Adsorption kinetics of phosphate onto sediments from the middle and lower reaches of the Yellow River

The adsorption kinetics and its influencing factors,and adsorption mechanism of phosphate(P) onto 10 different sediments from the middle and lower reaches of the Yellow River in the Yellow River water were investigated.The results showed that:(1) The adsorption abilities of different sediments to P were different,but the change of P adsorption amount onto different sediments with time had the same trend,and adsorption rates were all faster within 0-8 h,then gradually getting slowly within 8-48 h and the adsorption tended to the dynamic equilibrium at 48 h.Both of initial P concentration and sediment concentration had certain impact on P adsorption kinetics,and P adsorption amount on different sediments increased with initial P concentration increasing and decreased with sediment content increasing.(2) At different initial P concentration,P adsorption kinetics onto different sediments all followed second-order adsorption kinetic model and Weber-Morris diffusion equation which second-order adsorption rate constants and diffusion rate constants obtained by were in ranges of 11.986 6-157.55 g·mg-1·h-1 and 0.000 5-0.011 9 mg?g-1?h-1/2,respectively.The P adsorption process was controlled by the intra-particle diffusion.