Researchers compared different treatments to extract cellulose from agro-industrial waste in the Amazon region. They tested four methods on banana peel, cassava peel, sugarcane bagasse, and rice husk. Sodium hydroxide treatment removed the most lignin and increased cellulose content. Mohr's salt treatment had the lowest cellulose yield. Banana peel and rice husk had the highest cellulose yield. Distilled water treatment at medium temperature had similar results to sodium hydroxide and ethanol treatments. The study shows that agro-industrial waste can be a good source of cellulose using simple and eco-friendly methods.