Science topic

Odors - Science topic

The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)
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I am trying to write a systematic review on factors that affect human's discrimination ability of mixed odors. The data obtained from these types of studies will contain categorical data as observations like yes/no. Can I conduct a meta-analysis for such type of data?
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Yes! But, it must always follow the guidelines for doing systematic reviews. So, look for the guidelines and study them to understand what you need to include or exclude. Or, to understand how you should handle such a study. Thank you!
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As I understood, enzymes can accelerate the conversion of organic waste into CO2 and water, while preventing unwanted reactions leading to foul odor. Please let me know if this is incorrect.
Which waste management industries typically use enzyme-based odor control solutions available in the market for bulk applications?
Note: I am not talking about 'misting systems, which act only on the surrounding air and temporarily mask the odor. Is there a way to stop the odor generation process at the source (solid waste)?
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Dear Researcher.
Adding to information on odour removal or neutralisation is best done
by having bio activated carbon in flakes form. Pl assess if possible..
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I´m currently in an investigation related to the olfatory system and the possible conexion with empathy in people, so I need a relaible instrument to make the olfatory tests
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Hi,
UPSIT smell test. Follow the link below.
There are some articles on smell tests .Also, look into the cross-references:
Rezende GL, Sarmet M, Sousa GE, Krier FC, Parreira DR, Kuckelhaus SA. Olfactory Performance among Hospital Residents. Int Arch Otorhinolaryngol. 2021;26(1):e032-e037. Published 2021 Feb 19. doi:10.1055/s-0040-1719122
Joseph T, Auger SD, Peress L, et al. Screening performance of abbreviated versions of the UPSIT smell test. J Neurol. 2019;266(8):1897-1906. doi:10.1007/s00415-019-09340-x
Keck JW, Bush M, Razick R, Mohammadie S, Musalia J, Hamm J. Performance of formal smell testing and symptom screening for identifying SARS-CoV-2 infection. PLoS One. 2022;17(4):e0266912. Published 2022 Apr 12. doi:10.1371/journal.pone.0266912
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In the field of environmental protection and conversion of waste into compost, I am looking for a method that can reduce or eliminate leachate and eliminate its odor so that it can be easily used in parks and green spaces.
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Dear Mohammad,
The most common cause of bad smell during composting is existence of anaerobic condition. This situation is generally created by the presence of excess moisture. In your case, it is indicated by the occurrence of high amount of leachate.Some of our friends have already suggested several useful measures to overcome the problem. Addition of water absorbing materials like dry leaves, straws etc is likely to give better result. However, if your waste materials contain too high amount of water, you need to reduce them before using for composting.In addition, frequent turning of the substrate helps to add oxygen in the materials. These are a few simple and easily adoptale techniques to reduce the leachate amount and foul odor.
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The true choice olfactometer is the first olfactometer that does not present a gradient of odors to the subject. The test subject is always in a clean air flow until it reaches the choice area. This allows testing of repellents and push pull systems (repellents and attractants at the same time) in the laboratory. It is a development from ingenious Jim Estaver from Sigma Scientific LLC. We have recently started working with our new true choice olfactometer. Who has already gained experience with the system or has already published something? I would be happy if we could share our experiences here.
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Dear Paul and Warren,
the olfactometer you used in the paper is not exactly the olfactometer I mentioned in my question. You used a traditional dynamic 4-(or 2-)chamber olfactometer. I asked for the true-choice olfactometer, which is a new development (2020) by Jim Estaver.
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A few friends and I wrote a paper for the International Journal of Life Cycle Assessment suggesting a list of characterisation factors for odorants. This was an upgrade on the old Heijungs critical volumes approach, because it takes the persistence of odours into account. Our proposal has now been adopted by the Gabi LCA software, so anyone who did the upgrade to version 8.5 can now do rapid assessment of odour impacts without a lot of data entry. (For more info on the method: Peters et al Int J LCA 19(11)1891-1900)
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Thanks for the link Shuraik!
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For more context; I am working on an LCA of an innovative pig stable. According to the technology provider, the benefits of using this stable result in reduced "malodorous air" which is good for pig health. Peters et al., 2014 presented a framework to improve odour assessment in LCAs, but I was wondering if there are standardized LCIA methods for odour developed thereafter.
Thank you!
Peters, G.M., Murphy, K.R., Adamsen, A.P.S. et al. Improving odour assessment in LCA—the odour footprint. Int J Life Cycle Assess 19, 1891–1900 (2014). https://doi.org/10.1007/s11367-014-0782-6
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Dear Rahul Ravi ,
I would like to suggest you this resource:
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Hello, I work with ethylenediamine and I wash carefully my vials with water under a hood and I put them after in an oven, but it seems that there is still a characteristic smell and I worry if it is any dangerous for health over the time.. Have you any idea?
Thank you very much.
Best regards
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In part, the exposure guidelines address amount and length of exposure. In the US, exposure limits are generally identified as 10 ppm on average over an 8 hour period. While that may not be the safest level of exposure, you are not being exposure to a concentrated form of the chemical. In the end, if you really want to know if you are safe, you need an air level measurement to assess the ppm exposure level.
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By using boiling and roasting test,
Artificial nose
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I´m working with olfactometry and came across some strange odour threshold results.
All four members in a dynamic olfactometer panel smelled a sample consistently with high and low concentrations but not the concentrations in the mid range. Concentrations ranging from approx. 15 000 to 4 000 x dilution were detected as well as 500 to 250 x dilutions, but two steps in the middle (dilution factors approx. 2 000 and 1 000) were undetected throughout three panel sequences with same four panel members. The noses of trained panel were successfully calibrated with n-butanol shortly before the panel in question. Ascending concentration sequence and yes/no method was used. Enclosed is an example of a panel sequence result.
The sample contained for example bitumen and other (unknown) compounds related to asphalt manufacturing. However, samples from the same (and other corresponding) process containing similar compounds, or actually any other samples I can remember, have not behaved this way ever before, that being said with adequate control database.
I am aware that there are such compounds that behave this way, for example methylmerkaptan and thioacetone. My question is what compounds are "unlinearly" odorous in a described manner; odorous only in certain concentrations, but cannot be detected with human nose in certain others?
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It has been recently calibrated and all other results have been completely normal.
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For our database of odor responses (http://neuro.uni.kn/DoOR) I received data that uses the different chemical identifiers named above. I am looking for an easy way to look up/convert these into one another.
I already found the ChemCell macro (http://depth-first.com/articles/2010/11/01/chemcell-easily-convert-names-and-cas-numbers-to-chemical-structures-in-excel/) but would be happy to have some R code doing the work.
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Hi Marco,
I got it. Thanks.
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I am looking for wind tunnel olfactometer to observe the behaviour of insects towards odour source? Please guide me. Thanks.
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Thanks Kari and Rani for your response. I will check and will discuss, if required.
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I would like to study the impact of the diet on fecal odor in Beagles.
But I don't really sure that phenol, ammoniac, indole are the only species responsible of fecal odor. Moreover it is difficult to assay them because they are not stable. What is the best way.
Thank for your help
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I do agree with the previous two answers. Skatole is the major element responsible for the fecal odor, in addition to other minor gases and bacterial metabolites.
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I'm confused with the measurement of odor intensity introduced in VDI 3882 Part-1. Should dilution series be presented? Could the panellist just smell the undiluted sample and classify the odor impression with number 0~6? And what does "the series of measurements shall be repeated (at least twice; 3 runs)" mean?
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In my understanding, it might be hard to specify the intensity level by sniffing the sample directly without comparing. Presenting panelists with a series of dynamic dilution steps may help them select a reasonable scale value for each dilution step. It is also possible to relate intensity values with odor concentrations for each panelist. The relationship curve can also be used to check if a panelist's intensity value selection is reasonable for a single dilution step in a series of dilution steps.
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Are there documented examples in which the odor plume emanating from an island (at sea) would follow two different paths, one by water and one by air? In other words, the odor emanating from an island would follow a given direction in the water (because the prevailing current goes in that direction), but such odor would follow a different path by air, because the prevailing winds follow a different direction.
This possibility may be relevant for organisms that use the odor of landmasses for guidance, e.g., sea turtles.
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Hi. I hope the following handbook (softcopy) could help you:
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My name is Li Lin, I am a student of SGH Warsaw School of Economics, majoring in International Business. I would like to thank you for kindly participating in the survey. The obtained results will be used for the purposes of my master's thesis “The Impact of Scents on Impulsive Buying Behaviour. The Example of Poland.” It takes less than 3 minutes : )
Wish you all have a lovely Friday and sunny weekend!
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One of the primary purposes of creating product displays is to engage customers through visual merchandising. By creating themed displays, you anticipate what might attract certain types of buyers and help point them in the right direction
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Basically, I have formed a blend of synthetic nitrile latex and added tri ethylene glycol ester as Plasticizer, however the odor makes the conditions undesired at the work place. Hence I am trying to such a reagent or any other solution to minimise the odor.
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Dear Syed Muhammad Moazzam Ali, the solution is to work under a hood or well ventilation chamber with the use of masks. My Regards
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Dear Connections,
I have a sample which has a very strong odor of Kerosene, So I wanna cover this awful odor.
I made a trial using some esters but didn't work.
If there any suggestions, I'll be grateful
Thanks in advance!
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You may try to use coffee grounds, bake soda, white vinegar to mask the smell.
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I'm involved in a study of odor control technologies for municipal wastewater treatment plant. One of the control options involves a chemical 2-stage (acid/alkaline) packed bed scrubber. The alkaline stage uses sodium hypochlorite as an oxidant. The particular application involves emissions from the solids management activities at the treatment plant. That is the odorous air sources do not include the liquid treatment parts of the plat. The plant does not have anaerobid digesters. The odorous air results from management of screenings and processing of screenings and sludge from primary and secondary clarifiers.
I know that the use of hypochlorous acid in disnfection of water and wastewater leads to the formation of various halogenated disinfection byproducts that have toxicological concerns. This gives me concern about the use of hypochlorous acid in the odor control scrubber.
There is technical data indicating the efficiency of HOCl in oxidixing reduced odor compounds. But I have not been able to find any information regarding the presence or absence of byproducts of this oxidation process, particularly species such as haloacetics, halates, halites, and haloforms.
Is anybody aware of any information on this topic?
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Dear Stephen Nelson many thanks for raising this very interesting technical question. In fact, compounds like HOCl and ClO2 are strong oxidizing agents and highly reactive compounds. Thus it is not surprising that in contact with organic material volatile chlorinated organic compounds can be formed.
For more detailed information on this topic please have a look at the following relevant article
Wet Scrubber Analysis of Volatile Organic Compound Removal in the Rendering Industry
This article is freely available as public full text on ResearchGate. In the course of this study the chlorinated hydrocarbon derivative methanesulfonyl chloride has been identified in the outlet of a high-intensity wet scrubber, and various volatile organic compounds (VOCs) as well as chlorinated compounds have been identified in the scrubbing solution.
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I am looking for the best solution for septage odor control in a pretreatment system that designed for septage before discharge to head of municipal wastewater treatment plant. This pretreatment system include an underground reservation tank for septage and then ABR and equalization tank. If there is any exoeriences to odor control for this condition, please participate in this discussion.
Best regards
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We are need a cleaning products control bacteria, fungi, and mold which can cause stains, odors or surface damage, through a physical mode of action that neutralizes microbes that come in contact with treated surfaces. and create a durable coating on a surface for extended periods of time.
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It may depends on need based and environment will determine the type of disinfectants. In home maintenance the natural / herbal based cleaning is good than chemical products. Unknowingly the chemical products we may inhale /ingest - it gradually affects the health .
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Applying simulated Environmental Modeling results together with operational information:
Dustfall monitoring programmes
Leak detection and repair programmes
Odour Management Plans
Fugitive Management Plans
Pollution Prevention Plans
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Using satellites to extract air quality variables and track the changes, trend and dynamic will help in air quality management plan.
Best wishes.
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We need to remove the odor in a 1:1 blended mixture of pyridine and 2-chloropyridine (calcium tungstate). Some of the other components are Calcium at 24%, Carbon at 4.25% Phosphorous at 2.25% and Tungsten at 33%. The mixture has 46% moisture. We would like to leave some moisture in the material after calcination but definitely need the odor eliminated. Any assistance would be greatly appreciated.
Thank you,
JE
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Briefly, evaporate pyridine as much as you can, wash the organic layer with mild acidic aq. sol'n, then wash with sat. aq. sodium bicarbonate, and water or brine consequently unless your target product includes amino group. https://www.researchgate.net/post/What_is_best_method_to_remove_pyridine_from_a_reaction_mixture
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I remember a paper studied the effects of gender of handler on animal (mouse?) showing that male handler has more negative effects on animal (for example, causing animal anxious) compared to female technician. The animal can distinguish man and woman by their odor. This phenomenon disappears if the handler is well wrapped in gown to prevent odor from escaping it.
This paper seems published in Nature Methods. Unfortunately, I cannot find this paper now. Do you happen to know this paper? Thank you!
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I found that paper and I'd like to share with you that the original paper was published in Nature Methods. 2014 Jun;11(6):629-32 (PMID: 24776635). The comments were published in same issue of the journal [Nature Methods. 2014 Jun;11(6):623-4] ( PMID: 24874574).
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1. Single pit technology:
Advantages: Simple technology, low (but variable) capital cost
Disadvantages: Flies and odors are normally noticeable, low reduction of pathogens with possible contamination of groundwater, costs to empty may be significant compared to capital cost, and sludge requires secondary treatment and/or appropriate discharge
2. Double pit technology:
Advantages: longer life than the single pit, easier emptying, significant reduction in pathogens, flies and odors significantly reduced, and product can be used as soil conditioner
Disadvantages: Manual removal of humans is required, possible contamination of groundwater, higher capital costs than single pit but reduced operation costs if self-emptied.
3.Anaerobic technologies:
3.1 Septic Tank
3.2 Anaerobic Baffled reactor (ABR)
3.3 Biogas reactor
4. Aerobic technologies:
4.1 Free-water Surface Constructed Wetland
4.2 Horizontal Subsurface Flow Constructed Wetland
4.3 Vertical Flow constructed Wetland
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DEWATS Plants...agree with Ajit Seshadri
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Hi everyone, One type of Natural gas odorization system is drip odorizer. https://cdn.intechopen.com/pdfs/11460.pdf Where can I find more information about mechanism of Drip odorizers? How do they work? How does odorant drop in a line with pressure of 60 or 250 psi without any pump?  Thanks in advance for your attention and for answering the above questions.
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Thanks again John Machell
One type of drip odorizer may be similar to what you said. But I think in odorizer mentioned in my question there is not a chamber. My friend manufactured and used this type of odorizer that is consist of a tank and a needle valve without middle chamber! But he doesn't know how his odorizer works!
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Electronic nose uses digital sensors which mimic human nose to identify a particular odour. In what way it finds application in plant pathology. If it can detect odour caused by rotting of a plant part due to a disease how the electronic nose is able to distinguish between odours caused by different plant pathogens
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Read this article Electronic nose classification and differentiation of bacterial foodborne pathogens based on support vector machine optimized with particle swarm optimization algorithm
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I am a psychology researcher and am interested in purchasing an olfactometer for delivering odor stimuli during experiments with human.
Could you suggest some vendors (doesn't matter in which country) that sell olfactometers?
Thank you!
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There is also Burghart Messtechnik (https://www.burghart-mt.de/en/medical-devices/olfactometry-and-gustometry.html). The olfactometers here are a bit expensive, but can deliver odours in heated and humidified air.
Best, Alexander
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what are the different chemicals added in the sludge treatment to suppress the odour generated from H2S? I am also looking for the specific reference on lime.
Thanks in advance for your time and reply,
Veena.
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It's a pleasure Veena Bobade. I wish you excellent work, very good results and above all very good publications. Good luck and good luck.
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I'm formulating a natural deodorant and found that the 5% concentration of NaHCO3, it works great for inhibiting the scent of sweat, but about 15% of subjects get a rash with chronic usage, ie daily for weeks.
Would 1% still have an anti-microbial effect to prevent odor?
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could be written on canes as ingredients?
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I often see very high pH values (often over 9) at Lake Renvick at Icelandic State Park (North Dakota, USA). Is there a correlation between algae growth and pH
Part 5, July 2, 2019 (Lake Renwick at Icelandic State Park) - https://youtu.be/U9MS7mYgOPg
Also this is another reference:
"Water Quality
Water of Beira Lake is polluted, from which it gets a bad odour and green colour. But contray to the canal system of Colombo, the lake contains water with a very alkaline pH value got by primary production and continuous bloom. In August it gets its maximum value, but becomes more neutral from top to bottom, pH value decreasing from 10 to 8. Lake water never gets acidic pH.[3]
Conductivity of the water retains fairly stable between 250 μS/cm and 300 μS/cm, with a slight increase from May to August.[3]
Full temperature ranges between 29.3 and 35.4 °C. Average temperature is 31 °C and August is the warmest month. The temperature decreases rapidly 2 or 3 °C, from the surface to 60-100 cm in-depth and remains stable after that.[3]
Dissolved Oxygen generally follows the same trend than temperature in August. Likewise the thermocline, an oxycline appears exclusively in August. Below 1 meter depth, DO is stable at 7 mg/l during May, June and July. Though it is decreased during August from 13 mg/l to 6 mg/l, shallow depth allows preserving a sufficient level of oxygen. But it would be more stressful during dry season.[3]
Salinity is very stable (around 0.12 g/l) over time and along the water column."
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In algae blooming water, the pH may vary during day and night time. The difference may be around 2 (from 7+_ to 9+_) because of CO2 and oxygen content change in water.
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Water treatment plant systems (WTPS) to supply water need to amount of water inlet. Based on this, the beat water resources to supply is the Lake or Reservoir. Sometimes in spring and summer after increase of water temperature and nutrient Harmful Algae Bloom occurs and high volume of algae inter to the WTPS and cussed to taste and odor and sometimes toxins in drinking water.
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A simple screening could be done to remove.
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I ran an experiment to evaluate fly attraction to a number of bacterial cultures (n=50). Briefly what I did is: 20 male flies were exposed to two odour sources at a time-one containing a bacterial culture and other containing control; number of flies that showed attraction to the culture and control were counted after a certain time. The test was repeated 10 times for one bacterium. Similarly female flies attraction was also tested for the same bacterium. Thus for one bacterium I had 20 replicates in total (10 for males and 10 for females). Now, I want to analyse the data to evaluate which bacterium showed attraction at what extent and how they differ gender-wise. I am not certainly sure which statistical test will be suitable for this purpose. I was thinking about Kruskal-Wallis test but not sure if its the correct one. I am using SPSS. Could you please suggest which statistical test will be suitable to analyze this data set?
Thanks in advance.
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You could use the chi-square test. For one (each?) bacterium, the test was repeated 10 times; so, you could count the total number of flies who were attracted and not attracted, and this separately for male and female flies.
This could, for example, yield this crosstable (with the total counts in the cells):
----------Male----------Female
Yes--- 80--------------60
No-----20--------------40
In this example the chi-square is significant:
X-squared = 8.5952, df = 1, p-value = 0.00337
In this example the male flies were significantly more attracted than the females flies. With these residuals:
residuals male female yes 1.195 -1.195 no -1.826 1.826
See also the "jpeg" for these residuals.
I added the R script. You can run R code online:
For the chi-square using SPSS:
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To offer a suitable method for minimizing nuisance and pungent odors released from treatment units in a wastewater treatment plant, I should firstly evaluate the current condition of the plant regarding odor emission. For this purpose, I think I must measure the main volatile compounds present in odorous emissions of the WWTP. I reviewed the literature and I figured out that Hydrogen sulfide, Methyl Mercaptan, and Ammonia encompass the major part of the odor in a WWTP. However, I need your technical assistant to pick up there or four main compounds which I have to measure in the units of WWTP. Thank you for your valuable comments.
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Odor and VOCs from WWTP are related to the type of compounds in the influent. Generally, in sewage treatment plants, hydrogen sulfide and ammonia are known as typical odor materials. In addition to these two odorous substances, odorous substances that need to be investigated further need to be analyzed for acetaldehyde and trimethylamine.
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Hi!
I am trying to find out the complete genetic sequences of Odorant Binding Protein and Heat Shock Protein for an insect on NCBI nucleotide database, but I always end up with their partial mRNA complete codon sequences which contain Thymine in place of Uracil. I also tried searching for these genes in Gene database of NCBI but couldn't succeed. Can anyone please explain the reason behind the presence of T instead of U in mRNA? Also, can anyone provide an alternate way through which I can find the complete genetic sequences of these genes?
Thanking in anticipation.
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  1. If you are interested in the gene of any protein of interest, look for the protein and get out the nucleotide co-ordinates from the "/coded_by=" flag
  2. If there are Ts in the sequence, it is not the mRNA sequence. It is coding gene sequence.
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Odor can be measured with the help of field olfactometer in terms of OU/m3. But the toxicity level or the presence of pollutants has nothing to do with the odor in most of the cases, except the gaseous pollutants with an obnoxious smell and vice versa. Despite the real fact, as per human psychology, we presume if there is an odor there must be toxication of the ambient air which is completely illogical. Please share your views on it and what's the local believe in your area/ country. Also, inform others about it to avoid the myth.
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Thank you Atun Roychoudhury for this valuable information
Best Regards
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Currently, I'm working on a project for odor removal from medical-grade ethanol for an industrial ethanol plant. The main product of the plant, i.e., 96% ethanol, suffers from an unpleasant smell. My question is that which components are responsible for this bad smell? Is is possible to remove them by conventional distillation?
I know that there are some metabolites from fermentation process that are responsible for this smell.
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Marzieh Shafiei The composition of broth mainly depends on feedstock nature and operating conditions.In the case of using glucose as substrate, glycerol, Higher alcohols, and some organic acids like acetic acid , succinic acid are the major byproducts. You should identify these components and check its fusion temperature if it is below 78 c , will surely be found in the distillate during a conventional distillation.
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Reclaimed / re-refined used engine oil gives off a very bitter smell ! If the oil is treated with base the smell gets worse, treatment with acids produces a different bad odour albeit a little sweet !
What causes this ? Are there and solutions for this ?
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You are quite welcome!
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Need brief answers
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Follow
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What is your initial assessment before performing laboratory tests? In the flood season, the color of river water is blackened, noting that there is no oil pollution and there is no undesirable odor in the water.
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In the Amazon Basin some 14% of the water flow is black Rio Negro.
This color as alluded to by a previous contributor this darkness is associated with tannins which are the constitutents that color tea.
The dark colors can also be contributed by erosion this is not the case with Rio Negro or the black river of the Amazon Basin however which are some of the cleanest fresh water rivers globally.
Humic acid are black or dark brown and fluvic acids are golden. Solublized old clays will give a red or yellow appearance also.
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Hi Everyone. I wanted to use activated charcoal for an exhaust system on a waste storage room to remove odor. I wanted to know an estimated life span of an activated charcoal. Also would be nice to know an easy way of reactivating for reuse. Thanks
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Once used the activated charcoal loses it's adsorption capacity. The type of Woody materials used to prepare charcoal governs it's porosity and adsorption capacity, and so does LifeSpan. Activated carbon, having gone through the process of filtration, eventually loses its adsorption efficiency. This happens when the pore structure of the carbon is too full to adsorb any more impurities. At this point, the carbon is typically deemed spent, and would need replacing. The spent carbon is typically discarded,” explains Devendra.
But, there is another option: Reactivation. Reactivation uses a high-temperature thermal process that destroys the adsorbed organic compounds and restores the adsorptive capacity of the carbon, according to Adomaitis. Up to 95 percent of the virgin activated carbon can be recovered and blended with new virgin carbon.
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Propane cylinders are regularly purged with methanol to remove any excess moisture. I looking for a method of methanol removal from the cylinder after the moisture is removed as it is adding an odor and decreasing LPG purity.
Does anyone have a method or an idea for a method to remove methanol from these cylinders?
Thank you,
Mariah
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LPG is commonly used as a fuel and is not a pure chemical compound. What's the problem with an odor and purity? Natural gas is odorless and for safety reason mercaptan is always added. Traces of Methanol is odorless. Methanol is cheap but toxic. What about ethanol?
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I would like to identify the compounds with an unpleasant odor arising in the wastewater treatment plant and sorting of garbage
business. I assume that it will be mainly the sulfur compounds, volatile amines and hydrogen sulfide. Chemically, the concentration of these compounds is very high, therefore the most important thing is to take and concentrate the sample. I would like to make an HPLC determination.Is this possible? Please advise a literature with practical procedures. Thank you very much in advance.
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I think HPLC is unnecessary in this area
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How can I achieve the appetitive training at low cost. or can i make an elevator like structure with things easily found in the lab?
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Dear Daniela María Ramírez!
With my pleasure.
Please open an Attachment.
Vladimir
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Good morning,
I need to know where I can buy olfactometers, whether in y shape or four ways for entomological use, the idea is that in the odor chamber small samples can be disposed (essential oils)
Thanks,
Victor
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Hi Victor,
I agree with Charles comment.
The olfactometer consists of two material sets, 1. Behavior response arena (this varied according to insect order/or family) and tubing system, and 2. Air delivery system & flow meter. The first set you can fabricated at your labo but also you can buy it with Air delivery system & flow meter from here for example http://www.calservethailand.com/products_ars_olfactometer.html or from here http://www.sigmascientificllc.com/4-port1-vacuum-air-delivery-system
Best wishes,
Ammar
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Our 100 cmd AOP facility has an influent flow rate of 0.53 cubic meter per minute. The water from lift station of the septic tank passes through three reactor tanks (1.5 cubic meter). The water then passes through Activated carbon and multimedia filters and UV Light. Unfortunately, the effluent is physically in poor quality since it appears yellow and has a strong odor that resembles ammonia.
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Thank you so much Mr Henrik Rasmus Andersen and Ali Haseli . I will consider all your recommendation in this matter.
You are actually correct Amila Abeynayaka . We have recently installed a water valve to control the flow rate. Thank you as well.
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I'm looking for practical methods to reuse dyeing wastewater up to 90% and good COD/BOD , TSS and odor removal. I'll appreciate if someone helps.
best regards
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Dear Hamed
Membrane methods such as nano filtration and reverse osmosis are suitable.
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I tried distilling vanilla beans (hydrodistillation) but did not get any oil after 4 hours. However, the hydrosol had the same odor of vanilla. Is there a way to get the vanilla oil? Thank you!
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Hello,
there are some articles about the chemical nature of the characteristic "odor of rain" when rain begins to fall.
Always some chemicals in the soil or surface coming from plants are mentioned as the reason.
I was on a ship crossing the atlantic. 1000 km away from any coast it started raining. And I immediately smelled the typical odor of rain (it was a polymer covered floor).
Has anybody deeper knowledge??
Regards
Lothar
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Excellent question! We hypothesized that Petrichor is an indicator of soil health. Rain displaces gases from soil pores. These gases can be a carrier of useful information of the types of biochemical processes in the soil. Also, rain (humidity) improves human nose sensitivity. Interesting experience of smelling a land from 1000 km - could this be a long range transport of gases/aerosols/fine particles carrying the signature smell associated with soil?
Jacek
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Aldehydes and ketones are responsible for odourization of the edible oil. i am looking into deep that how can we replace chemical process with enzymatic process.
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i have done lab studies with enzymses but coudnt get results.
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I'm producing value added products from sea cucumbers. The major problem I'm facing is the peculiar odor that can't be accepted sometimes. If anyone applied any methods to remove bad odor from any type of meat please try to help me. I can make trails for my case.
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If you have no clue what it is I recommend head space analysis. After you have collected the volatiles you inject the concentrate into a GC (GC MS) to identify the chemical and based on that you can either remove or mask it.
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I am using 2-mercaptoethanol and it smells bad. Is there a way to decrease the smell of the solution after adding mercaptoethanol?
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Jacek A Koziel
Yes sir, I am following all the precautions.
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Hi please give me any idea about studies about bacteria that does not apply on human and all vertebrates. This is a school science experiment/research.
Ta!
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I have cleaned my CO2 incubator. After the few culture, I have noticed that bad odor was generated from my incubator and cells were died. Then, I cleaned by incubator again and thawed new vial of cells. In addition, I used fresh media before putting my cells on the incubator. But I have noticed same things that happened before. To my best knowledge, CO2 level, temperature and RH pan are working properly. I am eagerly waiting for your valuable suggestion. Thanks
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Dr. Jakaria,
You mentioned that there is a bad smell in the incubator. What kind of smell is it?
1. Mildew or mold? Make sure*** the incubator door seals and chamber walls around the inside of the door opening are clean of black mold. Make sure that the condensation/drip gutter on the inside of the door is clean... inside the gutter and underneath too.
2. Fermenting yeast? Yeast in chamber. Is anyone in the same lab or a neighboring lab growing yeast?
3..Foul/ sewage? E. coli or bacterial problem. Anybody nearby growing bacterial cultures?
4. Chemical odor? There should be no chemical odor inside incubator. If there is, identify the odor and either clean the incubator thoroughly or find and remove the source.
If this incubator was ever used to grow yeast or bacteria, then it needs a VERY thorough cleaning. If this is a shared incubator and another investigator is growing yeast or bacterial cultures in this incubator, then that is the problem. As soon as you see contamination in any culture in the incubator, it is best to immediately scrub out the incubator and discard ALL cultures, not just obviously contaminated cultures. As soon as you notice contamination problems in an incubator, you must immediately mount a very vigorous attack on the problem and maintain precautions in future or the problem will recur.
You mentioned a HEPA filter. Are there syringe type filters connected by tubing on the CO2 lines? Check the fan that circulates air inside the incubator for dirt or other foreign matter and clean. Replace any syringe type or other filters if possible, flush or replace tubing.
You did not mention how you are cleaning the interior of the incubator. We find the best thing to use is 70% ethanol with a few drops of detergent added. After cleaning, allow the incubator door to remain open for an hour or so to disperse residual fumes. Bleach or other cleaning agents may leave chemical residues that can damage your cultures.
What kind of culture vessels are you using? We find that the best types of vessels to use for preventing contamination problems are closed filter top flasks. Petri type culture plates, loosely capped flasks, or multiwell plates are too easily contaminated.
If you continue to have problems, always check your cultures in an inverted scope, even if they are dead, to see if the contamination is or is not present inside of your culture vessels and what kind of contamination is present (bacteria, yeast, other). After examining them, seal them up and discard them. Get them away from the incubator and out of the lab if possible.
Contamination problems in a tissue culture lab can be very frustrating and difficult to resolve. They don’t necessarily start inside incubator, but that’s the best place to begin looking for them. However, they can come from anywhere in the lab. Since contaminated cultures essentially shut down your research effort, it is of prime importance to find the source of the problem, resolve it, and then remain vigilant to prevent recurrence.
Good luck!
RW
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Hello, I am a college student, and this year I am working on the final work on eliminating odor on the sewer network. This is mainly H2S elimination. I would like to ask if you have any products, materials that are capable of removing H2S if these products were recyclable would be great. Thank you for your advice
Bc. Radim Žíla
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Dear Cleveland: I agree with you that field operating conditions are different from theoretical pathways. Many odorous compounds can be produced from wastewater containing mixed contamination like proteins, grease, sugars, starch etc. The odorous compounds produced are beside H2S, ammonium, merkaptans, amines and many more.
The question of Radim Žíla was aimed to H2S elimination. The sources of H2S in wastewater could be various, but commonly the main source is reduced sulfate biologically. The mixture of grease, proteins and other materials are source of odorous compounds too, but H2S forms only small portion.
We solved the problem of H2S production from industrial wastewater from sulfite pulp production in full scale as well as elimination of odorou compounds from waste sewage sludge treatment in wastewater treatmenmt plant using biofilters in full scale operation (35000 m3 of easte air per hour).
Best regards
Vit
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I am running a synthetic step to get Schiff's base today.
Methyl-4-aminosalicylate and benzaldehyde (in 1:1 molar ratio) in presence of 2-3 drops of acetic acid and absolute ethanol as solvent were taken and subjected to reflux for about 4 hrs.
To my surprise, from the reaction mixture, I am getting benzaldehyde odor and there is no precipitate formed from the reaction mixture.
Why the reaction not occured...? Is there any other method to get Schiff's bases of Methyl-4-aminosalicylate...kindly let me know.
Thank you.
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Presumably, the so formed imine is hydrolyzed back to SMs. I would use any dehydrating agent like 3 or 4 A molecular sieves. Or use toluene as the solvent and remove water by azeotropic removal by using Dean-Stark trap.
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How the single transmitter, the same action potential create different perceptions!!!
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I'm sorry I can't offer you the reference to this work, but it emphasizes the role of place in the brain rather than structure of the brain, indicating that cortex is pretty much cortex. If you cut a ferret's auditory nerve early enough in development, the optic nerve will project to the auditory cortex and not to the visual cortex. The ferret still learns to function visually.
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According to the literature, it is known that:
" Diethylamine is a secondary amine with the molecular structure CH3CH2NHCH2CH3. It is a flammable, strongly alkaline liquid. It is miscible with water and ethanol. It is a colorless liquid which often appears brown due to impurities. It is volatile and has a strong unpleasant odor... "
Does anyone know or suggest me any secure method which can be used to dry diethylamine?
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Hi Jean,
You can do distillation and then store it over molecular sieves.
Good Luck
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In conditioned odor aversion(COA) test, Lithium Chloride is used as an emetic agent. How do these agents work?
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Rats and mice do not have vomit center in brain. So, it is not possible to test the drugs on them.
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PP co polymer when molded has an odor. We collected yellow color residue left on the injection mold after molding this COPP. The FTIR search library gives good match but compounds identified are not relevant.
It is some straight chain (fatty ester?)) compound but I cannot identify.
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Hi,
Is it mould release agent residue?
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I want to know if fatty acids cause polyester garments to emit more odor than nylon garments. Has anyone studied this or is there an article that discusses this?
Thanks,
Albert
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Thanks!
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Rice is the most important food crop consumed by man in the world. Because of its
importance, rice breeders have been focused to develop rice quality. Rice flavor quality is a
critical breeding objective in that the quality has a significant impact on consumer preference.
Using a dynamic headspace system with Tenax trap, GC-MS, GC-olfactometry (GC-O), and
multivariate analysis, the aroma chemistry of various rice flavor types (aromatic rices, colored
rices, waxy rices) was analyzed and characterized. First, in black rice with a unique flavor, a total
of 31 odor-active compounds were determined. Among them, 2-acetyl-1-pyrroline (2-AP),
guaiacol, indole, and p-xylene largely influenced the difference the aroma in cooked black rice
and white rice. The former two compounds were key aroma compounds responsible for the
unique character of black rice due to lower odor threshold and unique odor description.
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Dear Sir. Concerning your issue about the preparation of the sample of Rice for GC/MS. Rice grain samples were finely ground then the samples (0.50 g) were separately placed in headspace vial with 1.00 µl of 1000 ppm TMP as the internal standard. Headspace vials were sealed before analysis by HS-GC/NPD and GC/MS. I think the following below links may help you in your analysis:
Thanks
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Asphalt roads can be damaged due to the effects of rainfall due to moisture infiltration, coupled with traffic loads. In areas where asphalt roads are laid especially rural areas where there are animal farms nearby, and cattle drives are common on the roads there is a very high chance that there is dung on the road and it is not cleared for a long time.
What are the effects on the road surface besides causing a runoff with high nutrient content to enter the waterways and causing an odour nuisance?
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laboratory testing is required to investigate the effects. Anyway, chemicals have bad effects on asphalt mixtures. Some chemicals can cause stripping which lead to deterioration.
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Can anyone suggest me how to make T maze in laboratory for Drosophila Olfactory Shock and Odor Assay? I really need it for my research.
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Hi,
This picture is a quick and affordable way to construct this device using just 4 common lab items: 50ml tubes, stryrofoam or plasticine, plastic connectors, and 1000ul tips.
Good luck with your experiments.
Aderemi.
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I once saw an entire field of ripe grain release odorous volatiles together with particulate material at dawn. Pretty amazing viewing.
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I think there does exist some volatile pheromone for synchronised hatching. However, I did observe a similar phenomena in Uzi fly pupa!! When pupae of Uzi fly were placed individually in containesr (pupae were from the same batch of eggs, all environmental conditions were controlled) the time of emergence was different. But, when pupa were placed in groups, they had synchronised emergence! We don't know the cause, however, we predict that there may be a form of communication between the pupae ... one form may be volatile pheromones!! Others can be vibrations or something else. Interesting !
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Can anyone help me to reduce enzyme odour? Is there any process or any additive to reduce enzyme odour?
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Hi there,
Is it actually the enzyme sample itself or the catalyzed reaction which is responsible for the phenomenon?
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Odors emitted from WWTPS contain many types of deleterious gases like H2S, CH4, NH3,....... I want the different processes used to control odor.
Good luck
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hello
biofilter
regards
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odor masking using any chemical without affecting the raw material?
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Dear Colleague - we published work on deodorization of fish bones:
Opalinski S., M. Korczynski, J.A. Koziel, F. Bubel, Z. Dobrzanski. Fish processing by-products: Olfactometric assessment of chemical deodorization. Przemysl Chemiczny (Chemical Industry), 2013, 92(6), 1159-1162.
Jacek Koziel
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Dear All, 
I'm having trouble devising a treatment for ethyl acrylate odor disposal. In my process I use supercritical CO2 for purification, then after some steps, the resulting gaseous CO2 is released, along with some solvents and ethyl acrylate. In this case, would the use of an activated carbon bed work and be safe (ie risk of violent polymerization?) note that the ethyl acrylate quantity is a few ppm.
Thank you
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not sure what your getting at; but do you release the co2 in to air? or do you capture it via other process?
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Customer can not accept caramel flavor.
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Hello,
Did you simply, first, try to remove the smell by addition of activated charcoal?
Kind Regards,
Francois
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Please answer the question.
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 Thank you very much Prof. Yehia F. Khalil
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I compared extracting flower under 80-100C with untrasonic under room temperature. And I would thought that the later one could be better to keep topnotes of the flower, avoid loss of fragrance and prevent off-odor. However, the results showed that the former heated one had sweeter and richer fragrance, while the later one was much weaker.
I just wonder, without considering heat can speed up the extraction:
1. May the thermal reaction generate some strong fragrance?
2. Do saccharide/sugar/the sweet fragrance or compounds contribute to increase the odor, that is, they would let us feel the same fragrance more richer?
Could anyone explain or provide information? I would appreciate it if you could provide other extraction method or related paper.
Thank you
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1. heat is energy. It takes energy to get compounds out of the cells.
2. sweet fragrance probably has no relation to saccharide or sugar.
What is the plant? You could try some different solvents which might tell about polarity of the fragrance.
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is there any parameter to determine or comparison of the duration of odor? what are everlasting smells in the world?
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When molecules of odorant interact with olfactory receptors, they generate miniature potentials that travel along the olfactory cilia, then along the body of olfactory neuron, then reach the olfactory axon, and collectively generate action potential. The action potential travel trough the neurons of olfactory bulb, and then to the brain.
When a short pulse odor is applied to olfactory epithelium by a short sniff (or by olfactometer), the part of olfactory epithelium is electrically depolarized, producing a short electrical pulse. This potential rises for a few fractions of a second, reach a maximum of a few mV, and then it decays within a second. It will require a few seconds before the normal olfactory response can be evoked by the next odorant pulse. During this time between pulses, some restorative physiological processes take place to prepare the system to the next odorant pulse. Thus if series of fast odorant pulses is applied, olfactory neurons cannot keep up with the speed of evoking pulses if they applied faster than ~2 seconds.
If the duration of evoking odorant pulses is increased, the electrical response of the olfactory neurons will stay the same to a certain duration of the odorant pulse. Say, you apply pulses of 0.1, 0.25, 1, 5, 10 s, the individual groups of neurons are able to produce responses with the same kinetics (~.3 s rise, ~1 s decay a few mV amplitude). When the duration of the odor impulses become longer than 10 s, like 20, 30 s, or very long, the kinetics is slowed and amplitude of the olfactory response is reduced until practically disappear at the long exposure to odorant. This phenomena is named "olfactory adaptation".  The olfactory adaptation is a physiological process that  can occur at multiple levels in the olfactory system and can involve both receptor level and more central (brain) components. Therefore, it is difficult to find a "super-odorant".  However, molecules that have physical advantages in travelling to receptor sites may be better.
There is a method for comparison of duration and other properties of odorant responses, that is based on the measurement of the electrical response to odorant, so called "Electroolfactogram (EOG). There is a   non-invasive version of EOG  that can be used in human. The  duration of the EOG response is measured in seconds and can be used for a quantitative comparison of odorants.
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I'm looking for essays focusing on odor perception recording methodology or any other essays that mention the details of such recordings in an experiment.
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I would recommend two noninvasive techniques that used in human experiments. One is the electroolfactogram (EOG) is recorded inside the nose, and another one is the olfactory-related potential (OERP) recorded on the scalp.In experiments with humans, the subjects’ detection threshold is found to be proportional to the EOG recorded inside the nose and the EOG amplitude is correlated with the amplitude of the olfactory event-related potential recorded on the scalp (Wang et al. 2004) (attached).
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Hello! I want to conduct a bioassay with weevils using a Y-olfactometer at lab. The problem is that the odor sources are big plants at field, and I don’t want to take tissue samples for the bioassay because the VOCs will probably change. Do you know any odorless substances for insects to dilute the previously extracted VOCs which I could use as the odor source at lab? Thank you!
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Hi Yedra,
I have read that  some people use pentane to test for pollinator behavioural responses to floral odours. Have a look to this paper:
Majetic C.J., Raguso R.A., Ashman T. (2009) The sweet smell of success : floral scent affects pollinator attraction and seed fitness in Hesperis matronalis. Functional Ecology 23:480–487.
Maybe it can give use some ideas.
Cheers!
Rubén
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We are doing behavioral tests on rats and mice on risk taking by using predator odors. So, we want to do the trials during the night as starving them during the nigh hours gave us significant results. I would like to know how do we gradually reverse their light-dark cycle in the laboratory conditions.
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Most of my research is in selectively bred rat animal models of alcoholism using a reversed dark-light cycle.  I believe a gradual reversal of the light phase will not be beneficial over an immediate reversal.  The animals will have to adapt either way and the gradual reversal will only create multiple adaptations.  You might look at the work of Alan Rosenwasser, Klaus Miczek, and Anantha Shekhar among others.
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I am endeavouring to develop an environment-friendly system which reduces smell from pig-sties, and measuring odorous gases before and after the system. Type(s) of equipment used and cost may be of help! Elly (Uganda)   
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Dear Elly - Iowa State University has a very good "starting point" for air quality and animal production systems - i.e., Air Management Practices Assessment Tool (AMPAT):
AMPAT's purpose is "The purpose of the Air Management Practices Assessment Tool (AMPAT) is to provide an objective overview of mitigation practices best suited to address odor, emissions and dust at your livestock operation so that livestock and poultry producers may compare and narrow their options of mitigation techniques. Practices are divided into three categories by source: 1) Animal Housing; 2) Manure Storage & Handling; and 3) Land Application."
The cost is addressed in AMPAT with user-friendly $-to-$$$ ranking.  Your point is well-taken - the cost is critically important especially for agricultural applications. 
We also published an open access companion review article on performance data for mitigation technologies: 
Maurer, D., J.A. Koziel, J.D. Harmon, S.J. Hoff, A.M. Rieck-Hinz, D.S Andersen. Summary of performance data for technologies to control gaseous, odor, and particulate emissions from livestock operations: Air Management Practices Assessment Tool (AMPAT).  Data in Brief, 7, 1413-1429. doi: 10.1016/j.dib.2016.03.070.
The AMPAT website has a direct access to the Summary spreadsheets on Scientific Literature that shows if and how effective control technologies were in actual farm-scale applications:
Good luck with your research,
Jacek