Towards the design of diversity: stochastic models for community assembly in wastewater treatment plants

2006 ◽  
Vol 54 (1) ◽  
pp. 227-236 ◽  
Author(s):  
T.P. Curtis ◽  
W.T. Sloan
Keyword(s):  
Wastewater Treatment ◽  
Functional Groups ◽  
Community Assembly ◽  
Stochastic Models ◽  
Wastewater Treatment Plants ◽  
Stochastic Approach ◽  
Functional Redundancy ◽  
Mathematical Framework ◽  
Design Diversity ◽  
Wastewater Treatment Systems

We believe that the engineering of wastewater treatment systems would be improved if we could predict and manipulate the composition, that is, the diversity of such systems. This ability would complement our established ability to predict the size of treatment communities. The theoretically based design of diversity in wastewater treatment systems is held by some to be unnecessary and by others to be impossible. In this paper we point to important phenomena in wastewater treatment, such as acclimation, adaptation and functional redundancy that would benefit from the ability to confidently design diversity. We set out a rationale and a mathematical framework for a stochastic approach to the design of diversity and show that, in principle, this approach works with two important functional groups in wastewater treatment. The implications for design and theory are briefly discussed.

scholarly journals The capacity of wastewater treatment plants drives bacterial community structure and its assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Community Assembly ◽  
Bacterial Communities ◽  
Wastewater Treatment Plants ◽  
High Capacity ◽  
Operating Conditions ◽  
Rrna Gene

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.

scholarly journals Occurrence of intestinal parasites in sewage samples and efficiency of wastewater treatment systems in Tunisia

2018 ◽  
Vol 53 (2) ◽  
pp. 86-101 ◽  
Author(s):  
S. Sabbahi ◽  
M. Trad ◽  
L. Ben Ayed ◽  
N. Marzougui
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Multiple Correspondence Analysis ◽  
Intestinal Parasites ◽  
Sampling Period ◽  
Hymenolepis Diminuta ◽  
Helminth Eggs ◽  
Wastewater Samples ◽  
One Year ◽  
Wastewater Treatment Systems

Abstract The present study aimed to: (i) identify helminth eggs and protozoan cysts in wastewater samples to which both human and animals could be exposed when they are reused in agriculture; and (ii) evaluate the efficiency of their removal by two wastewater treatment systems (activated sludge and lagoon). For these purposes, 234 wastewater samples (117 raw, 117 treated) were collected from 20 wastewater treatment plants (WWTPs) in Tunisia over a one-year sampling period. Parasitic load was enumerated by the modified Bailenger method. The results showed that helminth eggs found were Nematodes mainly represented by Ascaris sp. (95%), Hookworm species (50%), and Enterobius vermicularis (45%). For Cestodes, species identified were Taeniid eggs (85%), Hymenolepis nana (70%), Hymenolepis diminuta (55%) and digestive Strongyles. Among protozoa, Giardia sp., Entamoeba histolytica/dispar/moshkovskii and Entamoeba coli cysts were found in 100% of raw wastewater samples. The overall removal efficiency of helminth eggs and protozoan cysts in the treatment plants ranged from 56.5 to 100% and from 50.4 to 95.5%, respectively. The result from Multiple Correspondence Analysis (MCA) shows that the close clustering of the parasitic mean removal levels indicates that there is little difference in wastewater treatment processes between the WWTPs examined.

scholarly journals Comparison of Biodegradation of Fats and Oils by Activated Sludge on Experimental and Real Scales

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1286 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Patricia Arancibia-Avila
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Fats And Oils ◽  
Mass Loading ◽  
Physical Treatment ◽  
Treatment Unit ◽  
Wastewater Treatment Systems

Fats and oils are the most common pollutants in wastewater, and are usually eliminated through physical processes in wastewater treatment plants, generating large amounts of fats and residual oils that are difficult to dispose of and handle. The degradation of fatty wastewater was studied in a real wastewater treatment plant and a laboratory scale treatment unit. The wastewater treatment plant, located in Chile, was designed for a population of 200,000 inhabitants. It includes an aerobic digester that receives fat and oils retained in a degreaser and treats the fats and oils together with biomass. The biodegradation of fats and oils was analyzed in both wastewater treatment systems. Key parameters were monitored such as the concentration of fats and oils in the influents and effluents, mass loading, and the efficiency of biodegradation. The mass loading range was similar in both wastewater treatment systems. In the experimental activated sludge plant, the biodegradation of fats and oils reached levels in the range of 64% to 75%. For the wastewater treatment plant with an aerobic digester, the levels of biodegradation of fats and oils ranged from 69% to 92%. Therefore, considering the efficiency of the elimination of fats and oils, the results indicated that physical treatment should be replaced with biological treatment so that the CO2 generated by the biodegradation will be incorporated into the carbon cycle and the mass of fats and oils in landfills will be reduced.

scholarly journals Activity and Metabolic Versatility of Complete Ammonia Oxidizers in Full-Scale Wastewater Treatment Systems

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Yuchun Yang ◽  
Holger Daims ◽  
Yang Liu ◽  
Craig W. Herbold ◽  
Petra Pjevac ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Alternative Energy ◽  
Wastewater Treatment Plants ◽  
Selective Advantage ◽  
Full Scale ◽  
Survival Strategies ◽  
Ammonia Oxidizers ◽  
Gene Encoding ◽  
Metabolic Versatility ◽  
Wastewater Treatment Systems

ABSTRACT The recent discovery of complete ammonia oxidizers (comammox) contradicts the paradigm that chemolithoautotrophic nitrification is always catalyzed by two different microorganisms. However, our knowledge of the survival strategies of comammox in complex ecosystems, such as full-scale wastewater treatment plants (WWTPs), remains limited. Analyses of genomes and in situ transcriptomes of four comammox organisms from two full-scale WWTPs revealed that comammox were active and showed a surprisingly high metabolic versatility. A gene cluster for the utilization of urea and a gene encoding cyanase suggest that comammox may use diverse organic nitrogen compounds in addition to free ammonia as the substrates. The comammox organisms also encoded the genomic potential for multiple alternative energy metabolisms, including respiration with hydrogen, formate, and sulfite as electron donors. Pathways for the biosynthesis and degradation of polyphosphate, glycogen, and polyhydroxyalkanoates as intracellular storage compounds likely help comammox survive unfavorable conditions and facilitate switches between lifestyles in fluctuating environments. One of the comammox strains acquired from the anaerobic tank encoded and transcribed genes involved in homoacetate fermentation or in the utilization of exogenous acetate, both pathways being unexpected in a nitrifying bacterium. Surprisingly, this strain also encoded a respiratory nitrate reductase which has not yet been found in any other Nitrospira genome and might confer a selective advantage to this strain over other Nitrospira strains in anoxic conditions. IMPORTANCE The discovery of comammox in the genus Nitrospira changes our perception of nitrification. However, genomes of comammox organisms have not been acquired from full-scale WWTPs, and very little is known about their survival strategies and potential metabolisms in complex wastewater treatment systems. Here, four comammox metagenome-assembled genomes and metatranscriptomic data sets were retrieved from two full-scale WWTPs. Their impressive and—among nitrifiers—unsurpassed ecophysiological versatility could make comammox Nitrospira an interesting target for optimizing nitrification in current and future bioreactor configurations.

scholarly journals Profiling Bacterial Diversity and Potential Pathogens in Wastewater Treatment Plants Using High-Throughput Sequencing Analysis

2019 ◽  
Vol 7 (11) ◽  
pp. 506 ◽  
Author(s):  
Cecilia Oluseyi Osunmakinde ◽  
Ramganesh Selvarajan ◽  
Bhekie B. Mamba ◽  
Titus A.M. Msagati
Keyword(s):  
Wastewater Treatment ◽  
Pathogenic Bacteria ◽  
High Throughput Sequencing ◽  
Wastewater Treatment Plants ◽  
Bacterial Pathogens ◽  
Size Analysis ◽  
Sequencing Analysis ◽  
Linear Discriminant ◽  
Treated Effluent ◽  
Wastewater Treatment Systems

Next-generation sequencing provides new insights into the diversity and structure of bacterial communities, as well as the fate of pathogens in wastewater treatment systems. In this study, the bacterial community structure and the presence of pathogenic bacteria in three wastewater treatment plants across Gauteng province in South Africa were studied. The physicochemical results indicated that the quality of wastewater varies considerably from one plant to the others. Proteobacteria, Actinobacteria, Firmicutes, and Chloroflexi were the dominant phyla across the three wastewater treatment plants, while Alphaproteobacteria, Actinobacteria, Bacilli, and Clostridia were the dominant classes. The dominant bacterial functions were highly associated with carbohydrate, energy, and amino acid metabolism. In addition, potential pathogenic bacterial members identified from the influent/effluent samples included Roseomonas, Bacillus, Pseudomonas, Clostridium, Mycobacterium, Methylobacterium, and Aeromonas. The results of linear discriminant analysis (LDA) effect size analysis also confirmed that these bacterial pathogens were significantly abundant in the wastewater treatment systems. Further, the results of this study highlighted that the presence of bacterial pathogens in treated effluent pose a potential contamination risk, transmitted through soil, agriculture, water, or sediments. There is thus a need for continuous monitoring of potential pathogens in wastewater treatment plants (WWTPs) in order to minimize public health risk.

scholarly journals Environmental Concern Priming and Social Acceptance of Sustainable Technologies: The Case of Decentralized Wastewater Treatment Systems

2021 ◽  
Vol 12 ◽  
Author(s):  
Cristina Gómez-Román ◽  
José-Manuel Sabucedo ◽  
Mónica Alzate ◽  
Beatriz Medina
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Environmental Concern ◽  
Partial Solution ◽  
Environmental Concerns ◽  
Global Risk ◽  
Advantages And Disadvantages ◽  
Decentralized Wastewater Treatment ◽  
Priming Condition ◽  
Wastewater Treatment Systems

According to a report by the World Economic Forum, the water crisis is the fourth most serious global risk to society. The apparent limitations of the hydraulic paradigm to solving this crisis are leading to a change in water management approaches. Recently, decentralized wastewater treatment systems have re-emerged as a partial solution to this problem. However, to implement these systems successfully, it is necessary not only to design this technology but also to have social support and willingness among citizens to use it. Previous studies have shown that these technologies are often perceived as being too costly, and people often do not consider the need for adopting them. However, it has also been pointed out that thinking about these technologies as a sustainable endeavor to reduce human impact on the environment can help to overcome the barriers to usage. Thus, we test whether priming environmental concerns before presenting information about decentralized wastewater treatment plants will increase acceptance of those technologies. In this study, we test whether priming environmental concerns can enhance the acceptance of decentralized wastewater treatment plants even when presenting disadvantages of the technology. In order to do so, we designed an experimental study with a sample of 287 people (85.7% women, Mage=20, 28). The experimental design was 2 (priming the environmental concern vs. no priming)×2 (type of information: only advantages vs. advantages and disadvantages). The results showed that those in the environmental concern priming condition had more positive attitudes and behavioral intentions toward decentralized wastewater treatment plants than those in the control condition group. Participants who received only advantages information had a more positive perception toward the decentralized wastewater systems than in the condition, where disadvantages were present, but in the priming condition this difference was not significant. This implies that priming environmental concern helps to overcome the possible disadvantages that act as barriers to acceptance.

scholarly journals Modified Chitosan Forms for Cr (VI) Removal

2021 ◽  
Author(s):  
Şerife Parlayıcı ◽  
Erol Pehlivan
Keyword(s):  
Wastewater Treatment ◽  
High Activity ◽  
Functional Groups ◽  
Wastewater Treatment Plants ◽  
Batch Adsorption ◽  
Modified Chitosan ◽  
Natural Substances ◽  
Modified Adsorbents ◽  
Textual Content ◽  
Adsorption Systems

The forms of utility in the wastewater treatment of chitosan-based adsorbents acquired from natural substances have attracted numerous attentions in recent years. The use of chitosan modified adsorbents for removal of the chromium has aroused great interest. When chitosan-based modified adsorbents are considered, they have got large amount of an amino (-NH2) and hydroxyl (-OH) functional groups. Such adsorbents display that they have high activity and therefore they may be extensively utilized in wastewater treatment plants to cast off chromium. In this chapter, the utility outcomes of chitosan-based substances will be explained after applying different parameters to remove Cr (VI) from the aqueous surrounding with the information obtained the use of batch adsorption systems. Application of various chitosan-based adsorbents for Cr (VI) removal application will be demonstrated in a detailed way and they will be discussed within the textual content.

scholarly journals The differential proliferation of AOB and NOB during natural nitrifier cultivation and acclimation with raw sewage as seed sludge

RSC Advances ◽  
2020 ◽  
Vol 10 (47) ◽  
pp. 28277-28286
Author(s):  
Lifang Yu ◽  
Yu Wang ◽  
Ren Li ◽  
Ru Zhang ◽  
Xingxiu Zhang ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Process Modeling ◽  
Community Assembly ◽  
Seed Sludge ◽  
Wastewater Treatment Systems

Nitrifier immigration from sewers to wastewater treatment systems is attracting increasing attention for understanding nitrifier community assembly mechanisms, and improving process modeling and operation.

scholarly journals Biomedical Applications of Biomolecules Isolated from Methanotrophic Bacteria in Wastewater Treatment Systems

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1217
Author(s):  
Rana Salem ◽  
Ahmed ElDyasti ◽  
Gerald F. Audette
Keyword(s):  
Public Health ◽  
Wastewater Treatment ◽  
Biomedical Applications ◽  
Environmental Science ◽  
Wastewater Treatment Plants ◽  
Electronic Devices ◽  
Drug Carriers ◽  
Industrial Applications ◽  
Methanotrophic Bacteria ◽  
Wastewater Treatment Systems

Wastewater treatment plants and other remediation facilities serve important roles, both in public health, but also as dynamic research platforms for acquiring useful resources and biomolecules for various applications. An example of this is methanotrophic bacteria within anaerobic digestion processes in wastewater treatment plants. These bacteria are an important microbial source of many products including ectoine, polyhydroxyalkanoates, and methanobactins, which are invaluable to the fields of biotechnology and biomedicine. Here we provide an overview of the methanotrophs’ unique metabolism and the biochemical pathways involved in biomolecule formation. We also discuss the potential biomedical applications of these biomolecules through creation of beneficial biocompatible products including vaccines, prosthetics, electronic devices, drug carriers, and heart stents. We highlight the links between molecular biology, public health, and environmental science in the advancement of biomedical research and industrial applications using methanotrophic bacteria in wastewater treatment systems.

scholarly journals Genome-Enabled Insights into the Ecophysiology of the Comammox Bacterium “Candidatus Nitrospira nitrosa”

mSystems ◽  
2017 ◽  
Vol 2 (5) ◽  
Author(s):  
Pamela Y. Camejo ◽  
Jorge Santo Domingo ◽  
Katherine D. McMahon ◽  
Daniel R. Noguera
Keyword(s):  
Wastewater Treatment ◽  
Comparative Genomics ◽  
Functional Groups ◽  
Wastewater Treatment Plants ◽  
Complete Oxidation ◽  
Natural Ecosystems ◽  
Genome Sequences ◽  
Comparative Genomics Analysis ◽  
Functional Versatility ◽  
Nitrite Oxidizers

ABSTRACT Nitrospira-like bacteria are among the most diverse and widespread nitrifiers in natural ecosystems and the dominant nitrite oxidizers in wastewater treatment plants (WWTPs). The recent discovery of comammox-like Nitrospira strains, capable of complete oxidation of ammonia to nitrate, raises new questions about specific traits responsible for the functional versatility and adaptation of this genus to a variety of environments. The availability of new Nitrospira genome sequences from both nitrite-oxidizing and comammox bacteria offers a way to analyze traits in different Nitrospira functional groups. Our comparative genomics analysis provided new insights into the adaptation of Nitrospira strains to specific lifestyles and environmental niches. The recently discovered comammox bacteria have the potential to completely oxidize ammonia to nitrate. These microorganisms are part of the Nitrospira genus and are present in a variety of environments, including biological nutrient removal (BNR) systems. However, the physiological traits within and between comammox and nitrite-oxidizing bacterium (NOB)-like Nitrospira species have not been analyzed in these ecosystems. In this study, we identified Nitrospira strains dominating the nitrifying community of a sequencing batch reactor (SBR) performing BNR under microaerobic conditions. We recovered metagenome-derived draft genomes from two Nitrospira strains: (i) Nitrospira sp. strain UW-LDO-01, a comammox-like organism classified as “Candidatus Nitrospira nitrosa,” and (ii) Nitrospira sp. strain UW-LDO-02, a nitrite-oxidizing strain belonging to the Nitrospira defluvii species. A comparative genomic analysis of these strains with other Nitrospira-like genomes identified genomic differences in “Ca. Nitrospira nitrosa” mainly attributed to each strain’s niche adaptation. Traits associated with energy metabolism also differentiate comammox from NOB-like genomes. We also identified several transcriptionally regulated adaptive traits, including stress tolerance, biofilm formation, and microaerobic metabolism, which might explain survival of Nitrospira under multiple environmental conditions. Overall, our analysis expanded our understanding of the genetic functional features of “Ca. Nitrospira nitrosa” and identified genomic traits that further illuminate the phylogenetic diversity and metabolic plasticity of the Nitrospira genus. IMPORTANCE Nitrospira-like bacteria are among the most diverse and widespread nitrifiers in natural ecosystems and the dominant nitrite oxidizers in wastewater treatment plants (WWTPs). The recent discovery of comammox-like Nitrospira strains, capable of complete oxidation of ammonia to nitrate, raises new questions about specific traits responsible for the functional versatility and adaptation of this genus to a variety of environments. The availability of new Nitrospira genome sequences from both nitrite-oxidizing and comammox bacteria offers a way to analyze traits in different Nitrospira functional groups. Our comparative genomics analysis provided new insights into the adaptation of Nitrospira strains to specific lifestyles and environmental niches. Author Video: An author video summary of this article is available.

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