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Wang Z, Sun J, Yang P, Zhang W, Jiang Y, Liu Q, Yang Y, Hao R, Guo G, Huo W, Zhang Q, Li Q. Molecular Analysis of Indole and Skatole Decomposition Metabolism in Acinetobacter piscicola p38 Utilizing Biochemical and Omics Approaches. Microorganisms 2024; 12:1792. [PMID: 39338467 PMCID: PMC11434297 DOI: 10.3390/microorganisms12091792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Revised: 08/24/2024] [Accepted: 08/26/2024] [Indexed: 09/30/2024] Open
Abstract
Indole and skatole (3-methylindole, C9H9N) are common nitrogen-containing heterocyclic pollutants found in waste, wastewater treatment plants, and public restrooms and are the most notorious compounds in animal feces. Biodegradation was considered a feasible method for the removal of indole and skatole, but a comprehensive understanding of the metabolic pathways under both aerobic and anaerobic conditions was lacking, and the functional genes responsible for skatole biodegradation remained a mystery. Through metagenomic and gene cluster functional analysis, Acinetobacter piscicola p38 (NCBI: CP167896), genes 1650 (styrene monooxygenase: ACDW34_08180), and 1687 (styrene monooxygenase: ACDW34_08350) were identified as having the potential to degrade indole and skatole. The heterologous expression results demonstrate that the genes 1650 and 1651 (flavin reductase: ACDW34_08185), when combined, are capable of degrading indole, while the genes 1687 and 1688 (flavin reductase: ACDW34_08355), in combination, can degrade indole as well as skatole. These reactions necessitate the involvement of flavin reductase and NAD(P)H to catalyze the oxygenation process. This work aimed to provide new experimental evidence for the biodegradation of indole and skatole. This study offered new insights into our understanding of skatole degradation. The Acinetobacter_piscicola p38 strain provided an effective bacterial resource for the bioremediation of fecal indole and skatole.
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Affiliation(s)
- Zhonghao Wang
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Jiajin Sun
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Pu Yang
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Wanjun Zhang
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Yihong Jiang
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Qiang Liu
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Yunqi Yang
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Ruirong Hao
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Gang Guo
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Wenjie Huo
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
| | - Qiang Zhang
- College of Resources and Environment, Shanxi Agricultural University, Taigu 030800, China;
| | - Qinghong Li
- College of Animal Science, Shanxi Agricultural University, Taigu 030800, China; (Z.W.); (J.S.); (P.Y.); (W.Z.); (Y.J.); (Q.L.); (Y.Y.); (R.H.); (G.G.); (W.H.)
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Wine Minerality and Funkiness: Blending the Two Tales of the Same Story. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8120745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In wines, minerality is a complex concept with increasing popularity in scientific research and the wine press. The flavour conceptual space of mineral wines comprises sulphur-reduced aromas, such as flint, wet stone or chalk associated with freshness and lingering mouth perceptions. Professionals do not consider the perception of sulphur-reduced flavours as an off-flavour. Indeed, this sort of reduction is a cue for the recognition of minerality under a likely top-down mental process. However, untrained consumers perceive these aromas as unpleasant. This different qualitative assessment hampers the communication between professionals and amateurs. This review aimed to describe the perceptions of minerality by experts and novices to promote their mutual understanding. Funkiness is proposed as a descriptor of mineral wines when tasted by unexperienced consumers. The chemical basis of minerality and winemaking options were explored to understand their implications on sensory perception. Mineral flavours have two main features. The first comprises ephemeral aromas that may be described as funky, given their association with sulphur-reduced molecules. The second is linked to the fresh and vivacious lingering mouthfeel perceptions that remain after the reductive aromas vanish. Consumers recognise this dual perception by demonstrating positive emotional responses of surprise during tasting. Then, the perception of minerality is a question of cognition and not of particularly developed sensory skills. Appropriate tasting approaches encompassing emotional responses and emergent properties (e.g., harmony, depth, persistence, complexity) appear essential to understand the nature of wine minerality and to determine when it may be regarded as a surrogate for fine wine quality.
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Bonini A, Dellacassa E, Ares G, Daners G, Godoy A, Boido E, Fariña L. Fecal descriptor in honey: indole from a floral source as an explanation. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:6780-6785. [PMID: 35942662 DOI: 10.1002/jsfa.12166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/22/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Animal odor, is one of the most common aroma defects described in the honey odor aroma wheel. It comprises two secondary descriptors: 'fecal' and 'cowshed'. However, the compounds responsible for these honey defects have not been fully identified. In this context, the aim of this work was to identify the compounds responsible for the aromatic defect 'fecal' in Uruguayan honeys by means of gas chromatography coupled to olfactometry (GC-O). RESULTS Samples of honey described by beekeepers as having fecal aroma were analyzed by GC-O and gas chromatography coupled to mass spectrometry (GC-MS). Through GC-O, it was possible to establish the region of the chromatogram corresponding to the fecal descriptor, while the GC-MS analysis allowed to identify indole as the compound responsible for the fecal descriptor. The content of indole in the analyzed samples ranged between 132 and 414 μg kg-1 . The melissopalynological analysis indicated the presence of Scutia buxifolia ('quebracho' or 'coronilla') pollen in all samples studied. The volatile profile of Scutia buxifolia flowers was evaluated during the full day, enabling the identification of indole as one of its components. The detection threshold value for indole in honey was experimentally determined as 64 μg kg-1 of honey, a value lower than the concentration found in the evaluated samples. CONCLUSION Results from the study allowed the identification of indole as the compound responsible for the 'fecal' aroma defect in Scutia buxifolia honeys. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Ana Bonini
- Laboratorio de Biotecnología de Aromas, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Eduardo Dellacassa
- Laboratorio de Biotecnología de Aromas, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Gastón Ares
- Área Sensometría y Ciencia del Consumidor, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Gloria Daners
- Departamento de Paleontología, Instituto de Ciencias Geológicas, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ana Godoy
- Laboratorio de Biotecnología de Aromas, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Eduardo Boido
- Área Enología y Biotecnología de Fermentaciones, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Laura Fariña
- Laboratorio de Biotecnología de Aromas, Facultad de Química, Universidad de la República, Montevideo, Uruguay
- Área Enología y Biotecnología de Fermentaciones, Facultad de Química, Universidad de la República, Montevideo, Uruguay
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A Pilot Study to Quantify Volatile Organic Compounds and Their Sources Inside and Outside Homes in Urban India in Summer and Winter during Normal Daily Activities. ENVIRONMENTS 2022. [DOI: 10.3390/environments9070075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Indian cities have some of the poorest air quality globally but volatile organic compounds (VOCs)—many of which adversely affect health—and their indoor sources remain understudied in India. In this pilot study we quantified hundreds of VOCs inside and outside 26 homes in Ahmedabad and Gandhinagar, Gujarat, in May 2019 and in January 2020. We sampled in the morning and afternoon/evening to capture temporal variability. Total indoor VOCs were measured at higher concentrations in winter (327.0 ± 224.2 µgm−3) than summer (150.1 ± 121.0 µgm−3) and exceeded those measured outdoors. Using variable reduction techniques, we identified potential sources of compounds (cooking, plastics [with an emphasis on plasticizers], consumer products, siloxanes [as used in the production of consumer products], vehicles). Contributions differed by season and between homes. In May, when temperatures were high, plastics contributed substantially to indoor pollution (mean of 42% contribution to total VOCs) as compared to in January (mean of 4%). Indoor cooking and consumer products contributed on average 29% and 10% to all VOCs indoors in January and 16% and 4% in May. Siloxane sources contributed <4% to any home during either season. Cooking contributed substantially to outdoor VOCs (on average 18% in January and 11% in May) and vehicle-related sources accounted for up to 84% of VOCs in some samples. Overall, results indicate a strong seasonal dependence of indoor VOC concentrations and sources, underscoring the need to better understand factors driving health-harming pollutants inside homes to facilitate exposure reductions.
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Disaster Risk Management, Ventilated Improved Pit Latrines, and Sanitation Challenges in South Africa. SUSTAINABILITY 2022. [DOI: 10.3390/su14116934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
The current paper provides a review and meta-analysis of the practical implications of disaster risk management related to the ventilated improved latrines in South Africa. This technology is evaluated through its legacy and novel challenges of disaster risk reduction. In the current article, the methodology adopted was a literature review and meta-analyses. The results indicate that the in-situ treatment and breakdown of faecal sludge in the ventilated improved pit latrines is not always taking place and that anaerobic digestion might not always be feasible. New strategies are proposed to manage the sanitation-related risks in South Africa by specifying more exact dimensions for the newly built ventilated improved pit latrines by suggesting the use of novel sanitation additives such as fly ash to enhance on-site and in situ treatment, as well as ex situ treatment of the pit latrine faecal sludge. Regular maintenance can lead to prevention of the dysfunctional character of the ventilated improved pit latrines as a functional sanitation technology and a user-friendly hygiene barrier to the spread of sanitation/WASH-related epidemics or infectious diseases. The implementation of the novel strategies should be enhanced by the application of the (Environmental) Technology Assessment in sanitation service delivery in South Africa.
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Senanu BM, Boakye P, Oduro-Kwarteng S, Sewu DD, Awuah E, Obeng PA, Afful K. Inhibition of ammonia and hydrogen sulphide as faecal sludge odour control in dry sanitation toilet facilities using plant waste materials. Sci Rep 2021; 11:17803. [PMID: 34493737 PMCID: PMC8423729 DOI: 10.1038/s41598-021-97016-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/18/2021] [Indexed: 11/15/2022] Open
Abstract
On-site dry sanitation facilities, although cheaper than wet sanitation systems, suffer from high malodour and insect nuisance as well as poor aesthetics. The high odour deters users from utilizing dry sanitation toilets as an improved facility leading to over 20% open defecation in Sub-Saharan Africa. To address this malodour concern, this study first assessed odour levels, using hydrogen sulphide (H2S) and ammonia (NH3) as indicators, on two dry sanitation facilities named T1 and T2. The potential of using biomass (sawdust, rice husk, moringa leaves, neem seeds), ash (coconut husk, cocoa husk) or biochar (sawdust, rice husk, bamboo) as biocovers to remove or suppress odour from fresh faecal sludge (FS) over a 12-day period was investigated. Results showed that the odour levels for H2S in both T1 (3.17 ppm) and T2 (0.22 ppm) were above the threshold limit of 0.05 ppm, for unpleasantness in humans and vice versa for NH3 odour levels (T1 = 6.88 ppm; T2 = 3.16 ppm; threshold limit = 30 ppm limit). The biomasses exhibited low pH (acidic = 5–7) whereas the biochars and ashes had higher pHs (basic = 8–13). Basic biocovers were more effective at H2S emission reduction (80.9% to 96.2%) than acidic biocovers. The effect of pH on suppression of NH3 was determined to be statistically insignificant at 95% confidence limit. In terms of H2S and NH3 removal, sawdust biochar was the most effective biocover with odour abatement values of 96.2% and 74.7%, respectively. The results suggest that biochar produced from locally available waste plant-based materials, like sawdust, can serve as a cost-effective and sustainable way to effectively combat odour-related issues associated with dry sanitation facilities to help stop open defecation.
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Affiliation(s)
- Bernice Mawumenyo Senanu
- Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, PMB, UPO, Kumasi, Ghana
| | - Patrick Boakye
- Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology, PMB, UPO, Kumasi, Ghana.
| | - Sampson Oduro-Kwarteng
- Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, PMB, UPO, Kumasi, Ghana.
| | - Divine Damertey Sewu
- Life Green Technology Co. Ltd., 875 Yuseong-daero, Yuseong-gu, Daejeon, 34158, Republic of Korea.,Department of Chemical and Biological Engineering, Hanbat National University, 125 Dongseo-daero, Yuseong-gu, Daejeon, 34158, Republic of Korea
| | - Esi Awuah
- Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, PMB, UPO, Kumasi, Ghana
| | - Peter Appiah Obeng
- Department of Water and Sanitation, University of Cape Coast, Cape Coast, Ghana
| | - Kobina Afful
- Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, PMB, UPO, Kumasi, Ghana
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Ward BJ, Andriessen N, Tembo JM, Kabika J, Grau M, Scheidegger A, Morgenroth E, Strande L. Predictive models using "cheap and easy" field measurements: Can they fill a gap in planning, monitoring, and implementing fecal sludge management solutions? WATER RESEARCH 2021; 196:116997. [PMID: 33744658 DOI: 10.1016/j.watres.2021.116997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/19/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
The characteristics of fecal sludge delivered to treatment plants are highly variable. Adapting treatment process operations accordingly is challenging due to a lack of analytical capacity for characterization and monitoring at many treatment plants. Cost-efficient and simple field measurements such as photographs and probe readings could be proxies for process control parameters that normally require laboratory analysis. To investigate this, we evaluated questionnaire data, expert assessments, and simple analytical measurements for fecal sludge collected from 421 onsite containments. This data served as inputs to models of varying complexity. Random forest and linear regression models were able to predict physical-chemical characteristics including total solids (TS) and ammonium (NH4+-N) concentrations, and solid-liquid separation performance including settling efficiency and filtration time (R2 from 0.51-0.66) based on image analysis of photographs (sludge color, supernatant color, and texture) and probe readings (conductivity (EC) and pH). Supernatant color was the best predictor of settling efficiency and filtration time, EC was the best predictor of NH4+-N, and texture was the best predictor of TS. Predictive models have the potential to be applied for real-time monitoring and process control if a database of measurements is developed and models are validated in other cities. Simple decision tree models based on the single classifier of containment type can also be used to make predictions about citywide planning, where a lower degree of accuracy is required.
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Affiliation(s)
- Barbara J Ward
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland.
| | - Nienke Andriessen
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - James M Tembo
- Department of Civil and Environmental Engineering, School of Engineering, University of Zambia, Lusaka, Zambia
| | - Joel Kabika
- Department of Civil and Environmental Engineering, School of Engineering, University of Zambia, Lusaka, Zambia
| | - Matt Grau
- Department of Physics, ETH Zürich, 8093, Zürich, Switzerland
| | - Andreas Scheidegger
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - Eberhard Morgenroth
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
| | - Linda Strande
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
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Dennler-Church TE, Butz JC, McKinley JE, Keim EK, Hall MC, Meschke JS, Mulligan JM, Williams JF, Robins LI. Modification of Major Contributors Responsible for Latrine Malodor on Exposure to Hypochlorous Acid: The Potential for Simultaneously Impacting Odor and Infection Hazards to Encourage Latrine Use. Am J Trop Med Hyg 2020; 103:2584-2590. [PMID: 33073749 PMCID: PMC7695106 DOI: 10.4269/ajtmh.20-0553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 09/07/2020] [Indexed: 11/16/2022] Open
Abstract
Open defecation remains a common practice in developing countries and leads to high incidence and prevalence of acute gastroenteritis, which is most often caused by human noroviruses (human NoV). Encouraging the use of toilets and pit latrines is one method of improving sanitation; however, it is often hindered by not only cultural traditions but also from a reluctance to use latrines and toilets due to their odor and impression of uncleanliness. In an effort to establish new means to encourage toilet and latrine use, laboratory experiments tested the ability of hypochlorous acid (HOCl) to modify the malodorous compounds identified in the air in latrines in developing countries (indole, p-cresol, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), and butyric acid) and inactivate MS2 bacteriophage, a surrogate for human NoV. After 5 minutes, > 94% of indole, p-cresol, DMDS, and DMTS was modified as determined by high-pressure liquid chromatography in the presence of 100 ppm HOCl. A log10 reduction value (LRV) greater than 6 was seen for MS2 bacteriophage after 5 minutes of exposure to 100 ppm HOCl in solution. Sensory studies indicated that there was a significant difference (P ≤ 0.05) between the untreated and HOCl-treated samples for all five malodorous compounds tested. The findings suggest that introduction of HOCl into the headspace air could encourage latrine and toilet use. Optimization of HOCl dosing in air to accomplish both odor control and reduction of infectious hazards is worthy of further study.
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Affiliation(s)
- Tim E. Dennler-Church
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | - Jeremy C. Butz
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | - Joseph E. McKinley
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | - Erika K. Keim
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - Mary C. Hall
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - John S. Meschke
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington
| | - JoAnne M. Mulligan
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
| | | | - Lori I. Robins
- Department of Physical Sciences, University of Washington Bothell, Bothell, Washington
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9
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Baldovini N, Chaintreau A. Identification of key odorants in complex mixtures occurring in nature. Nat Prod Rep 2020; 37:1589-1626. [PMID: 32692323 DOI: 10.1039/d0np00020e] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to 2019Soon after the birth of gas chromatography, mass spectrometry and olfactometry were used as detectors, which allowed impressive development to be achieved in the area of odorant determinations. Since the mid-80s, structured methods of gas chromatography-olfactometry have appeared, allowing the determination of which odor constituents play a key role in materials. Progressively, numerous strategies have been proposed for sample preparation from raw materials, the representativeness evaluation of extracts, the identification of odor constituents, their quantification, and subsequently, the recombination of the key odorants to mimic the initial odor. However, the multiplicity of options at each stage of the analysis leads to a confusing landscape in this field, and thus, the present review aims at critically presenting the available options. For each step, the most frequently used alternatives are described, together with their strengths and weaknesses based on theoretical and experimental justifications according to the literature. These techniques are exemplified by many applications in the literature on aromas, fragrances and essential oils, with the initial focus on wine odorants, followed by a short overview on the molecular diversity of key odorants, which illustrates most of the facets and complexities of odor studies, including the issues raised by odorant interactions such as synergies.
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Affiliation(s)
- Nicolas Baldovini
- Institut de Chimie de Nice, Faculté des Sciences, Université Côte d'Azur, 06108 Nice Cedex 2, France.
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10
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Pfister P, Smith BC, Evans BJ, Brann JH, Trimmer C, Sheikh M, Arroyave R, Reddy G, Jeong HY, Raps DA, Peterlin Z, Vergassola M, Rogers ME. Odorant Receptor Inhibition Is Fundamental to Odor Encoding. Curr Biol 2020; 30:2574-2587.e6. [PMID: 32470365 DOI: 10.1016/j.cub.2020.04.086] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 03/31/2020] [Accepted: 04/28/2020] [Indexed: 11/18/2022]
Abstract
Most natural odors are complex mixtures of volatile components, competing to bind odorant receptors (ORs) expressed in olfactory sensory neurons (OSNs) of the nose. To date, surprisingly little is known about how OR antagonism shapes neuronal representations in the detection layer of the olfactory system. Here, we investigated its prevalence, the degree to which it disrupts OR ensemble activity, and its conservation across phylogenetically related ORs. Calcium imaging microscopy of dissociated OSNs revealed significant inhibition, often complete attenuation, of responses to indole-a commonly occurring volatile associated with both floral and fecal odors-by a set of 36 tested odorants. To confirm an OR mechanism for the observed inhibition, we performed single-cell transcriptomics on OSNs exhibiting specific response profiles to a diagnostic panel of odorants and identified three paralogous receptors-Olfr740, Olfr741, and Olfr743-which, when tested in vitro, recapitulated OSN responses. We screened ten ORs from the Olfr740 gene family with ∼800 perfumery-related odorants spanning a range of chemical scaffolds and functional groups. Over half of these compounds (430) antagonized at least one of the ten ORs. OR activity fitted a mathematical model of competitive receptor binding and suggests normalization of OSN ensemble responses to odorant mixtures is the rule rather than the exception. In summary, we observed OR antagonism occurred frequently and in a combinatorial manner. Thus, extensive receptor-mediated computation of mixture information appears to occur in the olfactory epithelium prior to transmission of odor information to the olfactory bulb.
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Affiliation(s)
- Patrick Pfister
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Benjamin C Smith
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Barry J Evans
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Jessica H Brann
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Casey Trimmer
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Mushhood Sheikh
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Randy Arroyave
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Gautam Reddy
- Department of Physics, UC San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Hyo-Young Jeong
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Daniel A Raps
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Zita Peterlin
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA
| | - Massimo Vergassola
- Department of Physics, UC San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Matthew E Rogers
- Firmenich Incorporated, 250 Plainsboro Road, Plainsboro, NJ 08536, USA.
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Fecal Malodor Detection Using Low-Cost Electrochemical Sensors. SENSORS 2020; 20:s20102888. [PMID: 32443709 PMCID: PMC7287618 DOI: 10.3390/s20102888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/14/2020] [Accepted: 05/17/2020] [Indexed: 11/16/2022]
Abstract
Technology innovation in sanitation is needed for the 4.2 billion people worldwide, lacking safely managed sanitation services. A major requirement for the adoption of these technologies is the management of malodor around toilet and treatment systems. There is an unmet need for a low-cost instrumented technology for detecting the onset of sanitation malodor and triggering corrective actions. This study combines sensory data with low-cost gas sensor data on malodor emanating from feces. The response of 10 commercial electrochemical gas sensors was collected alongside olfactometric measurements. Odor from fecal specimens at different relevant dilution as well as specimens with pleasant odors as a control were evaluated for a total of 64 responses. Several of the sensors responded positively to the fecal odor, with the formaldehyde, hydrogen sulfide, and ammonia sensors featuring the highest signal to noise ratio. A positive trend was observed between the sensors' responses and the concentration of the odorant and with odor intensity, but no clear correspondence with dilution to threshold (D/T) values was found. Selected sensors were responsive both above and below the intensity values used as the cutoff for offensive odor, suggesting the possibility of using those sensors to differentiate odor offensiveness based just on the magnitude of their response. The specificity of the sensors suggested that discrimination between the selected non-fecal and fecal odors was possible. This study demonstrates that some of the evaluated sensors could be used to assemble a low-cost malodor warning system.
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Pan J, Wang D, Zhang LX, Xue ZZ, Zhang D, Han SD, Wang GM. Pure Inorganic Iodocuprate Framework Embedding In Situ Generated [Pb4(OH)4]4+ Cubic Template. Inorg Chem 2019; 58:1746-1749. [DOI: 10.1021/acs.inorgchem.8b03352] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jie Pan
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
| | - Di Wang
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
| | - Li-Xin Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
| | - Zhen-Zhen Xue
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
| | - Di Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
| | - Song-De Han
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
| | - Guo-Ming Wang
- College of Chemistry and Chemical Engineering, Qingdao University, Shandong 266071, China
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Gould O, de Lacy Costello B, Smart A, Jones P, Macmaster A, Ransley K, Ratcliffe N. Gas Chromatography Mass Spectrometry (GC-MS) Quantification of Metabolites in Stool Using 13C Labelled Compounds. Metabolites 2018; 8:metabo8040075. [PMID: 30384466 PMCID: PMC6316270 DOI: 10.3390/metabo8040075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/24/2018] [Accepted: 10/29/2018] [Indexed: 12/27/2022] Open
Abstract
It has become increasingly important to qualitatively and quantitatively assess the volatile metabolites in a range of bodily fluids for use in monitoring health. There has been relatively little work on the quantitative analysis of compounds, particularly with respect to the effects of ethnicity or geographic location. A novel method for the quantification of compounds in stool using 13C labelled compounds as internal standards is presented. Using thermal desorption gas chromatography mass spectrometry, stool samples from 38 healthy volunteers were analysed. The 13C labelled compounds, acetone, ethyl butanoate, ethanoic acid, butanoic acid, 3-methylbutanoic acid, and indole, were added as internal standards. This process mimics the solubility characteristics of the compounds and thus the method was able to quantify the compounds within the solid stool. In total, 15 compounds were quantified: Dimethyl sulphide (26–25,626 ng/g), acetone (442–3006 ng/g), ethyl butanoate (39–2468 ng/g), ethyl 2-methylbutanoate (0.3–180 ng/g), dimethyl disulphide (35–1303 ng/g), 1-octen-3-one (12 ng/g), dimethyl trisulphide (10–410 ng/g), 1-octen-3-ol (0.4–58 ng/g), ethanoic acid (672–12,963 ng/g), butanoic acid (2493–11,553 ng/g), 3-methylbutanoic acid (64–8262 ng/g), pentanoic acid (88–21,886 ng/g), indole (290–5477 ng/g), and 3-methyl indole (37–3483 ng/g). Moreover, by altering the pH of the stool to pH 13 in conjunction with the addition of 13C trimethylamine, the method was successful in detecting and quantifying trimethylamine for the first time in stool samples (range 40–5312 ng/g). Statistical analysis revealed that samples from U.K. origin had five significantly different compounds (ethyl butanoate, 1-octen-3-ol, ethanoic acid, butanoic acid, pentanoic acid, and indole) from those of South American origin. However, there were no significant differences between vegetarian and omnivore samples. These findings are supported by pre-existing literature evidence. Moreover, we have tentatively identified 12 compounds previously not reported as having been found in stool.
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Affiliation(s)
- Oliver Gould
- Institute of Biosensor Technology, University of the West of England, Bristol BS16 1QY, UK.
| | - Ben de Lacy Costello
- Institute of Biosensor Technology, University of the West of England, Bristol BS16 1QY, UK.
| | - Amy Smart
- Institute of Biosensor Technology, University of the West of England, Bristol BS16 1QY, UK.
| | | | | | | | - Norman Ratcliffe
- Institute of Biosensor Technology, University of the West of England, Bristol BS16 1QY, UK.
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Stogin BB, Gockowski L, Feldstein H, Claure H, Wang J, Wong TS. Free-standing liquid membranes as unusual particle separators. SCIENCE ADVANCES 2018; 4:eaat3276. [PMID: 30151426 PMCID: PMC6108570 DOI: 10.1126/sciadv.aat3276] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/17/2018] [Indexed: 06/08/2023]
Abstract
Separation of substances is central to many industrial and medical processes ranging from wastewater treatment and purification to medical diagnostics. Conventional solid-based membranes allow particles below a critical size to pass through a membrane pore while inhibiting the passage of particles larger than that critical size; membranes that are capable of showing reversed behavior, that is, the passage of large particles and inhibition of small ones, are unusual in conventional engineering applications. Inspired by endocytosis and the self-healing properties of liquids, we show that free-standing membranes composed entirely of liquid can be designed to retain particles smaller than a critical size given the particle inertial properties. We further demonstrate that these membranes can be used for previously unachievable applications, including serving as particle barriers that allow macroscopic device access through the membrane (for example, open surgery) or as selective membranes inhibiting gas/vapor passage while allowing solids to pass through them (for example, waste/odor management).
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Affiliation(s)
- Birgitt Boschitsch Stogin
- Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
| | - Luke Gockowski
- Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802, USA
| | - Hannah Feldstein
- Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802, USA
| | - Houston Claure
- Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802, USA
| | - Jing Wang
- Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
| | - Tak-Sing Wong
- Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802, USA
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Chappuis CJ, Huber R, Niclass Y, Starkenmann C. Simulating latrine conditions to assess perfume performance against malodour. FLAVOUR FRAG J 2018; 33:313-321. [PMID: 30034087 PMCID: PMC6049876 DOI: 10.1002/ffj.3450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/14/2018] [Accepted: 03/14/2018] [Indexed: 11/12/2022]
Abstract
To evaluate perfume performance in toilets, we built model toilets in which critical factors such as background malodour, climate, and airflow were controlled. The models were equipped with an odour generator that injected hydrogen sulfide, methyl mercaptan, butyric acid, para-cresol, and indole, allowing us to accurately and reliably reconstitute toilet malodour headspace. The malodorant concentrations matched the quantitative headspace analysis performed in African and Indian toilets. The toilet malodour headspace performance was validated by chemical and sensory analysis. Olfactory stimuli were presented to participants in different simulated climates to assess the effect of climate on the perception of odours. The sensory data show that increasing temperature and humidity decreased the intensity ratings of odours without altering their quality. Perfume can be delivered in these toilets by forced evaporation to control the headspace concentration, or by delivery systems such as cellulosic pads, liquids, and powders. Our experimental set-up allowed us to establish dose-response curves to assess the performance of a perfume in reducing toilet malodour and increasing perceived pleasantness.
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Affiliation(s)
| | - Robin Huber
- Corporate R&D DivisionFirmenich SAGenevaSwitzerland
| | - Yvan Niclass
- Corporate R&D DivisionFirmenich SAGenevaSwitzerland
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Cid CA, Qu Y, Hoffmann MR. Design and preliminary implementation of onsite electrochemical wastewater treatment and recycling toilets for the developing world. ENVIRONMENTAL SCIENCE : WATER RESEARCH & TECHNOLOGY 2018; 4:1439-1450. [PMID: 33365135 PMCID: PMC7705125 DOI: 10.1039/c8ew00209f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/27/2018] [Indexed: 05/20/2023]
Abstract
Self-contained toilet wastewater treatment system prototypes based on electrochemical oxidation of feces and urine using bi-layered semiconductor anodes ([Bi2O3] z [TiO2]1-z/Ir x Ta y O2/Ti) have been designed, constructed, and implemented in regions where access to proper and sufficient sanitation is limited. Prototypes were designed to fit in shipping containers in order to provide toilets and onsite wastewater treatment with clean water recycling. Units were designed to handle the waste of 25 users per day (or 130 L of toilet wastewater). The first prototype was tested on the Caltech campus (Pasadena, California) followed by improved second-generation prototypes that were subsequently installed in India (Ahmedabad, Gujarat and Kottayam, Kerala) and China (Yixing, Jiangsu) for open use in various public settings. The prototypes were able to provide for the disinfection of pathogens (<10 MPN Total coliforms and <1 MPN Fecal coliform indicator organisms per 100 mL), reduction of chemical oxygen demand (<100 mg O2 L-1), ammonia (<10 mg N L-1), and color at an average energy consumption of less than 180 W h per user per day. The treated wastewater was recycled for use as toilet flushing water.
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Affiliation(s)
- Clément A. Cid
- Linde-Robinson Laboratories, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
| | - Yan Qu
- Linde-Robinson Laboratories, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
- Trussell Technologies Incorporation, 232 N Lake Ave., Suite 300, Pasadena, California, 91101, USA
| | - Michael R. Hoffmann
- Linde-Robinson Laboratories, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
- E-mail:
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Decrey L, Kohn T. Virus inactivation in stored human urine, sludge and animal manure under typical conditions of storage or mesophilic anaerobic digestion. ENVIRONMENTAL SCIENCE : WATER RESEARCH & TECHNOLOGY 2017; 3:492-501. [PMID: 33365134 PMCID: PMC7705124 DOI: 10.1039/c6ew00311g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/16/2017] [Indexed: 05/21/2023]
Abstract
Viruses represent major disease transmitting agents carried by human excreta and animal manure. Understanding virus inactivation is therefore essential in preventing microbial spread due to inadequate treatment of these materials. Here, we investigated the inactivation kinetics of the single-stranded (ss) RNA phage MS2, DNA phages T4 and ΦX174, andthe double-stranded DNA human adenovirus in stored human urine, sludge, and animal manure, at temperatures and pH valuestypical of storage under naturally occurring conditions or mesophilic anaerobic digestion (<40 °C). The ssRNA phage MS2 was most readily inactivated in all samples compared to the other viruses tested. This is consistent with previous findings in wellcontrolled buffer solutions of similar composition, where inactivation was found to be governedby bases (NH3, carbonate, hydroxide) that catalyze the transesterification and cleavage of the ssRNA. Correspondingly, MS2 inactivation kinetics in real matrices could be adequately modelled by only taking into account the effects of temperature, pH, carbonate and ammonia on the integrity of ssRNA. DNA viruses were more persistent compared to MS2;however, inactivation in selected sludge and manure samples proceeded at faster rates compared to well-controlled buffersolutions of similar composition. This indicates a contribution of microbial or enzymatic activity to inactivation of DNA viruses. Overall, this study identifies the most important factors contributing to inactivation of viruses in human excreta and manure, and highlights the differences in inactivation kinetics and mechanisms between ssRNA and DNA viruses.
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Affiliation(s)
- Loïc Decrey
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Tamar Kohn
- Laboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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18
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Lapworth DJ, Nkhuwa DCW, Okotto-Okotto J, Pedley S, Stuart ME, Tijani MN, Wright J. Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health. HYDROGEOLOGY JOURNAL 2017; 25:1093-1116. [PMID: 32055234 PMCID: PMC6991975 DOI: 10.1007/s10040-016-1516-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 12/06/2016] [Indexed: 05/18/2023]
Abstract
Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.
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Affiliation(s)
- D. J. Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB UK
| | - D. C. W. Nkhuwa
- University of Zambia, Great East Road Campus, P.O. Box 32379, Lusaka, Zambia
| | - J. Okotto-Okotto
- Victoria Institute for Research on Environment and Development (VIRED) International, Rabuour Environment and Development Centre, Kisumu-Nairobi Road, P.O. Box 6423-40103, Kisumu, Kenya
| | - S. Pedley
- Robens Centre for Public and Environmental Health, University of Surrey, Guildford, GU2 7XH UK
| | - M. E. Stuart
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB UK
| | - M. N. Tijani
- Department of Geology, University of Ibadan, Ibadan, Oyo State Nigeria
| | - J. Wright
- Geography and Environment, University of Southampton, Highfield, Southampton, SO17 1BJ UK
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Rtimi S, Robyr M, Pulgarin C, Lavanchy JC, Kiwi J. A New Perspective in the Use of FeOx-TiO2 Photocatalytic Films: Indole Degradation in the Absence of Fe-Leaching. J Catal 2016. [DOI: 10.1016/j.jcat.2016.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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20
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Metal organic frameworks as sorption media for volatile and semi-volatile organic compounds at ambient conditions. Sci Rep 2016; 6:27813. [PMID: 27324522 PMCID: PMC4914961 DOI: 10.1038/srep27813] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 05/25/2016] [Indexed: 12/24/2022] Open
Abstract
In this research, we investigated the sorptive behavior of a mixture of 14 volatile and semi-volatile organic compounds (four aromatic hydrocarbons (benzene, toluene, p-xylene, and styrene), six C2-C5 volatile fatty acids (VFAs), two phenols, and two indoles) against three metal-organic frameworks (MOFs), i.e., MOF-5, Eu-MOF, and MOF-199 at 5 to 10 mPa VOC partial pressures (25 °C). The selected MOFs exhibited the strongest affinity for semi-volatile (polar) VOC molecules (skatole), whereas the weakest affinity toward was volatile (non-polar) VOC molecules (i.e., benzene). Our experimental results were also supported through simulation analysis in which polar molecules were bound most strongly to MOF-199, reflecting the presence of strong interactions of Cu2+ with polar VOCs. In addition, the performance of selected MOFs was compared to three well-known commercial sorbents (Tenax TA, Carbopack X, and Carboxen 1000) under the same conditions. The estimated equilibrium adsorption capacity (mg.g−1) for the all target VOCs was in the order of; MOF-199 (71.7) >Carboxen-1000 (68.4) >Eu-MOF (27.9) >Carbopack X (24.3) >MOF-5 (12.7) >Tenax TA (10.6). Hopefully, outcome of this study are expected to open a new corridor to expand the practical application of MOFs for the treatment diverse VOC mixtures.
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Nakagiri A, Niwagaba CB, Nyenje PM, Kulabako RN, Tumuhairwe JB, Kansiime F. Are pit latrines in urban areas of Sub-Saharan Africa performing? A review of usage, filling, insects and odour nuisances. BMC Public Health 2016; 16:120. [PMID: 26846125 PMCID: PMC4743102 DOI: 10.1186/s12889-016-2772-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/22/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A pit latrine is the most basic form of improved sanitation which is currently used by a number of people around the globe. In spite of the wide spread use, known successes and advantages associated with pit latrines, they have received little attention in form of research and development. This review focuses on the usage and performance (filling, smell and insect nuisance) of pit latrines in urban areas of sub-Saharan Africa (SSA) and proposes approaches for their improvements and sustainability. METHODS Current pit latrine usage within urban SSA was calculated from Joint Monitoring Programme (JMP) water and sanitation country-files. We conducted a literature search and review of documents on pit latrine usage, filling, smell and insect nuisances in urban areas of SSA. Findings of the review are presented and discussed in this paper. RESULTS AND DISCUSSION Pit latrines are in use by more than half the urban population in SSA and especially among low income earners. An additional 36 million people in urban areas of SSA have adopted the pit latrine since 2007. However, their performance is unsatisfactory. Available literature shows that contributions have been made to address shortfalls related to pit latrine use in terms of science and technological innovations. However, further research is still needed. CONCLUSION Any technology and process management innovations to pit latrines should involve scientifically guided approaches. In addition, development, dissemination and enforcement of minimum pit latrine design standards are important while the importance of hygienic latrines should also be emphasized.
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Affiliation(s)
- Anne Nakagiri
- Department of Civil and Environmental Engineering, Makerere University, P.O Box 7062, Kampala, Uganda.
| | - Charles B Niwagaba
- Department of Civil and Environmental Engineering, Makerere University, P.O Box 7062, Kampala, Uganda
| | - Philip M Nyenje
- Department of Civil and Environmental Engineering, Makerere University, P.O Box 7062, Kampala, Uganda
| | - Robinah N Kulabako
- Department of Civil and Environmental Engineering, Makerere University, P.O Box 7062, Kampala, Uganda
| | - John B Tumuhairwe
- Department of Agricultural Production, Makerere University, P.O Box 7062, Kampala, Uganda
| | - Frank Kansiime
- Department of Environmental Management, Makerere University, P.O Box 7062, Kampala, Uganda
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Afful K, Oduro-Kwarteng S, Antwi EO, Awuah E. Odour Impact Determination of a Communal Toilet: Field Measurement with Panellists Using Dynamic Plume Method and Dispersion Modelling. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/ojap.2016.51001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Chappuis CJ, Niclass Y, Cayeux I, Starkenmann C. Sensory survey of key compounds of toilet malodour in Switzerland, India and Africa. FLAVOUR FRAG J 2015. [DOI: 10.1002/ffj.3293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Yvan Niclass
- Firmenich SA Corporate R&D Division P.O. Box 239 CH‐1211 Geneva 8 Switzerland
| | - Isabelle Cayeux
- Firmenich SA Corporate R&D Division P.O. Box 239 CH‐1211 Geneva 8 Switzerland
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Chappuis CJF, Niclass Y, Vuilleumier C, Starkenmann C. Quantitative headspace analysis of selected odorants from latrines in Africa and India. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:6134-6140. [PMID: 25946964 DOI: 10.1021/acs.est.5b00692] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This analytical investigation focuses on the quantification of odorant molecules in the headspace of latrines. Hydrogen sulfide and methyl mercaptan were derivatized under a more stable N-ethyl maleimide conjugate. Since the amount of odorant molecules is very low in the gas phase, we developed a method that had two steps of concentration. The first step consisted of the accumulation of volatiles in buffered water by bubbling 350 L of air in a bottle. The second step consisted of loading the water on a 1 g solid-phase extraction cartridge, shipping it to our laboratories, and desorbing with Et2O, which achieved a total concentration factor of 3.5 × 10(6). The acidification of the water phase gave us access to the acids, and an additional bottle containing an acidic ion-exchange resin gave us access to trimethyl amine. The limits of quantification in the gas phase were 8.7 × 10(-4) μg/L air for hydrogen sulfide, 1 × 10(-4) μg/L air for methyl mercaptan, 1 × 10(-3) μg/L air for butyric acid, 1 × 10(-4) μg/L air for p-cresol, 1 × 10(-5) μg/L air for indole, and 1 × 10(-5) μg/L air for skatole. The system was calibrated by using olfactometers, which can deliver a precisely known quantity of volatiles into the air. We were able to quantify all compounds near their odor detection thresholds (ODTs). All ODTs were measured in our laboratory with the same olfactometry method. This allowed accurate and comparable ODT values for malodorant compounds from toilets.
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Sorensen JPR, Lapworth DJ, Nkhuwa DCW, Stuart ME, Gooddy DC, Bell RA, Chirwa M, Kabika J, Liemisa M, Chibesa M, Pedley S. Emerging contaminants in urban groundwater sources in Africa. WATER RESEARCH 2015; 72:51-63. [PMID: 25172215 DOI: 10.1016/j.watres.2014.08.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/11/2014] [Accepted: 08/01/2014] [Indexed: 05/05/2023]
Abstract
The occurrence of emerging organic contaminants within the aquatic environment in Africa is currently unknown. This study provides early insights by characterising a broad range of emerging organic contaminants (n > 1000) in groundwater sources in Kabwe, Zambia. Groundwater samples were obtained during both the dry and wet seasons from a selection of deep boreholes and shallow wells completed within the bedrock and overlying superficial aquifers, respectively. Groundwater sources were distributed across the city to encompass peri-urban, lower cost housing, higher cost housing, and industrial land uses. The insect repellent DEET was ubiquitous within groundwater at concentrations up to 1.8 μg/L. Other compounds (n = 26) were detected in less than 15% of the sources and included the bactericide triclosan (up to 0.03 μg/L), chlorination by-products - trihalomethanes (up to 50 μg/L), and the surfactant 2,4,7,9-tetramethyl-5-decyne-4,7-diol (up to 0.6 μg/L). Emerging contaminants were most prevalent in shallow wells sited in low cost housing areas. This is attributed to localised vulnerability associated with inadequate well protection, sanitation, and household waste disposal. The five-fold increase in median DEET concentration following the onset of the seasonal rains highlights that more mobile compounds can rapidly migrate from the surface to the aquifer suggesting the aquifer is more vulnerable than previously considered. Furthermore it suggests DEET is potentially useful as a wastewater tracer in Africa. There was a general absence of personal care products, life-style compounds, and pharmaceuticals which are commonly detected in the aquatic environment in the developed world. This perhaps reflects some degree of attenuation within the subsurface, but could also be a result of the current limited use of products containing emerging contaminants by locals due to unaffordability and unavailability. As development and population increases in Africa, it is likely a wider-range of emerging contaminants will be released into the environment.
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Affiliation(s)
- J P R Sorensen
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK.
| | - D J Lapworth
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - D C W Nkhuwa
- University of Zambia, Great East Road Campus, P.O. Box 32379, Lusaka, Zambia
| | - M E Stuart
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - D C Gooddy
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - R A Bell
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - M Chirwa
- University of Zambia, Great East Road Campus, P.O. Box 32379, Lusaka, Zambia
| | - J Kabika
- University of Zambia, Great East Road Campus, P.O. Box 32379, Lusaka, Zambia
| | - M Liemisa
- Lukanga Water and Sewerage Company Limited, P.O. Box 81745, Kabwe, Zambia
| | - M Chibesa
- Lukanga Water and Sewerage Company Limited, P.O. Box 81745, Kabwe, Zambia
| | - S Pedley
- Robens Centre for Public and Environmental Health, University of Surrey, Guildford GU2 7XH, UK
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Sharma N, Doerner KC, Alok PC, Choudhary M. Skatole remediation potential of Rhodopseudomonas palustris WKU-KDNS3 isolated from an animal waste lagoon. Lett Appl Microbiol 2015; 60:298-306. [PMID: 25495851 DOI: 10.1111/lam.12379] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 11/25/2014] [Accepted: 12/01/2014] [Indexed: 11/29/2022]
Abstract
UNLABELLED Skatole (3MI) is a major contributor to the malodor emission resulting from ruminant and human faeces. The remediation of malodor has been a major challenge for the animal production industry. In this investigation, a pure culture of purple nonsulphur bacterium capable of degrading 3MI was isolated from a swine waste lagoon using an enrichment technique and identified as Rhodopseudomonas palustris WKU-KDNS3 based on 16S rRNA analysis and UV-visible spectroscopy. The cell structure of the organism was confirmed by transmission electron microscopy. Growth profile and 3MI removal pattern were determined using media supplemented with 0.1 μmol 3MI under short-term and long-term aerobic growth conditions. The organism grew on 3MI media as luxuriantly as control (without 3MI). Growth of R. palustris WKU-KDNS3 demonstrated a significant reduction in the level of 3MI (>48%) in 72 h. The level of 3MI dropped further by >93% of the total concentration present in the medium in 21 days. Skatole remediation potential of R. palustris WKU-KDNS3 can be judiciously utilized in various animal and industrial waste treatment systems. SIGNIFICANCE AND IMPACT OF THE STUDY Odour pollution is a serious environmental problem, particularly in the agriculture industry, and technologies based on chemical remediation are less effective and cost prohibitive. In this study, the newly isolated Rhodopseudomonas palustris strain WKU-KDNS3 causes biodegradation of 3-methylindole (skatole), which is one of the most offensive odorants present in wastewater lagoons. Aerobic degradation of this widely spread aromatic pollutant by Rhodopseudomonas strain is a significant finding that enhances the present understanding about metabolic versatility of purple photosynthetic nonsulphur bacteria. The remediation potential of R. palustris WKU-KDNS3 can also be gainfully utilized in various waste treatment facilities.
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Affiliation(s)
- N Sharma
- Department of Biology, Western Kentucky University, Bowling Green, KY, USA
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Gas analyzer for continuous monitoring of trace level methanethiol by microchannel collection and fluorescence detection. Anal Chim Acta 2014; 841:1-9. [PMID: 25109855 DOI: 10.1016/j.aca.2014.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 06/09/2014] [Accepted: 06/12/2014] [Indexed: 11/23/2022]
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Reid MC, Guan K, Wagner F, Mauzerall DL. Global methane emissions from pit latrines. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:8727-8734. [PMID: 24999745 DOI: 10.1021/es501549h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Pit latrines are an important form of decentralized wastewater management, providing hygienic and low-cost sanitation for approximately one-quarter of the global population. Latrines are also major sources of the greenhouse gas methane (CH4) from the anaerobic decomposition of organic matter in pits. In this study, we develop a spatially explicit approach to account for local hydrological control over the anaerobic condition of latrines and use this analysis to derive a set of country-specific emissions factors and to estimate global pit latrine CH4 emissions. Between 2000 and 2015 we project global emissions to fall from 5.2 to 3.8 Tg y(-1), or from ∼ 2% to ∼ 1% of global anthropogenic CH4 emissions, due largely to urbanization in China. Two and a half billion people still lack improved sanitation services, however, and progress toward universal access to improved sanitation will likely drive future growth in pit latrine emissions. We discuss modeling results in the context of sustainable water, sanitation, and hygiene development and consider appropriate technologies to ensure hygienic sanitation while limiting CH4 emissions. We show that low-CH4 on-site alternatives like composting toilets may be price competitive with other CH4 mitigation measures in organic waste sectors, with marginal abatement costs ranging from 57 to 944 $/ton carbon dioxide equivalents (CO2e) in Africa and 46 to 97 $/ton CO2e in Asia.
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Affiliation(s)
- Matthew C Reid
- Department of Civil and Environmental Engineering and ‡Woodrow Wilson School of Public and International Affairs, Princeton University , Princeton, New Jersey 08544, United States
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