scholarly journals Different engineering designs have profoundly different impacts on the microbiome and nitrifying bacterial populations in municipal wastewater treatment bioreactors

Author(s):  
Taegyu Kim ◽  
Sebastian Behrens ◽  
Timothy LaPara

Numerous wastewater treatment processes are designed by engineers to achieve specific treatment goals. However, the impact of these different process designs on bacterial community composition is poorly understood. In this study, 24 different municipal wastewater treatment facilities (37 bioreactors) with various system designs were analyzed by sequencing of PCR-amplified 16S rRNA gene fragments. Although a core microbiome was observed in all of the bioreactors, the overall microbial community composition (analysis of molecular variance; P = 0.001) as well as a specific population of Nitrosomonas spp. ( P = 0.04) were significantly different between A/O (anaerobic/aerobic) systems and conventional activated sludge (CAS) systems. Community α-diversity (number of observed operational taxonomic units [OTUs] and Shannon diversity index) was also significantly higher in A/O systems compared to CAS systems (Wilcoxon; P < 2 × 10 −16 ). In addition, wastewater bioreactors with short mean cell residence time (< 2 days) had very low community α-diversity and fewer nitrifying bacteria compared to other system designs. Nitrospira spp. (0.71%) and Nitrotoga spp. (0.41%) were the most prominent nitrite oxidizing bacteria (NOB); because these two genera were rarely prominent community members at the same time, these populations appeared to be functionally redundant. Weak evidence (AOB:NOB ≪ 2; substantial quantities of Nitrospira spp. sublineage II) was also obtained suggesting that complete ammonia oxidation by a single organism was occurring in system designs known to impose stringent nutrient limitation. This research demonstrates that design decisions made by wastewater treatment engineers significantly impact the microbiome of wastewater treatment bioreactors. IMPORTANCE Municipal wastewater treatment facilities rely on the application of numerous “activated sludge” process designs to achieve site-specific treatment goals. A plethora of microbiome studies on municipal wastewater treatment bioreactors have been previously performed; however, the role of process design on the municipal wastewater treatment microbiome is poorly understood. In fact, wastewater treatment engineers have attempted to control the microbiome of wastewater bioreactors for decades without sufficient empirical evidence to support their design paradigms. Our research demonstrates that engineering decisions with respect to system design have a significant impact on the microbiome of wastewater treatment bioreactors.

2021 ◽  
Author(s):  
GM Itheshamul Islam

Nitrification is an essential microbial process in the global nitrogen cycle. The first step of nitrification is ammonia oxidation which is achieved by bacteria and archaea and is crucial in decreasing ammonia concentrations that are persistently high in wastewater. This study examined the composition, abundance and identity of the microbial community in activated sludge with a focus on characterizing ammonia oxidizing bacteria and archaea in a full-scale municipal wastewater treatment plant (MWTP). Specifically, two pharmaceutical compounds Tetracycline and Ibuprofen, and their effects on the community composition of bacteria and protozoa in activated sludge was investigated using PCR coupled with denaturing gradient gel electrophoresis (DGGE). In addition, the composition, abundance and activity of the ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) were analyzed from aerobic activated sludge, recycled sludge and anaerobic digesters of the Humber MWTP using molecular techniques such as PCR, Quantitative PCR, Reverse Transcription-PCR and DGGE. The findings demonstrated that Tetracycline did not appear to alter community composition of bacteria in the activated sludge, rather, the operational parameters of the sequencing batch reactors such as feeding rates and SRT have shown to alter the richness of bacterial communities. However, Ibuprofen affected some members in the protozoan community in activated sludge. In the full-scale Humber MWTP using the conventional activated sludge system, the aeration tanks contained 1.8 × 105 copies of the AOB amoA gene per 100 ng of DNA. In contrast, the anaerobic digester tanks contained 7.3 × 102 copies of the AOA amoA gene per 100ng of DNA. This study also found that AOB were dominant in activated sludge samples, regardless of the operational parameters. The quantification of cDNA transcripts of the amoA gene also indicated that AOB may be more active than AOA in the activated sludge system. Overall, it appears that AOA are very niche specific and thrive in very low oxygenated environments, while AOB proliferate and play a major role in aerobic ammonia oxidation occurring in MWTPs.


2021 ◽  
Author(s):  
GM Itheshamul Islam

Nitrification is an essential microbial process in the global nitrogen cycle. The first step of nitrification is ammonia oxidation which is achieved by bacteria and archaea and is crucial in decreasing ammonia concentrations that are persistently high in wastewater. This study examined the composition, abundance and identity of the microbial community in activated sludge with a focus on characterizing ammonia oxidizing bacteria and archaea in a full-scale municipal wastewater treatment plant (MWTP). Specifically, two pharmaceutical compounds Tetracycline and Ibuprofen, and their effects on the community composition of bacteria and protozoa in activated sludge was investigated using PCR coupled with denaturing gradient gel electrophoresis (DGGE). In addition, the composition, abundance and activity of the ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) were analyzed from aerobic activated sludge, recycled sludge and anaerobic digesters of the Humber MWTP using molecular techniques such as PCR, Quantitative PCR, Reverse Transcription-PCR and DGGE. The findings demonstrated that Tetracycline did not appear to alter community composition of bacteria in the activated sludge, rather, the operational parameters of the sequencing batch reactors such as feeding rates and SRT have shown to alter the richness of bacterial communities. However, Ibuprofen affected some members in the protozoan community in activated sludge. In the full-scale Humber MWTP using the conventional activated sludge system, the aeration tanks contained 1.8 × 105 copies of the AOB amoA gene per 100 ng of DNA. In contrast, the anaerobic digester tanks contained 7.3 × 102 copies of the AOA amoA gene per 100ng of DNA. This study also found that AOB were dominant in activated sludge samples, regardless of the operational parameters. The quantification of cDNA transcripts of the amoA gene also indicated that AOB may be more active than AOA in the activated sludge system. Overall, it appears that AOA are very niche specific and thrive in very low oxygenated environments, while AOB proliferate and play a major role in aerobic ammonia oxidation occurring in MWTPs.


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.


2021 ◽  
Vol 7 (1) ◽  
pp. 232-232
Author(s):  
Daniel Sauter ◽  
Agata Dąbrowska ◽  
Robert Bloch ◽  
Michael Stapf ◽  
Ulf Miehe ◽  
...  

Correction for ‘Deep-bed filters as post-treatment for ozonation in tertiary municipal wastewater treatment: impact of design and operation on treatment goals’ by Daniel Sauter et al., Environ. Sci.: Water Res. Technol., 2021, DOI: 10.1039/d0ew00684j.


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.


2011 ◽  
Vol 2011 (3) ◽  
pp. 328-349
Author(s):  
Ernest R. Blatchley ◽  
ShihChi Weng ◽  
Mehrnaz Zare Afifi ◽  
Hsiao-Han Chiu ◽  
Douglas B. Reichlin ◽  
...  

Author(s):  
Ю.А. Егорова ◽  
В.И. Кичигин ◽  
О.И. Нестеренко ◽  
А.А. Юдин

Осадки городских очистных канализационных сооружений являются самым массовым технологическим отходом, создающим проблемы утилизации для любого города. Рассмотрены возможные методы обработки осадков сточных вод на городских очистных канализационных сооружениях городского округа Самара с целью их последующей утилизации. Обозначены причины и приведены документальные подтверждениянекорректности возложения ответственности за обращение с такими отходами только на организации водопроводно-канализационного хозяйства. Рассмотрен способ захоронения обезвоженного осадка сточных вод в обвалованном полигоне. Установлено, что обработанные на очистных сооружениях осадки относятся к V классу опасности для окружающей среды. Обработанные, стабилизированные, подсушенные, обезвреженные отходы осадков сточных вод (малоопасный осадок с песколовок при очистке хозяйственно-бытовых и смешанных сточных вод, практически не опасный осадок с песколовок при очистке хозяйственно-бытовых и смешанных сточных вод и избыточный ил биологических очистных сооружений в смеси с сырым осадком) могут быть использованы в качестве наполнителей бетонно-цементных смесей и органоминеральных удобрений или переданы для утилизации сторонним организациям. Sludge from the municipal wastewater treatment facilities is the most massive technological waste that causes trouble for any city. Possible methods of wastewater sludge treatment at the municipal wastewater treatment facilities of the Samara Urban District with the purpose of its further utilization are considered. The reasons are indicated and documentary evidence of the incorrectness of assigning the responsibility for processing such wastes only to the water and wastewater utilities is provided. The method of landfilling dewatered wastewater sludge in a ridged landfill is considered. It has been established that the sludge processed at the wastewater treatment facilities is referred to the V class of environmental hazard. Sludge subjected to the treatment, stabilization, drying and neutralization (low hazardous sludge from grit chambers for domestic and mixed wastewater treatment; almost non-hazardous sludge from grit chambers for domestic and mixed wastewater treatment and excess sludge from biological treatment facilities mixed with raw sludge) can be used as fillers for concrete-cement mixtures and organo-mineral fertilizers or transferred for disposal to outside companies.


1998 ◽  
Vol 38 (1) ◽  
pp. 303-310 ◽  
Author(s):  
V. Naidoo ◽  
V. Urbain ◽  
C. A. Buckley

Denitrification kinetics and wastewater characterization of eight different plants in Europe are discussed. Denitrification batch tests revealed three distinct rates except in the cases of Plaisir, Rostock and Orense where 4 rates were observed. The latter three plants revealed atypical rapid initial rates which were between 7 and 21 mgN/gVSS.h. All denitrification kinetics under non-limiting carbon conditions revealed fast first rates which ranged between 3.0 and 7.3 mgN/gVSS.h. Acetate was used to simulate denitrification kinetics with readily biodegradable COD present. Two subsequent rates were observed. Rates 2 and 3 ranged between 2 and 3 mgN/gVSS.h, and 1 and 2 mgN/gVSS.h, respectively. The RBCOD fraction varied between 10 and 19%, except for one of the plants where the value determined was 7%.


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