scholarly journals Enhanced Nitrogen and Phosphorus Removal by Natural Pyrite based Constructed Wetland with Intermittent Aeration

2021 ◽  
Author(s):  
Liya Li ◽  
Jingwei Feng ◽  
Liu Zhang ◽  
Hao Yin ◽  
Chunli Fan ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Nitrification Rate ◽  
Intermittent Aeration ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Monooxygenase Activity ◽  
Ferrous Sulfide ◽  
Natural Pyrite ◽  
Front Section

Abstract Four subsurface flow constructed wetlands (SFCWs) filled with different substrates including ceramsite, ceramsite + pyrite, ceramsite + ferrous sulfide, and ceramsite + pyrite + ferrous sulfide (labeled as SFCW-S1, SFCW-S2, SFCW-S3, and SFCW-S4) were constructed, and the removal of nitrogen and phosphorus by these SFCWs coupled with intermittent aeration in the front section was discussed. The key findings from different substrate analyses, including nitrification and denitrification rate, enzyme activity, microbial community structure, and the X-ray diffraction, revealed the nitrogen and phosphorus removal mechanism. The results showed that the nitrogen and phosphorus removal efficiency for SFCW-S1 always remains the lowest, and the phosphorus removal efficiency for SFCW-S4 is recorded as the highest one. However, after controlling the dissolved oxygen by intermittent aeration in the front section of SFCWs, the nitrogen and phosphorus removal efficiencies of SFCWs-S2 and S4 becomes higher than those of SFCW-S1, and SFCW-S3. It was noticed that the pollutants were removed mainly in the front section of the SFCWs. Both precipitation and adsorption on the substrate were the main mechanisms for phosphorus removal. A minute difference of nitrification rate and ammonia monooxygenase activity was observed in the SFCWs aeration zone. The denitrification rates, nitrate reductase, nitrite reductase, and electron transport system activity for SFCW-S2 and SFCW-S4 were higher than those detected for SFCW-S1 and SFCW-S3 in the non-aerated zone. Proteobacteria was the largest phyla found in the SFCWs. Moreover, Thiobacillus occupied a large proportion found in SFCW-S2, and SFCW-S4, and it played a crucial role in pyrite-driven autotrophic denitrification.

Comparison of nitrogen and phosphorus removal efficiency between two types of baffled vertical flow constructed wetlands planted with Oenanthe Javanica

2020 ◽  
Vol 81 (9) ◽  
pp. 2023-2032
Author(s):  
Jingqing Gao ◽  
Lei Yang ◽  
Rui Zhong ◽  
Yong Chen ◽  
Jingshen Zhang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Drinking Water Treatment ◽  
Domestic Sewage ◽  
Good Choice ◽  
Vertical Flow ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Oenanthe Javanica

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.

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
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Phosphorus Removal ◽  
P Uptake ◽  
Flow Mode ◽  
Bypass Flow ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
University Of Cape Town ◽  
P Removal

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.

scholarly journals Use of zeolites for macronutrients removal from wastewater

2019 ◽  
Vol 12 (1) ◽  
pp. 150-161
Author(s):  
Barbora Urminská ◽  
Ján Derco ◽  
Ronald Zakhar ◽  
Adriana Korpicsová
Keyword(s):  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Natural Zeolite ◽  
Ammonium Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Physical Chemical ◽  
Synthetic Zeolites ◽  
Modified Zeolites ◽  
Preliminary Research

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.

Two stage intermittent aeration membrane bioreactor for simultaneous organic, nitrogen and phosphorus removal

2000 ◽  
Vol 41 (10-11) ◽  
pp. 217-225 ◽  
Author(s):  
G.T. Seo ◽  
T.S. Lee ◽  
B.H. Moon ◽  
J.H. Lim ◽  
K.S. Lee
Keyword(s):  
Phosphorus Removal ◽  
Membrane Bioreactor ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Intermittent Aeration ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Aeration Conditions ◽  
Two Phases ◽  
Filtration Experiment

A submerged membrane bioreactor (SMBR) was operated in 2-stage intermittent aeration for simultaneous removal of organic matter, nitrogen and phosphorus. The system consists of two reactors with a total volume of 0.27 m3 (1st reactor 0.09 m3 and 2nd 0.18 m3). Real domestic wastewater was used as influent to the system. Membrane used for this experiment was hollow fiber polyethylene membrane with pore size of 0.1μm and effective surface area, 4 m2. The membrane was submerged in the 2nd reactor for suction type filtration. Experiment was carried out in two phases varying the time cycles of aeration and non-aeration. SRT was maintained at 25 days and HRT, 16–19 hours. MLSS concentration in the reactors was in the range of 2,700–3,400 mg/l. The MLSS internal recycling ratio was maintained at 100% of influent flow rate. When time cycles of aeration and non-aeration were set at 30/90 min and 60/60 min in reactor 1 and 2, the removal of BOD and COD was 98.3% and 95.6%, respectively. A relatively low nitrogen and phosphorus removal was observed in this condition (73.6% as T–N and 46.6% as T–P). However, with 60/60 min intermittent aeration conditions for both reactors, the removal rate of nitrogen and phosphorus for two weeks steady state were enhanced to 91.6% as TN and 66% as TP, respectively. Further a high organic removal (98% BOD and 96.2% COD) was achieved too. In these conditions, the membrane of flux declined from 0.1 m/d to 0.08 m/d and suction filtration was at 10–12 kPa for a month long operation period.

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