Nitrogen removal by recycle water nitritation as an attractive alternative for retrofit technologies in municipal wastewater treatment plants

2004 ◽  
Vol 49 (5-6) ◽  
pp. 39-46 ◽  
Author(s):  
K.-I. Gil ◽  
E. Choi
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Biological Nutrient Removal ◽  
Recycle Water ◽  
Municipal Wastewater Treatment ◽  
Effluent Quality ◽  
Municipal Wastewater Treatment Plants ◽  
Final Effluent

The recycle water from sludge processing in municipal wastewater treatment plants causes many serious problems in the efficiency and stability of the mainstream process. Thus, the design approach for recycle water is an important part of any biological nutrient removal system design when a retrofit technology is required for upgrading an existing plant. Moreover, the application of nitrogen removal from recycle water using the nitritation process has recently increased due to economic reasons associated with an effective carbon allocation as well as the minimization of aeration costs. However, for the actual application of recycle water nitritation, it has not been fully examined whether or not additional volume would be required in an existing plant. In this paper, the addition of recycle water nitritation to an existing plant was evaluated based on a volume analysis and estimation of final effluent quality. It was expected that using the reserve volume of the aeration tank in existing plants, recycle water nitritation could be applied to a plant without any enlargement. With the addition of recycle water nitritation, it was estimated that the final effluent quality would be improved and stabilized, especially in the winter season.

Performance of a combined eco-system of ponds and constructed wetlands for wastewater reclamation and reuse

2005 ◽  
Vol 51 (12) ◽  
pp. 315-323 ◽  
Author(s):  
L. Wang ◽  
J. Peng ◽  
B. Wang ◽  
R. Cao
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
National Standards ◽  
Municipal Wastewater Treatment ◽  
Wastewater Reclamation ◽  
Effluent Quality ◽  
Major Mechanism ◽  
Removal Efficiencies ◽  
Municipal Wastewater Treatment Plants

An on-site study on the operational performance of a combined eco-system of ponds and SF constructed wetland for municipal wastewater treatment and reclamation/reuse in Donging City, Shandong, China was carried out from January 2001 through October 2003. The removal efficiencies for various main parameters were: TSS 84.8±7.3%, BOD5 87.2±5.3%, CODCr 70.2±18.6%, TP 52.3±23.1%, and NH3-N 54.8±23.9% with effluent concentration of TSS 9.12±5.12 mg/l, BOD5 6.44±4.58 mg/l, CODCr 42.8±6.7 mg/l, TP 0.94±0.27 mg/l and NH3-N 7.95±2.36 mg/l. In addition, the removal efficiencies for faecal coliforms and total bacteria were >99.97% and >99.998% respectively, which well meet Chinese National standards for effluent quality of municipal wastewater treatment plants. The composition of TSS was closely related to CODCr and BOD5 variations, and nitrification-denitrification is the major mechanism of nitrogen removal both in ponds and in wetlands. In addition, sedimentation also played an important role in the removal of TSS, nitrogen, phosphorus and BOD5. The removal efficiencies of various parameters, the number of species and biomass of biological community in the system increased gradually with the ecological maturation.

scholarly journals Municipal wastewater treatment plants as pathogen removal systems and as a contamination source of noroviruses and Enterococcus faecalis

2012 ◽  
Vol 10 (3) ◽  
pp. 380-389 ◽  
Author(s):  
Hui-Wen A. Cheng ◽  
Frances E. Lucy ◽  
Michael A. Broaders ◽  
Sergey E. Mastitsky ◽  
Chien-Hsien Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Enterococcus Faecalis ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Pathogen Removal ◽  
Wastewater Treatment Process ◽  
Human Wastes ◽  
Municipal Wastewater Treatment Plants ◽  
Final Effluent

Municipal wastewater treatment plants play a crucial role in reducing the microbial and pathogen load of human wastes before the end-products are discharged to surface waters (final effluent) or land spread (biosolids). This study investigated the occurrence frequency of noroviruses, Enterococcus faecalis and Enterococcus faecium in influent, final effluent and biosolids from four secondary wastewater treatment plants in northwestern Ireland (plants A–D) and observed the seasonal and spatial variation of the plant treatment efficiencies in the pathogen removals. It was noted that norovirus genogroup II was more resistant to the treatment processes than the norovirus genogroup I and other active viral particles, especially those in the discharge effluents. The percolating biofilm system at plant D resulted in better effluent quality than in the extended aerated activated sludge systems (plants A and B); primary biosolids produced at plant D may pose a higher health risk to the locals. The spread of norovirus genogroup II into the environment, irrespective of the wastewater treatment process, coincides with its national clinical predominance over norovirus genogroup I. This study provides important evidence that municipal wastewater treatment plants not only achieve pathogen removal but can also be the source of environmental pathogen contamination.

scholarly journals Effect of COD:N ratio on biological nitrogen removal using full-scale step-feed in municipal wastewater treatment plants

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Supaporn Phanwilai ◽  
Pongsak Noophan ◽  
Chi-Wang Li ◽  
Kwang-Ho Choo
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Biological Nitrogen Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Scale Step ◽  
Biological Nitrogen

Abstract This study investigated the effect of low and high chemical oxygen demand (COD):N ratios on biological nitrogen removal and microbial distributions in full-scale step-feed (SF) municipal wastewater treatment plants (WWTPs) in Thailand (SF1) and Taiwan (SF2). The SF1 WWTP had a low COD:N (4:1) ratio, a long solids retention time (SRT) (> 60 d), and low dissolved oxygen (DO) conditions (0.2 mg L− 1 in anoxic tank and 0.9 mg L− 1 in aerobic tank). The total nitrogen (TN) removal efficiency was 48%. The SF2 WWTP had a high COD:N (10:1) ratio, a short SRT (7 d), and high DO (0.6 mg L− 1 in anoxic tank and 1.8 mg L− 1 in aerobic tank). The TN removal efficiency was 61%. The nitrification and denitrification rates from these two plants were inadequate. Using a quantitative polymerase chain reaction (qPCR) technique, the populations of ammonium oxidizing bacteria (AOB) and ammonium oxidizing archaea were quantified. Measurement of ammonia monooxygenase (amoA) gene abundances identified these AOB: Nitrosomonas sp., Nitrosospira sp., Nitrosoccus sp. and Zoogloea sp. Higher amounts of the archaeal-amoA gene were found with long SRT, lower DO and COD:N ratios. Abundance of Nitrobacter sp. was slightly higher than Nitrospira sp. at the SF1, while abundance of Nitrobacter sp. was two orders of magnitude greater than Nitrospira sp. at the SF2. More denitrifying bacteria were of the nirS-type than the nirK-type, especially at higher COD:N ratio. Most bacteria belong to the phyla Acidobacteria, Actinobacteria Bacteroidetes, Chloroflexi, Proteobacteria. The results from this work showed that insufficient carbon sources at the SF1 and high DO concentration in anoxic tank of SF2 adversely affected nitrogen removal efficiencies. In further research work, advanced techniques on the next generation sequencing with different variable regions should be recommended in full-scale WWTPs.

Extension of two large wastewater treatment plants in Stockholm using membrane technology

2016 ◽  
Vol 11 (4) ◽  
pp. 744-753 ◽  
Author(s):  
S. Andersson ◽  
P. Ek ◽  
M. Berg ◽  
J. Grundestam ◽  
E. Lindblom
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Action Plan ◽  
Municipal Wastewater Treatment ◽  
Large Cities ◽  
Effluent Quality ◽  
Municipal Wastewater Treatment Plants ◽  
The Baltic ◽  
The Eu

Like many other large cities, Stockholm is facing increased urbanization with densification of infrastructure as a result. At the same time, implementation of the Baltic Sea Action Plan and the EU Water Framework Directive is expected to result in more stringent effluent quality demands. The current situation gives rise to new challenges for the municipal wastewater treatment plants (WWTPs). This paper describes how two of Sweden's largest municipal water organizations; Stockholm Vatten and Syvab, will face these challenges using ultrafiltration (UF) membrane bioreactor (MBR) technology. The effluent requirements for the rehabilitated plants are expected to be tightened to 6 mg/l and 0.2 mg/l for total nitrogen (TN) and total phosphorus (TP), respectively.

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