Study on Simultaneous Nitrification–Denitrification in Membrane Bioreactor

2011 ◽  
Vol 347-353 ◽  
pp. 1878-1882
Author(s):  
Lu Xin ◽  
Kai Sun

This study was conducted to evaluate the performance of membrane bioreactors (MBR) for organics and nitrogen removal. The membrane bioreactor was fed with domestic sewage and operated at different contents of dissolved oxygen (DO), different hydraulic retention time (HRT), and various mixed liquor suspended solid (MLSS) concentrations. The results showed that the distribution of DO level in MBR imposed a significant effect on simultaneous nitrification–denitrification (SND), and the optimal DO concentration should be controlled between 0.5 mg/L to1 mg/L. The denitrification was found to show the best performance for total nitrogen (TN) removal when the HRT reached 5 hours. Higher MLSS concentration led to the improvement in TN removal and the optimal MLSS concentration was 9000mg/L. In fact, more than 90% Chemical Oxygen Demand (COD) and ammonia nitrogen (NH3-N) were reduced when the MLSS concentration exceeded 3000mg/L.

2016 ◽  
Vol 73 (12) ◽  
pp. 2904-2912 ◽  
Author(s):  
D. Güven ◽  
E. Ubay Çokgör ◽  
S. Sözen ◽  
D. Orhon

Abstract High rate membrane bioreactor (MBR) systems operated at extremely low sludge ages (superfast membrane bioreactors (SFMBRs)) are inefficient to achieve nitrogen removal, due to insufficient retention time for nitrifiers. Moreover, frequent chemical cleaning is required due to high biomass flux. This study aims to satisfy the nitrification in SFMBRs by using sponge as carriers, leading to the extension of the residence time of microorganisms. In order to test the limits of nitrification, bioreactor was run under 52, 5 and 2 days of carrier residence time (CRT), with a hydraulic retention time of 6 h. Different degrees of nitrification were obtained for different CRTs. Sponge immobilized SFMBR operation with short CRT resulted in partial nitrification indicating selective dominancy of ammonia oxidizers. At higher CRT, simultaneous nitrification–denitrification was achieved when accompanying with oxygen limitation. Process kinetics was determined through evaluation of the results by a modeling study. Nitrifier partition in the reactor was also identified by model calibration.


Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yue Li ◽  
Qi Hu ◽  
Da-Wen Gao

An integrated anaerobic fluidized-bed membrane bioreactor (IAFMBR) was investigated to treat synthetic high-strength benzothiazole wastewater (50 mg/L) at a hydraulic retention time (HRT) of 24, 18, and 12 h. The chemical oxygen demand (COD) removal efficiency (from 93.6% to 90.9%), the methane percentage (from 70.9% to 69.27%), and the methane yield (from 0.309 m3 CH4/kg·CODremoved to 0.316 m3 CH4/kg·CODremoved) were not affected by decreasing HRTs. However, it had an adverse effect on membrane fouling (decreasing service period from 5.3 d to 3.2 d) and benzothiazole removal efficiency (reducing it from 97.5% to 82.3%). Three sludge samples that were collected on day 185, day 240, and day 297 were analyzed using an Illumina® MiSeq platform. It is striking that the dominant genus of archaea was always Methanosaeta despite of HRTs. The proportions of Methanosaeta were 80.6% (HRT 24), 91.9% (HRT 18), and 91.2% (HRT 12). The dominant bacterial genera were Clostridium in proportions of 23.9% (HRT 24), 16.4% (HRT 18), and 15.3% (HRT 12), respectively.


REAKTOR ◽  
2017 ◽  
Vol 5 (1) ◽  
pp. 35
Author(s):  
Budiyono Budiyono

Pemodelan dan simulasi pada keadaan transien dilakukan terhadap sistem pengolahan air limbah dengan proses lumpur aktif tanpa resirkulasi lumpur. Model matematika pada keadaan transien disusun dengan membuat neraca massa substrat dan neraca massa sel. Persamaan yang diperoleh diselesaikan secara numerik. Beberapa parameter yang digunakan untuk penyusunan modelyaitu konsentrasi COD umpan 2.000 mg/l dan waktu tinggal cairan (Hydraulic Retention Time, HRT) bervariasi dari 8, 16, 24 hingga 32 hari. Konsentrasi mikroba (Mixed Liquor Suspended Solid, MLSS) awal divariasikan dari 250, 500, 1000 hingga 2000 mg/l. substrat terlarut awal di dalam bak aerasi divariasi dari 100, 300, 500 hingga 1000 mg/l. Parameter kinetika yang digunakan diperoleh dari literature yaitu laju pertumbuhan maksimum spesifik, laju kematian specific, koefisien perolehan sel dan konstanta setengah jenuh masing-masing 0,589 hari-1, 0,248 hari-1, 0,515 (mg sel/ mg substrat) dan 589 mg/l.Hasil simulasi menunjukkan bahwa waktu yang diperlukan untuk mencapai keadaan tunak tergantung pada HRT dan MLSS awal di dalam bak aerasi. Konsentrasi COD dan MLSS  di dalam bak aerasi pada keadaan transien  tergantung pada MLSS dan konsentrasi COD terlarut awal di dalam bak aerasi dan SRT. Dari hasil simulasi ini bias diambil rele of thumbs bahwa waktu yang diperlukan untuk mencapai keadaan tunak adalah sebesar 1-3 kali HRT pada HRT rendah satu kali HRT pada HRT tinngi.Kata kunci : simulasi dan pemodelan, proses lumpur aktif, keadaan transien


2022 ◽  
Vol 10 (E) ◽  
pp. 6-11
Author(s):  
Zulfikar Zulfikar ◽  
Nasrullah Nasrullah ◽  
Kartini Kartini ◽  
Wiwit Aditama

BACKGROUND: Domestic wastewater can cause health problems and pollute groundwater sources. Such pollution not only has a negative impact on health and the environment, but also on the cost in providing clean water. AIM: The outcome of domestic wastewater treatment through a proper technique is expected to meet the clean water quality standard for sanitation purposes. MATERIALS AND METHODS: The experiment was conducted to determine the effect of Hydraulic Retention Time (HRT) on the levels of Biochemical Oxygen Demand (BOD) and Total Suspended Solid (TSS) of domestic wastewater. The experiment was carried out with 6 variations of HRT, namely 1 hour, 2 hours, 4 hours, 6 hours and 8 hours with 4 repetitions. The media running process was carried out for 14 days until the reactor condition was in steady state. RESULTS: The results showed that the removal values ​​for COD, Oil and Fat, Ammonia and Total Coliform parameters were 68.03%, 46.51%, 69.64% and 68.99%, respectively. Based on the variation of HRT of 1 hour, 2 hours, 4 hours, 6 hours and 8 hours on the BOD parameter, the removal values ​​obtained were 11.7%, 21.3%, 34.7%, 49.0% and 64.1%, respectively. Furthermore, for the TSS parameter, the values obtained were 17.3%, 25.4%, 30.6%, 42.3% and 50.4%, respectively. CONCLUSION: HRT was proven to have a significant effect on the levels of BOD and TSS of domestic wastewater with a p-value of <0.05 at the 95% confidence level


2017 ◽  
Vol 8 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Xiaojie Mei ◽  
Zhiwei Wang ◽  
Yan Miao ◽  
Zhichao Wu

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.


1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.


2006 ◽  
Vol 53 (11) ◽  
pp. 269-276 ◽  
Author(s):  
C.T. Hay ◽  
D.D. Sun ◽  
S.L. Khor ◽  
J.O. Leckie

A high strength industrial wastewater was treated using a pilot scale submerged membrane bioreactor (MBR) at a sludge retention time (SRT) of 200 d. The MBR was operated at a high sludge concentration of 20 g/L and a low F/M ratio of 0.11 during 300 d of operation. It was found that the MBR could achieve COD and TOC overall removal efficiencies at more than 99 and 98% TN removal. The turbidity of the permeate was consistently in the range of 0.123 to 0.136 NTU and colour254 absorbance readings varied from 0.0912 to 0.0962 a.u. cm−1. The sludge concentration was inversely proportional to the hydraulic retention time (HRT), yielded excellent organic removal and extremely low sludge production (0.0016 kgVSS/day).


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