FINAL Research Paper

RUST CONVERTING CAPACITY OF TANNIC ACID FROM BANANA ETHANOLIC EXTRACT

An investigatory project in partial fulfillment of the requirements in Research II B

Edward Jairus T. D!" J#$ V%&air" R. Ja%a%$ Ma'"ri!( La$!" N. L)%a Ma. S*ia Issa+"%%" DC. A$&$i B"a&ri!" R. Ba!as$ Ri A$,"%a F. Cas&r Gw)$"&# Maria$ P. Trr"!a-

/UE0ON CITY SCIENCE HIGH SCHOOL SY. 123451236

Mr. Mr. Ia$ Ia $ Mar( F. A%%as Ms. Ma. Pi%ar P. Car-$a Research Advisers TABLE OF CONTENTS

Ti&%" Pa,"

i

Ar'a% S#""&

ii.

A!($w%"d,"-"$&

iii.

A+s&ra!&

iv. iv.

Lis& * Ta+%"s

v.

Lis& * Fi,ur"s

vi.

Lis& * P%a&"s

vii

I$&rdu!&i$

Background of the Study

1

Statement of the Prolem

1

!ypothesis

1

"jectives

1

Significance of the Study

#

Scope and $imitations

#

R"'i"w * R"%a&"d Li&"ra&ur"

%

M"&#d%,)

&lo'chart

(

)eneral Procedure

*

R"su%&s a$d Dis!ussi$

1+

C$!%usi$s

1,

R"!--"$da&i$

1-

Bi+%i,ra#)

1

A"$di!"s

Appendi/ A

1(

Appendi/ B

1*

APPROVAL SHEET

0he investigatory project entitled Rus& C$'"r&i$, Caa!i&) * Ta$$i! Ta$$i! A!id *r- Ba$a$a E&#a$%i! E7&ra!& 'as prepared and sumitted y Ma. S*ia Issa+"%%" D.C. A$&$i8 B"a&ri!" R. Ba!as$8 Ri A$,"%a F. Cas&r8 Gw)$"&# Maria$ P. Trr"!a-8 Edward Jairus T. D!"8 J#$ V%&air" R. Ja%a%$8 and Ma'"ri!( La$!" N. L)%a in partial fulfillment of the requirements for Research II B.

 222222222222222222222   222222222222222222222  3ate

Ms. Ma.Pi%ar P. Car-$a R"s"ar!# Ad'is"r

Approved and accepted in partial fulfillment of the requirements for Research II B.

Mr. Ia$ Mar( F. A%%as

Ms. Ma. Pi%ar P. Car-$a

R"s"ar!# Ad'is"r

R"s"ar!# Ad'is"r

ii.

AC9NO:LEDGEMENT

4tmost gratitude is herey e/tended to the follo'ing 'ho never ceased in helping until the completion of this research5

0he Research Advisers Ms. Ma. Pi%ar P. Car-$a and Mr. Mr. Ia$ Ia $ Mar( F. A%%as for their trust and support

 D" La Sa%%" U$i'"rsi&) Dr. E'a$,"%i$" A-r of the I$s&i&u&" 0he 6onsultants Mr. Da%&$ Fr&i$ of  D" * C#"-is&r)5U$i'"rsi&) * &#" P#i%ii$"s Di%i-a$ and Mr. Vi$!" S&. M"sias of the Bur"au * Si%s a$d :a&"r Ma$a,"-"$& for their un'avering guidance and for sharing their scientific e/pertise

Maria 9ris&i$" L. Bau&is&a and F"%i!idad C#ris&i$a Ra-ir"; of A$a%)&i!a% S"r'i!"s La+ra&r)5U$i'"rsi&) * Sa$& T-as and Mrs. Mari+"% Ja%a%$ of the Bur"au * Si%s a$d :a&"r Ma$a,"-"$& for performing a crucial process in this research

&or the un'avering moral emotional and financial support of the proponents7 family family teachers and friends.

Aove all heartfelt appreciation to the Almighty )od for the divine intervention in this academic endeavour.

iii.

ABSTRACT

8etals are very common materials used in construction of several structures. !o'ever due to o/idation rusting occurs lessening the metal7s quality. 3ue to this prolem commercial rust converters are manufactured. !o'ever their price makes them unavailale to certain individuals. In order to address this a comprehensive research on rust conversion has een organi9ed. 0his study aims to test the rust converting capaility of tannic acid e/tracted from commonly found anana peels and to utili9e it as a cheaper and equally effective alternative for commercial rust converters. 0he e/tract 'as otained y oven:drying pulveri9ed anana peels for + "6 for #, hours and soaking them in *-; ethyl alcohol efore having them rotary evaporated for 1# hours to isolate the needed component. 0he resulting e/tract 'as then sujected to column chromatography. It 'as applied to rusted iron plates 'ith different treatments. 0he plates under'ent under'ent a color test program for the results to e analy9ed. 3ata 'ere then gathered and organi9ed. 0he results sho'ed that the tannin e/tract yielded a lo'er amount of converted rust molecules compared to the amount of rust conversion y the 1.+ g concentration of commercial tannic acid. !o'ever !o'ever it displayed a higher amount of converted rust compared to the +.1 g and +.+1 g concentrations of commercially availale tannic acid. Since the tannic e/tract has the second highest and closest color depth values it can e concluded that it is effective in converting rust to iron tannate. 0herefore tannic acid from anana peels is an effective rust converter.

iv. iv.

LIST OF TABLES

Table 1.


v.

Page 1#

LIST OF FIGURES

 Figure  Figure 1.

alues of +.1g 0annin 0reatment=

Page 1+

 Figure  Figure 2. 2.

alues of 1.+g 0annin 0reatment=

Page 1+

 Figure  Figure 3. 3.

alues of +.+1g 0annin 0reatment=

Page 1+

 Figure  Figure 4. 4.

alues of 0annin ?/tract 0reatment=

Page 11

 Figure  Figure 5. 5.

alues of 6ontrol )roup=

Page 1#

vi.

LIST OF PLATES

 Plate 1.

<)athering and preparation of anana peels=

Page (

 Plate 2.

<" <"taining of crude anana e/tract from pu pulveri9ed oven:dried peels=

Page (

 Plate 3.

<&iltering and sujecting of crude e/tract to rotary evaporator=

Page (

 Plate 4.

<0esting of e/tract for tannic acid=

Page (

 Plate 5.

<"taining of final e/tract through column chromatography=

Page (

 Plate 6.


Page (

 Plate 7.


Page (

 Plate 8.


Page (

 Plate 9.


Page (

 Plate 10.

<3ata gathering and conclusion of results=

Page (

vii.

INTRODUCTION

Ba!(,ru$d * &#" S&ud)

Rust is the common name for the compound &e #"% 'hich is also kno'n as Iron o/ide. 0his compound is produced through the process of corrosion: an electrochemical process 'hich involves an anode
S&a&"-"$& * &#" Pr+%"-

6an the tannic acid from anana peels e used as an effective rust converter

H)&#"sis

0annic acid from anana peels 'ill e an effective rust converter. O+<"!&i'"s

a.

)eneral : 0o dete determ rmin inee the the effe effect ctiv iven enes esss of tann tannic ic acid acid from from anan ananaa peel peelss as a rust rust

converter.  . Specific : 0o test test the the rust:c rust:conver onverting ting capacity capacity of tanni tannicc acid acid from from anana anana peels peels : 0o apply apply tannic tannic acid to strip stripss of rust:cov rust:covere ered d iron to measur measuree its rust rust convert converting ing capacity.

1

Si,$i*i!a$!" * &#" S&ud)

Bananas are popular fruits consumed 'orld'ide 'ith a yearly production of over 1-+ million tonnes each year. It is eaten ra' or cooked y removing the outer peelings. 0he discarded peelings contriute to the massive amount of organic 'aste rotting in various dumpsites therefore releasing multiple to/ic gases into the atmosphere. 0his study 'ill provide a 'ay to take advantage of the aundance of 'asted anana peelings. 0he tannic acid e/tracted from anana peels 'ill e used for rust conversion 'hich 'ill not only reduce the  proaility of acquiring acquiring rust:related diseases diseases
S!" a$d Li-i&a&i$s

0his study aims to cover the e/traction of tannic acid from anana peels and its application to rust:covered iron to test the effectiveness of tannic acid in converting rust. Rust converters usually have t'o components5 tannic acid and an organic polymer like #: Buto/yethanol. Aside from that they may also include other acids that may speed up the process of rust conversion such as phosphoric acid. !o'ever !o'ever this study 'ill only test tannic acid7s effectiveness in rust conversion. @o organic polymers or additional acids 'ill e included.

2

REVIE: OF RELATED LITERATURE

 Banana Banana plants are giant perennial monocotyledonous hers of the order  Zingiberales  Zingiberales a sister group to the 'ell:studied  Poales.  Poales. A huge amount of morphological variaility is presented in the cultivated anana. 0hey are not trees ut rather giant hers 'ith a pseudostem or stems formed from the  ases of leaves rolled tightly tightly around each other. other. 8emers of of this genus are the largest largest perennial hers in in the 'orld gro'ing up to 1- meters tall. 8ain taproots are asent in anana plants cultivated vegetatively. vegetatively. 0he diversity 'ithin the anana fruit is huge ranging from s'eet to savoury savoury ent to straight and they also vary in color.

Banana plants are gro'n in the tropical countries. 0hey are found in Africa 6ariean $atin America Pacific and etc. 0hey need as much 'armth as can e given to them as 'ell as 'ind protection. 0hey 'ill thrive on most soils e/cept on salty ones. 0hey also gro' est on rich and 'ell:drained soils. Aside from this they also favor acidic soils 'ith a p! et'een -.- and .-.

Bananas contain high levels of minerals such as phosphorus calcium and potassium as 'ell as vitamins A and 6. 0hey also have a lot of cardiovascular health and digestive enefits5 ananas can lo'er  lood pressure and regulate regulate the speed of digestion. digestion. Bananas also have many many medicinal uses. 0he 0he flo'ers can e used to treat ronchitis and diaetes. 0he astringent plant7s plant7s sap is reputed to e effective in treating hysteria epilepsy epilepsy fever and diarrhea and can also relieve hemorrhoids insect ites and stings. 0he young leaves are used as poultices on urns. 0he roots are used for digestive prolems and the peel and  pulp of ripe ananas are are found to have anti:fungal anti:fungal and antiiotic properties. properties. Aside Aside from this ananas also also contain high levels of tannic acid.

Tannin 0annin or 0annic Acid < Aciu!tannicu < Aciu!tannicu! ! = generally occurs in the roots 'ood ark leaves and fruits of many plants particularly in the nutgalls formed y insects on t'igs of oak trees <"uercusin#ectoria  and other Cuercus species=. It is a group of pale:yello' to light:ro'n amorphous sustances in the form of po'der flakes or a spongy mass.

3

It is used mainly in tanning leather making ink dyeing faric and also used as medicine. In addition to its primary applications in leather manufacture and dyeing tannic acid is also used in the clarification of 'ine and eer and also in oiler 'ater to prevent scale formation. 0annic acid may e classified chemically into t'o main groups hydroly9ale and condensed. !ydroly9ale tannic acid is decomposale in 'ater 'ith 'hich they react to form other sustances. It yields various 'ater:solule products such as gallic acid protocatechuic acid and sugars. 0he est kno'n hydroly9ale tannic acid is the gallotannin or the common tannic acid. It is produced y e/traction 'ith 'ater or organic organic solvents from 0urkish 0urkish or 6hinese nutgall. 0he condensed tannic acid mean'hile forms insolule precipitates called tanner7s reds or phloaphenes. Some important condensed tannins are the e/tracts from the 'ood or ark of queracho mangrove and 'attle. 0annic acid is a primary active ingredient of commercial rust converters together 'ith organic  polymer.  polymer. Rust converters are chemical solutions solutions used to convert convert iron o/ides or rust rust into a protective chemical arrier y applying directly to an iron or iron alloy surface. 0hese compounds interact 'ith iron o/ides converting them into an adherent lack layer that is more resistant to moisture and protects the surface from further corrosion. In this solution tannic acid chemically converts the reddish iron o/ides into luish:lack ferric tannate that acts as a 'etting agent and provides a protective primer layer in conjunction 'ith an organic polymer emulsion. Rust converter is usually applied to ojects 'hich are difficult to sand last such as vehicles trailers fences iron railings sheet metals and the outside of storage tanks. It may also e used to restore and preserve iron:ased items of historical importance. According to 6hrurch 8uto and Striegel <#+1#= as compared to other commercially availale rust converters the one that is tannic acid ased stood out the most 'hich is Rust:oleumD Rust ReformerD. In this rust converter tannic acid acts as a chelating agent 'hile the copolymer has a p! of #.1%. At the end of their e/perimentation only the samples treated 'ith the tannic acid ased converter sho'ed no slight signs of any failure and no active corrosion. As mentioned earlier tannic acid is found in many plants. Some common plants that contain it are cranerries grapes ananas persimmons and mangos. Bananas compared to other common plants have the highest amount of tannic acid found in their peel. 0hey are the fourth largest fruit crop in the 'orld meaning they are easy to find. Since tannic acid is mainly found in anana peels it can e used to convert rust
4

 $e%erse P&ase '&ro!atogra(&) '&ro!atogra(&) Reverse Phase 6hromatography
 *ron Iron according to )rolier International ?ncyclopedia <3elu/e !ome ?dition= is a silvery 'hite solid metal that appears in )roup >III of the periodic tale. Its atomic numer is # and it is a transition element in the periodic tale. 0he chemical symol of the said element is E&eE 'hich is derived from the $atin 'ord ferrum. Iron is a 'ell:kno'n metal ecause of its many uses including its contriution to the formation of numerous useful alloys. In terms of Biology Biology iron is also very important. Iron in its pure form is soft and malleale. It melts at 1-%- F6 and oils at %+++ F6. hen an iron is at room temperature it e/hiits ferromagnetism 'hich is a strong magnetic ehavior that allo's the metal to retain its physical properties even at the asence of an e/ternal magnetic field. !o'ever 'hen iron is heated at G( F6 it loses its ferromagnetic property and e/hiits paramagnetism a 'eaker attraction to an applied magnetic m agnetic field. Although Although iron can conduct electricity electricity compared to other metals such as copper or silver it is a poor conductor.

5

Iron easily reacts 'ith o/ygen and this process is called o/idation. hen iron atoms in steel react 'ith o/ygen in the air the result is the compound Iron
acid surface 'ill remain. But if insufficient insufficient amount of rust converter is applied not all the rust 'ill e converted and thus 'ill leave residual rust. 0he residual rust 'ill serve as the starting point for ne' corrosion processes. Because of these reasons rust converters are not therefore permitted in many areas of steel construction. 0hey are useful as a chemical rust removal measure after 'hich e/cess solution is rinsed off efore a coating is applied.

7

METHODOLOGY A. F%w!#ar&

8

B. G"$"ra% Pr!"dur"

&resh ananas 'ere gathered from the local market. 0he peels 'ere removed and oven:dried at +F +F6 for #, hours. 0he oven:dried peels 'ere pulveri9ed through lending and 'ere soaked in *-; ethyl alcohol. 0he resulting e/tract 'as filtered and the solvent 'as evaporated at ,++ F6 in a rotary evaporator for 1# hours efore eing tested for tannic acid through the ferric chloride test. 0he remaining solvent 'as evaporated through air:drying. 0he e/tract 'as sujected to column chromatography y using a 61( column. 0he final e/tract 'as compared to a standard isual >isual Basic #+1+. 3ata 'ere gathered and organi9ed.

9

RESULTS AND DISCUSSION

Figure 1. Red, Green, and Blue Values of 0.1g Tannin Treatment

0he results sho' sho'n n in &igu &igure re 1 sho' that the highest  in for the red value of the plates plates treate treated d 'ith +.1g tannin is ,+ 'ith 'ith a freque frequency ncy of  1*++- 'hile the # nd highest in is #+ 'ith a frequency of   1G1 1G11-. 0he highes highestt  in for the green valu alue is #+ 'ith ith a frequency frequency of %(1*+ %(1*+ and and the the high highes estt in in for the lue value is #+ 'ith 'ith a freque frequency ncy

%1++,. Since red lue and green form lack 'hen comined and since tannin reacts 'ith rust to form iron tannate 'hich is lack in color having close values of the color depths 'ould indicate that most of  the rust 'as converted. !aving higher red color depth values and lo'er green and lue color depth values indicate that a large numer of rust remained. !o'ever having e/tremely high red color depth values and e/tremely lo' lue color depth values 'ould indicate that little to no rust 'as converted. Since the red value of the +.1g tannin treatment is higher than the lue and green value this indicates that a large numer of the rust remained and 'as not converted. !o'ever the red values are close to the lue and green values 'hich indicates that many rust molecules 'ere converted to iron tannate. Anal Analys ysis is of  the 1.+g tannin treatment yielded the follo'ing results5 the high highes estt in in for for the the red value is + 'ith a frequency of   #(,-+ #(,-+ the highes highestt  in for the green Figure 2. Red, Green, and Blue Values of 1.0g Tannin Treatment

10

value is + 'ith a frequency of %,%G, and for the lue value the highest in is + 'ith a frequency of  %1-- <&igure #=. Since the R ) and B values all have the same highest in and frequencies close to each other this indicates that a large numer of rust had een converted. &igure # also sho's that the ne/t highest in for the red value is (+ 'ith a frequency of #G%-* indicating that a portion of the rust still remained. 0he results of  the +.+1g tannin treatment are as follo' follo's5 s5 for the red value the highest in is (+ 'ith a frequency of 1(+*+. 0he 0he high highes estt in in for  for  the green value is ,+ 'ith 'ith a freque frequency ncy of  #%1 #%1(% (% and and for for the the  lue value the highest in is #+ 'ith a freq freque uenc ncy y #,G #,G(* (* <&igure %=.0h .0hese resul results ts indica indicate te that that Figure 3. Red, Green, and Blue Values of 0.01g Tannin Treatment though there 'as conversion only a small amount of rust 'as converted and the majority of the rust remained. &igure , sho's that the results for the tannin e/tract treatment are as follo's5 the highest in for  the red value is + 'ith a frequency of %G1*# in ,+ is the highest 'ith a frequency of --#G* for the green value for the lue value in ,+ is the highest 'ith a frequency of -%(-1 Based on the results a large portion of  the the rust rust 'as 'as conv conver erte ted d sinc ince the R ) and B values ar e close. !o'ever the highest in of the red value 'hich is + + is high higher er than than the the highest in of the green and lue values 'hich is ,+. ,+. 0his 0his indi indica cate tess that that many rust molecules have Figure 4. Red, Green, and Blue Values of Tannin Extract Treatment

11

 een left unconverted. unconverted. Results for the control group are as follo's5 the highest in for the red value is 1+ 'ith a frequency of #*(, the highest in for the green value is (+ 'ith a frequency of #*-,( the highest in for the lue value is #+ 'ith a frequency of #G1% <&igure -=. Because the lue value is e/tremely lo' and the red value is e/tremely high these results indicate that little to no rust 'as converted.

Figure (. Red, Green, and Blue Values of )ontrol Grou%

Dis!ussi$ As previously discussed there are t'o possile results5 that the amount of rust converted y the tannic tannic e/tract e/tract and the differen differentt concentra concentration tionss of the commercial commercially ly availale availale tannin is significa significantly ntly different and that the amount of rust converted is not significantly different. 0he results support the first  possiility for for t'o concentrations concentrations ut not for the highest highest concentration. Tale 1. !ig"est in #it" fre$uencies of t"e color de%t" &alues for t"e di'erent treatments

Red

Green

Blue

Treatment High Highes estt Bin Bin

re! re!ue uen" n"# #

High Highes estt Bin Bin

re! re!ue uen" n"# #

High Highes estt Bin Bin

re! re!ue uen" n"# #

0.01g Tannin

80

18$090

40

23$183

20

24$789

0.1g Tannin

40

19$005

20

38$190

20

31$004

1.0g Tannin

60

28$450

60

34$374

60

31$556

Tanni" %&tra"t

60

37$192

40

55$279

40

53$851

'(ntr(l

160

29$864

80

29$548

20

27$613

12

As sho'n in 0ale 1 the 1.+g tannin treatment eing the one 'ith closest color depth values converted the most rust. 0his is follo'ed y the tannic e/tract 'hich has the ne/t highest and closest color depth values then the +.1g tannin concentration +.+1g tannin and the control group 'hich had no conversion.

13

CONCLUSION

0his purpose of this research 'as to test the rust converting capaility of tannic acid e/tracted from commonly found anana peels. 0he results sho'ed that the tannin e/tract yielded a lo'er am ount of  converted rust molecules compared to the amount of rust conversion y the 1.+ g concentration of commercial tannic acid. !o'ever it displayed a higher amount of converted rust compared to the +.1 g and +.+1 g concentrations of commercially availale tannic acid. In general the e/perimental data supported the hypothesis that tannic acid from anana peels 'ill e an effective rust converter. Although Although 6hrurch 8uto and Striegel reported that samples treated 'ith tannic acid ased converter sho'ed no slight signs of any failure and no active corrosion signs of unconverted rust 'ere found in this e/periment. 3iscrepancies in the findings could e attriuted to the lack of an organic polymer polymer 'hich is an essential component of rust converters. In 6hurch 8uto and Striegel7s Striegel7s e/periment a complete rust converter 'ith oth tannic acid and an organic polymer 'as used 'hereas in this study only tannic acid7s rust converting capaility 'as tested.

14

RECOMMENDATION

0he researchers recommend that further studies should use Sephade/ $!:#+ to make the tannin e/traction easier and much less time:consuming. Also Also it is suggested that the e/tracted tannin e lyophili9ed so that its po'derEs consistency 'ill accurately match that of the commerciali9ed tannin. &urther investigations should also scan the iron platesE red:lue:green pi/els efore and after the application of the various treatments. 8oreover it is advised to use qualitative data to yield more accurate results.

15

BIBLIOGRAPHY

Beall !. Bro'er 3. $e8ay !. HRolee J. <1**=.'&e!istr) <1**=. '&e!istr) 'onnections to +ur '&anging ,orl . ,orl .  @e' Kersey Kersey 4nited States of America5 Simon H Schuster. Schuster. Bo/er R. <1**G=. -ssentials <1**G=. -ssentials o# +rganic +rganic '&e!istr). '&e!istr) . 4nited States of America5 Bro'n 6o. 6omparative Study of 6ommercially Availale Availale Rust 6onverters. <#+1, August =. In  ational 'enter #or   Preser%ation  Preser%ation Tec&nolog) Tec&nolog) an Training  Training . Retrieved from http5LLncptt http5LLncptt.nps.govLlogLcomp .nps.govLlogLcomparative:study:of: arative:study:of: commercially:availale:rust:convertersL 6ondensed tannin.
16

rust converter. . <#++G=. Antio/idant properties of phenols. T&e ournal o# P&ar!ac) an P&ar!acolog) P&ar!acolog)  -*<1#=51G%:(-. Stripping paint. <#++G August #*=. In  )TractorForu!.co!  )TractorForu!.co!.. Retrieved from http5LL'''.mytractorforum.comL1%:toro http5LL''' .mytractorforum.comL1%:toro:'heelhorse:forumL,G :'heelhorse:forumL,G,+%:stripping ,+%:stripping:paint.html :paint.html tannin. <#+1-=. In -nc)clo(:ia In  -nc)clo(:ia Britannica Britannica.. Retrieved from http5LL'''.ritannica.comLtopicLtannin tannin. <#+1-=. In Acae!ic In  Acae!ic ictionaries ictionaries an -nc)clo(eias -nc)clo(eias . Retrieved from http5LLuniversalium.academic.ruL#+(--Ltannin hat chemical 'ill turn Rust into 8etal the Best 8any products on the market ut 'hich one 'ill 'ork.
17

APPENDIX A

A. Average verage of color depth depth values values of +.1g +.1g tannin tannin treatment treatment Red

Green

B lue

57.81 7.8172 726 6

34.50 4.5018 183 3

35.20 5.2013 135 5

B. Average verage of color color depth value valuess of 1.+g tannin tannin treatment treatment Red

Green

B lu e

63.59 3.5940 406 6

53.0 53.07 7849 849

60.7 60.79 9024 024

6. A'"ra," * !%r d"&# 'a%u"s * 2.23, &a$$i$ &r"a&-"$& Red 89. 89.5585 55850 0

Green 48. 48.1773 17734 4

B lu e 38. 38.4047 40475 5

3. A'"ra," * !%r d"&# 'a%u"s * &a$$i$ "7&ra!& &r"a&-"$& Red 46. 46.5394 53940 0

Green 34. 34.4201 42014 4

B lu e 39. 39.8756 87568 8

?. A'"ra," * !%r d"&# 'a%u"s * !$&r% ,ru Red 161 161.402 .40206 06

Green 85. 85.5247 52478 8

B lu e 36. 36.3751 37515 5

18

APPENDIX B

A. Preparation of anana peels y lit9ing lit9ing using a food processor and oven drying drying

B. Iron Iron plate platess treat treated ed 'ith 'ith 'ater  'ater  6.

Iron plates treated 'ith +.+1g 6ommercial 0annin 0annin 3. Iron plates plates treate treated d 'ith +.1 +.1 g 6ommercial 6ommercial 0annin

19

?. Iron plates plates treated treated 'ith 'ith 1.+ g 6ommercial 6ommercial 0annin &.

Iron plates treated 'ith 0annic ?/tract

20