Application of immersed-type membrane separation activated sludge process to municipal wastewater treatment

2000 ◽  
Vol 41 (10-11) ◽  
pp. 295-301 ◽  
Author(s):  
T. Murakami ◽  
J. Usui ◽  
K. Takamura ◽  
T. Yoshikawa

Pilot plant studies were carried out using actual wastewater to investigate the applicability of a membrane separation activated sludge (MSAS) process to municipal wastewater treatment. A small-scale pilot plant (6.7 m3/day) with immersed flat sheet membrane was operated at the flux of 0.4 m3/m2/day. Continuous operation for 140 days without chemical cleaning was possible. Average Sludge production ratio was about 0.6. No significant difference was observed in the dewaterability between membrane separation activated sludge and conventional activated sludge at the CST test. Large-scale pilot plants (30–70 m3/day) with five types of membrane were also operated. In these plants nitrogen removal by nitrification and denitrification, and phosphorus removal by coagulant addition were carried out. Stable operation with HRT of six hours, flux of 0.4–0.8 m3/m2/day was possible, the average nitrogen and phosphorus removal efficiency being more than 80 and 95%, respectively.

1997 ◽  
Vol 35 (6) ◽  
pp. 37-44 ◽  
Author(s):  
Boran Zhang ◽  
Kazuo Yamamoto ◽  
Shinichiro Ohgaki ◽  
Naoyuki Kamiko

Activated sludges taken from full-scale membrane separation processes, building wastewater reuse system (400m3/d), and two nightsoil treatment plants (50m3/d) as well as laboratory scale membrane separation bioreactor (0.062m3/d) were analyzed to characterize membrane separation activated sludge processes (MSAS). They were also compared with conventional activated sludges(CAS) taken from municipal wastewater treatment plants. Specific nitrification activity in MSAS processes averaged at 2.28gNH4-N/kgMLSS.h were higher than that in CAS processes averaged at 0.96gNH4-N/kgMLSS.h. The denitrification activity in both processes were in the range of 0.62-3.2gNO3-N/kgMLSS.h without organic addition and in the range of 4.25-6.4gNO3-N/kgMLSS.h with organic addition. The organic removal activity in nightsoil treatment process averaged at 123gCOD/kgMLSS.h which was significantly higher than others. Floc size distributions were measured by particle sedimentation technique and image analysis technique. Flocs in MSAS processes changed their sizes with MLSS concentration changes and were concentrated at small sizes at low MLSS concentration, mostly less than 60 μm. On the contrary, floc sizes in CAS processes have not much changed with MLSS concentration changes and they were distributed in large range. In addition, the effects of floc size on specific nitrification rate, denitrification rate with and without organic carbon addition were investigated. Specific nitrification rate was decreased as floc size increased. However, little effect of floc size on denitrification activity was observed.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 852 ◽  
Author(s):  
Ning Xie ◽  
Liping Zhong ◽  
Liao Ouyang ◽  
Wang Xu ◽  
Qinghuai Zeng ◽  
...  

Municipal wastewater treatment plants (WWTPs) use functional microorganisms in activated sludge (AS) to reduce the environmental threat posed by wastewater. In this study, Illumina NovaSeq sequencing of 16S rRNA genes was performed to explore the microbial communities of AS at different stages of the two WWTP projects in Shenzhen, China. Results showed that Proteobacteria, Bacteroidetes, Acidobacteria, Firmicutes, and Nitrospirae were the dominant phyla in all the samples, with Proteobacteria being the most abundant and reaching a maximum proportion of 59.63%. There was no significant difference in biodiversity between the two water plants, but Stage 1 and Stage 2 were significantly different. The Mantel test indicated that nitrate, total nitrogen (TN), chemical oxygen demand (COD), and nutrients were essential factors affecting the bacterial community structure. FAPROTAX analysis emphasized that the leading functional gene families include nitrification, aerobic nitrite oxidation, human pathogens, and phototrophy. This study reveals changes in the community structure of AS in different treatment units of Banxuegang WWTP, which can help engineers to optimize the wastewater treatment process.


1998 ◽  
Vol 38 (4-5) ◽  
pp. 429-436 ◽  
Author(s):  
N. Engelhardt ◽  
W. Firk ◽  
W. Warnken

Energy-efficient membrane modules for microfiltration are available to realize a new process engineering in municipal wastewater treatment. The microfiltration membrane ensures that all microorganisms are retained in the aeration tank. A content of mixed-liquor suspended solids of e.g. 15 gMLSS/l can easily be achieved in a large scale plant. Thus the aeration tank is considerably reduced in size. A secondary clarifier is no longer needed. A filtration and a disinfection can be dismissed. A pilot plant gives first knowledge on the application of the activated sludge process with submersed membrane filtration. Based on the tests' results and the knowledge gained during the operation of the pilot plant, a WWTP with membrane filtration for 3000 inhabitants is designed. The costs of investment and operation are estimated.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.


1996 ◽  
Vol 33 (12) ◽  
pp. 199-210
Author(s):  
R. Gnirss ◽  
A. Peter-Fröhlich ◽  
V. Schmidt

For municipal wastewater treatment, space-saving 10m deep activated sludge tanks are an interesting alternative to conventional tanks of shallow construction. Results from pilot tests in the Berlin-Ruhleben WWTP have shown that the biological P-elimination, nutrification and denitrification processes can be implemented as in shallow tanks. However, the activated sludge did not settle satisfactorily. Flotation was implemented in the process for secondary clarification and in the meanwhile has shown to be advantageous. Tests run over a period of some years with the pilot plant have proven the feasibility of this process. Energy requirements for both systems were found to be approximately the same. A cost estimate based on a preplan revealed a 10% advantage in favour of the 10m WWTP with flotation. For these reasons, one 10m WWTP with flotation for secondary clarification and a capacity of 80,000 m3/d will be built in Berlin in the near future.


1994 ◽  
Vol 30 (4) ◽  
pp. 211-214 ◽  
Author(s):  
E. Brands ◽  
M. Liebeskind ◽  
M. Dohmann

This study shows a comparison of important parameters for dynamic simulation concerning the highrate and low-rate activated sludge tanks of several municipal wastewater treatment plants. The parameters for the dynamic simulation of the single-stage process are quite well known, but parameters for the high-ratellow-rate activated sludge process are still missi ng, although a considerable number of wastewater treatment plants are designed and operated that way. At present any attempt to simulate their operation is restricted to the second stage due to missing data concerning growth rate, decay rate, yield coefficient and others.


2007 ◽  
Vol 133 (4) ◽  
pp. 397-403 ◽  
Author(s):  
Enrique J. La Motta ◽  
Eudomar Silva ◽  
Adriana Bustillos ◽  
Harold Padrón ◽  
Jackeline Luque

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