 and C/N=7:1 were 87.47% and 95.97%, respectively. The release rate of N2O from the original 1.14 mg/(g • min) decreased to 0.10 mg/(g • min) after increased the C/N from 4:1 to 7:1.


2013 ◽  
Vol 864-867 ◽  
pp. 1503-1508 ◽  
Author(s):  
Ming Fen Niu ◽  
Hai Jiao Yu

Shortcut Nitrification-Denitrification Simultaneous Phosphorus Removal applying in sequencing batch reactor were achieved successfully by Changing the run mode of SBR and controlling the operating conditions. When the MLSS:4700mg/L, PH:7.5~8.0 and DO:0.3~0.5mg/L(Aerobic phase), the removal rate of TP was more than 98%, the nitrite accumulation rate was more than 85%. After the reaction period of Shortcut Nitrification-Denitrification simultaneous Phosphorus Removal, the concentration of NH4+-N was below 50mg/L and the concentration of TP was less than 0.5mg/L.


2014 ◽  
Vol 955-959 ◽  
pp. 339-342 ◽  
Author(s):  
Xin Gang Wang ◽  
Bing Lin ◽  
Yu Bin Tang ◽  
Hai Feng Chen

The aerobic granular sludge (AGS) was used to remove pollutants (COD, NH3-N, TN and TP) in wastewater under different salinity in a sequencing batch reactor (SBR). The results show that: the salinity has a significant impact on the removal of COD and TN, and the removal rate declines to 60% and 56% respectively when the water salinity rises from 5g/L to15g/L. The NH3-N removal is not much affected by the salinity, and the average removal rate is 75%. TP removal rate changes little at low-salted environment (the salinity less than 10g/L), however, the rate declines heavily when the salinity gets more than 10g/L, 70% in 10g/L and 57% in 15g/L.


2014 ◽  
Vol 955-959 ◽  
pp. 3389-3392
Author(s):  
Li Cheng Zhang ◽  
Wei Dang ◽  
Jie Li ◽  
Jun Sui

The intermittent aeration strategy was applied to the sequencing batch biofilm reactor (SBBR) for the enhanced treatment of urban sewage. Ammonia oxidizing bacteria was cultivated by inoculation. After 25 days cultivation shortcut nitrification was successfully achieved and nitrite accumulation rate could be up to 93%. In the start-up phase of shortcut nitrification, intermittent aeration could increase production of nitrite and promote the enrichment of ammonia oxidizing bacteria. It was concluded that temperature could affect nitrite accumulation. When temperature is in 25~35°C, the nitrite accumulation rate could be up to 90%.


2011 ◽  
Vol 356-360 ◽  
pp. 1267-1271
Author(s):  
Feng Jiang ◽  
Yang Li Zhao ◽  
Shuai Fu Chen ◽  
Rui Liang

Aerobic granular sludge (AGS) was cultivated successfully in a sequencing batch reactor (SBR), which has floc sludge as seeding sludge in synthetic wastewater. Removal efficiency in the reactor during the entire working period was investigated. Controlling strategy for filamentous bulking and the effect of a filamentous microorganism on granulation of sludge were discussed. The results showed that whether filamentous bulking occurred or not, there was little impact on the removal rate of phosphorus and ammonia nitrogen, which maintain about 90% and 95%, respectively. Increasing the hydrodynamic shear force has certain effects on the controlling of filamentous bulking. Declining C/N ratio, balancing nutrition in feed water can fundamentally solve the problem of filamentous bulking in the cultivation process of aerobic granular sludge.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 229
Author(s):  
Sabin Pathak ◽  
Shuai Wang ◽  
Eshetu Janka

Removing ammonium via the partial nitritation anammox (PNA) process has been widely applied because of its cost and energy effectiveness. However, the first stage of PNA, partial nitritation, is hard to implement practically due to the challenging suppression of nitrate oxidizing bacteria (NOB) and should be achieved in the anammox environment to extend it to one stage PNA. Hence, this article evaluates different techniques, such as the combination of low dissolve oxygen (DO) and high free ammonia (FA), and the intermittent aeration cycle to achieve partial nitritation in an anammox start-up environment. For this purpose, a 10.5 L lab-scale moving bed biofilm reactor was set up and fed with synthetic wastewater and the transformation of influent ammonium into nitrate and nitrite was measured. The results showed that, despite applying low DO and higher free ammonia than the inhibition range of NOB, the nitrate production rate (NPR) was consistently higher than the nitrite accumulation rate (NAR), signifying no sufficient NOB suppression, partial nitritation under continuous aeration and up to a 0.27 gN/m2.d surface ammonium loading rate (SALR). Higher SALR than 0.27 gN/m2.d could result in partial nitritation since nitrogen compounds transformation was closer to partial nitritation when the reactor was subjected to 0.27 gN/m2.d rather than 0.14 gN/m2.d. Lifting up the SALR, on the other hand, results in a bad anammox environment and cannot prolong it to one-stage PNA. An intermittent aeration cycle with four different cycle lengths sets, obtained by monitoring nitrogen compound transformation, was, therefore, applied to the reactor. The relatively shorter aerobic length of 10 min ON and 30 OFF intermittent aeration cycle with 0.5 mg/L aerated DO was successful in achieving the partial nitritation with NPR, NAR, and ammonium removal efficiency (ARE) values of 17%, 78%, and 37%, respectively, showing that shorter aerated length suppresses NOB to a high degree due to less available time for NOB after oxygen starvation.


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