Enhancing nitrogen and phosphorus removal in the BUCT–IFAS process by bypass flow strategy

2015 ◽  
Vol 72 (4) ◽  
pp. 528-534 ◽  
Author(s):  
Yang Bai ◽  
Xie Quan ◽  
Yaobin Zhang ◽  
Shuo Chen

A University of Cape Town process coupled with integrated fixed biofilm and activated sludge system was modified by bypass flow strategy (BUCT–IFAS) to enhance nitrogen and phosphorus removal from the wastewater containing insufficient carbon source. This process was operated under different bypass flow ratios (λ were 0, 0.4, 0.5, 0.6 and 0.7, respectively) to investigate the effect of different operational modes on the nitrogen (N) and phosphorus (P) removal efficiency (λ = 0 was noted as common mode, other λ were noted as bypass flow mode), and optimizing the N and P removal efficiency by altering the λ. Results showed that the best total nitrogen (TN) and total phosphorus (TP) removal performances were achieved at λ of 0.6, the effluent TN and TP averaged 14.0 and 0.4 mg/L meeting discharge standard (TN < 15 mg/L, TP < 0.5 mg/L). Correspondingly, the TN and TP removal efficiencies were 70% and 94%, respectively, which were 24 and 41% higher than those at λ of 0. In addition, the denitrification and anoxic P-uptake rates were increased by 23% and 23%, respectively, compared with those at λ of 0. These results demonstrated that the BUCT–IFAS process was an attractive method for enhancing nitrogen and phosphorus removal from wastewater containing insufficient carbon source.

2000 ◽  
Vol 42 (3-4) ◽  
pp. 89-94 ◽  
Author(s):  
H.Y. Chang ◽  
C.F. Ouyang

This investigation incorporated a stepwise feeding strategy into the biological process containing anaerobic/oxide/anoxic/oxide (AOAO) stages to enhance nitrogen and phosphorus removal efficiencies. Synthetic wastewater was fed into the experimental reactors during the anaerobic and anoxic stages and the substrates/nutrients were successfully consumed without recycling either nitrified effluent or external carbon source. An intrinsic sufficient carbon source developed during the anoxic stage and caused the NOx (NO2-N+NO3-N) concentration to be reduced from 11.85mg/l to 5.65mg/l. The total Kjeldahl nitrogen (TKN) removal rate was between 81.81%∼93.96% and the PO4-P removal ratio ranged from 93%∼100%. The substrate fed into the anaerobic with a Q1 flow rate and a Q2 into the anoxic reactor. The three difference experiments contained within this study produced Q1/Q2 that varied from 7/3, 8/2, and 9/1. The AOAO process saved nearly one-third of the energy compared with typical biological nutrient removal (BNR) system A2O processes.


2009 ◽  
Vol 59 (11) ◽  
pp. 2093-2099 ◽  
Author(s):  
H. Lee ◽  
J. Han ◽  
Z. Yun

A lab-scale UCT-type membrane bio-reactor (MBR) was operated for biological nitrogen (N) and phosphorus (P) removal simultaneously. In order to examine biological nutrient removal (BNR) characteristics of MBR, the lab unit was fed with a synthetic strong and weak wastewater. With strong wastewater, a simultaneous removal of N and P was achieved while application of weak wastewater resulted in a decrease of both N and P removal. Recycled nitrate due to the limited organic in weak wastewater operation probably caused a nitrate inhibition in anaerobic zone. In step feed modification with weak wastewater, both N and P removal capability recovered in the system, indicating that the allocation of COD for denitrification at anoxic zone was a key to increase the biological P removal. In addition, the analysis on the specific P uptake rate in anoxic zone demonstrated that denitrifying phosphorus accumulating organism (dPAO) played an important role to remove up to 40% of P along with N. The sludge production characteristics of UCT-type MBR were similar to ordinary activated sludge with BNR capability.


2007 ◽  
Vol 55 (1-2) ◽  
pp. 477-484 ◽  
Author(s):  
Y.W. Lee ◽  
Y.J. Kim ◽  
N.I. Chang ◽  
J.G. Lee ◽  
B.H. Lee

SBR process shows high nitrogen and phosphorus removal in countries where separated sewers are used. On the other hand, removal efficiency is low in countries where combined sewers are used though the same SBR is applied. This is because the organic concentration (as BOD), which is used as carbon source for denitrification, of combined sewers is much lower than that of separated sewers. Almost all sewers in Korea are combined, and their BOD is low by about 1/2 over the level needed for denitrification. In this study, a SBR process that can optimise organic usage by step feed and recycle is thus developed to increase the removal efficiency of nitrogen and phosphorus, and the results show that the removal rates of BOD, T-N and T-P are 95.4, 81.4 and 86.1%, respectively, though influent BOD is low.


2020 ◽  
Vol 81 (9) ◽  
pp. 2023-2032
Author(s):  
Jingqing Gao ◽  
Lei Yang ◽  
Rui Zhong ◽  
Yong Chen ◽  
Jingshen Zhang ◽  
...  

Abstract The environmental problems related to rural domestic sewage treatment are becoming increasingly serious, and society is also concerned about them. A baffled vertical flow constructed wetland (BVFCW) is a good choice for cleaning wastewater. Herein, a drinking-water treatment sludge-BVFCW (D-BVFCW) parallel with ceramsite-BVFCW (C-BVFCW) planted with Oenanthe javanica (O. javanica) to treat rural domestic sewage was investigated, aiming to compare nitrogen and phosphorus removal efficiency in different BVFCWs. A removal of 23.9% NH4+-N, 24.6% total nitrogen (TN) and 76.7% total phosphorus (TP) occurred simultaneously in the D-BVFCW; 56.4% NH4+-N, 60.8% TN and 55.2% TP respectively in the C-BVFCW. The root and plant height increased by an average of 7.9 cm and 8.3 cm, respectively, in the D-BVFCW, and by 0.7 cm and 1.1 cm, respectively, in the C-BVFCW. These results demonstrate that the D-BVFCW and C-BVFCW have different effects on the removal of N and P. The D-BVFCW mainly removed P, while C-BVFCW mainly removed N.


1991 ◽  
Vol 24 (10) ◽  
pp. 231-237
Author(s):  
W. G. Werumeus Buning ◽  
F. W. A. M. Rijnart ◽  
P. P. Weesendorp

To meet two levels of nitrogen and phosphorus removal (effluent standards Ntot 20 and 10 mg/l and Ptot 2 and 1 mg/l respectively) various systems were compared in a desk study. After a cost estimate and an assessment f the advantages and drawbacks, the oxidation ditch with biological by pass phosphate removal turned out to be the best system.


2019 ◽  
Vol 12 (1) ◽  
pp. 150-161
Author(s):  
Barbora Urminská ◽  
Ján Derco ◽  
Ronald Zakhar ◽  
Adriana Korpicsová

Abstract Natural or synthetic zeolites have unique physical, chemical and structural properties that predetermine their use in many processes, including wastewater treatment. This study presents the results of our preliminary research in the field of nitrogen and phosphorus removal using adsorption and adsorptive ozonation with natural and modified zeolites. Iron-modified zeolite was the most efficient for the removal of ammonium nitrogen by adsorption. Phosphorus removal efficiency using adsorption was relatively low and natural zeolite was not suitable for the phosphorus removal at all. Ozone had no significant impact on the removal efficiency. Regeneration of loaded zeolites with ozone has also been studied. This method was partly efficient but it needs be further examined.


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