Adsorptive removal of basic dye by chemically activated Parthenium biomass: equilibrium and kinetic modeling

This paper reports the removal of a basic dye (rhodamine-B) by the activated carbon prepared from Parthenium biomass by sulphuric acid treatment method (SWC). The effectiveness of the prepared adsorbent has been studied as a function of agitation time, adsorbent dosage, initial dye concentration and pH. The removal of rhodamine-B by SWC followed second order kinetic model. The second order model best describes adsorption kinetic data. Adsorption data were modeled using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity Q 0 was 18.52 mg/g at initial pH 7 for the particle size 0.3–1 mm. The equilibrium time is about 60 min for the studied initial dye concentrations. Maximum dye removal (99.2%) was obtained at pH 7 using an adsorbent dose of 16.0 g/L for 50 mg/L dye concentration in the aqueous solution. FT-IR spectra of the adsorbents were recorded to explore the number and position of functional groups available for the binding of dye onto studied adsorbents. The presence of O-H, C=O and C-O groups was identified in the adsorbent. SEMs of the native and exhausted (SWC) were recorded to explore the morphology of the adsorbent.