scholarly journals Single-Stage Biofilm-Based Total Nitrogen Removal in a Membrane Aerated Biofilm Reactor: Impact of Aeration Mode, HRT and Scouring Intensity

Author(s):  
Sadaf mehrabi ◽  
Dwight Houweling ◽  
Martha Dagnew

Abstract High energy costs, organic carbon availability, and space limitation are some of the barriers faced by wastewater treatment processes. This research investigates the impact of membrane aeration mode, scouring intensity, and loading rate in a single-stage total nitrogen removal process in a membrane aerated biofilm reactor (MABR). Under ammonia loading of 2.7 g N/m2.d, continuous process aeration led to 1.7 g NH4-N/m2.d and 0.8 g TN/m2.d removal, respectively. Conversely, intermittent (5/12 min on/off) aeration resulted in 35% less ammonia removal but 34% higher total nitrogen (TN) removal. The MABR under ammonia load of 1.6 g N/m2.d showed an enhanced effluent quality with an average of 2.5 mg/L effluent ammonia concentration. This finding highlights the nitrification potential of a flow-through MABR as a standalone treatment step without any downstream process. Also, slough-off, a common issue in the biofilm process and was hypothesized to reduce the removal efficiency, showed increased ammonia removal rates by 20%. The microbial analysis indicated the dominant AOB and NOB species as Nitrosomonas spp. and Nitrospira spp, respectively. Moreover, the relative abundance of denitrifying bacteria (40.5%) were found twice in intermittently-aerated MABR compared to the continuously-aerated one (20.5%). However, NOB and denitrifying bacteria relative abundances were comparable where continuous air was supplied.

2017 ◽  
Vol 76 (12) ◽  
pp. 3468-3477 ◽  
Author(s):  
Weixing Mi ◽  
Jianqiang Zhao ◽  
Xiaoqian Ding ◽  
Guanghuan Ge ◽  
Rixiang Zhao

Abstract To investigate the characteristics of anaerobic ammonia oxidation for treating low-ammonium wastewater, a continuous-flow completely autotrophic nitrogen removal over nitrite (CANON) biofilm reactor was studied. At a temperature of 32 ± 1 °C and a pH between 7.5 and 8.2, two operational experiments were performed: the first one fixed the hydraulic retention time (HRT) at 10 h and gradually reduced the influent ammonium concentrations from 210 to 50 mg L−1; the second one fixed the influent ammonium concentration at 30 mg L−1 and gradually decreased the HRT from 10 to 3 h. The results revealed that the total nitrogen removal efficiency exceeded 80%, with a corresponding total nitrogen removal rate of 0.26 ± 0.01 kg N m−3 d−1 at the final low ammonium concentration of 30 mg L−1. Small amounts of nitrous oxide (N2O) up to 0.015 ± 0.004 kg m−3 d−1 at the ammonium concentration of 210 mg L−1 were produced in the CANON process and decreased with the decrease in the influent ammonium loads. High-throughput pyrosequencing analysis indicated that the dominant functional bacteria ‘Candidatus Kuenenia’ under high influent ammonium levels were gradually succeeded by Armatimonadetes_gp5 under low influent ammonium levels.


2017 ◽  
Vol 77 (6) ◽  
pp. 1483-1492 ◽  
Author(s):  
Yue-mei Han ◽  
Feng-xia Liu ◽  
Xiao-fei Xu ◽  
Zhuo Yan ◽  
Zhi-jun Liu

Abstract This study developed a partial nitrification (PN) and anaerobic ammonia oxidation (Anammox) process for treating high-ammonia wastewater using an innovative biofilm system in which ammonia oxidizing bacteria grew on fluidized Kaldnes (K1) carriers and Anammox bacteria grew on fixed acryl resin carriers. The airlift loop biofilm reactor (ALBR) was stably operated for more than 4 months under the following conditions: 35 ± 2 °C, pH 7.5–8.0 and dissolved oxygen (DO) of 0.5–3.5 mg/L. The results showed that the total nitrogen removal efficiency reached a maximum of 75% and the total nitrogen removal loading rate was above 0.4 kg/(d·m3). DO was the most efficient control parameter in the mixed biofilm system, and values below 1.5 mg/L were observed in the riser zone for the PN reaction, while values below 0.8 mg/L were observed in the downer zone for the Anammox reaction. Scanning electron microscopy and Fluorescence In Situ Hybridization images showed that most of the nitrifying bacteria were distributed on the K1 carriers and most of the Anammox bacteria were distributed within the acryl resin carriers. Therefore, the results indicate that the proposed combined biofilm system is easy to operate and efficient for the treatment of high-ammonia wastewater.


2021 ◽  
pp. 100817
Author(s):  
Withanage Buddhima Sharmane Siriweera ◽  
Lee Yun-Je ◽  
Kobayashi Masumi ◽  
Chettiyappan Visvanathan

2014 ◽  
Vol 955-959 ◽  
pp. 2318-2321
Author(s):  
Dong Yuan

The objective of this work was to evaluate the performances of A lab-scale innovative sequencing batch biofilm reactor (SBBR) to treat domestic wastewater,in which a acryl cylinder (height 200 mm, diameter 70 mm) was equipped and many fiber threads were attached to the surface of the cylinder as the bacteria carrier. No time and volume for settling was required in this system. After one year’s operation, each parameter achieved the wastewater discharged criterion in 2 cycles (4 h). It was found that COD removal efficiency was up to 90% in 3 h, and ammonium nitrogen concentration approached the least value; total nitrogen removal efficiency reached 55%-71%. In this SBBR system simultaneous nitrification and denitrification was completed at the end of 2 cycles.


2021 ◽  
Author(s):  
Patrick M. D'Aoust ◽  
Simon Vincent ◽  
Guillaume Leblond ◽  
Raheleh Arabgol ◽  
Richard Hérard ◽  
...  

In this study, a municipal lagoon with high wintertime effluent total ammonia nitrogen (TAN) concentrations was upgraded with a pilot-scale NIT-NIT-DENIT moving bed biofilm reactor (MBBR) treatment train to characterize its effluent over wintertime operation, investigate the feasibility of upgrading lagoons to achieve substantial biological total nitrogen removal across ultra-low temperatures (0.6 – 3.0°C) and investigate nitrification inhibition pathways in facultative lagoon systems at ultra-low temperatures. Throughout the study, it was observed that the system substantially reduced total nitrogen (TN) and total phosphorus (TP) effluent concentrations by an average of 69.0 ± 24.5% and 74.7 ± 20.1%, respectively, with average TN and TP concentrations exiting the treatment train of 7.60 ± 5.60 mg-N/L and 0.05 ± 0.02 mg-P/L, respectively, indicating the feasibility of upgrading municipal lagoons to meet increasing stringent effluent standards to ensure the perenniality of water resources. Furthermore, it was observed that sulfide toxicity may play an important role in the inhibition of nitrifying organisms in lagoons.


Author(s):  
Oscar Samuelsson ◽  
Gustaf Olsson ◽  
Erik Lindblom ◽  
Anders Björk ◽  
Bengt Carlsson

Abstract This study highlights the need to increase our understanding of the interplay between sensor drift and the performance of the automatic control system. The impact from biased sensors on the automatic control systems is rarely considered when different control strategies are assessed in water resource recovery facilities. Still, the harsh measurement environment with negative effects on sensor data quality is widely acknowledged. Simulations were used to show how sensor bias in an ammonium cascade feedback controller impacts aeration energy efficiency and total nitrogen removal in an activated sludge process. Response surface methodology was used to reduce the required number of simulations, and to consider the combined effect of two simultaneously biased sensors. The effects from flow variations, and negatively biased ammonium (−1 mg/L) and suspended solids sensors (−500 mg/L) reduced the nitrification aeration energy efficiency by between 7 and 25%. Less impact was seen on total nitrogen removal. There were no added non-linear effects from the two simultaneously biased sensors, apart from an interaction between a biased ammonium sensor and dissolved oxygen sensor located in the last aerated zone. Negative effects from sensor bias can partly be limited if the expected bias direction is considered when the controller setpoint-limits are defined.


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