Nitrogen removal from reject water with primary sludge as denitrification carbon source

2010 ◽  
Vol 61 (12) ◽  
pp. 2965-2972 ◽  
Author(s):  
L. Zhang ◽  
S. J. Zhang ◽  
J. Zhou ◽  
S. Y. Wang ◽  
Y. P. Gan ◽  
...  

A novel system was used for nitrogen removal from reject water. This system includes one anoxic/oxic reactor for nitrification and a special reactor for denitrification in which primary sludge was added intermittently as electron donor. In denitrification reactor, sludge fermentation and denitrification reaction took place simultaneously and promoted each other. It was found that effluent recycle could improve nitrogen removal efficiency due to reclaiming of alkalinity. Under steady state conditions, the average solid retention time (SRT) in denitrification reactor was 12–15 d, a total nitrogen loading rate was 0.2 kg N/(m3 day) and TN removal efficiency was more than 90% without extra carbon source addition. Primary sludge was degraded so that volatile suspended solid (VSS) decreased by 50%. Further investigation showed that ORP could be taken as a control parameter for sludge addition.

2011 ◽  
Vol 281 ◽  
pp. 101-105
Author(s):  
Cheng Cheng Wu ◽  
Yong Zhen Peng ◽  
Liang Zhang ◽  
Shu Ying Wang

A novel post-denitrification system fed by carbon source from primary sludge (PS) was used for enhancing biological nitrogen removal (BNR) of low C/N wastewater. This system included one anoxic/oxic (AO) reactor and a special reactor for simultaneous sludge fermentation and denitrification (Sifeden). Ammonia was nitrified to nitrate in AO and then the nitrate was reduced to dinitrogen in Sifeden , into which PS was added intermittently. Results showed that this system had high performance on nitrogen removal. Total nitrogen (TN) removal efficiency was higher than 85% and the effluent TN≤10mg/L in the condition of influent C/N≤2. In Sifeden, volatile fatty acid (VFA) produced from PS fermentation provided electron donor for nitrate reduction, and PS was preliminarily stabilized simultaneously. Oxidation-Reduction Potential (ORP) had a significant correlation with the denitrification performance. TN removal efficiency could be further improved if adopting proper PS addition strategy according to the ORP profiles.


2014 ◽  
Vol 17 (2) ◽  
pp. 69-79
Author(s):  
Linh Van Tran ◽  
Phuoc Van Nguyen ◽  
Phuong Thi Thanh Nguyen

The SBMBMBR technology (sequencing batch moving bed membrane bioreactor), a combiantion of membrane filtration MF process in activated sludge with sequencing batch (SBR) moving bed using Anox Kaldnes K2 (MBBR), has been studied for the removal of organic and total nitrogen in tannery wastewater. After 170 days, reasearch results showed that the COD removal efficiency was ranged from 89,2±0,6 to 95,9±0,3% when the organic loading rate changed from 0,564±0,019 to 1.207±99 kgCOD/m3/day. The total nitrogen removal efficiency reached 30,0±4,9 to 65,9±13,3. The highest COD removal efficiency was 0,72±0,02 kgCOD/m3/day. The lowest nitrogen removal efficiency was 10,8±5,4% at 0,327±0,020 kgTN/m3/day of nitrogen loading rate. During the research, the adhensional tension of microorganism was insignificant. The biomass remained unchanged with 6.808±226 mg/L of Mixed liquor suspended solids (MLSS). When the salinity went up from 3.500 to 8.000 mgCl/l, the COD and nitrogen removal efficiency decreased. However, the conversion of nitrogen was improved and the recovery of biomass following the changed loading rate was quite fast.


2012 ◽  
Vol 65 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Liang Zhang ◽  
Shujun Zhang ◽  
Xiaoyu Han ◽  
Yiping Gan ◽  
Chengcheng Wu ◽  
...  

The effects of free ammonia (FA) or free nitrous acid (FNA) on partial nitrification (PN) has been well investigated. Nevertheless, little information was known about the combined effects of nitrogen loading rate (NLR) and substrate inhibition, as well as the impact on the community structure of nitrifiers. In this work, real reject water was treated in a pre-denitrification reactor. PN was achieved by gradually increasing NLR, and it was successfully maintained when average FA and FNA were within 0.8–3.2 mg NH3-N/L and 0.003–0.067 mg HNO2-N/L, respectively. When NLR was reduced, PN was slightly affected due to the FA declination. As FNA inhibition was also eliminated by adding alkalinity into the influent, PN was completely destroyed quickly. FISH results indicated the deterioration of the PN was mainly attributed to the recovery of NOB when inhibition effects were limited. It concluded the increase of NLR benefited the partial nitrification. However, the stability of the nitrite path way was more dependent on selective substrate inhibition effects, especially the FNA inhibition. These findings would be important for further treatment of actual reject water.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 487-492 ◽  
Author(s):  
D. Pak ◽  
W. Chang

A two-biofilter system operated under alternating anaerobic/aerobic conditions was tested to remove nutrient as well as organics from wastewater generated from car-washing facility. The wastewater was characterized by relatively low organic and high phosphorus content. The factors affecting phosphorus removal in the two-biofilter system were investigated. Operational parameters examined in this study were hydraulic retention time, organic, suspended solid and nitrogen loading rate. The factors affecting phosphorus removal in biological filter appeared to be influent COD, COD/T–P, BOD/COD, nitrogen, and SS/T–P. Nitrite and nitrate produced in the biofilter in aerobic condition affected phosphorus removal by the two-biofilter system. The biomass wasted during backwash procedure also affected total phosphorus removal by the system.


2014 ◽  
Vol 69 (9) ◽  
pp. 1805-1812 ◽  
Author(s):  
Jian Zhou ◽  
Guangxu Qin ◽  
Jianbing Zhang ◽  
Yancheng Li ◽  
Qiang He ◽  
...  

The coping strategy of a CANON (completely autotrophic nitrogen removal over nitrite) reactor working at room temperature was investigated using response surface methodology. The total nitrogen (TN) removal efficiency was taken as a dependent variable. The temperature (X), dissolved oxygen (DO) concentration (Y), and influent nitrogen loading rate (Z) were taken as independent variables. Results showed that the relation of these three independent variables can be described by the TN removal efficiency expressed as −5.03 + 1.51X + 45.16Y + 30.13Z + 0.26XY + 1.84XZ − 0.04X2 − 9.06Y2 − 99.00Z2. The analysis of variance proved that the equation is applicable. The response surface demonstrated that the temperature significantly interacts with the DO concentration and influent N loading rate. A coping strategy for the CANON reactor working at room temperature is thus proposed: altering the DO concentration and the N loading rate to counterbalance the impact of low temperature. The verification test proved the strategy is viable. The TN removal efficiency was 91.3% when the reactor was operated under a temperature of 35.0 °C, a DO of 3.0 mg/L, and a N loading rate of 0.70 kgN/(m³ d). When the temperature dropped from 35.0 to 19.2 °C, the TN removal efficiency was kept at 88.7% by regulating the influent N loading rate from 0.7 kgN/(m³ d) to 0.35 kgN/(m³ d) and the DO concentration from 3.0 to 2.6 mg/L.


2015 ◽  
Vol 72 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Massimo Raboni ◽  
Renato Gavasci ◽  
Paolo Viotti

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.


2009 ◽  
Vol 59 (12) ◽  
pp. 2371-2377 ◽  
Author(s):  
Q. Yang ◽  
X. H. Liu ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
H. W. Sun ◽  
...  

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.


2010 ◽  
Vol 61 (3) ◽  
pp. 671-676 ◽  
Author(s):  
W. Chen ◽  
F. Y. Sun ◽  
X. M. Wang ◽  
X. Y. Li

A hybrid system has been developed for biological nitrogen removal through nitrification-denitrification. The system includes an aerobic tank and an anoxic tank with an intermediate sludge settler connected to a membrane bioreactor (MBR) with a submerged 0.4 μm hollow-fiber membrane module. The laboratory system has a total working volume of 6.5 L treating a glucose-based synthetic wastewater. The experimental results demonstrate that the new process is highly effective for simultaneous organic and nitrogen removal. During the stationary operation, a sludge SS (suspended solids) concentration of 6 g/L or higher can be maintained in the reactors. The system has a COD (chemical oxygen demand) loading rate of up to 2,100 mg/L-d and a total nitrogen loading rate of up to 170 mg N/L-d. More than 95% COD can be degraded, and the total nitrogen removal efficiency can be 90% or higher as the nitrogen is reduced from 100 to around 7.5 mg/L. A high quality effluent is produced with a SS of less than 1 mg/L. With the MBR, organic degradation, nitrogen removal and sludge-liquid separation can be well achieved within a short HRT of about 10 hr.


2017 ◽  
Author(s):  
S. Suneethi ◽  
Kurian Joseph

Anaerobic Membrane Bioreactor (AnMBR) is an innovative high cell density system having complete biomass retention, high reactor loading and low sludge production and suitable for developing slow growing autotrophic bacterial cultures such as ANAMMOX. The Anaerobic Ammonium Oxidation (ANAMMOX) process is an advanced biological nitrogen removal removes ammonia using nitrite as the electron acceptor without oxygen. The NH4+-N in the landfill leachate that is formed due to the release of nitrogen from municipal solid waste (MSW), when discharged untreated, into the surface water can result in eutrophication, aquatic toxicity and emissions of nitrous oxide (N2O) to atmosphere. Besides, NH4+-N accumulation in landfills poses long term pollution issue with significant interference during post closure thereby requiring its removal prior to ultimate disposal into inland surface waters. The main objective of this study was to investigate the feasibility and treatment efficiency of treating landfill leachate (to check) for removing NH4+-N by adopting ANAMMOX process in AnMBR. The AnMBR was optimized for Nitrogen Loading Rate (NLR) varying from 0.025 to 5 kg NH4+-N/ m3/ d with hydraulic retention time (HRT) ranging from 1 to 3 d. NH4+-N removal efficacy of 85.13 ± 9.67% with the mean nitrogen removal rate (NRR) of 5.54 ± 0.63 kg NH4+-N/ m3/ d was achieved with nitrogen loading rate (NLR) of 6.51 ± 0.20 kg NH4+- N/ m3/ d at 1.5 d HRT. The nitrogen transformation intermediates in the form of hydrazine (N2H4) and hydroxylamine (NH2OH) were 0.008 ± 0.005 mg/L and 0.006 ± 0.001 mg/L, respectively, indicating co-existence of aerobic ammonia oxidizers (AOB) and ANAMMOX. The free ammonia (NH3) and free nitrous acid (HNO2) concentrations were 26.61 ± 16.54 mg/L and (1.66 ± 0.95) x 10-5 mg/L, preventing NO2--N oxidation to NO3--N enabling sustained NH4+- N removal.


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