Sorption of textile dyes from textile wastewater by chitosan-based hydrogel

Abstract

With the excessive risks that are present in today's environment, it is of great importance to treat wastewaters before their discharge in water streams. One of the everyday challenges is design of a low-cost and environmentally friendly sorbent such as hydrogel based on chitosan, itaconic and methacrylic acid that can remove wide range of textile dyes. In the present study, this hydrogel has been utilized for investigation of removal of three different azo dyes from simulated textile wastewater: C.I. Basic Blue 9, C.I. Basic Red 1 and C.I. Acid Orange 7. It was found that pH value of the solution had significant effect on dye sorption. Removal of basic dyes was successful at higher pH values, while sorption of acid dye was possible only at low pH value of solution. Simulated textile wastewater is a complex system with various salts, acids and polymers present beside dyes. Regardless of these components, excellent sorption capacity was achieved (more than 80% of dyes were removed), which makes this hydrogel attractive for use under real conditions.

Zbog sve više rizika koji se javljaju po životnu sredinu, veoma je važno prečistiti otpadne vode pre njihovog ispuštanja u vodotokove. Zato je jedan od izazova današnjih istraživanja dizajn jeftinog i ekološki prihvatljivog sorbenta, kao što je hidrogel na bazi hitozana, itakonske i metakrilne kiseline, koji može da ukloni širok spektar tekstilnih boja. U ovom radu je korišćen hidrogel za ispitivanje uklanjanja tri različite azo boje iz simulirane otpadne vode iz tekstilne industrije: C.I. Basic Blue 9, C.I. Basic Red 1 i C.I. Acid Orange 7. Utvrđeno je da pH vrednost rastvora značajno utiče na sorpciju boja. Uklanjanje baznih boja je uspešno pri višim pH vrednostima, dok je sorpcija kisele boje moguća samo pri niskoj pH vrednosti rastvora. Simulirana otpadna voda iztekstilne industrije je složen sistem sačinjen od različith soli, kiselina i polimera koji su prisutni pored boja za tekstil. Bez obzira na ove komponente, ostvaren je odličan kapacitet sorpcije (uklonjeno je više od 80% boje iz rastvora), što ovaj hidrogel čini atraktivnim za upotrebu u realnim sistemima.