Study of the Chemical Composition of Banana Peel Waste (Musa paradisiaca) and Evaluation of Its Bioflocculant Properties

---

Résumé

Wastewater treatment is a major environmental issue, requiring effective and sustainable solutions around the world. In this study, plantain peel is used as a natural coagulant-flocculant in the wastewater treatment process. To do this, decoctions of ripe and unripe banana peels were prepared. The main chemical constituents were then identified using characteristic reagents. The total oses, total phenolic compounds, and condensed tannins were measured using the phenol-sulfuric acid, Folin-Ciocalteu, and vanillin methods in an acidic medium, respectively. Finally, the flocculant-coagulant properties of the different aqueous extracts were evaluated using the Jar Test method. The yields of dry crude extracts were 17.91% and 25.4% for ripe and unripe banana peels, respectively. Qualitative tests revealed the presence of polysaccharides, alkaloids, tannins, and lignins in both extracts. The various assays performed showed that ripe banana peels contain significant levels of total oses, total phenolic compounds, and condensed tannins, with values of 621.297 µg EG/mg, 72.514 µg EAG/mg, and 17.315 μg EC/mg of dry extract, respectively. Fourier Transform Infrared (FTIR) analyses of the two plantain peel extracts qualitatively revealed the presence of certain functional groups characteristic of polysaccharides and phenolic compounds. The evaluation of flocculant-coagulant properties showed a better reduction in wastewater turbidity with a reduction rate of 96.93% and 88.81% at pH = 2 for concentrations of 40 µg/mL and 60 µg/mL of dry extracts from ripe and unripe banana peels, respectively. The same extracts have been shown to be effective in the reduction of organic load COD and BOD5 and the removal of certain heavy metals such as Zn, Mn, and Hg.

Mots-clés

Wastewater, Banana Peels, Polysaccharides, Coagulant-Flocculant, Jar Test, Heavy Metals