removal of alizarin red and purpurin from aqueous solutions using fe3o4 magnetic nanoparticles

the applicability of fe3o4 nanoparticles (fe3o4nps) for removing alizarin and purpurin from aqueous solutions has been reported. the influence of nanoparticle dosage, ph of the sample solution, individual dye concentration, contact time between the sample and the adsorbent, temperature, and ionic strength of the sample solution were studied by performing a batch adsorption technique. the maximum removal of 5-100 mg l-1 of individual dyes from an aqueous sample solution at ph 5.0 was achieved within 5.0 min when an adsorbent amount of 20 mg was used. the kinetic results revealed that the pseudo-second-order equation is the best model to analyze the adsorption mechanism. the isotherm analysis indicated that the equilibrium data are well fitted to the langmuir isotherm model with maximum adsorption capacities of 45.87 and 40.48 mg g-1 of the adsorbent for removal of alizarin and purpurin, respectively. according to the experimental results, about 99% of alizarin and 95% of purpurin were removed from aqueous solutions under applying the optimal experimental conditions.