Adsorptive removal of imazethapyr and imazamox from aqueous solution using modified rice husk

The potential of untreated, chemically, thermally and chemical-thermal treated rice husk adsorbents to adsorb imazethapyr and imazamox from aqueous solution was explored. The adsorption kinetics of imazethapyr and imazamox on untreated and treated rice husk adsorbents was well described by pseudo second order kinetic model and the adsorption isotherms fitted well to Langmuir model. The adsorption capacity of untreated and treated rice husk adsorbents for herbicides ranged from 0.158 x 10(3) to 0.636 x 10(3) and 34.161 x 10(3) to 166.514 x 10(3) mu g g(-1) indicating greater potential of treated rice husk adsorbents to adsorb imazethapyr and imazamox as compared to untreated rice husk. The synthesized adsorbents exhibited comparatively greater potential to adsorb imazethapyr (0.636 x 10(3) to 166.514 x 10 (3) mu g g(-1)) than imazamox (0.158 x 10(3) to 131.835 x 10(3) mu g g(-1)). Desorption of imazethapyr and imazamox from rice husk adsorbents ranged from 92.82 to 99.34%. The results revealed that rice husk has the potential to act as an effective and promising low cost adsorbent for removal of imazethapyr and imazamox from water. (C) 2019 Elsevier Ltd. All rights reserved.