Kinetic study on the adsorption of arsenic in the Yellow River sediment with different gradation

The aim of this article is to understand the adsorption mechanism and adsorption kinetics law of Yellow River sediment on arsenic with different gradations. Adsorbent particles with different sizes and states were tested in order to acquire better insight into the adsorption process. Different kinetic models, such as the first order kinetic model, the two-level kinetic model and the particle diffusion model, were used to fit the experimental results. The correlation coefficient of the silver sand were all above 0.9200 in the first kinetic fitting curves and that of the coarse sand were all above 0.9900 in the two-level kinetic fitting curves. Both of the first order kinetic and the two-level kinetics model fitting results indicated that silver sand and the coarse sand had good correlation. The mass transfer kinetic model fitting results indicated that the adsorption reaction was mainly controlled by intra particle diffusion. By fitting the experimental results of silver sand in static and turbulent conditions, concluded that the average values of correlation coefficient were 0.9600 and 0.9368 in static and turbulent conditions respectively, which manifested that under static conditions had better correlation, at the same time, because the value of c was not equal to 0, the adsorption reaction was mainly controlled by intra particle diffusion, liquid film diffusion and surface adsorption.