On the effect of pharmaceuticals on bacterial nitrite oxidation

2004 ◽  
Vol 50 (5) ◽  
pp. 341-346 ◽  
Author(s):  
S.N. Dokianakis ◽  
M.E. Kornaros ◽  
G. Lyberatos
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Reduction Rate ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Nitrite Reduction ◽  
Municipal Wastewater Treatment ◽  
Nitrite Oxidizing Bacteria ◽  
Municipal Wastewater Treatment Plants

Pharmaceuticals or their metabolites are partially excreted with urine or faeces ending up in raw sewage. Many of these substances are not biodegradable and their presence in influents of municipal wastewater treatment plants may cause adverse effects to sensitive biological processes such as nitrification, while on the other hand, they may go through the activated sludge process unreacted. The second step of nitrification, i.e. oxidation of nitrite to nitrate is particularly sensitive. Inhibition of this step under uncontrolled conditions may lead to accumulation of nitrite nitrogen in the plant effluent, a form of nitrogen which is particularly toxic. The effects caused by the presence of seven different pharmaceuticals to a culture of nitrite-oxidizing bacteria isolated from activated sludge are presented. These pharmaceuticals were ofloxacin, propranolol, clofibrate, triclosan, carbamazepine, diclofenac and sulfamethoxazole. Different effects were observed for each of the pharmaceuticals tested in this study. In the cases of ofloxacin and sulfamethoxazole significant inhibition was observed. Triclosan presented a substantial inhibitory effect on the substrate (nitrite) reduction rate. The long-term effect of triclosan on nitrite oxidizers was also examined in a CSTR reactor and conclusions were drawn regarding the reversibility of the inhibition caused by this compound.

PARAMETERS FOR DYNAMIC SIMULATION OF W ASTEW ATER TREATMENT PLANTS WITH HIGH-RATE AND LOW-RATE ACTIVATED SLUDGE TANKS

1994 ◽  
Vol 30 (4) ◽  
pp. 211-214 ◽  
Author(s):  
E. Brands ◽  
M. Liebeskind ◽  
M. Dohmann
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Dynamic Simulation ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
High Rate ◽  
Yield Coefficient ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Low Rate

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.

Characterization of wastewater and activated sludge from European municipal wastewater treatment plants using the NUR test

1998 ◽  
Vol 38 (1) ◽  
pp. 303-310 ◽  
Author(s):  
V. Naidoo ◽  
V. Urbain ◽  
C. A. Buckley
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Batch Tests ◽  
Denitrification Kinetics ◽  
Municipal Wastewater Treatment Plants

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%.

scholarly journals Casimicrobium huifangae gen. nov., sp. nov., a Ubiquitous “Most-Wanted” Core Bacterial Taxon from Municipal Wastewater Treatment Plants

2019 ◽  
Vol 86 (4) ◽  
Author(s):  
Yang Song ◽  
Cheng-Ying Jiang ◽  
Zong-Lin Liang ◽  
Bao-Jun Wang ◽  
Yong Jiang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Short Chain Fatty Acids ◽  
Municipal Wastewater Treatment ◽  
Content Type ◽  
Bacterial Taxon ◽  
Municipal Wastewater Treatment Plants

ABSTRACT Microorganisms in wastewater treatment plants (WWTPs) play a key role in the removal of pollutants from municipal and industrial wastewaters. A recent study estimated that activated sludge from global municipal WWTPs harbors 1 × 109 to 2 × 109 microbial species, the majority of which have not yet been cultivated, and 28 core taxa were identified as “most-wanted” ones (L. Wu, D. Ning, B. Zhang, Y. Li, et al., Nat Microbiol 4:1183–1195, 2019, https://doi.org/10.1038/s41564-019-0426-5). Cultivation and characterization of the “most-wanted” core bacteria are critical to understand their genetic, physiological, phylogenetic, and ecological traits, as well as to improve the performance of WWTPs. In this study, we isolated a bacterial strain, designated SJ-1, that represents a novel cluster within Betaproteobacteria and corresponds to OTU_16 within the 28 core taxa in the “most-wanted” list. Strain SJ-1 was identified and nominated as Casimicrobium huifangae gen. nov., sp. nov., of a novel family, Casimicrobiaceae. C. huifangae is ubiquitously distributed and is metabolically versatile. In addition to mineralizing various carbon sources (including carbohydrates, aromatic compounds, and short-chain fatty acids), C. huifangae is capable of nitrate reduction and phosphorus accumulation. The population of C. huifangae accounted for more than 1% of the bacterial population of the activated sludge microbiome from the Qinghe WWTP, which showed seasonal dynamic changes. Cooccurrence analysis suggested that C. huifangae was an important module hub in the bacterial network of Qinghe WWTP. IMPORTANCE The activated sludge process is the most widely applied biotechnology and is one of the best ecosystems to address microbial ecological principles. Yet, the cultivation of core bacteria and the exploration of their physiology and ecology are limited. In this study, the core and novel bacterial taxon C. huifangae was cultivated and characterized. This study revealed that C. huifangae functioned as an important module hub in the activated sludge microbiome, and it potentially plays an important role in municipal wastewater treatment plants.

scholarly journals Community Composition and Function of Bacteria in Activated Sludge of Municipal Wastewater Treatment Plants

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 852 ◽  
Author(s):  
Ning Xie ◽  
Liping Zhong ◽  
Liao Ouyang ◽  
Wang Xu ◽  
Qinghuai Zeng ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Municipal Wastewater Treatment ◽  
Significant Difference ◽  
Municipal Wastewater Treatment Plants

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.

Effects of the membrane technology of the dimensioning of municipal wastewater treatment plants

1998 ◽  
Vol 38 (3) ◽  
pp. 173-178
Author(s):  
A. Seyfried ◽  
E. Dorgeloh ◽  
E. Brands ◽  
P. Ohle
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Lower Energy ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Solids Retention ◽  
Municipal Wastewater Treatment Plants

The successful application of membrane filtration on the activated sludge process is a recent development. Two processes are most common: separate modules and submerged modules, with the former being the more promising due to the lower energy consumption. While they allow high sludge ages, conventional sludge ages are equally viable, thus allowing the use of tested and reliable dimensioning techniques. The near perfect solids retention of the membrane filtration, however, can lead to problems with the accumulation of inert solids and heavy metals in the activated sludge. In that area, further research is necessary to develop safe dimensioning methods.

Design of fine-bubble aeration systems for municipal WWTPs with high sea salt concentrations

2017 ◽  
Vol 75 (7) ◽  
pp. 1555-1563 ◽  
Author(s):  
S. Sander ◽  
J. Behnisch ◽  
M. Wagner
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Sea Salt ◽  
Favourable Effect ◽  
Municipal Wastewater Treatment ◽  
Fine Bubble ◽  
Municipal Wastewater Treatment Plants ◽  
The Impact

The impact of sea salt on the aeration coefficient kLa of fine-bubble aeration systems was investigated in clean water and in a model substance for simulating activated sludge. The investigations were carried out at laboratory and pilot scale. Sea salt was dosed in the form of artificial seawater, real seawater or simplified, by adding NaCl. The investigated media showed an increase of kLa with rising sea salt concentrations up to 10 g/L. The ratio between kLa and sea salt concentration is impaired by the air flow rate and the type of applied diffusers. Literature data show that the favourable effect of sea salt on kLa can also be found in the activated sludge of conventional municipal wastewater treatment plants. The results of this study allow the derivation of salt correction equations to be used in the design of fine-bubble aeration systems for taking into account the favourable impact of sea salt on kLa. By that means, a more precise design of respective systems will be enabled.

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