removal of hazardous reactive blue19 dye from aqueous solutions by agricultural waste

low-cost grapefruit peel (agricultural waste) was used for removal of reactive blue19 dye fromaqueous solutions. the process was studied as a function of contact time, initial dye concentration andph. adsorption process was attained to the equilibrium within 45 min for initial dye concentrations of 50,75, and 100 mg l-1. an acidic medium was the optimum condition for adsorption of dye at roomtemperature. the maximum dye removal of 83.56 % could be achieved at initial ph 2 using adsorbentdosage of 0.5 mg in 150 ml (50 mg l-1 dye concentration) and agitation rate of 180 rpm. the adsorptioncapacity was found to be about 12.534 mg g-1. the isotherm data could be well described via langmuirequation with the correlation coefficient of 0.986 in dye concentration range of 50-100 mg l-1 at 25 ◦c.kinetic studies revealed that the experimental data correlated well with pseudo second-order modelpossessing regression coefficient of r2 ≥ 0.999. scanning electron micrographs provided a supportingevidence for efficient dye sorption onto grapefruit peel.