scholarly journals Quantifying Community Dynamics of Nitrifiers in Functionally Stable Reactors

2007 ◽  
Vol 74 (1) ◽  
pp. 286-293 ◽  
Author(s):  
Lieven Wittebolle ◽  
Han Vervaeren ◽  
Willy Verstraete ◽  
Nico Boon

ABSTRACT A sequential batch reactor (SBR) and a membrane bioreactor (MBR) were inoculated with the same sludge from a municipal wastewater treatment plant, supplemented with ammonium, and operated in parallel for 84 days. It was investigated whether the functional stability of the nitrification process corresponded with a static ammonia-oxidizing bacterial (AOB) community. The SBR provided complete nitrification during nearly the whole experimental run, whereas the MBR showed a buildup of 0 to 2 mg nitrite-N liter−1 from day 45 until day 84. Based on the denaturing gradient gel electrophoresis profiles, two novel approaches were introduced to characterize and quantify the community dynamics and interspecies abundance ratios: (i) the rate of change [Δ t (week)] parameter and (ii) the Pareto-Lorenz curve distribution pattern. During the whole sampling period, it was observed that neither of the reactor types maintained a static microbial community and that the SBR evolved more gradually than the MBR, particularly with respect to AOB (i.e., average weekly community changes of 12.6% ± 5.2% for the SBR and 24.6% ± 14.3% for the MBR). Based on the Pareto-Lorenz curves, it was observed that only a small group of AOB species played a numerically dominant role in the nitritation of both reactors, and this was true especially for the MBR. The remaining less dominant species were speculated to constitute a reserve of AOB which can proliferate to replace the dominant species. The value of these parameters in terms of tools to assist the operation of activated-sludge systems is discussed.

2003 ◽  
Vol 48 (8) ◽  
pp. 9-18 ◽  
Author(s):  
C. Fux ◽  
K. Lange ◽  
A. Faessler ◽  
P. Huber ◽  
B. Grueniger ◽  
...  

Separate biological elimination of nitrogen from the digester supernatant of a municipal wastewater treatment plant (WWTP) was investigated in pilot and full-scale plants. Denitrification mainly via nitrite was achieved in a sequencing batch reactor (SBR) and a continuous flow reactor (CSTR or SHARON). Suppression of nitrite oxidation in the SBR was feasible at short aerobic/anaerobic intervals allowing for immediate denitrification of the produced nitrite. Nitrate production could also be stopped by exposing the biomass to anaerobic conditions for 11 days. Temporarily high concentrations (up to 80 gNH3-Nm-3) of free ammonia could not be considered as the major reason for inhibiting nitrite oxidation. In a full-scale SBR plant 90% of the nitrogen load was denitrified in a total hydraulic retention time (HRT) of 1.6 days and with a sludge age between 15 and 20 days. Ethanol and methanol were used for denitrification. The specific average substrate consumption was 2.2 gCODdosedg-1Nremoved with an effective biomass yield of 0.2 gCODbiomassg-1CODdosed. No dosing with base was required. In the SHARON process full nitrogen elimination was achieved only with a total HRT greater than 4 days at 29°C. The overall costs were estimated at €1.4 kg-1Nremoved for the SBR and €1.63 kg-1Nremoved in SHARON mode, respectively. The SHARON process is simple in operation (CSTR) but the tank volume has to be significantly greater than in SBR.


2014 ◽  
Vol 1030-1032 ◽  
pp. 387-390
Author(s):  
Chun Di Gao ◽  
Shi Xin Fan ◽  
Er Long Jiao ◽  
Hao Li ◽  
Wei Xiao Wang

A novel alternating oxic-anoxic operation mode of shortcut nitrification-denitrification was developed in a sequencing batch reactor at ambient temperature. Operational parameters favorable for maintaining the shortcut nitrification-denitrification were investigated and optimized. The experiments showed that alternating oxic-anoxic shortcut nitrification-denitrification system was able to be an independent treatment process in domestic wastewater treatment. And the optimization approach was so efficient that the main pollutant discharge targets achieved Standard A of the first class in "Discharge standard of pollutants for municipal wastewater treatment plant". Moreover, the reliability of the operation strategy in this experimentation was proved, which indicated the excellent nitrogen removal performances.


2014 ◽  
Vol 9 (2) ◽  
pp. 235-242 ◽  
Author(s):  
S. Morling ◽  
A. Franquiz ◽  
J. Måhlgren ◽  
Å. Westlund

A biological wastewater treatment plant, Nynäshamn treating municipal wastewater and septic sludge operated with a combination of sequencing batch reactor (SBR) units and constructed wetland is presented in this paper. The plant has to treat low temperature wastewater in winter time, still with demands for a biological nitrogen removal. Treatment results from a 13 year operation period are presented. Special attention was given to the nutrient removal during low temperature conditions. The combination of a SBR system along with classical chemical precipitation and a polishing step based on ‘natural’ extensive treatment has been a sustainable way to keep the discharge levels low. The combined treatment with SBR and the wetland at the Nynäshamn plant has resulted in improved discharge levels typically as follows (annual mean values); BOD7 3 mg/l, to be compared with the formal consent value of <15 mg/l, total P < 0.1 mg/l, to be compared with the formal consent value of <0.5 mg/l and total N 7 mg/l, to be compared with the formal consent value of <15 mg/l. It is also important to underline that the change of process train has resulted in a substantial saving of the precipitant agent for phosphorus removal. The needed dosage is now 50% of the previous dose, before the implementation of the SBR-units.


2014 ◽  
Vol 1073-1076 ◽  
pp. 849-853
Author(s):  
Xiu Bin Lv ◽  
Zhi Hong Yang ◽  
Hai Zhao Zhao ◽  
Hong Ping Chen

A waste water treatment plant (WWTP) adopts sequencing batch reactor (SBR) process, which exist the problem of instable treatment effect on denitrification and dephosphorization. The total nitrogen (TN) and total phosphorus (TP) of the effluent could not reach the class A standard of discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002) (hereinafter referred to as the class A standard) as a result of different order in utilizing the carbon source between nitrification and denitrification. The step-feed procedure is used to improve the efficiency of denitrification and dephosphorization. Field experiments about the effects of the different influent distribution ratio (marked as λ) on denitrification and dephosphorization were carried out and the results showed that the effect of the effluent TN is the best and other indexes could also achieve class A standard when λ is 5:3.


2016 ◽  
Vol 74 (11) ◽  
pp. 2727-2735 ◽  
Author(s):  
Yixuan Yang ◽  
Fei Tang ◽  
Xiaoling Su ◽  
Hua Yin ◽  
Fei Ge

To access better removal of nutrients with algae-based techniques, a dominant alga from real municipal wastewater was identified and its capacity in removing low concentrations of nitrogen (NH+4 or NO−3) and phosphorus (PO3−4) was evaluated. Results showed that Oedogonium brevicingulatum, a filamentous green alga, was confirmed as the dominant alga in the secondary effluent of a municipal wastewater treatment plant by polymerase chain reaction-denaturing gradient gel electrophoresis. Low concentrations of NH+4 or NO−3 (≤5 mg N L−1) and PO3−4 (≤0.5 mg P L−1) were 100% removed by the algae in a 7-d test. The maximum nutrient removal rate (Vmax) and the half-saturation constant (Km) for NH+4 (10.03 ± 0.95 mg g−1d−1 and 0.19 ± 0.03 mg L−1) and NO−3 (8.43 ± 0.21 mg g−1 d−1 and 0.27 ± 0.11 mg L−1) indicated the uptake capability for NH+4 is higher than that for NO−3. Meanwhile, it showed higher affinity for PO3−4 (Vmax: 1.42 ± 0.02 mg g−1 d−1; Km: 0.02 ± 0.00 mg L−1) with NH+4 as nitrogen source than that (Vmax: 1.24 ± 0.15 mg g−1 d−1; Km: 0.06 ± 0.03 mg L−1) with NO−3 as nitrogen source. Moreover, nutrient removal efficiencies were observed steady when nitrogen/phosphorus ratio ranged from 5:1 to 20:1. These results suggest that the dominant algae from municipal wastewater have potentials to be applied in nutrient removal.


1994 ◽  
Vol 30 (4) ◽  
pp. 125-132 ◽  
Author(s):  
D. Carnimeo ◽  
E. Contini ◽  
R. Di Marino ◽  
F. Donadio ◽  
L. Liberti ◽  
...  

The pilot investigation on the use of UV as an alternative disinfectant to NaOCI was started in 1992 at Trani (South Italy) municipal wastewater treatment plant (335 m3/h). The results collected after six months continuous operation enabled us to compare UV and NaOCl disinfection effectiveness on the basis of secondary effluent characteristics, quantify photoreactivation effects, evidence possible DBP formation and assess costs.


1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.


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