kinetics and equilibrium studies of the removal of blue basic 41 and methylene blue from aqueous solution using rice stems

synthetic dyes are among the most common contaminants of the environment. therefore, the aim of this study was investigation the removal of basic blue 41 (bb41) and methylene blue (mb) from industrial effluents by useing raw and modified rice stems. in this study raw and modified rice stems treated chemically with citric acid (ca) and were used to explore the potentiality of rice stems for removal of bb41 and mb dyes. effect of various parameters including ph, contact time, adsorbent dose and initial dye concentration on the adsorption were studied. to characterize the adsorbents, scanning electron microscope (sem) was used. the adsorbent surface functional groups identified with fourier transform infrared (ft-ir) spectroscopy.the applicability of the adsorption data was explained by langmuir, freundlich, temkin and bet isotherms. the results showed that increasing of contact time and adsorbent dose, dye removal increases for both raw and modified adsorbents. dye adsorption on to adsorbent increased with increasing of ph. also the results indicated that dye removal efficiency was increased by decreasing initial dye concentration. among studied isotherms, data were fitted well by langmuir model (r2>0.98) for both raw and modified adsorbents. also, adsorption kinetics were more fitted by pseudo second order model (r2>0.99).the results of the present work showed that rice stem was a good, low cost and effective adsorbent for removal of bb14 and mb from industrial effluents.