Background & objectives: Bisphenol A is as environmental and toxic pollutant that releases from industries and at low concentration can be dangerous. Therefore, the aim of this study is the investigation of bisphenol A adsorption by modified azolla.

Methods: This study was conducted in laboratory scale. The prepared Biomass Azolla was crushed and pulverized by standard ASTM sieves with range of 10-18 mesh. The effects of various parameters on adsorbents performance were investigated. The isotherms and kenitics models were used to describe the adsorption data.The chemical composition and solid structure of biomass Azolla were analyzed by Scanning Electronic Microscopy (SEM). Measurement of the surface area was carried out by N2 gas via BET isotherm and Belsorb software.  The concentration of Bisphenol A was measured by HPLC.

Results: Predominant Chemical composition of Biomass is C and O with 34 m²/g surface area. The maximum Bisphenol A removal was observed in pH =3, biomass dose of 12 g/L and contact time of 90 min. The Bisphenol removal percentage decreased from 98 to 44 at 90 min when the concentration of Bisphenol was increased from 10 mg/L to 100 mg/L. The Langmuir and pseudo- second order model provided the best fit for the experimental data. The maximum adsorption capacity was calculated to be 9.6 mg/g.

Conclusion: The result of present work shows that the Azolla can be used as an effective and better adsorbent for removing of phenolic compound from industrial waste water.