Study on adsorption of chromium in wastewater by meal fiber in garlic slag

In order to study the adsorption of Cr6+ with garlic bolt slag, garlic slag was used as adsorption materials, and effects of five factors were analyzed such as adsorption rate of Cr6+ concentration, garlic bolt slag quantity, the solution to pH value, adsorption temperature and adsorption time. The five factors were studied using two regressions orthogonal rotating combination designs. From the model, it could be concluded that the best adsorption rate was 94.14% when pH was 5, temperature was 40 ℃, time was 2 h, concentration was 40 mg·L-1, addition amount was 0.5 g. From the experiment, it could be concluded that garlic bolt slag could be used for adsorbing low concentration wastewater. The isothermal adsorption Langmuir and Freundlich model could describe isothermal adsorption behavior of Cr6+ in garlic bolt, Langmuir model was fit than Freundlich. From the dynamics experiment of garlic bolt absorption Cr6+, conclusion was made that the adsorption processes fitted the secondary dynamic model. It indicated that adsorption process was a mixed adsorption process and chemical adsorption was given priority to physical adsorption. Secondary dynamic adsorption curve could well describe the adsorption dynamics condition.