Removal of Procion Red MX-5B from songket's industrial wastewater in South Sumatra Indonesia using activated carbon-Fe3O4 composite

Songket is traditional costume in South Sumatra, Indonesia. This study investigates the feasibility of using activated carbon-Fe3O4 composite to adsorb the Procion Red MX-5B dye from songket's industrial wastewater. The adsorbent was characterized using the surface area analyzer, X ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Analysis, Fourier Transform Infrared and Vibrating Sample Magnetometer. The effects of pH, weight of composite and the contact time were evaluated to determine the adsorption efficiency. The kinetic and isotherm were carried out to evaluate the adsorption behavior of composite. The toxicity level of songket's industrial wastewater was measured using Tilapia fishes as the biological indicator. The 24-h LC50 was calculated using Probit analysis method. The results show that the adsorption process of Procion Red MX-5B using activated carbon-Fe3O4 composite follows a pseudo first order kinetic and the experimental data show a good correlation with Freundlich isotherm. Songket's industrial wastewater has the 24-h LC50 for Tilapia of 5.6% ± 0.6. After treatment using activated carbon-Fe3O4 composite at pH 6 and contact time of 50 min, the adsorbent can reduce concentration of the Procion Red MX-5B by 94% and chemical oxygen demand by 96%. The experimental results indicate that the activated carbon-Fe3O4 composite is effective as an adsorbent for the treatment of songket's industrial wastewater.