scholarly journals Evaluation of the Efficacy of SIFT-MS for Speciation of Wastewater Treatment Plant Odors in Parallel with Human Sensory Analysis

Environments ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 90
Author(s):  
Vaughan S. Langford ◽  
Cassandra Billiau ◽  
Murray J. McEwan

Odors from wastewater treatment plants (WWTPs) have frequently been attributed primarily to hydrogen sulfide (H2S). Low-to-medium cost hydrogen sulfide sensors have been utilized as odor indicators. However, other odorous species are usually present that may have lower odor thresholds than hydrogen sulfide. Hydrogen sulfide is not always present in odorous environments and the correlation of hydrogen sulfide to odor at a treatment facility is inconsistent. Such factors determine hydrogen sulfide an inconsistent indicator and more sophisticated measurement techniques are required to accurately predict odor intensity from complex gaseous mixes. In this paper, the performance of a direct mass spectrometric technique, selected ion flow tube mass spectrometry (SIFT-MS), is evaluated for analysis of odors from diverse sources at a modern WWTP. The soft chemical ionization employed in SIFT-MS provides detection and quantification of a wide range of potential odorants to below, or close to, the human odor detection threshold (ODT). The results presented demonstrate that methyl mercaptan is almost always a more significant odorant at this WWTP than hydrogen sulfide and confirm that the relative abundances of these odorants vary significantly. Parallel SIFT-MS chemical analysis and human sensory analysis (olfactometry) was conducted in this study. Good agreement was observed for samples of moderate to strong “sewage” or “chemical” character. However, in samples that were otherwise low in odor intensity, sensory analysis did not attribute “sewage” odor notes as the predominant odor character. Chemicals attributed with this odor character were present significantly above the ODTs in the mixed samples and were detected by SIFT-MS. A weak correlation was obtained between total odor activity values measured using SIFT-MS and the odor concentration (in odor units per cubic meter) determined using dilution olfactometry. The complexity of the wastewater matrix and complexity of human odor recognition from mixed samples is thought to be the underlying cause of less-than-ideal correlation, perturbing both olfactometry and SIFT-MS analyses.

2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.


2021 ◽  
Vol 13 (13) ◽  
pp. 7358
Author(s):  
Dong-Hyun Kim ◽  
Hyun-Sik Yun ◽  
Young-Saeng Kim ◽  
Jong-Guk Kim

This study analyzed the microbial community metagenomically to determine the cause of the functionality of a livestock wastewater treatment facility that can effectively remove pollutants, such as ammonia and hydrogen sulfide. Illumina MiSeq sequencing was used in analyzing the composition and structure of the microbial community, and the 16S rRNA gene was used. Through Illumina MiSeq sequencing, information such as diversity indicators as well as the composition and structure of microbial communities present in the livestock wastewater treatment facility were obtained, and differences between microbial communities present in the investigated samples were compared. The number of reads, operational taxonomic units, and species richness were lower in influent sample (NLF), where the wastewater enters, than in effluent sample (NL), in which treated wastewater is found. This difference was greater in June 2019 than in January 2020, and the removal rates of ammonia (86.93%) and hydrogen sulfide (99.72%) were also higher in June 2019. In both areas, the community composition was similar in January 2020, whereas the influent sample (NLF) and effluent sample (NL) areas in June 2019 were dominated by Proteobacteria (76.23%) and Firmicutes (67.13%), respectively. Oleiphilaceae (40.89%) and Thioalkalibacteraceae (12.91%), which are related to ammonia and hydrogen sulfide removal, respectively, were identified in influent sample (NLF) in June 2019. They were more abundant in June 2019 than in January 2020. Therefore, the functionality of the livestock wastewater treatment facility was affected by characteristics, including the composition of the microbial community. Compared to Illumina MiSeq sequencing, fewer species were isolated and identified in both areas using culture-based methods, suggesting Illumina MiSeq sequencing as a powerful tool to determine the relevance of microbial communities for pollutant removal.


2012 ◽  
Vol 2012 (3) ◽  
pp. 654-662
Author(s):  
Raymond C. Porter ◽  
Teresa Ruiz ◽  
Matthew Ward ◽  
Pérez Juan Carlos

Author(s):  
Е.В. Алексеев

Широкое распространение реагентного коагулирования в технологии очистки природных и промышленных сточных вод обусловлено, с одной стороны, сложностью химического состава и фазово-дисперсного состояния их аквасистем, с другой – многофакторностью действия на них коагулянтов. Рассмотрены основные механизмы взаимодействия коагулянтов и загрязняющих веществ на примере очистки промышленных сточных вод, содержащих органические вещества (поверхностно-активные вещества и синтетические красители). Физико-химическое понятие «коагуляция» отражает только один из механизмов действия коагулянтов на загрязнители. Принятые в настоящее время технологические показатели «доза коагулянта» и «удельная доза коагулянта» также не отражают многообразие взаимодействий загрязняющих веществ с солями коагулянтов и не привязаны к результату коагулирования. Это обусловливает трудность описания совокупного действия физико-химических процессов при добавлении коагулянтов в очищаемые воды и его количественной оценки. Решение проблемы возможно введением понятия «коасорбция», определяющего многофакторность взаимодействия коагулянтов с загрязняющими веществами в процессах очистки сточных вод коагулированием, и технологического показателя «удельная коасорбция», устанавливающего количественную взаимосвязь между величинами загрязняющих веществ в исходной и очищенной воде с дозой коагулянта. Графически представлены функции удельной коасорбции в форме изотерм коасорбции для двух типов поверхностно-активных веществ и синтетических красителей. На основании результатов анализа особенностей изотерм показано, что они отражают разные механизмы взаимодействия коагулянтов и загрязняющих веществ. Использование коасорбции как технологического понятия способствует выявлению механизмов взаимодействия загрязняющих веществ с коагулянтом и созданию наилучших условий для осуществления процесса коагулирования. Функциональное описание изотерм коасорбции позволяет экстраполировать результаты пробного коагулирования в широком интервале концентраций загрязняющих веществ. Практическое значение изотерм удельной коасорбции состоит в возможности определения доз реагентов при коагулировании воды по начальному содержанию загрязняющих веществ и требуемому в очищенных водах. The widespread use of chemical coagulation in purification of natural water and industrial wastewater is due, on the one hand, to the complex chemical composition and phase-disperse state of their aqua systems, and on the other hand, to the multifactorial effect of coagulants on them. The main mechanisms of interaction between coagulants and pollutants are considered through the example of industrial wastewater treatment containing organic substances (surfactants and synthetic dyes). The physicochemical term «coagulation» reflects only one of the mechanisms of the effect of coagulants on pollutants. The currently accepted process parameters «dose of coagulant» and «specific dose of coagulant» do not reflect the variety of interactions of pollutants with coagulant salts either, and are not linked to the result of coagulation. This makes it difficult to describe the collective effect of physicochemical processes while adding coagulants to the treated water and to quantify it. The solution to the problem is possible introducing the concept of «coasorption» that determines the multifactorial origin of the interaction of coagulants and pollutants in the processes of wastewater treatment by coagulation; and the process parameter «specific coasorption» that establishes a quantitative relationship between the concentrations of pollutants in raw wastewater and effluent with a dose of coagulant. The specific coasorption functions are graphically presented in the form of coasorption isotherms for two types of surfactants and synthetic dyes. Based on the results of the analysis of the features of the isotherms, it is shown that they reflect different mechanisms of interaction between coagulants and pollutants. The use of coasorption as a technological concept provides for identifying the mechanisms of interaction of pollutants with a coagulant and establishing the best conditions for the coagulation process. The functional description of the coasorption isotherms allows extrapolating the results of trial coagulation in a wide range of pollutant concentrations. The practical importance of specific coasorption isotherms provides for determining the dosages of chemicals during coagulation of water based on the initial concentration of pollutants and effluent standard.


2003 ◽  
Vol 47 (1) ◽  
pp. 113-120 ◽  
Author(s):  
D.S. Chaudhary ◽  
S. Vigneswaran ◽  
V. Jegatheesan ◽  
H.H. Ngo ◽  
H. Moon ◽  
...  

Wastewater treatment has always been a major concern in the developed countries. Over the last few decades, activated carbon adsorption has gained importance as an alternative tertiary wastewater treatment and purification process. In this study, granular activated carbon (GAC) adsorption was evaluated in terms of total organic carbon (TOC) removal from low strength synthetic wastewater. This paper provides details on adsorption experiments conducted on synthetic wastewater to develop suitable adsorption isotherms. Although the inorganics used in the synthetic wastewater solution had an overall unfavourable effect on adsorption of organics, the GAC adsorption system was found to be effective in removing TOC from the wastewater. This study showed that equation of state (EOS) theory was able to fit the adsorption isotherm results more precisely than the most commonly used Freundlich isotherm. Biodegradation of the organics with time was the most crucial and important aspect of the system and it was taken into account in determining the isotherm parameters. Initial organic concentration of the wastewater was the determining factor of the model parameters, and hence the isotherm parameters were determined covering a wide range of initial organic concentrations of the wastewater. As such, the isotherm parameters derived using the EOS theory could predict the batch adsorption and fixed bed adsorption results of the multi-component system successfully. The isotherm parameters showed a significant effect on the determination of the mass transfer coefficients in batch and fixed bed systems.


1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.


Author(s):  
Md. Aejazur Rahman ◽  
Joel N. Glasgow ◽  
Sajid Nadeem ◽  
Vineel P. Reddy ◽  
Ritesh R. Sevalkar ◽  
...  

For centuries, hydrogen sulfide (H2S) was considered primarily as a poisonous gas and environmental hazard. However, with the discovery of prokaryotic and eukaryotic enzymes for H2S production, breakdown, and utilization, H2S has emerged as an important signaling molecule in a wide range of physiological and pathological processes. Hence, H2S is considered a gasotransmitter along with nitric oxide (•NO) and carbon monoxide (CO). Surprisingly, despite having overlapping functions with •NO and CO, the role of host H2S in microbial pathogenesis is understudied and represents a gap in our knowledge. Given the numerous reports that followed the discovery of •NO and CO and their respective roles in microbial pathogenesis, we anticipate a rapid increase in studies that further define the importance of H2S in microbial pathogenesis, which may lead to new virulence paradigms. Therefore, this review provides an overview of sulfide chemistry, enzymatic production of H2S, and the importance of H2S in metabolism and immunity in response to microbial pathogens. We then describe our current understanding of the role of host-derived H2S in tuberculosis (TB) disease, including its influences on host immunity and bioenergetics, and on Mycobacterium tuberculosis (Mtb) growth and survival. Finally, this review discusses the utility of H2S-donor compounds, inhibitors of H2S-producing enzymes, and their potential clinical significance.


2014 ◽  
Vol 955-959 ◽  
pp. 175-179
Author(s):  
Lin Ying ◽  
Li Na ◽  
Yu Yang Zhou ◽  
Yin Jun

Silica nanoparticles (Si NPs) have a wide range of uses in semiconductors, battery cathode material, and high power laser source materials. However, Si NPs would flow into the wastewater treatment inevitably, and then potentially harmful interactions can occur between nanoparticles and wastewater systems, especially in denitrification process. The present study was aimed to investigate the effects of Si NPs on nitrate nitrogen removal under anaerobic conditions by employing activated sludge. Our data demonstrates that Si NPs had positive effects on denitrification at the beginning and did not display any measurable effect on nitrite nitrogen removal at the concentration of 100 mg/L and below. The denitrification process was elucidated by using the first-order reaction kinetics equation. This study provided useful data for understanding the effects of Si NPs on wastewater treatment.


Sign in / Sign up

Export Citation Format

Share Document