Artifical Photosynthesis

[irregular]

Hi Donna,

I actually got back home late at 10, and my dad wasn't at home, and I just realized that you meant adding a whole new 200ml to the sample and storing the pretreatment solution separately, and the procedure took some time. I was a little worried that removing the pretreatment solutions would mean loss of some broken down newspaper and not knowing how much I lost, and how much newspaper was broken down.

Thank you for the good idea! I added the HCI late at night, but today I'll be adding everything about 3-4 hours earlier. So do you mean that I add the red cabbage juice, neutralize the newspaper samples, boil the sugar sample, and then store 20ml of ALL of the samples?

Thanks!

[donnahardy2]

Hi Irregular,

I think you understood the suggestion and I'm sorry it was so tedious to separate the newspaper from the pretreatment solution, but I'm sure that removing the inhibitors along with the hydrogen peroxide/ethylene glycol will improve the fermentation results.

Yes, you got it. Add everything, and then store 20 ml of all of the samples, preferably in the freezer, but in the refrigerator if there's not room available. This will be your "before" fermentation samples for the freezing point/boiling point tests.

Do you have test tubes available that are big enough to hold a few milliliters of sample and a thermometer, and that will fit into the freezer for the freezing point test?

Donna Hardy

[irregular]

Hi Donna,

The newspaper in teh organosolv and hydrogen peroxide samples are much more decomposed than the newspaper of the acid sample - that's a good sign!

My dad and I were going to do neutralization, yeast addition, etc by the end of today. We started at 7:30, but the neutralization process took some time (The pH of the acid 1, organosolv 2, and hydrogen peroxide 2 got high, so we had to add 1ml of HCI to balance it), and then we had to eat a late dinner. It got pretty late, and would've taken another hour at least, so early tomorrow morning we will continue, and confirm that everything's neutralized, take out 20ml, add the yeast and nutrients.

Is it essential to place the samples in the fridge or freezer? I hope that it doesn't touch or contaminate the food.

I do not have test tubes at home, but I could check on Monday at school. I do have a thermometer.

Thanks!

[irregular]

Hi Donna,

By the way, the plant nutrient I used in my last experiment is called "Soil Acidifier", I tested it in plain water with the cabbage juice, and it turned dark blue to an aqua, blue-green colour. I don' want to risk it changing the pH, so I will use my other palnt nutrient with 5% nitrogen.

I stored the 20ml of each sample in old containers and put them in the fridge.

Also, this morning when I took the cylinders out of the water bath, I noticed that the acid 1 sample had about a 50ml bigger volume than before. I think this is so because the baggie in which the cylinder was placed had detached from the duct tape holding it against the water bath wall, and fell (all overnight) so there was some contact between the water and the sample. Even though the sample was sealed with the plastic wrap, I think it might have seeped through. I will continue neutralizing and adding yeast and nutrients to this sample. What comments do you have about this situation?

Thanks!

[donnahardy2]

Hi Irregular,

It is good that you noticed the pH effect of the plant nutrient. The dark blue to aqua color indicates the pH is too high for optimum yeast growth. This is strange for a product called a soil acidifier, which should cause a lower pH, and more of a pink color when mixed with the cabbage juice. What are the ingredients, or the brand name of this fertilizer? I thought we had checked the composition of the fertilizer before the last experiment. I will have to look back at our notes, because I think you listed the composition. Switching to the 5% nitrogen fertilizer was a good idea since this will provide your yeast with a source of nitrogen without affecting the pH.

It is very common for unexpected things happen to individual samples in science experiments. The additional 50 ml volume in the acid 1 sample is a good example, and one reason that duplicate samples are always recommended. You should proceed with testing this sample; you have noted that the volume increased and so you sample is slightly diluted. If results of this sample are completely different compared to the second acid sample, then you will have an explanation. At least you didn’t lose the entire sample.

Donna Hardy

[irregular]

Hello Donna,

Yes, you are right, I had mentioned the name and composition in one of my past replies. THe soil acidifier was called Miracid Soil Acidifier Plant Food.

What do you think I should do with the separated ethylene glycol and hydrogen peroxide that I stored? Could they possibly become useful at the end of my experiment? I ask because I'm quite sure that I'll have to return some of the materials I borrowed back to the school including the flasks I stored them in, the school hydrometer and the beaker caps before our one week break, which starts on the 12th.

Is there another product that I can use instead of the test tubes, like an ordinary glass jar etc?

Also, I wanted to let you know that I only have 180ml of my sugar sample left (20ml removed for storage), and I'm not able to take any hydrometer readings with it, at least so far.

Thanks!

[donnahardy2]

Hi Irregular,

Thanks. I tried to find the composition of the Miracid Soil Acidifier plant food, but I could not find enough details. It is described as an acid fertilizer, so I don’t know why it raised the pH of your solution. What is the color of the cabbage pH indicator in your samples now? Let me know if it changes during the fermentation. Fermentation should lower the pH so the solution should become pinker.

You need hydrometer readings on the sugar control, so make up some additional sugar control, boil it, and after it has cooled down, add enough of the newly prepared solution so that is matches volume of the other samples; make a note that you have done this. You don’t need to worry about adding more yeast, as the yeast should be growing well in this sample by now. If you have already started the fermentation on this sample, make enough volume so that you can get a time zero hydrometer reading for the sugar sample.

When you test your samples, you can make a note of whether or not you can smell the ethanol in the fermenting sample, also make a description of the fermentation samples. You should be able to tell if the sample is becoming cloudier, and whether or not bubbles are being produced. The visual observations will complement your analytical measurements. Are you taking measurements just once a day?

I cannot think of any use for the hydrogen peroxide and ethylene glycol pretreatment solutions, so I think it would OK to discard these solutions. Can you tell if you lost a significant amount of the newspaper in these solutions?

Donna Hardy

[irregular]

Hi Donna,

The cabbage juice pH indicator isn't showing in the samples anymore, I think that it's because of the amount of yeast I added. I have been using pH strips though, there isn't any significant change so far.

I added 30ml of a 5g/200ml dilution to my sugar sample.

So far, I have been able to smell ethanol, see cloudiness in my samples, and see bubbles. Yes, I am taking measurements once a day. The weight and volume measurements are done pretty quick, the conductivity meter readings takes about 3 minutes each, but the hydrometer readings take a long time. Do you suggest I take more readings per day? Maybe an additional weight and volume measurement in the day?

My pretreatment solutions do contain some newspaper. It looks like quite a bit of newspaper in each solution, not too much though, but it looks thin so it actually might not be very much. It's hard to tell just by looking.

I will organize my data and send you what I have so far in my next post.

Thanks!

[donnahardy2]

Hi Irregular,

This is a good progress report. The ethanol smell, cloudiness, and bubbles confirm that fermentation is progressing, so this is good news. When the pH starts to go down at the end of fermentation, then the yeast growth will be inhibited, so it’s good that the pH is stable so far. I don’t recommend taking measurements more than once a day; I think it probably better not to disturb the samples any more than necessary.

It’s interesting that the acid did not completely hydrolyze the newspaper sample. I hope that enough of the cellulose was hydrolyzed to release a significant amount of glucose. Do all of the samples contains leftover bits of newspaper, or was there any difference at all between the samples.

I’ll look forward to seeing your data. I assume that you will be reserving enough time during your break next week for data analysis and completing your report?

Donna Hardy

[irregular]

Hi Donna,

My pretreatment solutions do contain some newspaper. It looks like quite a bit of newspaper in each solution, not too much though, but it looks thin so it actually might not be very much. It's hard to tell just by looking.

To confirm; above I was talking about my stored pretreatment samples. My current samples do have some little traces of newspaper (ex. stuck on the upper walls of the cylinder), but, visually, they seem to have been hydrolyzed. Both my stored pretreatment solutions and current samples contain some traces of newspaper.

Yes, I will be devoting a lot of time to my project throughout the break. I had previously come across the Google Science Fair, and found it quite interesting. Would you recommend me to participate? (http://www.google.com/events/sciencefair/index.html) I am willing to work hard on my project everyday.

I have attached my spreadsheet, and will complete the pH column tomorrow. I only have about 3 readings ever since I added the yeast, so it's hard to tell how the fermentation is going according to my density measurements (ie. my density fluctuates up and down in many sections). Also, the hydrometer readings and density readings have quite a big difference. My current samples are also pretty viscous, but I can still take readings. There is still some minor evaporation taking place.



Thanks!

[donnahardy2]

Hi Irregular,

Thanks for the data; we will be able to see what’s happening in the next day or two. I’m happy to see that you still have the conductivity monitor.

The Google science fair looks interesting, and it might be worthwhile unless it would take too much time away from what you are doing with your current project. You might want to double check with your teacher and make sure entering in the Google fair would not interfere with eligibility for Canada Wide. Have you found the detailed instructions on the Google website? I looked just briefly and didn’t’ see them.

Donna Hardy

[irregular]

Hi,

I will inquire about the eligibility for both science fairs.

Here is the spreadsheet of my data so far. I've noticed that the pH has started to decrease, at what point should I stop taking measurements?

Also, I have a doubt in the accuracies of my measurement. The cylinders my samples are in have a scale of 10ml, I have done my best at noting the volume, but even if I made a mistake of even 2 or 3 ml, my density could change quite a bit.



If you don't mind, I will be sending you my introduction and research report in a day or so, so you can look it over.
Do you recommend that I use parenthetical citation in my introduction and research portion?
Also, I'd like to confirm with you that my experiment was one of the first to use the organosolv process on newspaper, and the first to use oxidative delignification on newspaper. I'd like to make sure that this fact is clear and evident in my report.

Thanks!

[donnahardy2]

Hi Irregular,

Thanks for the data. I will review it and post comments as early as possible tomorrow morning. If the density measurements don’t make sense, you may want to include a discussion on possible measurement errors in your discussion, or perhaps include some additional calculations. There is a standard way to calculate standard error, because there is always some error in measurements, and this might be useful, depending on your results.

If your teacher or the science fair hasn’t specified the format for the citation, I recommend that you follow the style of one of the journal articles. Scientific notation is fairly standard, but there are some variations.

I would love to see your introduction and research report, and I’ll send back comments as quickly as possible so you can complete your project.

Donna Hardy

[irregular]

Hello,

By the way, I also obtained the test tubes from my school. How would I go about completing the freezing point test?

The boiling point test would just include sticking a thermometer in the sample, boiling it, and observing at which temperature it stars forming bubbles, right?

Thanks!

EDIT: I will update my spreadsheet from last night's measurements, and send them to you in the next few hours.

[donnahardy2]

Hi,

Here’s a freezing point test that should work well for your samples. I recommend starting with a sample of water first. Put some distilled water in a test tube and freeze it, and then measure the temperature when the ice melts:

http://www.ehow.com/how_5936072_measure ... iquid.html

The freezing and melting points of water are similar.

http://en.wikipedia.org/wiki/Melting_point

Test a sample twice to make sure you can get reproducible results. I am hoping you can get some definitive results with the melting point test so you won’t need to do a boiling point test. The problem with the boiling point test is that ethanol is volatile, so you would only be able to do the test one time with your reserved samples.


Donna Hardy

[irregular]

Hello Donna,

Thank you for the information on the freezing point test. Other than the distilled water test, should I do a sucrose test too to represent my sugar sample?

Sorry for getting back to you with my updated spreadsheet later than I noted. I added 10g of yeast after taking my measurements tonight, just for the sake of it, and because I will be concluding my experiment soon.

Also, my sugar sample readings with the hydrometer are now inaccurate because the quantity is too less for the hydrometer to read.

I have been focusing more on my report right now, but when you return with your comments about my data I will analyze it more extensively and calculate a few things. Firstly, I want to calculate, theoretically, how much ethanol I should produce in my newspaper 10g/200ml and sugar 5g/200ml sample. Wikipedia notes that "one of glucose is converted into two moles of ethanol and two moles of carbon dioxide". Pure ethanol has a specific gravity of 0.789. My specific gravities are far, far from that. If I can calculate how much ethanol I should get, I think that I should be able to figure out my ethanol dilution. This should help quite a bit, because if the majority of the dilution is water, which I predict, then that could explain the reason of my high densities and specific gravities (since they are showing up around 1, the specific gravity of water. However, that rises another question... why are my gravities and densities exceeding 1?) Second, I should compare the potential alcohol before and after fermentation.

Thank you for mentioning standard error. That could definitely be handy. The discussion will be an important part of my project.

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Thanks!

[donnahardy2]

Hi,

I think you reserved aliquots of all of your samples, so you will have a reference point to compare to in case your values don’t match the tables you found on the internet. You will hopefully see a decrease in the freezing point to confirm your results.

You would not be able to obtain more than 10-12% ethanol with the amount of sugar you have available, and the acid samples will contain salt, which inhibits growth, so you will probably have less than that. You would only be able to get a higher concentration if you distilled your sample and that it another project, outside the scope of your current project. Hopefully, you will be able to determine the approximate concentration of ethanol and you can calculate a yield.

I have printed out your results again, but haven’t had a chance to look at the data today. We definitely need to get your results on Excel graphs so we can “see” what’s happening. Why don’t you concentrate on your report; I think your ideas are very good, and we can start on data analysis tomorrow.

Donna Hardy

[irregular]

Hello!

Thank you for the feeback. I will ask my dad to help me make the Excel graphs today.
I will also complete the freezing point tests today. After this, do I have to take any more measurements?

So you do not recommend that I do the boiling point test, right? If I do so, then the ethanol will vaporize and I'll lose it, right?

After taking my measurements last night, the 1st set of results with 10g more yeast added, I saw that that the hydrometer readings actually increased.

Are you familiar with Fehling's test? Could this help me calculate the amount of glucose that I have calculated?

I have attached my "Materials and Methods" section of my report with this post so you can take a look.

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Thanks!

[donnahardy2]

Hi Irregular,

If the hydrometer measurements are not changing, you don’t need to do any more measurements. Can you detect any ethanol in any of the newspaper samples?

See if this helps you:

1. If you used 5 grams of newspaper, composed of 85% cellulose and 15% lignin, then you would have started with 4.25 grams of cellulose or 4.25 grams of potential glucose.

2. 4.25 grams of glucose is equal to .0236 moles of glucose.

4.25 grams x mole glucose/180 grams

3. One glucose molecule can be converted to 2 ethanol molecules and 2 carbon dioxide molecules.

C6H12O6 → 2C2H5OH + 2CO2

4. So, 0.0236 moles of glucose could be converted to at most 0.0472 moles of ethanol.

5. 0.0472 moles of ethanol is equal to 2.17 grams of ethanol

.0472 moles x 46 grams/mole= 2.17 grams of ethanol

Does this make sense, or should I try to explain in more detail. I think you could explain the theoretical potential with this information and use your actual results to compare with the potential.

You will have one chance to do the boiling test, so I would make sure you have good freezing point results before you try a boiling point test. You don’t really need the boiling point test if your freezing point test is definitive.

Adding yeast to the sample would increase the density of the solution, so it makes sense that the hydrometer readings would increase.
I am familiar with Fehling’s test. This is a test for reducing sugars, and I remember it was the first lab I did in organic chemistry lab in college. It would be have been interesting to do this test on an acid hydrolyzed sample to verify the presence of glucose, but this is fairly complicated and requires chemicals that I don’t think you have readily available. If you wanted to try preparing another hydrolyzed sample and if you could get the chemicals from your Dad’s work or school, you could try it. I think that the urine glucose strips are based on Fehling’s reaction, but I don’t think these worked out for you. You don’t need to do this if you are short of time, and I think the theoretical calculations will be suitable for your project write up.

Your materials and methods section is impressive. I will read it tonight and post some comments tomorrow.

Donna Hardy

[donnahardy2]

Hi Irregular,

I have attached an edited materials and methods section, with a few comments. I have suggested that you start with a list of all of your materials and equipment used, then list the samples, then include the details of each step. You did a really good job of including all of the details in your project, and my comments are mainly for organization. Your materials and methods section is very similar to a really scientific paper in its detail.

Also, this is very important for really complicated projects like yours. It is very easy for readers who are not familiar with your project to get lost in the details and not understand what you are doing. You can make your project clearer by adding a flow diagram with some pictures or words to describe the outline of the experiment. This will be absolutely essential on your board.

For your board, if there is room you can consider having a little side bar on the cabbage juice, with a small flow diagram with color pictures showing how you made the pH indicator and used it to monitor the pH in your samples. This will be kind of a project within a project, but an important detail in your project.

Another comment related to the sucrose control. I had suggested that you use sucrose as a fermentation control because yeast can utilize this sugar as well as glucose and produce ethanol just as efficiently. However, you had mentioned Fehling’s reagent, which will detect reducing sugars like glucose, but not disaccharides like sucrose.

How are you doing on your background section?

Donna Hardy

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[irregular]

Hi,

Thank you for the glucose to ethanol theoretical conversion, I understand it. In my case, I used 10g for the newspaper samples, so I should theoretically obtain 4.34g of ethanol, right?

I conducted the freezing point tests today, but I will do them again tomorrow because I detected an error with my thermometer. I will send you the graphs and freezing point test results tomorrow.

I realized today that I should have waited and let the newspaper samples dry after hydrolysis, and then weigh them, so I could have some idea of how much glucose I have. Luckily, I have the the 20ml stored to use for the freezing point tests, which is better than nothing. I will filter the newspaper from each of the portions, let them dry, weigh them, and adjust the proportions to 200ml. I will also re-add the portions I took out of my current fermented samples back to their cylinder, filter, dry, then weigh them.

Thank you very much for your comments. I will definitely make a flow chart and try to fit in a section on the pH indicator.

I have attached my introduction, background, objective and hypothesis.

a) I have left a "line" in my introduction section. I wasn't quite sure what to write for that paragraph.
b) I have a feeling that I should add some more information onto my introduction and research, but I'm not sure what to include. What do you think?
c) The organosolv process and oxidative delignification are supposed to be pretreatment methods especially good at lignin biodegradation. I haven't talked about this because my experiment doesn't focus on that portion. Do you suggest that I include it, and if so, where?
d) The introduction and research sections are more in a journal style. I wouldn't be able to fit all of that information up on my display board, so what part do you think that should I include for the background section on my board?

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Thank you!

[donnahardy2]

Hi Irregular,

Your paper is really good. There’s so much information, but it’s all related to your project so you need to include it.. I’m sorry I’m so slow in responding today, but I will post more detailed comments tomorrow with just a few minor suggestions and make sure you have included all of the scientific principles needed to understand your project.

Here are a few comments.

For the blank line, you can just say that newspapers are a potential source of cellulose for biofuel production, but the subject has not been studied extensively, and the purpose of your project is to evaluate the potential of using this economical and readily available resource for recyling as biofuel.

You will probably need to explain the purpose of the organosolv and delignification steps and why they are necessary for ethanol production for certain types of samples.

How much room do you have on your board? You want to try to include as much detail as possible, but leave the type size large enough so the judges can read it. Try a preliminary layout and decide how much space you allocate to the introduction and research sections, and you can start editing for the board. This is one of the reasons I had started to suggest that you work on a flow diagram for your experiment. Anything you can do to replace typed words with a visual aid will help the judges understand what you have done. Your board will be an overview of your project and anyone interested can refer to your research paper for more detail on the background information.

Donna Hardy

[irregular]

Hello,

Thank you for your comments so far about my report.

Today I was completing my data analysis (on my spreadsheet) and there are a few things which confuse me quite a bit. There is a lot of data, I'm a little unsure of how to organize it all. Your comments are appreciated.

1) At the start of my experiment, and the end, given below are the calculated densities (or specific gravity) measured using volume and weight. (Additionally, I used 2 hydrometers, one called Lakeshore and one called Corunna). I have faith in my calculated density or specific gravity based on measured volume and weight.

Acid 1
star: 1.075
end: 0.97

Acid 2
start: 1.005
end: 1.05

Or 1
start: 1.021
end: 1.058

Or 2
start: 1.011
end: 1.049

HP 1
start: 1.029
end: 1.051

HP 2
start: 1.016
end: 1.02

sugar
start: 0.96
end: 0.97

As you can see, all of the calculated densities except for the acid 1 show an increase in density. The attached spreadsheet also indicates clearly the density increase. Ideally, my densities should be decreasing, indicating the prescence of ethanol. This data would result in quite an important graph, but nothing is really making sense. Why?

2) In order to make sense from the data I did the following. The values given below are of the CALCULATED potential alcohol by volume in percent (obtained from a conversion of the calculated density using a conversion chart online).

Acid 1: 5.1
2: 8.25
Average: 6.675

Org 1: 5.8
2: 4.3
Av: 5.05

Hyd P 1: 3.6
2: 4.7
Av: 4.15

Sug: 2.7

Please see the attached histogram of potential alcohol in the spreadsheet. I would have expected sugar to be highest, acid to be lowest, and the pretreatment methods in between. However this shows the opposite. How come? Also, does "potential alcohol" tell me the amount of alcohol in the sample, right?

3) I have also completed a CALCULATED sugar content using a conversion chart online, as for potential alcohol indicated above from my density. What exactly does the sugar content tell me - how much sugar I have in the sample? If so, it confuses me why I have such high levels when I only added 10g of potential glucose (newspaper) in my samples.

3) Please see the attached 5 graphs and the data in the spreadsheet and offer any valuable comments. I understand that there may some standard error in my data, but am not sure how it could result in so much of my data not very clear.

My freezing point and filtering test results will be sent tomorrow hopefully, as I am a litte behind too trying to make sense of my data.

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Thank you for your time!

[donnahardy2]

Hi Irregular,

I was going to comment on your introduction section today, but the data analysis is more important so I will skip the introduction for the moment. I can understand why you are concerned.

Can you confirm that there were bubbles and that you could smell ethanol in all of the samples? The increase in density is certainly not consistent with production of ethanol; however, you saw a slight increase even in the plain sugar sample that should have certainly produced ethanol. You saw an increase in density with the first experiment, and we thought the problem was due to evaporation, but you covered the sample this time, so that doesn’t explain the increase. You did use a lot of yeast, and if the yeast grew in the sample, perhaps the accumulation of yeast cells increased the density of the sample more than the decrease in density due to ethanol production. All of the values you are using are based on brewing samples, and the composition of your samples, except for the control, are much different.

Did you measure the density of the acid control that did not contain yeast? If so, what were all of the readings? This sample should not have changed at all, so maybe we can use these readings to calculate the standard error of your measurements. That might help explain the results.

I don’t think the potential alcohol calculations are valid for your samples because the density of your samples includes the acid, base, and glucose. If the primary solid in the sample was only glucose, then the potential alcohol calculations would be useful. I don’t know how to subtract out just the acid values. Potential alcohol would be glucose that could be converted to ethanol by the yeast. Your bar graph is very well done, but will have to be revised once we can figure out what the real alcohol values are.

The Excel graphs of salinity and pH of your samples are very well done. The salinity results are expected; all of the samples containing acid and base have a high conductivity and the sucrose control is low conductivity. What is the value on the y axis? Conductivity is usually given in milli Siemens/cm. The significance of the high salt in the samples is that yeast growth will be inhibited somewhat. You knew this before you started the experiment, but did not have a good way to deionize the samples for this experiment.

The pH chart is also good and shows expected results. You successfully adjusted the pH after the acid hydrolysis into the optimum pH range for yeast growth and the pH remained constant for the duration of the experiment. If the yeast had grown really well, you would have expected the pH to decrease to pH 4-5 due to production of lactic acid by the end of the experiment.

I can’t wait to see the freezing point results. I am hoping they will more definitive than the density results for confirming ethanol. If not, then I will help think of a creative explanation for your results.

Donna Hardy

[irregular]

Hi,

Thank you so much for help! (By the way, in the conductivitiy graph the axis was labelled as "Milli-Siemens".)

I myself have reviewed my introduction and background and made some changes, including some based on your comments so far. I am hoping to start my write up for data analysis on some of my easier to explain graphs first (ie. pH, temperature, conductivity, etc.)

Yes, I can confirm cloudiness, bubbles, and alcohol smell in all of my samples throughout fermentation. Density would be an important factor for determining if and possibly how much ethanol I produced, but since I added too much yeast I can't really figure that out. I agree with you where you say that the yeast probably does explain the high density.

Unforunately, I didn'dt conduct an acid control with no yeast.

I will make a graph on temperature to prove that my temperatures were constant throughout the experiment, as well as one of the freezing point test.

I'm considering adding small text boxes onto some of my graphs when I added something for example, since some graphs result in a sudden increase or decrease onwards. For example, at the point in my pH graphs where my pH increases, I could mark "Neutralization" for example.

Also, I am finding that my graphs are quite crowded, having 7 sets of data. I am thinking of splitting each graph into two where necessary organized into the first samples and the duplicate samples (for now, I would say that only the potential alcohol line graph would be in need of that, however I might not be using the graph since I have the bar graph and still need to adjust the data like you mentioned earlier.)

What other graphs do you recommend I create? I was thinking about the hydrometer (specific gravity, potential alcohol and sugar content for each of my two hydrometers)readings, and density and calculated sugar content, since I haven't created a graph for those sets of data. Even though some of the data would make sense and will need an explanation behind it (ie. density and specific gravity), do you recommend that I graph all of those? Additionally, what kind of revisions did you mean in your last post in the subject of my potential alcohol bar graph?

I filtered out the newspaper in the "before fermentation" portions and dried them overnight. The weight of the newspaper was 0.2g, and each portion was about 20ml. That would be 2g/200ml, meaning that 8g of my newspaper converted to glucose. I will have to check on my spreadsheet the total volume of each sample before fermentation and adjust it to that proportionally. I believe that all of my samples were at 220ml, unincluding one that was at 210ml.

I have attached my freezing point results in the bottom of the spreadsheet, and fortunately the after fermentation batch temperatures decrease.

Thanks!

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[donnahardy2]

Hi Irregular,

Here are some comments on your Introduction section. I’m sorry for the delay in sending comments. I have just some very minor comments.

Your first and second paragraphs, describing the problem with recycling newspapers and the reason that newspapers are a potential source of cellulose for ethanol production are very good. For the last sentence with the blank, I think I had suggested just saying something like, “using newspaper as a source of cellulose has not been extensively reported and most research in the area has been done using wood, and other plant materials like corn, corn stover and citrus peels. Using newspapers as an alternative needs more investigation.”

The two paragraphs describing organosolv and hydrogen peroxide treatment are good.

You should end this section with an overall statement of your overall purpose. You have stated this again in your objective, but it won’t hurt to summarize it here also:

"The purpose of my investigation is to evaluate the possibility of using newspaper for the production of ethanol using acid hydrolysis to convert the cellulose to glucose, and to determine if pretreatment with either the organosolv or hydrogen peroxide delignification process prior to the acid hydrolysis would improve bioethanol production."

The background research is very detailed and comprehensive. You have done an excellent job in explaining the problem and setting the stage so the reader will understand the significance of your project. You should add more reference citations, especially to the first and second paragraphs. I don’t think petroleum is derived form animals, but you should check and make sure this statement is correct.

The figures and chemical equations are excellent. After the description of plant structure, with the explanation of the chemistry of lignin, cellulose, and hemicellulose, you need a statement about the composition of newspaper, which as I recall from one of the references is about 85% cellulose and 15 % lignin. Do we know if newspapers contain hemicellulose? I don't remember from the papers. We should check this detail.

Last paragraph of objective section. I would change the wording slightly:

The results of using the organosolv process and oxidative delignification for as a pretreatment step for newspapers have not been reported in the literature, so I decided to try these methods in this project to determine if they would improve bioethanol production.

Hypothesis section: Again, I would change the wording slightly to make your hypothesis very clear:

My hypothesis is that the organosolv or hydrogen peroxide delignifcation pretreatment steps prior to acid hydrolysis on newspaper will increase bioethanol production compared to using acid hydrolysis alone.

Have your put the bibliography together to add at the end of the research paper?


Great job!

Donna Hardy

[donnahardy2]

Hi Irregular,

I’m having trouble keeping up with you. Here are some comments on your latest results section.

You have become very proficient in using Excel; your tables are very clear. The titles and the labels on the graphs will be much appreciated by the judges and make it very clear what data you are presenting.

Your results are making more sense now. You didn’t see a decrease in density for the control or the other samples during the experiment with the hydrometer measurements, but your observations about bubbles and the ethanol smell confirm that your experiment was working. Your sucrose control results were consistent with the other samples and also did not decrease in density either, so the density measurements apparently did not work well for these samples. It’s possible that since the hydrometers were designed to work with traditional fermentation samples, that they were not suitable for the composition of the newspaper acid hydrolyzed samples. It’s also possible that the variation in hydrometer readings was not precise enough for you to measure a difference in density. (I know, all that work for results that are not definitive!). But this will give you something to talk about in the discussion section.

I think your Excel table with the alcohol readings was taken from the hydrometer readings and represents potential ethanol, which is not the same as actual ethanol production. Also, it doesn’t make sense that the acid hydrolyzed samples are so much higher than the sucrose sample. I think we had calculated that the amount of glucose in the newspaper samples was going to be slightly less than the 5 grams in the control sample, so the control sample should have the highest level of ethanol production. So this graph may not be an accurate reflection of your data. Hopefully, your freezing point results, showing a shift in the freezing/melting point between first and final samples will give you the data you need to actually quantitate the ethanol.

Small text boxes on your graphs explaining what happened when you neutralized the sample would be very helpful. Good idea. Anything you can do to add a note or figure to clarify the experiment or results would be beneficial. For your board, you might consider starting each section with a one sentence summary of whole section to keep your reader on tract. You should also write an abstract to summarize the entire project into 3-4 sentences.

You can try splitting the graphs to see what it looks like, but it might be more confusing to have to look at two graphs to get results. Your most important results are the sucrose control, the acid hydrolysis, the organosolv, and the hydrogen peroxide samples. If you make these lines bold and keep each sample the same color through all of the graphs, then the viewer will be able to follow the results. You could try adding a text box to label each line on the first graph and look at it to see if it is clearer.

Yes, please do a graph of the specific gravity and sugar readings. Also a summary graph of the freezing point results.

The freezing point results are your most important data now and the difference between the time zero and end of fermentation is your best quantitation of the results. Just looking at the results, it looks like the sugar sample produced the most ethanol, as expected, dropping minus 3.75 degrees, the acid sample went down 2.5 degrees; the oranosolv samples decreased 3 degrees and the hydrogen peroxide samples decreased by 2.75 degrees. Yeah!!!! You have definitive results and you can make conclusions related to your hypothesis. You should make a bar graph showing the decrease in freezing point from the beginning to the end of the experiment for each sample and make your conclusions. You should use this bar graph and omit the first alcohol graph.

Donna Hardy

[donnahardy2]

Hi Irreguar,

Here are some comments about your materials and methods section.

At the end of the paragraph starting with “10 g of Fleischmann’s yeast,” add a statement about why you added the various ingredients. Fleichmann’s yeast contains Saccharomyces cerevisiae, a yeast that will convert sugars like glucose and sucrose to ethanol. In my experiments, glucose (from newspaper) or sucrose was used as the primary carbon source. The balanced fertilizer provided a source of nitrogen and phosphorus and potassium. The vitamin pill provided the essential elements magnesium, iron, calcium and zinc, which are also required for yeast growth.

Also, I did not realize it until I was looking at your results again, but you need to include a little more information the methods that you used to measure your results. So, add a description of the device that you used to measure each parameter and why you measured it.

For example, Temperature: Temperature was monitored with a (name of brand or type of) Centigrade thermometer and measured to the closest degree. The optimum temperature for Saccharomyces cerevisiae is between 25 and 30 degrees Centigrade, and I maintained the temperature at 25 degrees Centigrade for my experiments.

Do the same for conductivity, total dissolved solids, weight, density, pH, specific gravity, potential alcohol, sugar content, and most important, describe freezing point and why you did this test. I think you have the information you need for each method, but let me know if you need more information. You don't need an extensive explanation, just one or two sentences, so don't spend a huge amount of time on this. Your conclusion and analysis sections are more important.

Donna Hardy

[irregular]

Hello,

Thanks for the incredible amount of input and help!!! I really, really appreciate it! I think that I can finish all my graphs and writing related things by Wednesday-Thursday.

For the graph on freezing points, I created a double bar graph. I was thinking about a different type of graph I could possibly do instead, where I would also be able to show a direct decrease between the before and after freezing points and in a text box indicate the depression in degrees. I'm not completely sure what this is called, but it sort of resembles a scatter plot. Above each sample label, I would plot two points (before and after) and be able to connect an arrowed line in between them. It looks a bit like this graph (http://2.bp.blogspot.com/_ts9uSrDvi1I/S ... Legend.png), but both data points are on top of one sample label. What do you think about this?

Also, in my freezing point graphs I know that I would have to explain how I know that a decrease in freezing point signifies a production of ethanol. Based on seeing this top table (http://www.engineeringtoolbox.com/ethan ... d_989.html), I concluded that yes, as ethanol is produced, the freezing point decreases, the lesser, the more ethanol. Could I could use the concentration by volume that they've indicated to explain how much ethanol I've produced (in the after sample, around 20% or -9 for my newspaper samples and 15% for my sucrose sample, around -6. I used 5g sucrose as opposed to 10g newspaper, so theoretically, if I had used 10g sucrose, my freezing point would've been -12, correct?)? I do realize that I may have acid and salts in my samples as well, so this may not be 100% accurate.

I also have yet to make a section for my data on my cellulose-to-glucose conversions. When I filtered out the newspaper from the before fermentation 20ml portions, and weighed the newspaper, this is what I got:

acid 1: 0.4g
acid 2: 0.6g
org 1: 0.5g
org 2: 0.6g
hyd 1: 0.5-0.6g
hyd 2: 0.5g

It is a little odd that the acid 1 newspaper weighed less than the rest, but I think that that was caused by possible standard experimental error, perhaps the portion was a little less than 20ml. I would've expected lower weights in the organosolv and hydrogen peroxide samples, as well, since they had been pretreated and more newspaper should've been converted into glucose. However, when looking at the big picture, I can say that 40 or 50% of the newspaper in each sample converted into glucose. This would have to be converted to a total volume of 230ml (after hydrolysis, before portion separation) for all of my newspaper samples except for hyd 2 (210ml).

I checked out the participation registeration form for my science fair, and noticed there was a section asking about a mentor who helped out if any. I put down your name, but they ask for other information as well such as your phone number, email address, position and organization. I know that giving out your email and such is not possible on the forum boards. What what you like me to put down in this case?

My father will try to see if my samples can be tested on a NMR machine at work.

Thanks so much!

[donnahardy2]

Hi Irregular,

You are welcome. I was so excited when I saw your melting point results yesterday. You had done a lot of work, and you finally obtained some definitive results.

One of the important points about doing a science fair project is communicating your results and it is better to simplify the data for your board, even though you will include all the calculations in your research paper. You want everyone reading your board to understand the basic purpose and outcome of your project. A double bar graph is more complicated, and for your conclusion, the beginning and ending temperature are not that critical. The important number is the magnitude of the decrease in the freezing point from the beginning to the end of the experiment. So, I recommend using a simple bar graph for each sample showing the change in the freezing point from the beginning to the end. This graph should be the centerpiece of your results section, and can be larger than the other graphs

You need to mention that NaCl affects the freezing point, however, you are assuming that since all of your samples contain the same amount of salt, that the change in the freezing point is due the production of ethanol.

http://www.worsleyschool.net/science/fi ... water.html

You can estimate the concentration of ethanol by comparing the decrease in freezing point to the information on the website. Since pure water freezes at zero degrees and 10% ethanol freezes at minus 4 degrees, you should assume a linear relationship and draw a standard curve using Excel or a traditional piece of graph paper and determine the concentration of ethanol in each sample.

http://www.engineeringtoolbox.com/ethan ... d_989.html

What is the title of your project?

Remind me again. Did you use 5 or 10 grams of newspaper? I think the results of the residual newspaper left in the sample, with about 0.5 gram remaining from each sample, are remarkably consistent. You are on the right track to assume that you should subtract this number (adjusted for the full volume) to estimate the amount of hydrolyzed cellulose/glucose that was available for the fermentation. In your discussion section you might want to mention that the unhydrolyzed newspaper could be recycled in the next fermentation to ensure utilization of all of the raw material in the process, or perhaps you could say that you could improve the process by investigating an alternative method of shredding the newspaper to cut it into smaller pieces prior to the acid hydrolysis.

You need to explain the effect of salt on your fermentation samples. If you remember, sodium chloride or NaCl will inhibit fermentation and decrease the amount of ethanol produced. However, since all of your samples contained the same amount of salt, you can compare results of the various treatment methods. In your discussion/conclusion section, you should mention that you knew the salt would inhibit fermentation somewhat, but that you did not have a way to deionize the samples. If you were doing the experiment again, you would add a deionizing step to remove the sodium chloride, and expect to see higher concentrations of ethanol.

You can use my name as a mentor and include Science Buddies as the organization, and perhaps include the website address, https://www.sciencebuddies.org. Science Buddies is a non-profit organization and its sole purpose is helping students with their science fair projects. I am a volunteer for Science Buddies and also a scientist working for a private company. If anyone at your school has a question about the advice you received, they can contact Science Buddies at the website. I agree it is kind of strange not to have a phone number.

An NMR analysis would be very interesting; however, your samples are not suitable for this type of analysis. I have never done NMR analysis, but I believe that it requires very high purity samples and your samples contain ethanol, salt, yeast cells, microbial metabolites, and many other compounds. I think you would need to distill the ethanol to get a suitable sample, and this would equivalent to another science project, and I don’t think you have time. If your Dad knew someone who has an HPLC system with an alcohol analysis column or a gas chromatograph with a suitable column, it would be possible to inject a sample and obtain quantitative results. However, your freezing point results are definitive, and you really don’t need another method of analysis. But let me know if you do get NMR results.

You can post additional sections for review if you get a chance. I’ll send back replies as quickly as possible since I know you are working on deadline.

Donna Hardy