American Journal of Environmental Protection. 2013, 1(1), 1-9DOI:
Abstract: Zeolite synthesized from cyclone ash (ZCA) was modified with various loadings of hexadecyltrimethylammonium bromide (HDTMA-Br) and was used as adsorbent to remove Reactive Orange 16 (RO16), an azo reactive dye, from aqueous solution. The RO16 adsorption efficiencies for ZCA and surfactant-modified zeolites from cyclone ash (SMZCAs) were compared. SMZCAs presented higher RO16 adsorption efficiency than ZCA, and SMZCA with higher loading amount of HDTMA-Br exhibited higher RO16 adsorption efficiency. A series of experiments was conducted to examine the effects of contact time, solution pH, and adsorbent dosage on dye removal. The adsorption kinetic of RO16 onto adsorbents was discussed using the pseudo-first order, pseudo-second order and intra-particle diffusion models, and the pseudo-second order model provided the best correlation of the experimental data. The equilibrium adsorption data were well represented by Langmuir isotherm model with maximum adsorption capacity of 0.58 and 12.6 mg g-1 for ZCA and SMZCA, respectively.The toxicity tests of dye solutions before and after the adsorption treatment were evaluated with D. simlis and V.ficheri.